Below are observations made at star parties using a variety of equipment. These reports provide a useful comparison of what can be seen through many types of telescopes under the same viewing conditions. There are reports made with telescopes larger than 6" included - another useful comparison.
| Observer: | Jeff Barbour |
| E-mail address: | barbour@ihwy.com |
| Web site: | astro.geekjoy.com |
| Date and time of Observation: | Saturday-Sunday July 21&22, 2001 9:30pm - 2:15am PDST |
| Observing Location: | SCAC Bonny Dune Observing Site |
| Object Observed: | Mars, Antares, NGC6541, IC4651!, Milky Way, M22, M17, M57, M27, Double Double, Delta Cygni, Pi Aquilae, BU63, STF2403, STT457, BU694 |
| Viewing conditions: | Transparency: 5.5+ ZULTM, Stability: 7/10 |
| Telescope | Leon's Coulter 10" Dob, Ralfs 10" LX200, Jack's XT10 Dob, (mostly) Jeff's 150mm MCT |
| Eyepiece | Various & Panoptic |
| Observing notes: |
Friday evening's clouds nixed plans for organized observations at China Ridge. With an impending moon, that workload shifted over to last night's SCAC star party. Earlier that day I received a series of charts to help locate four "challenge doubles" (from fellow observer Cor Berrevoet). Even with the combined workload, I broke away occasionally for play. Leon's excellent 10 inch Coulter dob provided wonderful views of the Omega Nebula and Veil Complex. Ralph's Meade 10" LX200 gave a fine view of the Cat's Eye Planetary's central star. Jack's Orion XT10 revealed the presence of the aptly named "Eagle Nebula". Argo gave fine views of the incomparable Globular Cluster M22, the Ring of Rings (M57) and the smartest Dumbbell in the heavens - M27. But the evening started ominously with a silver crescent Moon
obediently following the Sun over the horizon to the west. Meanwhile Mars lay well above the southeastern horizon. Knowing that soon this apparition will be a memory, I turned Argo on Mars and hoped for that one sharp-hewn view of the planet yet to materialize.
Mars, of course, is very near its rival - Antares. Despite the stability in the region - and to my puzzlement - no definitive view of the stars 5.4 magnitude companion was possible. Nor were the required preconditions evident. As it its usual want, the star showed a flashing spurious image - lacking in the pre-requisite airy disk needed to disclose its diminutive neighbor... As of last evening one final low declination study remained on my observing plan - Globular Cluster NGC6541 (in Coronae Australis). This 13 arc-minute, 6.6 magnitude globular would easily rival the fine Ophiuchan clusters M10 and M12 in presentation. But alas, low sky position and an early hour of culmination took its toll. Under ULTM 4.0 - 4.5 conditions, I was able to make out some 4X3 arc-minutes of core, core region and beginnings of a bright halo at 180x. There was a very definite "roughness" about the cluster that screamed "dozens and dozens" of resolvable stars. (A 10th magnitude star could be seen some 5 arc-minutes east of the core. But is undoubtedly a field star.) The cluster appeared flattened southwest. Some flaring possible on eye movement but this technique needs the advantage of darker skies to give reliable results. Following this success, I made a quick check for Alpha Ara and open cluster IC4651 (located a degree or so to the stars' west). Third magnitude Alpha was easily located some seven degrees south of Theta Scorpii. The smallish (12 arc-minute), 6.9 magnitude open cluster was not. At best detected a faint, vaguely circular patch of "haze" roughly one 70X field width west. The clusters 12.0 average surface brightness is simply not susceptible to a 150mm scope while hanging three degrees above the southern horizon at culmination... By this time skydark was upon us. And what a wonderful skydark it was. The Milky Way wended its way across the heavens. From the Scorpion's tail, through Sagittarius and southern Ophiuchus, Scutum, Aquila, Cygnus, obscure Lacerta and onward to a distant Cassiopeia to the northeast. Breathtaking. Filled with brightenings vast and small, large dark bars and bays, and curiously attractive islands of illumination. Later near midnight, and well overhead countless dim stars lay at or near naked eye visibility. A feast for the unaided eye, remarkable in binoculars or rich field scopes and simply overwhelming in detail for large scale views of small scale studies in scopes of all apertures at higher magnifications. Having noted this splendour, I elected to continue pursuit of the evening's agenda - but not without dwelling on The Great Sagittarian Cluster - M22. Spectacularly riddled with hundreds of resolved starry points. Always a delight! Meanwhile neighbor Leon turned up the Omega Nebula (M17 north of Mu Sagittarii) in his 10 inch dob. Aided by OIII filter and framed by a superb wide field 22mm Panoptic eyepiece, the 10 inch not only rendered the brighter "check mark" region obvious - but also a much larger region of extended nebulosity. About this time I was visiting the King of Rings with Argo. The planetary stood out in bold relief against an essentially pitch black field of view at 180X. The 13 magnitude field star just east of the Rings trailing ansae clearly discernable as a small point of light. Inspecting the star at several magnifications, I found that - even at 50X - it could be held with moderate aversion. Now some of my readers may be aware that I am generally unhappy with the amount of coma and astigmatism displayed by Argo at low magnifications. Assuming the 35mm and 25mm Ultrascopic eyepieces I use for low power views were properly field stopped, - I concluded that Argo not the eps were the source of the problem. While viewing the Omega Nebula, "Jeff the Scopist" emerged and got the idea that - Leon permitting - it would be nice to try the Panoptic in Argo. HUGE mistake. The Panoptic performed incredibly. Stars were gorgeous! And this across the entire 60 plus degree field of view. In fact I didn't even notice the strange aberrations usually seen while moving the eye above the eyelens. Planning to return this fine instrument to Leo quickly, I didn't get a chance to exhaustively evaluate its potential, but this cursory experiment really whetted my appetite. (And oh yes, despite the large number of elements used in the Panoptic's construction, I didn't even notice a loss in transparency while checking the Ring's 13th magnitude star.) About this time noticed Ralf between studies, so I recommended he turn the LX200 onto the Cats Eye Planetary in Draco. Two evenings ago, I had personally spent thirty minutes tracking down this camouflaged cat in the hinterlands above the Dragon's Head. Ralph promptly entered the keystrokes (NGC6543 - BTW: I love this designation) into the goto handset and within a minute (and after some brief sweeping in the general locale at low power) the Cat was staring back at us. Ralf then spent the next thirty minutes or so on his observing stool getting acquainted with the planetary at a variety of magnifications. Later, I was invited to look at 500+X. After a few seconds, the 11.3 magnitude central star clearly revealed itself - barely outshining the elongated disk of blue-green nebulosity it spawned and stimulates to iridescence. For me the real "work" of the evening was about to begin. There was a depth and quietness to the sky that cried out for a challenge - and I had just the ticket. Four tight doubles, each with primaries at or near magnitude 6. Each with secondaries at or near magnitude 8. Each with separations less than or equal to 1.1 arc-seconds. Each with charts to aid in tracking them down with confidence. The first (BU63) was rather easily located some one degree southwest of Epsilon Delphini. The stats on BU63 are 6.23/8.05, .9" PA: 349 degrees. These numbers suggest that Argo would need a night of 8/10 stability supporting 440X to get a clean split. On turning it up, I instantly noticed the fine whitish airy disk of the primary, surrounded by a single diffraction ring and two main areas of concentrated brightening located at precise right angles to one another. These brightenings appeared to be about magnitude 7.5 in intensity. Neither fell north-northwest of the primary. But at this point I consciously chose to not exploit position angle data while searching. For the next forty-five minutes I scoured the region near the star at 210, 360 and 540X (without right ascension drive!). Not seeing anything suggesting a dim companion, I confirmed the star against the chart - while even viewing some neighboring stars - all to no avail. Moved on to STF2403 in Draco. This one required the usual Draconian half-hour track-down time. Stats on STF2403 are 6.28/8.4, 1.1" PA: 281 degrees. Nice yellow airy disk - again surrounded by a single diffraction ring with two right angle areas of brightening. Again the same process. High magnifications star drift, verification of star location, check of nearby stars - nothing. Now how about 6.04/8.2, 1.1" PA:245 STT457 in Cepheus? Easier to locate (in the middle of the "house") but after everything said and done, only a note that says "Brightening on diffraction ring south of west." Finally, 5.74/7.81, 1.1" PA:2 BU694 Lacerta: "Closest to resolving of all four, possible faint secondary to north". So what's going on here? Diffraction rings. Yup, the secondaries really are no brighter than the primaries first diffraction ring. Quality apochromatic refractor (without obstruction) would have had nailed these down - I'm sure. But not a scope with a 34% central obstruction. Argo just pushes too much light out of the airy disk into the ring. In terms of 6 mag stars, the average surface brightness of the ring itself is maybe magnitude 8. At 1.1 arc-seconds a secondary sits right on top of this ring. So no show. Can I prove it? No, not to you - but to me (and for the time being). For you see I came to this conclusion while observing the doubles. One check? Dropped in on 1.4 arc-second 6.0/6.8 double Pi Aquilae. Absolutely beautiful, clean split at all magnifications. Room for another 6 mag airy disk between the two near-equal brigtness components. Primary yellow, leads white secondary across the sky. Fine double and a good reminder to me of just how far apart 1.4 arc-seconds is at 540X. So I revisited the .9 mag separated BU63 in Delphinus. There, in the expected position - slightly west of north was a dim, barely perceptible, averted vision companion - closer to the primary than the two brighter right angle brightenings on the diffraction ring. It was now 2:00am PDST. I checked Delta Cygni - past culmination. 7.8 companion not visible. As stable as he sky was, I can make no claim to it meeting the calculated requirement of 8/10 seeing stability - very close however. Before knocking off I turned Argo on the Dumbbell Nebula in Vulpecula. Extremely present - a glittering of a half dozen stars visible at various points across its apple core shape. This was the evening's final treat and one, in my estimation, well deserved... |
| Observer: | Jeff Barbour |
| E-mail address: | barbour@ihwy.com |
| Web site: | astro.geekjoy.com |
| Date and time of Observation: | Saturday, July 14, 2001: 9:00 - 10:00 PDST |
| Observing Location: | SCAC Bonny Dune Observing Site |
| Object Observed: | Mars, Polaris, Antares, M97, M108 |
| Viewing conditions: | Transparency: What?, Stability: 8/10 |
| Telescope | Dan's FS-102 Apochromat,
"New Yorks" Celestron 8, Jeff's 80mm Achromat, Florida's 6" F8 Homebrew |
| Eyepiece | Various |
| Observing notes: |
So you makes the drive, and you takes your chances. Admittedly, the sky looked a bit "iffy" on the way up, but I was hoping that putting a couple thousand feet between the scope and sea level would make all the difference. And it did to - for about 45 minutes. Then "low flying clouds" moved inland, and that was that.
But the "party" wasn't really over as the clouds rolled in. Dan, Leon and I spent another hour discussing things astronomical. One topic of interest: "Different scopes for different folks." Leon likes his 10" Dob for the aperture and the fact that it fits into his Honda Accord. Dan likes the 102mm Takahashi because he views from Backyard Santa Cruz and has to burrow his way through the light dome. I like my scopes, well, because these are the ones I got and I do alright by them. The Pup for big scoops of chocolate sky-pudding, and Argo for portability - and that little bit of extra reach and resolution.
But before the sky fell apart, we did take in a few views. Mars for instance - damn the planet's edge was sharp in the Tak - Pup too, but the Tak had the resolution and image scale. And what did we see? Large bright oval right where Syrtis Major should have been. Storm's up!
Dan's Tak is well equipped - synchronous RA drive and all. But no matter how good your drive is, it won't track if it isn't well aligned to the pole. So Dan took a few moments to dress up the alignment. This meant turning the 4 incher on Polaris. At the time, I'd say the sky was maybe 4.5 ULTM deep. Under such conditions the Pup has a lot of trouble revealing 8.8 mag Polaris-B. But what about the Tak? Well let's take a look, shall we? Damn! Right there, no vision tricks, nothing. Pup? Full-on avert. 20mm more aperture account for it? Not at all. Takahashi drops 8 baffles into the OTA and probably coated the hell out of it too. Add an excellent diagonal, fine eyepieces and voila -high contrast views of anything in reach. (Actually Dan's eyepieces aren't quite as good as they were - I drooled all over them.)
OK, so let's really push this baby. What about the 5.4mag /2.3 arc-second distant companion of ANTARES? Nothing at 120X. Let's push it. 300x! Woh, Direct acquisition. Color (bluish green). The sky is good, but I'm not convinced Argo could have matched it. Excellent! (More drool.)
About this time, Dan and I get a visitor: "Say anybody here know anything about M97? What's it take to turn it up? I'm having the darndest time!" "Well says I, through a decent sky anything 60mm or larger can show you all the Messiers - but M97 is one of the toughies. What you got?" "C8." Should do, let's get on it.
As it turned out, our visitor now lives in Santa Cruz - but had a strong "Big Apple" accent - so I'll give him the handle "New York".
Now New York's C8 doesn't have goto. What it does have is a database full of objects that you call up after you align everything properly. Then you move the scope around manually until you "zero out the deltas". New York had done the alignment - and it wasn't far off. There were a few other issues with the scope however: One, the finder was way out of focus - I'd seen this before on a C9.25. Focus mechanism is a bit strange - you loosen a collar and spin the dewcap around to set it. I explained what I was doing to New York...
A second problem with the scope was the dewcap - homemade. New York was right on top of things when he figured out out the need for one. But unfortunately, the dewcap collapsed to one side and vigneted the light path. How did I figure this out? Well, of course I couldn't help but defocus the scope to check the optics (not bad at all) - but seeing the image truncated by a third was a dead giveaway...
Third problem: The mount's slow motion controls are "clutched". This means you have to release the clutch to spin the manual adjustment knobs. However when you do so, the scope "sags" and you lose your reference point. On this last score, I suspect that New York is better able to use the clutch than I - so the problem pretty much lay with me.
About twenty minutes later, New York and I got a look at The Owl Nebula - and as usual - this was proceeded by seeing galaxy M108. In both cases - not the best views - but this had nothing to do with the scope. Skydark hadn't really arrived - but the beginnings of an overcast had...
I did get a look through one other scope - and boy, did it take me back... A homemade F8 6 inch - complete with weld-shop equatorial mount permanently set to latitude 35 degrees north (Florida, USA). The owner's Dad ground the mirror and assembled the OTA back in the early 60's. Dad's friend welded the mount from commonly available pipes and pipe fittings. The scope had an overlong extension of the main tube - so Dad knew a thing or two about eliminating stray light. The optics showed decent outfocus but inside was a bit "pointy". The son recently had the mirror aluminized. The mount seemed excessively "squirrely". But you know what? Dad built it, and son used it.
Different scopes for different folks. |
| Observer: | jeff barbour |
| E-mail address: | barbour@ihwy.com |
| Web site: | www.ihwy.com/~barbour/jeff/astro/ |
| Date and time of Observation: | 9:30 - 2:00 PDST, May 19/20, 2001 |
| Observing Location: | SCAC Bonny Dune Observing Site |
| Object Observed: | Omega Centauri, Centaurus A, Globular Cluster's: M3, 4, & 13, Galaxies: M81/2, NGC4565, 4631, Planetary Nebulae M97 & NGC4361, Quasar 3C273, Planet: Mars |
| Viewing conditions: | Transparency: 5.2 ZULTM, Stability: 6/10 |
| Telescope | Leon's 10 & Tim's 10 and 12 Chris' 16 inch Dobs, Derrick's 200 & Ralph's 250mm SCTs Jeff's 150mm MCT |
| Eyepiece | Various |
| Observing notes: |
The drive "up" to Santa Cruz Astronomy
Club's Bonny Dune observing site was just that. You start at about 400 feet
above sea level in Felton CA. Take a right at the light (if you're
driving from Boulder Creek like I do). It's all uphill from there.
Fortunate, that ascent. For you see, low flying clouds rolled in throughout the
San Lorenzo Valley. And socked in Santa Cruz to the southeast. Back in
the lowlands, this would put pause to any aspirations to observe. But
tonight it was a good thing. Why? Because the fog cap suppressed light
pollution from down below us. And although light pollution doesn't choke
your lungs, it does choke your aperture.
The sky was dark to the southeast. It was dark to the north. It was
dark to the west. It was dark all over. Had the sky been a bit more
transparent, it would have been really dark. With all this dark sky to play
with what do you think we did?
First we talked. Ralph, Chris, son Eric and I wrestled with a few
touchy issues. Automated CCD imaging. Set up a fully automated scope. Turn
on your off-axis guider. Press the OK button. Grab a thermos of hot
coffee. Kick back and let the full panoply of post-modern, computer-based,
servo-driven technology capture picture perfect images of the cosmos.
Good thing? Bad thing? Who knows? We also talked about goto mounts. Grab
the handset, input the DSO's designation, click the Go button and
gee-WHIZZ-bang, put eye to eyepiece and stare away. Good thing? Bad thing?
Who knows. We did agree on this: You get out of something what you put
into it.
So having successfully navigated though potentially politically charged
waters, the dance began. The early haze shrouding the high sky
dissipated. Skydark was upon us. First off, let's turn that big dob on
something equally big: M81. This is where we learn that a six inch scope only
shows you about a third of everything. My, M81 is huge. Outside the
easily visible core and core region there's a lot of galactic sprawl left
over. From tip to tip maybe 2/3rd the Moon's diameter. And it's all
there plainly arrayed before you. No, eyepatches, towels over the head, or
eye-flitting visual gymnastics. M82: Broken, craggy, long, luminous.
Put a yoke-type equatorial under this photon cannon. Wrap a small
observatory around it. And have at it: "Galactic Wanderer".
As nice as that 16 inch light-bucket is, I kinda like the stuff with
aperture plus tighter optics. Last night's prize for this heady
combination goes to Tim with his homemade 12 inch truss-tube dob. Tim is a new
member of SCAC. Just to be especially friendly at his first SCAC star
party, he didn't just bring along his 12" masterpiece. He also brought
version 1.0: A 10 inch dob. The 10 inch is another fine specimen of the
breed. We had some fun comparing the two. Ten inch: Great views of
globular clusters, galaxies, planetary nebulae. 12 inch: Even better views.
Why? Does 2 extra inches make that much difference? No way. Somehow,
the 12 inch paints things against a darker sky. The view was rich with
contrast. So the hundreds of globular cluster members you could see
directly (without averting your vision) in the 10 inch, could also be seen -
against a pitch-black sky - in the 12 inch.
Meanwhile, Leon got the "Full Tilt" bug and laid his fine wide-field
Coulter 10 inch dob horizontal on Omega Centauri. Again, due to low sky
position, Omega was not amenable to resolution. However, in looking
around it I noticed dozens of stars not susceptible to six inch Argo. No
doubt the outer layers of this huge onion were being pealed by the 10
inches superior light grasp and fine optics.
What do you look for after viewing Omega Centauri? Centaurus A, of
course. Huge ball of light broken by a large dark band leaking luminosity -
in photo's. To the eye? Derrick's SCT showed it about the way Argo
does. You see the smile on the bottom and cap on the top. The 16 inch
however... Wow! More light means the smile and cap expand. What looked like
two separate nebulae in smaller scopes, becomes a singularity. The dark
band obviously splitting it in half. Once viewed through the sixteen
inch, views through all the other scopes made sense. We superimposed the
obvious over the subtle in our imaginations. We got it!
About this time I noticed Corvus high to the south. Planetary NGC4361
came to mind. Conveniently positioned, and easy to find, the Dobs were
on it. Very obvious in the bigger scopes. Rectangular, pinched at the
waist outer region. Brighter well-defined central shell. 12.8 magnitude
star at the center. Again the big uns made obvious what Argo struggles to
give a hint of. Yes, Argo showed the star, the core, and the haze - but
it looked round. The larger scopes revealed the rectangularity. Before
this we also turned the 16 and 12 inch dobs on the Owl Nebula. The
theme here was to catch the eyes. On this occasion both the larger scopes
showed one - but not obviously. You just sensed it was there. At one
point I caught the central star - through the 16 inch at the time (if I
recall correctly).
Not too long after viewing Centaurus A, Chris packed up the 16.
Meanwhile, the rest of us went "edge-on" galaxy questing. M104: Sharp, well
defined in all scopes. And yes, there was the extension of the core on
the far side of the dark band. Every scope showed it. Even Argo - but
only when I first looked at it, then the Cheshire Cat disappearing act set
in. Interestingly enough it didn't just disappear - it was swallowed up
by nebulous glow from the brighter portion across the sharp, dark,
divide.
As nice as the Sombrero galaxy looked, it was edged out by the view of
NGC4565. I was really impressed by this "slice of luminosity" through
Argo two days previous. But now, through the 12 inch Dob, the view was
spectacular. The thin extensions well outside the mottled core were
directly perceptible. The full 15 arc-minute major-axis of this galaxy was
visible. Derrick turned up a comparable edge-on using the 200mm SCT.
NGC4631 gave a fine view - even at 200mm. Again it's full length was
possible. However, unlike 4565, this galaxy looked gently curved along it's
spine - like a dinner plate. We all noticed a very peculiar star edging
right up against core-central. Estimated at magnitude 12.5, the star
had a peculiar sharpness to it that caught the eye. There was a bit of a
buzz about the possibility of supernovae. As it turned out there is
such a star in photos - so no Supernova SCAC in NGC4631.
1 am and things are winding down. Scopes disassembled, packed into
trunks and pick-up beds. Derrick was the last to leave. Son Eric had gone
off to knap in the car. Meanwhile, I spent a demanding 45 minutes
tracking down field stars associated with 3 billion light-year distant 12.8
magnitude quasar 3C273. The field turned out to be precisely the one
I'd found a week ago while observing out of Boulder Creek Elementary. Now
I can make this real easy: The quasar's documented magnitude is
incorrect - at least last night it was (quasars can be variable). It took all
of 180X and extreme averted vision to hold. Earlier in the evening, I
could just hold Praesepe's 12.7 magnitude test star with mild aversion
at the same magnification. So the quasar, under full aversion, must be
at least magnitude 13.4 - visual.
Now, of course, it's 1:30 in the AM. Mar's is brilliant. About 40
degrees above the southwest horizon. So what do I do? I spend the next
half-hour watching it's unprecedentedly large, over-bright disk at 180x.
That disk was so bright, I had to use filters. So I cycled through all of
them - medium blue gave the best view. There were moments when I
literally could not believe my eyes. To the south, a huge greenish ring of
sumptuously dark material enshrouded a hemispherical region of white
luminosity. Opposite this (to the north), I could make out a wedge-like
shape of greenish detail. All this was only possible during the rare
instants when the sky steadied enough to show a sharp planetary limb. This occurred
maybe 15% of the time. Now, I don't know very much about
Mars-ography but you know, I get a feeling that this lamentable state of
ignorance is about to change!
Comment: Another fun SCAC event!
|
| Observer: | Jeff Barbour |
| E-mail address: | barbour@ihwy.com |
| Web site: | www.ihwy.com/~barbour/jeff/astro/index.html |
| Date and time of Observation: | Saturday, April 14 - Sunday April 15, 2001 8:00 - 1:15 PDST |
| Observing Location: | SCAC Bonny Dune Observing Site |
| Object Observed: | Jupiter, Saturn, Mars, Zeta Cancri, Gamma Leonis, Castor, Antares, M81, 82, NGC2419, 3077, 2976, M108, 97, 40, 106, 101, The Great Cluster of the North - M13 |
| Viewing conditions: | Transparency: 5 ZULTM, Stability: 8/10 |
| Telescope | 150mm MCT & 200mm SCT |
| Eyepiece | Various |
| Observing notes: |
Like most astronomy clubs, SCAC - Santa Cruz Astronomy Club - schedules star parties around the Moon. These are typically held two consecutive Saturday evenings immediately after the 3rd quarter. Tonight was no exception. One pattern I've noticed is that
attendance tends to be low whenever daylight conditions are less than promising. Until about 4:00 PM this afternoon, prospects for a star party were poor. In fact, while stretching on the back deck, I saw numerous low
cumulous clouds drift toward the west, while simultaneously, high thin cirrus clouds swept eastward. Personally, I've never seen anything like "contrapuntal" cloud motion before. This might very well have been worth the loss of the party alone. But that sacrifice to the Meteorological Gods did not have to be made.
Around 4:00, clouds began vacating the sky - by whatever direction. However, well above the lower
cumulous and higher cirrus, a third layer could be detected. From one end of the sky to the other, a very thin layer of "moist air" gave the sky that "metallic silver-white" sheen which always means limited sky transparency. (Along with more than the usual amount of light pollution.) As it turned out, transparency proved to be somewhat better than expected (5.0+ at the zenith). More importantly, sky stability was outstanding (8/10). So all in all, not a bad deal. Especially given the view of the planets (Jupiter in particular) and Saturn (to a lesser degree) at dusk - even with Argo suffering a touch of tube currency.
The sky was so stable that two of the scopes present (Argo being one) achieved clean splits of the .9 arc-second Zeta Cancri pair. High magnifications (roughly 350X) were required by both scopes (the other was Derrick's 8" Meade LX200). A lot of ducks have to line up on a pond to split a sub one arc-second double. First you need aperture (125mm +). And not only aperture but well-shaped optics. And not only refined optics, but good optical collimation. Then there's the right binary (equal magnitudes in the range of magnitude 4 to 8). And finally - most unpredictably - the right night. (I had not been able to conclusively split this pair earlier under 7/10 seeing.) Like I said - a lot of ducks...
Speaking of Derrick's scope. Last time we observed together, the SCT's correction lens looked a bit "dust-afflicted". At that time, the 200mm performed only marginally better than 150mm Argo. Tonight was a different story. In every area of comparison, the 200mm SCT gave the better views - especially on the galaxies - but also in double-star resolution. (I was unable to tear myself away from Jupiter long enough to determine what kind of view the SCT was getting there - but I'm sure it was fine.) So, that extra 50mm's does make a difference! But, as I say again, not enough an advantage to encourage me to move up to that aperture. And only in the particular case of a scope bearing optics on par with Argo.
As mentioned, the evening's 8/10 stability conduced to incredible views of stars and double stars and multiple stars of all types. Basically every star in the magnitude range of 2 to 8 showed nice tight airy disks surrounded by lovely , but not entirely circumferential - diffraction rings. Zeta Cancri was almost easy in both scopes - particularly the 200mm. The gold and green pair Gamma Leonis (magnitudes 2.3 and 3.5 at 4 arc-seconds) was stunningly beautiful. Brilliant Castor could be split at 50X in the 200mm and was better than elongated at the same power in 150mm Argo. There were exceptions. I turned Argo on the Trapezium for about a five minute 360X search for dimmer companions. No go. To find 11.0 and 11.5 magnitude stars within 4 arc-seconds of brighter 6th magnitude companions, in a glowing region of nebulous dust and gas requires a dark steady well-positioned location in the sky. Thinking back, I'd say the Trapezium was within 30 degrees of the southwest horizon at the time. As mentioned, the sky, in general, just wasn't all that transparent. Sky position was also a factor much later when we turned both scopes on the Antares double (1.5, 3.2 - 3 arc-seconds) but very poor sky position (probably 20 degrees above the southeast horizon) made that split impossible.
After the Antares attempt, I noticed the Hercules Keystone perhaps forty degrees above the northeast horizon. Certainment we simply had to view M13 mais oui! But first let's set the stage. On the plus side: M13 is reasonably well positioned. The sky is rock steady. Both scopes are in fine form. The negatives: A bit of light pollution. Reduced atmospheric transparency. What do you think? Bon cherche, oui ou non? Incredibly, both scopes resolved stars completely across the core. Hundreds of tiny pin prick jewels of light! Sweeping arches of stars looping and swirling like a spirograph. Never have I seen The Great Hercules Cluster so finely crafted. Surely the hand of God shaped magnificently' Now I can truly understand why so many amateurs exalt M13 to demi-god status. The effect was transcendental. Even a sense of psychological color about the globular. There's gold in them stars! And another heirloom memory: Two pairs of extended star arcs streaming east and west. Each arc closing back toward its opposite after greatest divergence north and south. The total effect was that of a double-ended scarab. Two long arching tusks - fore and aft - leading and trailing Le Grande Assemblage across the sky.
Now back to some practical realities... The stillness of the sky was only matched by its humidity. Both scopes required frequent, and repeated de-humidification. This was particularly needful during extended forays into Ursa Major and Canes Venatici. Such forays took up the bulk of the viewing time between the hour of Zeta Cancri (9:00PDST) and Antares (12:30 PDST).
Derrick and I delayed departure until we had a chance to turn our scopes on Mars. Unfortunately, the Red Planet was even lower in the sky than Antares. Both showed considerably atmospherically-induced chromatic aberration. Mars showed perhaps a hint of detail - between the red and orange chroma regions. And this only just before Derrick packed up the 200mm. (I preceded him by about 15 minutes in breaking down Argo around 1:00PDST.)
As mentioned, the bulk of the evening was devoted to the Galaxies of Spring. Argo - on those in
Ursa Major - while the 200mm with goto turned freely to Leo as well.
To be complete M13 wasn't the only globular viewed tonight. The Intergalactic Wanderer begged for a little more aperture, so Derrick turned the 200mm on it. Definitely brighter and more present at 8 inches. However, no sign of anything resembling resolution. Basically, the core could be picked out, along with perceptible dimming to the frontier. All, at least to me, with direct perception. Argo's view of the Wanderer was similar to past reports. Again that extra 50mm in objective cross-section does help. What a difference five orders of magnitude make! One cluster (mag 5.9 M13) bearing a princely mantle of hundreds of perceptible stars. The other (10.4 magnitude NGC2419) barely bright enough to be held directly by the eager eye of the observer.
Due to low turnout (there was a third observer, Dave(?) who brought along his virgin Orion XT-8) I was able to treat much of the evening as an opportunity to extend my observing plan. Three galaxy studies (NGC's 3077 and 2976 - near M81 & M82 - and M108) plus planetary nebula M97 (the Owl nebula complete with background hooting at the observing site) were detailed. During every instance of parallel observation between the 150 and the 200, Derrick's SCT performed as I might expect Argo would if an extra 50mm of apertures were magically added.
Well it's now 4am. Sharon just reminded me that I committed to quitting. So I'm going to post this part of the report and finish up the rest sometime tomorrow. No final edit either, so now you will will see just how poorly I really write! Good Night, World!
It's 11:15PDST Sunday the 15th. I just edited and extensively revised the first half of this report. Got a gig in Scotts Valley. Later this afternoon I'll move on to cover the middle third of last evenings observations. Stay tuned!
The gig went very well, thank you. Bassist Bill and guitar-/vocal-ist Jeff are starting to pull it together. Bill used to play for the USAF swing band in Europe - so he knows what he's about. I started playing jazz maybe three years ago and am finally starting to pull my own weight both instrumentally and vocally. Pity the poor ears that heard me sing and play early on. Ouch.
At magnitude 9.9 spread out over 18 arc-minutes, NGC3077 was not an easy find. But was bright enough to be held at 50X with direct vision. Only about 4 round arc-minutes of the galaxy could be seen. The view at 120x showed a bright central core with a dimmer surface glow bleeding off into space. Contrast was quite low. Moderately averted vision caught perhaps another arc-minute of the galaxy. There was no obvious frontier however - so more is out there. The galaxy formed a right triangle with a pair of brighter 8/9th magnitude stars. One lay due west by perhaps 5 arc-minutes. The other north of that by 10.
While 3077 locates about one degree east and 30 arc-minutes south of M81, NGC2976 is a little more distant - perhaps 2 degrees south and 1 degree west. 2976 is also more edge on (actually elliptical) is shape oriented north-northwest to south-southeast. A wedge shaped asterism of 10th and 11th
magnitude stars brackets it 10 arc-minutes to the east. The wedge takes up perhaps one-half of the 50X 1 degree 35mm Ultrascopic field. Although the galaxy can be held directly at 50x, there is not much in the way of detail. Unlike 3077, no star-like core - only a gradual bleed of luminosity into space. Under moderate aversion the entire listed 3X5 arc-minutes of 2976 could be detected. I suspect that neither 2976 or 3077 are likely to be seen in the Pup under similar conditions. It is no surprise that Messier missed these two galaxies.
Charles Messier did manage to turn up the next studies from my observing list - M108 and M97. These two Messier's are intermediate between M81&82 and the two NGCs discussed above in terms of susceptibility. M108 should be easy to find - but for some reason I kept having difficulties. As it turned out the source of the problem was meniscus dewing. I was easily losing a full magnitude to a fine spray of atomized water on the lens surface. Fortunately Derrick brought along a field battery and "mini-hair drier" unit. I'd say we used the thing at least a half a dozen times each. Typically when we
noticed that stars were winking out in the field of view - or as in my case - as a nice excuse for not finding stuff.
M108 is even more edge on than NGC2976 and, as mentioned, appreciably brighter. In fact it looks similar to M82 but requires a larger scope to make out any texture. I caught perhaps 10x2 arc-minutes of the galaxy with moderate aversion. M108, unlike M82, does seem to have a more definitive core. Though distinct, the core appeared to be about as bright as a 12th magnitude star. 108's contrast with the background sky was OK, but again not as sharp as 82. I noticed a 12th magnitude star leading the tip of 108 across the sky to the west. Two 10th magnitude stars, separated by about 10 arc-minutes pointed at the galaxy - also from the west - and if memory serves, slightly north. M108 is not quite needle-like in shape - I believe the common term is "cigar-shaped".
I had previously viewed the next study - M97 - through the Pup at the last SCAC star party. The sky was at least .5 magnitudes deeper at the time. Even so, at 11.2 magnitudes spread over perhaps 12 square-minutes - I was pleased to get any sense of detail in this "roundish" apparition. With Argo, more uniqueness was possible. The east seemed slightly oblate and trailed off in terms of surface brightness. The leading western region was brighter and had better definition. Certainly the frontier was detectable. Between the two I could just catch a dark "owls eye" to the south. Very near the northern edge of the planetary I could see a 12th magnitude field star. Didn't notice any stars within the nebula itself. The northern owls eye was not detectable. Perhaps "closed to public viewing" on this occasion...
Having payed obeisance to the "Gods of Self-Imposed Discipline", I was now free to observe as I wilt. One Messier discovery of questionable provinces is M40. This wide double of 9th magnitude stars is found about a degree north-northwest of Beta Ursa Majoris. The brighter of the two leads the dimmer across the sky. Separation very close to 1 arc-minute. Colors were mildly intriguing: The brighter blue and the dimmer greenish-blue. There is nothing about this pair that smacks of nebulosity. What was the "Comet Ferret" thinking? (Or possibly "What was he drinking?")
Like M81 & M82 - M106 in Canes Venatici is located in the "celestial sticks". I finally located it by creating an imaginary right triangle off Delta and Chi Ursa Majoris - then swept the field like you would do with a Dob. The interesting thing about the galaxy is the sense of having "dual star-like cores".
Perhaps the most interesting of the evenings "new lights" was galaxy M101 -located well east of the wide double Mizar-Alcor. This thing is huge! And offers lots of
possibilities for seeing detached nebulosity. In fact using the 200mm, I was just able to catch a spiral arm. A darker night and lots of quality time - who knows - Argo may just show something similar.
And thus an evening well spent. Excellent planetary. Passable deepsky. Amiable, amenable, and knowledgeable company. And The Great Globular Cluster of Northern Skies Incredibly Well Presented. Ho hum, just another night in the life.
How's your night life?
|
| Observer: | jeff barbour |
| E-mail address: | barbour@ihwy.com |
| Web site: | www.ihwy.com/~barbour/jeff/astro/index.html |
| Date and time of Observation: | Saturday & Sunday, March 17 & 18, 2001 7:00pm - 2:30am PST |
| Observing Location: | SCAC Bonny Dune Observing Site |
| Object Observed: | Planets: Venus, Jupiter, Saturn, Mars, (Earth) Stars: Iota Cassiopeia, La Superba, Xi UMa, M's: 103, 34, 42, 45, 65, 66, 81, 82, 97, 108, 3, 13, 57 NGC's: 1788, 869, 884, 2244, 2022, 2023, 2024, 3628, IC434, B33 |
| Viewing conditions: | Transparency: Variable 5.0 - 5.7 ZULTM, Stability: Variable 6-8/10 |
| Telescope | Various: Jeff's ShortTube 80, Jack's XT10 Dob, Ralph's LX200 250mm SCT, Chris's Meade DS-16 Dob, Mark's TeleVue 85, Leon's Coulter 10" Dob, Richard's C9.5 SCT, Dan's ETX 60, Dan Elli's ETX 125 |
| Eyepiece | Various Eyepieces Plus Ultrablock, OIII & Skyglow Filter's |
| Observing notes: |
The extended drought of clear skies,
seemingly omnipresent Moon, and an impending Messier Marathon season, drew a
large contingent of Santa Cruz Astronomy Club members to the club's
Bonny Dune observing location last night. Such pent-up demand for serious
photonage can only lead to long hours at the eyepiece, dilation-strained
entrance pupils, hallucinatory sleep deprivation, and extensive crow's
feet around the eyes - from an excess of smiling. Although the sky was
not as fine as I've seen it, it certainly didn't fight the assembled
equipment. Respectable views of a wide variety of shallow and deepsky
denizens were had by all. Plus a nice first for me, Chris (SCAC club
president), brought out his version of an astro-convenient store's "Big
Gulp" - a Meade DS-16 16 inch Dobsonian. Despite it's gargantuan size,
Chris had no trouble attracting help in setting up. (Enthusiasm waned a bit
about the time he needed to break it down :>( sometime around 1:00!
AM).
By the time I pulled in (around 7:00PM) several conclaves of observers
were already busily pulling together equipment and accessories. One
reason: Venus was rapidly sinking to the west. Of course, with tube
currents running amuck, and the Veiled Beauty's low sky position, no one
expected to get a sharp view. However, despite the poor image quality,
Venus' amazonian, but shapely thinning crescent, holds it's own special
allures. Personally, the view through the ShortTube (the Pup) offered its
own special challenges. It was impossible to null out the chromaticism
even through the most adept tweaks of the focuser. Between the scope's
own refractive elements and those of the thick low atmosphere, the best
I could do was swing between focus modes and examine Her light through
a range of spectroscopic possibilities. However, I did notice one
extraordinary thing, and this needs to be verified. I thought I saw the
backside of Venus glowing with a very faint luminescence. Could this have been "Earth-shine"?
Jupiter made an obvious next choice. My own view (at 132X) hinted at
another range of details for the Pup to reveal. Certain edge
irregularities in the NEB were apparent. On one occasion I thought I caught part of
the NTB. But beyond the usual concerns with such features, there was an
obvious 6 or 7th magnitude star that looked like it was heading for a
near miss of the south polar limb. Later I had a look through neighbor
Ralph's 10" SCT. Many of the feature's I see on a fair (6/10) stability
evening with the 150mm Orion Argonaut (Argo) were present. Ralph later
setup a laptop computer and hooked up a video camera CCD and interface.
Although he has yet to fine tune his equipment, we could make out the
two equatorial bands. Ralph explained that later he would overlay a
series of better images and send me the results. (I'll post this in this
report once received.) I also got a look at Jupiter through Jacks' Orion
XT10. In sliding through focus, I found the same "repositioning" !
of the outfocus limb glow that I've seen on Argo when it is miscollimated. Jack and I took a few moments. I got to tweak the knobs on the
primary while he inspected the reflected beam from the laser collimator.
Within a few moments, the improvement was obvious. Due to it's short
focal ratio, Jack's scope couldn't quite resolve Jupiter as well as Ralphs
(very fine) SCT but it was game and provided a very bright (but
under-sized) image of Jupiter clearly revealing the two main equatorial belts.
The sky was quickly darkening by this time. I turned the Pup on Saturn.
Very, very, nice. Cassini's division, though not tack sharp, was
cleanly defined. I could also make out the planet's shadow against the
trailing ring structure. There is hope for the Pup in this regard. But 132X
images are too small for much in the way of micro-feature detection.
Unfortunately, I had no opportunity to view Saturn through Jack or Ralph's
scope. I doubt we would have caught Encke (as we had on a previous
occasion) but such a view would have been re-assuring. (Atmospheric
stability has been poor in these parts since the weather broke.)
I came with a bit of a plan for this evening. I needed to do a bit of a
sanity check in regards to the Deepsky Objects by Optimal Aperture
List. I figured there would be a couple of 250mm scopes in attendance (Ralph's for one) so I hoped to get a peak at one 10" object from the list
(Bright Nebula NGC1788 in Eridanus just west of Orion). As it turned
out, both Jack and Ralph were happily willing to give it a go. I gave Jack
a little impromptu point and wave session about where to look, while
Ralph picked up his handy-dandy keypad and punched in the reference.
Whir, grind, silence, look in the eyepiece. Thank you! Just north of the
middle of the field of view, there it was: Ruddy-orange, cigar-shaped
nebulosity extending between two 10th magnitude stars oriented
north-south. Unlike the view in Argo I could clearly determine that the bulk of
the nebulosity was concentrated near the dimmer member of the 5
arc-minute separated star pair . Ralph also took a look, but hasn't really !
had the chance to get accustomed to faint fuzzies. He picked out the
nebulosity, wasn't sure if there was any color, but did notice the
brightening near the dimmer component.
Meanwhile Jack used his 1X finder to orient the 10" dob about 2 degrees
north of Beta Eridani. He swung the scope through the field but
couldn't find it immediately. He then began a thorough and systematic star
hopping exercise referencing a star atlas showing stars to magnitude 8.5.
His patience was ultimately rewarded. He found his nebula. The view was
certainly better than Argo's (on an even better seeing night) but not
quite up to that of the SCT. Not bad for a low tech, easily transported
scope costing less than a third of Ralph's tech-savvy light bucket.
Although Ralph got their first, and had the better view, Jack now knows
that region of the sky intimately. His diligent efforts hearken back to
the great pioneers of our Art and Science who painstakingly examined the
fabric of space and learned something of it's every stitch and fold...
About this time I realized that I had my own observing plan for the
Pup. There would be very few chances to catch the Perseus Double-Cluster
between now and next Fall. This pair of clusters is just the sort of
deepsky denizen that the Pup excels at. With it's three-degree 16X field,
it easily captured both clusters and left room to reveal a beautiful
arc of 7th and 8th magnitude stars cascading down from the northwest to
the more condensed western component (NGC869). For the first time I also
noticed that the western cluster and eastern are somewhat complimentary
in central condensation. The eastern cluster (884) seems short on
bright stars near the core, while having a large corona of brighter stars
outside that region. The western cluster is just the opposite. Its
brighter members are found in the core. It would be neat if someone were to
take the time to superimpose the two clusters photographically...
To catch my next target, I needed to reposition my scope. Cassiopeia
was dropping rapidly to the northwest. Meanwhile Jack mentioned that he
had yet to split a double star tighter than 4 arc seconds (from his home
in the San Lorenzo Valley). Despite Cassiopeia's westering, Iota was
still possible. I got Jack started on this fine triple. He soon tracked
it down and got a nice clean split of the tighter 2.5 arc-second primary
and secondary. Since I was in "wide field" mode I made no attempt to
resolve the pair with the Pup. I was personally intent on M103.
The Deepsky Objects by Optimal Aperture list assigns M103 to the 100mm
target class. Despite this, I was able to see perhaps eight 9th and
10th magnitude stars in a "mini-dipper" shape at 44X. Although some stars
could be resolved, it really looked more like an asterism than a
cluster. The extra 20mms might very well have made the difference.
Like 103, M34 is also classified 100mm optimized. Despite this, the
80mm showed perhaps a dozen 9th and 10th magnitude stars arranged in a
"fighter-jet" shape at 44X. Since I could actually resolve some stars, and
it did look sort of like "a cluster" I imagine the main reason it's
assigned to the 100mm class is due to the need to display it at high
magnification for best visual effect.
While I was exploring these two 100mm objects, Ralph decided to spend
some time viewing M42 through the 250mm SCT. When I approached, he was
well steeped in the view, but it wasn't long before he gave me a peak.
Through the ten inch I noticed that the brightest portion of the nebula
(around the Trapezium) held a nice soft blue gray color, while the
darker nebulosity that cradles the region looked faintly ruddy-red. I
remarked about this to Ralph - but he seemed a bit skeptical. I also
mentioned something I'd picked up from fellow amateur Otto Piechewski. The
Great Nebula is remarkably amenable to magnification and reveals tufts and
folds not apparent in the usual 1 degree fields most amateurs frame it
in. Ralph then dialed on the power and continued his contemplations of
this extraordinary region at 200X. Later he gave me a quick glance
through the scope and I told him I had caught an all too brief glimpse of
the "E" member of Trapezium. In detecting this, it helped that I'd seen this 11th magnitude component with Argo (while observing under
reasonably transparent, and stable conditions from China Ridge). Ralph then
spent some time looking over the Trapezium and I gave him some guidance
about where to look - a very important part of detecting this faint
member. Unfortunately, my own view was too fleeting, so it is not
surprising that Ralph didn't catch the specter himself.
It was now time for me to shift venues. Chris came by and let me know
that the 16 inch was setup. Previously I had talked with Jack about the
Zeta Orionus region. At that time we looked through the ten inch and
had no trouble making out the tripartite bright nebula NGC2024, along
with the obviously brighter star haze that reveals NGC2023. Finally we had
traced out the faint linear region of bright nebulosity (IC434) that
acts as the background to the Horsehead Nebula (part of B33). All these
main components were visible in Jack's scope - but we just didn't have
the depth to make out the Horsehead itself. So in talking with Chris,
the decision was made to make a go of reproducing Jack's efforts in that
same region.
Meanwhile, before heading off to join Chris with the 16", Jack and I
took a quick peek at M45 hoping to catch something other than "starhaze".
And that we did. With filter in place, we scanned all around the
cluster noticing obvious regions of extensive nebulosity - even where no
stars were found. The big dob had proven itself a fine nebula sweeper -
both in the region of Zeta Orionis and the Pleiades.
Now, I really haven't seen a truly big scope before. The largest had
been a C12 at an earlier SCAC star party at Quail Hollow Ranch. Now I
headed off in the direction of a copse of scopes to the southwest. As I
approached it seemed that the sky darkened and the lawn dimmed. Why, the
Big 16 inch was absorbing all the local photons! There could be no
other explanation.
And boy was it big. Huge. Even at F4.5, it was loooooong. At 40 cm's,
it was also wiiiiiiide. I'd have liked to give the thing a hug, but I
don't think I could have wrapped my arms around it.
After a period of push and shove, tug and lug, we got the thing
oriented on the southeastern member of the Hunter's Belt. Nebulosity was
everywhere and obvious. The huge 2 inch, 70 plus degree eyepiece was also
covering a lot of sky. The installed paracorr must have really helped out
in the field flattening department. Although it wasn't flat to the
edge, you had to look hard to tell. Inside-outside focus shifts did reveal
some telltale traversing of star-images but the collimation was close
enough for the project we had in mind. Unfortunately, about this time
high-thin clouds drifted over the entire sky and reduced transparency
noticeably (maybe by 3/4 magnitude). The clouds hung around for at least
30 minutes and by that time "the Quest for the Head of Black Beauty" had
been abandoned after getting results similar to those seen with the 10
inch Dob.
Here's where Mark and Leon enter in. Before this there had been a bit
of a buzz about turning up views of the Rosette Nebula (NGC2237)
surrounding open cluster 2244 in Monoceros. Jack and I had viewed the Rosette
through the 10 inch Dob and got excellent results with the OIII filter
on his scope. Mark had been looking for objects that would showcase the
wide-field virtues of his TeleVue 85mm apochromatic. Leon also wanted
to visit this region. (He hadn't looked it up in over 5 years.) Soon,
Leon had the cluster and nebulosity in sight. The view was excellent.
Optically, Leon has one of the best 10" dobs I've ever looked through
(Coulter manufacture). I had seen some wonderful views of the Veil complex
through his scope so I wasn't surprised when, through the 30X 80 degree
filtered view, the thing showed up almost as nice as the Great Orion
Nebula in a small rich field telescope. (Well, almost, anyway). The main
lobe was OBVIOUS. I could easily make out both large and small scale
variations in surface brightness. I remarked that I had seen the
Rosette in the Pup - but nothing like this. Mark was eager to try out
Leon's filter (Skyglow?) in his Tele Vue 85mm. I returned to get the Pup
for a little comparo. The $200 Achromatic Pup was going to be very tough
for Mark's $1K apochromat to beat. Honest. The Pup gives 1/8+ wave
performance, has perfectly matched and concentric intra-extra focal
diffraction rings and, under steady sky conditions, shows 2 perfectly
concentric in-focus diffraction rings at 132X. I figured he would need every
one of those 5 extra millimeters of aperture, plus the high reflectivity
mirror diagonal, and high quality ultra-wide 2 inch eyepieces just to
stay up.
As it turned out, the Televue gave a detectably better view of the
Rossette. (I, of course, attribute that to the superb eyepieces and 5 extra
millimeters of aperture.)
We also made a check of Jupiter (Televue: 2, the Pup: 0). And later
Mars (Televue 3: the Pup 0). La Superba carbon star (Televue 4: Pup 0), Xi
Ursa Majorus: (Televue 4.5: Pup .5) Star images: (Televue 4.5, Pup 1.5
- go Pup!), Galaxies (Televue 5, Pup 2). Gllobular Clusters: (Televue 6,
Pup 2). Money not spent: (Televue 6, Pup 6) - I call it a draw.
So those extra 5 millimeters, fully color-corrected optics, and high
quality eyepieces do make a difference. But Argo would have kicked the
85mm silly. (That's it Argo, stick up for little brother.)
OK, so I've covered the shootout - everyone happy. (Mark, let me know
if you think I was too hard on your scope, and I'll post a retraction in
8pt type somewhere obscure on this website.)
Time was now pretty close to midnight. As implied above, having
exhausted the denizens of the winter season, we moved on to Spring and
Galaxies.
Richard had setup his C9 off in the hinterlands of the observing site.
Every once in a while he would pop by, say hi and retreat to the
fastnesses of the Great Western Plain again for more private viewing. Later,
he stopped by to say he had found M81 in Ursa Major and would I like to
take a look. He also warned me that he wasn't sure that he had found
M81 for sure but whatever he had found was purty. So I headed on down.
Yup, there be a galaxy in that field. And it sure was purty. But was it
really M81? Tube pointed in the right direction (from what little I can
tell, this being my first full season of deepsky since using a
Criterion 4" Dynascope at the age of 11). So now we began a systematic check
against the charts and star fields to determine venue. We found two stars
(5th and 6th magnitudes) that pointed at M81 on the charts.
Unfortunately, Richard's 10X50 finder was out of focus, so we spent the next five
minutes figuring out the mechanism. With this accomplished, I left!
Richard hot on the trail to return to my own scope. (Later Richard
confirmed that he had gottent nice views of both M81 & M82.)
Now the fun really began. Mark's expertise is in galaxy hunting.
Normally he drags out the big iron (12"), but tonight he had his airporter
(the Televue). So he turned me on to the joys of the Messier Galaxies.
And incredibly, 5 of the seven galaxies we viewed looked fine in our
small scopes. Galaxies M65 and M66 in Leo were easily en flagrante delecto
with an NGC galaxy (3628). The Messiers were easily picked out. Each
showed a bright central core with extended cigar-shaped arms going out
several arc-minutes. In the Televue, the third galaxy (forming the apex
of an extended triangle) could also be detected and acquired with direct
vision. I too, found the Messiers, but couldn't see 3628 anywhere in
the field. I capitulated, the Pup began to tuck his tail and whimper.
Televue rules!
Not exactly, Mark peaked through the Pup. Shifted the field slightly
and declared that the Pup too showed the NGC and that I was using a
little more magnification than he was. Peering into the eyepiece: "And so it
was.". The Pup's view was every bit as present as that of the 85mm. The
Pup rose up. His self-esteem swelled. "Today I am a dog!"
About this time, Chris had swung the huge Dob around to the north. The
sky near Ursae Major darkened. I was beckoned to the eyepiece. And all
the heavens stood forth before me. When it comes to galaxies: Aperture
is King! Wow. (But those little ones sure gave unexpectedly fine
views.)
Later, Mark and I turned our little 'uns on M81 and 82. Sweet! Like the
Leo Trio, the Ursa Majorus Duo sang a tune. Both galaxies fit nicely,
one showed a very prominent core, both showed elongated arms. The two
galaxies looked like a pair of cats eyes peering down at the Big Cat to
the South.
Earlier in the evening, Chris had turned the 16 inch on the NGC2024
planetary in Orion. After the usual lugging and tugging, Chris and I made
out the small bright disk of the planetary. To me it resembled a true annularity. However, I recall seeing the same planetary through Ralph's
250mm SCT. The more highly collimated and longer focal length optics of
the ten inch clearly delineated the planetary. This under even slightly
poorer observing conditions. So the perennial question remains. What
type scope is best? Depends on what you want to look at.
Later in the evening I turned the Pup on M108, another Ursa Major
galaxy. 108 did not show an obvious central core. Some brightening was seen
toward the center. It was your basic diffuse football-shaped
nebulosity. (M108 is actually listed under the 250mm bin in the Deepsky Objects
by Optimal Aperture list. To better understand how this list works, M65
& NGC 3628 are on the 200mm list, M81 & M82 on the 150mm list. Only M31
is found on the 75mm list. M31 is an anomaly. - Because of its huge
apparent size, it get's assigned to a scope size well-beyond what it
displays well in. Frankly, all things considered, it probably shows better
in a 6X35mm finder than any of these other galaxies in their
respectively optimized scope sizes).
Now it was close to 2:00am. Mars was just clearing the trees to the
east. Meanwhile, several globular clusters were spinning into range.
Although M3 in Canes Venitici was unresolvable in either of the refractors,
it showed a very condensed core, surface brightness roll-off to the
frontier, and visible oblation along the east-west axis. M3 is the perfect
object for this size. It may take more aperture to resolve stars, but
as a whole M3 showed definite, and describable variation in surface
brightness, a discernable frontier, and a sense of form. It was also bright
and contrasty. A 75mm classic!
M13 was also easily turned up (though still low). Everything about M3
was visible in M13. In addition, I caught telltale scintillation, and
resolution with averted vision that indicates that our 3 inch plus
refractors are on the limits of showing this cluster to great advantage. (M13
is on the 50mm list.)
Before wrapping up. Mark noticed that Lyra had cleared the trees to the
northeast. Now I was home. My own celestial odyssey had begun with Lyra
on the zenith last September. This long night had brought me
full-circle. I was once again on coelum cognita. Everything from Gemini on that
evening had been new celestial terrain for me. Hungrily, I turned the
Pup on M57. Beautiful. Both small refractors showed its clearly annular
shape.
Now earlier I had exhorted my comrades in the night to wait until we
could make Mars the last view of the night. Now was the time. We turned
our refractors on the Red Planet. The God of War was now struggling
mightily against the Earth's limb to rise unshacked into the empirian.
Though the atmosphere beset him, we hungrily feasted our eyes upon His
travail. The globe was very small. It's reddish-orange disk obvious. I
thought I saw a bit of gibbousness about the edge. Mark and I both made out
a small dark area near the limb. Enough for a start!
ADDENDUM: The preceding narrative didn't quite capture all objects
viewed, So in the interests of completeness (especially for my personal
future reference): Around midnight, Leon and Mark pulled up the carbon
star La Superba on their scopes. I didn't get a chance to view through
Leon's 10" dob, but Mark said La Superba was well, simply superb. I did
see the star through Mark's TV-85. I found the color to be slightly
orange - a sort of "pumpkin-red". The red was quite present - certainly not
as pale as Aldebaran for instance. Mark and I also turned up the Owl
Nebula (M97) in Ursa Major on our scopes. Contrast was surprisingly
bright in the Pup - no sign of the "eyes" however. It was at this time that
I looked up Galaxy M108.
Finally and unfortunately, I was unable to capture the impressions of
several groups of other amateurs who assembled with Richard out on the
"Great Western Prairie". No doubt, a good time was had by all.
|
| Date and time of Observation: | Saturday, January 27, 2001 6-10:30PST |
| Observing Location: | Quail Hollow County Park |
| Object Observed: | Iota Cassiopeia, Saturn, M42, M78, Perseus Double-Cluster, M31,M32, M110, M33, NGC604, NGC1300, NGC2022, NGC206, NGC891 |
| Viewing conditions: | Stability: poor,Transparency:4.6+ ULTM |
| Telescope | 4" NextStar to an 11" Celestron (C11), 10" Dobsonian, MK-67 and a 60mm refractor |
| Observing notes: |
Amateur astronomy can be an excellent cure for "Saturday Night Fever". On
this particular Saturday, the Fever took me away from the usual lonely
sojourn (to the Ridge), and deposited me down in the Hollow of the Low
Flying Fowl. There I, and perhaps twenty other amateur astronomers,
temporarily commandeered the park's south field and set up our scopes.
Dominating the scene were a number of SCTs. Apertures ranged from a single
four inch NextStar to an eleven inch Celestron (C11). Several 10 inch Dobs
were also present, along with at least one eight and one ten inch LX200. I
set up the MK-67 near fellow Santa Cruz Astronomy Club member Ralph. Ralph
and I had observed together previously at the private SCAC observing site
in Bonny Dune. His scope has excellent optics. More importantly Ralph is a
genuinely likeable fellow. I truly enjoy his fine, cultured company.
Most participants had arrived well before dusk. The event was well
publicized and a large contingent of "the interested public" were
anticipated. As the sky slowly darkened, the bulk of the tubes were turned
on M42 in Orion. This impressive object (and later the Pleiades) would prove
most popular with the crowds that later started showing up (headlights
ablaze) just as our eyes were becoming dark-adapted...
As observations began in earnest, the crescent moon (replete with
"Earthglow") hung about 20 degrees over the southwest horizon. In fact the
theme for this particular evening was "the Moon". A slide show and
presentation by a SCAC club member was in progress in the Quail Hollow Main
House. (At one time Quail Hollow Ranch had been privately held. Cattle and
horses probably once grazed in the large field where we setup.) A visitor
approached me, and at her request I turned the scope on the moon. At 50X it
fit nicely within the FOV. Mares Focundatitatis and Crisium dominated the
view. Of the large craters, Stevinus was most obvious. The edge of the moon
"shivered" with turbulence. (As the night progressed, all in attendance would "shiver" as well - with the cold.) Atmospheric stability was none too
good. (It had not been very good the last - first -time I had observed here
either). General instability was verified when I made my usual checks of
Iota Cassiopeia (elongated - not even a dirty split) and Saturn (Cassini
visible intermittently). The temperature was dropping. Earlier Ralph had
turned his scope on Venus. The defocused image showed some marginal tube
currents. The temperature gradient, however, was not enough to cause
ongoing problems with our scopes. But it did result in the last of the
scopes being packed up and moved out by 10:30PST. (The last Quail Hollow
session ended at the "Witching hour" with the gentle encouragement of the
park docent.)
Even with the moon up, transparency was pretty good (for this particular
locale). To the unaided eye, Iota Cassiopeia was just direct (ULTM=4.6). As
the night progressed (especially after moon-set), I would say (light domes
of Santa Cruz - southwest - and San Jose - north - notwithstanding),
transparency improved to an ULTM of 5.0. Interestingly enough, later in the
evening, I had a visitor who asked me what I thought of sky conditions.
With my usual enthusiasm for this topic, I approached an answer by
explaining how I usually assess the sky based on stars in Cassiopeia and
how this translated into what I would later be able to see through the
scope. I made the especial point of saying that I needed good dark nights
(ULTM>5.0) to get the kind of deepsky views my neighbor Ralph and his 10
inch scope would get even on "poor" (ULTM<4.0) nights.
My other neighbor - Jeff - had setup a four inch NextStar "next door". We
took a look at M42 in his scope, followed by mine, then Ralphs. The
NextStar could just barely reveal the 7.9 magnitude member of the
trapezium. (Unfortunately, the ep's FOV was "curved" and the trapezium could
only be resolved near the center of the field.) Nebular gases were gray and
less expansive than in the six inch. The tongue of darkness licking at the
Trapezium lacked depth of contrast. There was no sense of the dark slash of
absorption nebulosity opposite the trapezium from the tongue behind it. The
six inch showed the bright nebula as "white" rather than "grey". The
trapezium was visible no matter where its position in the FOV. The dark
slash was just visible with averted vision. The ten inch showed the dark
slash obviously. (In fact I had first noticed this feature in the ten inch,
then traced my way backwards through the series of scopes to determine
where it was lost. I had never seen it before in my six inch.) The ten inch
also showed only the four main stars of the trapezium - stability was just
too poor for detecting any others.
Ralph and I then turned the 10 inch on M78. M78 was very obvious in his
scope. (I had seen it before in mine and didn't bother to view it.) I was
particularly interested in viewing NGC 2071 (north-northeast of M78). This
"bright" nebulosity surrounds a 9.5 magnitude star. A second star of
similar magnitude lies very close by in the same field. Both stars showed
"star glow" in his scope (as I have seen in mine). Although the nebula
should be easy in a ten inch (even under less than perfect skies) it
was confounded with the star. Again a tough call.
Earlier I had toured around the observing site. During the tour, I came
across a first-time observer - Matt. The sky was still relatively light at
that time but Orion's Sword could be made out. I helped Matt take aim on
M42 and we checked it out through his 30X 50mm super wide field ep. The low
power and bright sky robbed the image of contrast but the 10 inch Discovery
Dob-Newt gave a decent view. After this we turned the scope on Jupiter. The
low power view showed a very bright tight disc with 3 tack sharp satellites
in attendance. The SEB and NEB were possible even at this low power. Later
I had a chance to view M31 through the scope as well. Dust lanes between
M31 core from M110 were obvious. (They are difficult in my 6 inch under
similar conditions.) M32 and M110 gave nice views as well. Matt showed a
lot of enthusiasm for these objects. I also turned him on to the Double
Cluster in Perseus. It really hasn't been that long ago that I was just
learning about some of these same objects.
With the sky getting "dark", I returned to my own scope. Showed a nice old
lady the Pleiades (at her request). I explained that the best view was
through the finderscope. We talked a little about how the Pleiades could be
thought of as "The Seven Wives" joined with the "Seven Husbands" of Ursa
Major.
I resumed my own agenda: Find NGC206 in M31! With Ralph's "Goto" and one
magnitude deeper reach, this turned out to be a cinch. Unfortunately after
determining 206's position in Ralph's scope, I was only able to just barely
imagine it in my own scope. So final, certain detection of this object will
have to wait for a clear, dark, night up on the Ridge.
While looking for 206, I misquoted the reference as "NGC604". This swung
the scope around on M33. Once again, what is obvious in the ten inch is a
challenge in the six. The "Great Nebula of the Triangulum Galaxy" was easy.
By this time Ralph was starting to show enthusiasm for the faint stuff. So
we rolled up the planetary NGC2022 in Orion. Damn, the thing was sharp and
tight. Again, in my scope it is difficult and diffuse. In the ten inch,
obvious and well aspected. (Circular, greyish white with a sharp outer edge
between frontier and space.) Finally one more object: Galaxy NGC1300 in
Eridanus. Punch in the coordinates. Listen to the coffee grinder mechanism
chug along until the scope stops. Then there it is. Large oval fuzzy patch,
barely brighter than the murky gray sky surrounding it. (This one will be
a challenge in the 6 inch -- I'm sure of it.)
As I was tracking down NGC206 in my own scope, I overheard Ralph talking
with a visitor about seeing some "spiral arms" on a galaxy. I suggested
they view M33 (since it was face on rather than edge on like M31). Ralph
re-oriented the scope on M33 again. His visitor wandered off and I
explained what to look for to Ralph. First I centered NGC604 in the FOV.
Then I described 604's position in relation to the spiral arm. Ralph used
my observing chair to sit comfortably and allow his observing eye to relax
using NGC604 as a target. After awhile I heard Ralph begin sub-vocalizing
phrases like "I see it", and "wow". I think Ralph had his breakthrough.
Earlier in the evening we had also turned the ten inch on NGC891 in
Andromeda. Again the galaxy was an obvious "scratch of light" in the ten
inch. (Under similar conditions it would prove somewhat difficult in the 6
inch.) It was in seeing NGC891 that Ralph began to get "deep fuzzy" fever.
My own scope was broken down and stored in the hatchback before 9:30. Ralph
had left earlier. (He had another commitment.) I spent about a half an hour
talking with the park's docent about the gravitational effects galactic
core black holes on nearby globular clusters. The docents background was in
ecology. The idea of "herding for protection" seemed like a perfectly good
metaphor as to why such clusters took form...
After storing the scope and accessories, I noticed a small group of folks
struggling to set up and use a 60mm refractor in the parking lot. It was
clear they were having problems. I stopped by to help out. Though the
little scope had decent optics, the altazimuth mount was unstable and
difficult to line up on any particular object. (It had its own mind about
where it was willing to point. Rather than fight it I tended to reposition
the tripod as a unit.) The finder also required some adjustment. We were
able to get a look at Jupiter, Saturn, the Pleiades, and M42 through the
little scope. Planet views were nice and sharp. Stars in the Pleiades also.
M42 was unspectacular. Only noticed the Trapezium as a single star -- but
we were using the low power ep due to the problems with the mount. With a
decent equatorial mount this little scope could be fun! But the current
high level of frustration with the mount was likely to simply turn off most
users.
Once small scope viewing was over, we had an extended conversation about
stellar evolution. Discussion centered on the fact that the Pleiades were
probably once very much like M42 in Orion. We also talked a little about
the fusion of heavy elements in massive stars. The lyrics "We are stardust,
we are golden, and we've got to get ourselves back to the garden." came to
mind. Someone said, "It makes you feel so insignificant!". More lyrics came
to mind: "Wake up and find out that you are the eyes of the world..."
|
| Observer: | James R. Johnson |
| E-mail address: | viking313@earthlink.net |
| Date and time of Observation: | August 5 between 7:30 - 11:30 pm |
| Observing Location: | Valley Forge, Pennsylvania |
| Object Observed: | Various |
| Viewing conditions: | Good |
| Telescope | Various |
| Eyepiece | Various |
| Observing notes: |
I went to my first Star party...It was
hosted by The Delaware Valley Amateur Astronomers Club (www.dvaa.org) at
Valley Forge,Pa. It was a warm Friday night and I was impressed by the
number and friendliness of the people hosting and attending. I was able to
observe the moon early thru an AstroView 6" refractor. The detail was
amazing and crystal clear. A 2" eyepiece really made for a great view.
I also had the chance to look at the moon with another 6" refractor
that had a binocular eyepiece! All I can say is WOW!!! The detail is excellent with both eyes!
I talked with other people and killed some time until the Big Dipper
showed, then split the double on a guys 8" Meade Starhopper.
After talking awhile I got a chance to see M13 on a 10" Coulter
Odysee. At the same scope I also got to see the Trifid Nebula thru a filter.
I moved on and was able to see the Andromeda Galaxy and the Ring Nebula
thru a StarMaster 13" truss dob.
Around 11:15 the skies got very hazy from the humidity and people
started packing up. I stayed and spoke with some of the DVAA members about
joining and thanked them for a fun night. I think they will have a new
member soon!!
|
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Despite a fine, stable southern sky, there was no "once in an apparition" view last evening. Under blue filter, both polar caps (or their
atmospheric shrouds) were clearly discernable. A bright grin of "limb haze" could be seen - tracing the earth-western limb of the planet from pole to pole. Of the maria, only the dark collar demarking the NPC was obvious. The remainder of the planet definitely in "Maria Obscura" - only vague intimations possible. It was very easy to conclude that the planet resumed its stormy ways. Views at 360 and 540x showed decent edge-focus. The problem was not in our skies - but in those of Mars itself...
Knowing we will lose the last of the decent views of Jupiter within a month, I spent almost an hour in slack-jawed jubilation executing the humble "labor of love" you see at left. While sketching, I mentally ticked off the list of features seen: Belt edge irregularities in both the NEB and SEB. Obvious split of the SEB into three lesser belt zones. A small light oval at NEB east. The EB bisecting the EZ. Faint corriolus lines leading into the EZ - especially from the NEB. A nicely delineated NTB. An NNTB almost completely distinct from the NPR. Nice blue gray contrast gradients leading toward both poles. Had the planet been a little higher - under the same conditions - I have no doubt that a plethora of intra-equatorial belt detail would have been revealed. - Something to look forward to next cycle...
While Jupiter was not more than 40 degrees elevated above the western horizon - Saturn was half that. This detracted somewhat from the view. Even so, Cassini was quite sharp at times, the SEB was very distinct, the planet's shadow on the posterior east ring was nicely delineated, and a bit of the inner dusky ring was possible. Essentially, the nicest view of Saturn seen since late January. So all in all, the drawing at left shows how a primetime Saturn looks in Argo on a slightly better than average night (6/10). While that of Jupiter
equaled (or perhaps slightly surpassed) that seen on a solid 7/10 night near opposition last year.