This page is dedicated to observations made with a 90mm refractor. The observing reports shown below should give you a flavour of what you can see with this type of instrument.
Observer: | David W. Myers |
E-mail address: | dwmyers@mindspring.com |
Web site: | www.mindspring.com/~dwmyers |
Date and time of Observation: | August 15, 2001, 9:30pm-11:15pm EDT |
Observing Location: | S. of Mansfield GA, near Charlie Elliot Center. |
Object Observed: | M7, M4, Uranus (scope); many (binoculars) |
Viewing conditions: | dark skies, limiting magnitude well over 6. skyglow to east, west, but mostly north. |
Telescope | Meade DS-90EC (90mm f/11) and binoculars (10x50) |
Eyepiece | 40mm and 17mm Sirius plossls; 9.7 and 6.4mm Meade Series 4000 plossls |
Observing notes: |
I was trying to get to the Atlanta
Astronomy observing field at the Charlie Elliot Wildlife Center but the
entrance was locked; I parked my car about a half mile away and observed
there. It wasn't ideal, the grass was calf to knee high and the ground
uneven and run over by tractors, but the skies were the darkest I'd seen in
ages and I had to look at something. Mostly I was using binoculars
through the night, sweeping upward from M7 and M6, to M8, then across to
the left, to another fuzzy (presumably M22), then up and to the right, to
M24, then further up, to Brocchi's cluster and into the skies in
Cygnus.
This is the first time I've had a sky clear enough, in GA, to actually
figure out the stars in Cassiopeia. I picked out Corona Borealis naked
eye, the constellation Capricornus. I didn't need binoculars to see
Saggita, it was an easy naked eye object. In large part I was overwhelmed
by the sky; I don't get many seeing nights so clear and pretty. There
was skyglow, more noticeable to the North and West; I'd not have trusted
my scope to have found fuzzies in Ursa Major that night, but the South
was so amazingly clear. M4 was a naked eye object tonight, so I trained
my scope on that, using 40mm at first and then 17mm. 17mm was
tantalizing; I would see tiny stars in the fuzz with averted vision, but I
wasn't at all sure if I was picking out bright stars from M4 or seeing very
faint stars behind it.
I pointed my scope at M7 with a 40mm and prowled as much of the sky as
it continued to turn dark; I started looking for M31 with binocs but my
red flashlight had fallen apart (so much for cheaply made flashlights)
and I didn't want to lose my night vision. I don't know that part of
the sky well and I couldn't locate it immediately. But by then (10:30ish)
, the eastern tip of Capricorn had risen enough to get out of the
skyglow, and there was a quartet of stars just above delta Capricornus. I
was pretty sure one of them was Uranus. I found 4 stars easily in the
40mm, and moved quickly to a higher field plossl, not even sure initially
which one I had. But I was able to focus in on Uranus and take a look.
It was -so- tiny; the tiniest little ball, pale and white in appearance
under my conditions. It was so small I spent a lot of time focusing
tightly on nearby stars, to see if the tiny circularity would go away. It
didn't. I compared the positions of the other nearby stars, just !
to be sure of what I was looking at. I upped my power, I found my 6.4mm
and looked again at 156x. Still tiny, so small it left me wondering if
I has seen the right thing.
Before the night ended, I broke down, turned on car lights, dug out
"Nightwatch", tracked down the square of Pegasus and found M31 under the
binoculars. I briefly scanned Cassiopeia with binocs; that part of the
sky was partly affected by skyglow, but I think I sighted NGC457.
Next morning I confirmed that I had seen Uranus using Cartes du Ciel.
David.
|
Observer: | David W. Myers |
E-mail address: | dwmyers@mindspring.com |
Web site: | www.mindspring.com/~dwmyers |
Date and time of Observation: | 7/29/2001 5:00am to 6:00am or so |
Observing Location: | Norcross, GA, a suburb of Atlanta. |
Object Observed: | Saturn, Venus, the Pleiades, the Hyades |
Viewing conditions: | Transparency about 4.5, some thin clouds with occasional obscuration. |
Telescope | Meade DS-90EC 90mm refractor |
Eyepiece | 40mm Sirius plossl, 26mm Sirius plossl, 9.7mm Meade Series 4000 plossl, 6.4mm Meade Series 4000 plossl |
Observing notes: |
This was one of those weekend nights when I
couldn't sleep, and for that matter, because of the rain, I had mostly
abandoned any hope of viewing. But it was very deep into the night when
I realized it was about 5am, and just as a lark, took a step out of the
apartment and checked out the sky. Whoa, it was clear, with just a few
patches of clouds to obscure the view. Now, the view to the east from
my apartment is partly blocked by trees, but there were a pair of stars
side by side, about where Aldebaran should be, and that other one...ran
back into the apartment, got the binoculars and scanned the skies to
the east. The left most object wasn't blinking really, under the
binoculars, and was sporting that "one horned devil" look I'd seen from Saturn
before. Oooooh yeah, time to drag out the scope. Because of the time
and the location, I was going to view right outside the apartment door,
right by the porch lights of everyone. Ugh, ugh, ugh, but if I could get Saturn in my eyepiece, I'd be the first time I'd have done it
without anyone else helping. So yes, I pretty much had no choice. I
scanned the skies for Venus, but for now, it was behind tall pines. Get the
scope up and running, no time to align the Autostar. Still using the
Autostar, it's a better motor drive controller than the manual one.
Checked out the scope motion, this is the first time I've tried the system
since the Weiller wire-tangle fix, and I'm using the AA battery pack
this time.
The biggest problem I had now was moving the scope into a position that
Saturn wasn't blocked by trees or power lines. I used the 26mm eyepiece
and sighted down the barrel by eye, then in the finder. Eyeballing it
put it easily within finder view, and I'd aligned the finder using a
star one frustrating night when all the electronics went south on me. So
there it was, small but distinct in the eyepiece. Tiny! with a yellow
hue and the roundness of the rings very clear. At this magnification
(48x), no sign of a Cassini division. Two starlike objects very near
Saturn, one below and to the right in this viewpiece, another further out and
more directly right. I'm guessing those are the moons. One is Titan and
I can't name the other offhand.
I switched to a 9.7mm eyepiece and ... there it was, just a hint of the
Cassini division, a thin dark band in the rings themselves. It was
there and then it was gone. Up the eyepiece again, to 6.4mm. Saturn is
holding up well to increased magnification, and no sign of achromatic
distortion. It took a couple tries to get Saturn in view with the 6.4.
Tracking wasn't on, so I had to correct for drift before the eyepiece
switch. Found it. The Cassini division is more prominent at this magnification,
the ring itself looking a bit like a split level ringed frisbee. At
least one band on Saturn is evident, around the middle. A second sometimes
appears, about half way between the middle and the poles. It's all good
now. The second band isn't there often, the main (middle) band is faint
but often there. Viewing is sharpest if I open both eyes and let my
eyes relax.
I look up, Venus has risen just over the tree tops. I should be able to
get it into the view if I ... oh man, I'm standing on the stair case to
get this view. Position is very cramped now. But as bright as Venus is,
it's easy to find. When I focus on it, I'm getting some serious
chromatic distortion, reds on one side, green on the other, a blue halo. Never
seen it this bad before. Clouds are coming in, Venus winks in and out
on me, and sometimes ripples, like an otherwise calm pool when a stone
strikes it. I want to say the view is out-of-round, that I'm seeing a
3/4 phase or something, but I just can't be sure. Damn the chromatic aberration. This is the first time it's gotten in the way of the viewing.
It's larger than Saturn in the same eyepieces, bright, no details.
I get up, the position is cramped, and it's later. I decided to move
into the parking lot now, as it's a "darker site" (i.e. I'm more than 5
feet from the street lights). What to do? I realize I haven't planned
any strategies for these skies, but I can easily see the Plieades naked
eye. Ooo-kay. Pull out the 40mm and go find the Pleiades. Wooo, nice.
Maybe not as nice as a binocular view under dark skies but lots to see.
I count stars, numbering about 40 in this field. Scoot on down to the
Hyades, and another really nice view. Stars here number perhaps a dozen
in the wide field view.
I pause again, and begin turn tests with the DS-90EC. I haven't put
this scope through cord-winding battery-plug stress since I added the
clothes line hook to the mount. So I begin to spin it, watching to see if I
lose power. No problems tonight, the hook seems for now to help, as
does using the battery pack. I'm about to find a double star when Carlos
shows, and starts wanting to talk about telescopes. Another stranger,
attracted by the scope. I swear, telescopes are human magnets. So I stop,
drop in a wide field lens, let Carlos see Saturn. We talk a while, I
give him some scope URLs.
My seeing was done, but the public relations went on for another half
an hour. I think I need to photocopy some dobsonian plans and keep them
with me, it'd be easier. Most of the guys I meet are really handy
people, I'm sure they're capable of making a scope if they wanted. And
usually, the idea that they can excites them even more.
Comment: Serendipity. If I'd been better rested, I'd not have seen a
thing!
|
Observer: | David Myers |
E-mail address: | dwmyers@mindspring.com |
Web site: | www.mindspring.com/~dwmyers |
Date and time of Observation: | July 21, 2001, ca 11:30pm - July 22, 2001, 2am. |
Observing Location: | Norcross, GA |
Object Observed: | epsilon Lyrae, M57. |
Viewing conditions: | Poor, growing worse through the night. Tranparency about 3.5 to 4.5 within 25-30 degrees of zenith, milky white and hazy opaque otherwise. |
Telescope | Meade DS-90EC (90 mm f/11 refractor) |
Eyepiece | 40mm Sirius Plossl, 25mm Sirius Plossl, 9.7mm Series 4000 Meade Plossl, 6.4mm Series 4000 Meade Plossl |
Observing notes: |
I do a lot of my observing from the parking
lot in front of my apartment,
largely out of convenience. This night wasn't much different.
Originally
my goal was to complete an alignment of the scope using the Autostar,
but the loss of stars except at the zenith eventually prevented that
(i.e., it's very hard to set up a GOTO when the star "done gone"). And
as well, having a telescope in a large parking lot invariably attracts
people (though this one wanted a pair of ears more than something to
look through). Eventually though, I was free enough to get around to
doing something. Lyra was viewable, so I started by going to the famous
"double-double". I wanted to confirm I could split it in this urban
sky.
I had succeeded once before and failed once. I had accomplished the
split with my highest magnification eyepiece. the 6.4, and that's one
whose usefulness is often dependent on viewing conditions.
It was a humid night and my finder soon became blurry. I had brought a
pair of 10x50 binoculars to scan the skies as well, and after a few
minutes, I managed to get the target in the field of the 40mm eyepiece.
Thankfully, the sky was transparent in the region I was viewing; stars
focused down to sharp precise points and so the only problem was
keeping my eyes in the eyepiece long enough to partly dark adjust (the
lot is brightly lit; any hope of total dark adjustment is dashed here).
I worked my way up the range of eyepieces I had until the pair was in
the field of view of my 6.4mm. For a long minute it just appeared as
if it were two stars, but careful viewing eventually revealed the
split.
Cupping a hand over my eye helped a bit, to kill the sodium glare of
streetlights.
I had made binocular searches for M57 before, without much luck, but
before this night, I had made charts with Cartes du Ciel, which showed
that M57 would be in the field of view of my 40mm eyepiece if I
centered
it on HR 7162, a 5th magnitude star between gamma and beta Lyrae. It
took
a few minutes to find, in part because I had to invert the binocular
image in my mind, and then shrink it (my finder is 6x, my binoculars
10x.
apparent distances are smaller in the finder). Once I had HR 7162 in
target,
I moved the star into the upper right quarter of the 40mm field,
because
it would give a little more field view of the Messier. And there it
was,
very evident, a patch of haze forming the tip of a triangle with two
other
stars. No fine detail was visible, but it clearly was larger than a
star
and hazy. Averted viewing seemed to give more of a hazy appearance and
less
of a starlike one. I was very pleased. I did later switch to a 26mm
lens
and centered it in the field, but finding it in the 40 was very
pleasing.
All the Messier objects I had seen to date have been bright objects,
and have tended to be naked eye visible under dark skies. This one is
far dimmer than the others I had observed. I watched it for nearly half
an hour, then cleaned up and went to bed.
|
Observer: | Richard Pollard |
E-mail address: | alphacent@iprimus.com.au |
Web site: | home.iprimus.com.au/alphacent |
Date and time of Observation: | 26/11/2000 |
Observing Location: | Mount Martha, Victoria, Australia |
Object Observed: | LMC, Tarantula Nebula |
Viewing conditions: | Clear but unsteady at times |
Telescope | Meade 395 90mm refractor |
Eyepiece | Celestron 32mm Plossl |
Observing notes: |
As twilight turns to dark, a good measure we use down under to determine limiting magnitude is seeing how defined the LMC and SMC are. Through the scope, it's easy to loose count of the knots of nebulosity in the LMC. The biggest by far, the Tarantula Nebula, reveals easily seen structure and dark strips, that give it it's name. The SMC is similar, though somewhat less easily defined. Nearby is the globular 47 Tucanae, and even in a 90mm many stars can be resovled, It's truly great. A poor S/E horizon prevented viewing Eta Carinae and Omega Centauri, In a month or so I'll attempt them. |
Observer: | Richard Pollard |
E-mail address: | alphacent@iprimus.com.au |
Web site: | home.iprimus.com.au/alphacent |
Date and time of Observation: | 25 November 2000, 9:00pm - 1:00am AEDT |
Observing Location: | Mount Martha, Victoria, Australia |
Object Observed: | Saturn |
Viewing conditions: | Clear |
Telescope | Meade 395 90mm refractor |
Eyepiece | Televue 17mm plossl |
Observing notes: |
Initially, Saturn was too low on the north east to observe, and unsteady air due to a warm day was a problem, but as it rose, seeing improved to the point that the Cassini division (the gap in the rings) was obvious, as was the shadow of the rings on the planet. Titan was easily visible also. |
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