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A galaxy is a vast collection of stars that can take one of several shapes. The most common view is that all galaxies are spiral in shape, this is not so. The table below gives details on the types of galaxies you may see and their classification though there are many sub categories of those shown. |
| Galaxy Type | Description | Example |
| E0 | Elliptical galaxy spherical in shape. | M87 |
| E4 | Elliptical galaxy slightly flattened. | NGC147 |
| E7 | Elliptical galaxy highly flattened. | NGC205 |
| Sa | Spiral galaxy with large nucleus and tight spiral arms | M51 |
| Sb | Spiral galaxy with small nucleus and fairly loose spiral arms. | M81 |
| Sc | Spiral galaxy with an undefined nucleus and very loose spiral arms. | M33 |
| SBa | Barred galaxy with small bar but prominent spiral arms emanating from the bar. | NGC3504 |
| SBb | Barred galaxy with prominent bar and smaller spiral arms. | NGC7479 |
| SBc | Barred galaxy with very prominent bar and extremely small spiral arms. |
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Our galaxy, the Milky Way is part of a local group of galaxies that are traveling through space together. All other galaxies are actually moving away from us. One of our nearest galactic neighbours is a mere 2 million light years away! This is the Andromeda galaxy (M31) in the constellation of Andromeda. This was the first galaxy that I managed to view through a telescope and it was a little disappointing (I guess my expectations were clouded a little by pictures like the one opposite!) as it appeared as a big fuzzy patch, no detail of the spiral arms could be made out. In fact all you're looking at is the central hub of the galaxy. Even so it makes you realise just how enormous the galaxy is as from end to end it is larger in size than the full moon. To date I've not located any other galaxy in our local group. |
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My next galactic target is going to be M81 and M82 in the constellation of Ursa Major as I've heard that they're good targets and quite easy to find. Watch this space for details....
Update
Well I've not bagged M81 or M82 yet, perhaps later in the year. However, I have managed to track down M65 and M66 in Leo during the summer nights. This has really whetted my appetite for galaxy hunting. My observing report is shown below:
Located two galaxies M65 (mag 9.3) and M66 (mag 8.9). Hopped from J to 73 (by moving south halfway between J and i ) and centered on a small star to the east of 73 (they're in the same field of view with a 25mm eyepiece). Both galaxies are very faint and would be easily overlooked if you didn't know they were there! They're slightly above the small star centered in the eyepiece. M65 was elongated in shape and quite thin. M66 was larger in size and not quite as elongated as M65. There appeared to be a band diagonally through the galaxy that wasn't visible giving the impression that the galaxy was split in two. There were also two small stars in the same line of sight that appeared to be sitting on top of the galaxy.
Finding these two galaxies made me realise two important facts, namely the objects we're looking for can be very small and very faint. This could be the main reason why I've failed to locate them before, I just wasn't looking hard enough! Now I know what to look for I've started to find many more objects.
Update March 2001
I still haven't tracked down M81 or M82 yet but I have found M101 (mag 7.9), M51 (mag 8.4) and its companion NGC 5195 (mag 9.6). As with the other galaxies I've found they're very faint. Here's how I tracked these three galaxies down:
I star hopped from Alkaid (the last star in the big dippers handle) and was sure I was in the area where M51 (mag 8.4) and NGC 5195 (mag 9.6) should be. I couldn't make them out. I was scanning the area in the 32mm eyepiece when I caught sight of M51 with averted vision. After a few minutes I could see the cores of M51 and NGC 5195 clearly and plenty of light grey fuzz surrounding them but no real detail in their structure. Higher magnification did nothing to enhance the view but I was thrilled to have found these two at last - I've been looking all winter!
I then went in search of M101 (mag 7.9). I used Alkaid as my starting point for the star hopping and thought that as it was brighter than M51 it would be easier to see. Wrong! I again landed in the area where I thought M101 should be, all the stars on my chart matched up. I could see M101 with averted vision using the 32mm eyepiece and it gave up a small dim diffuse central core, much smaller than M51 and NGC 5195 who now seemed to be very bright by comparison. As I couldn't see much I moved on... might catch it another night and see if its improved.
Once again my observations make me realise just how important dark skies really are. The Moon was below the horizon but still seemed to have an effect on the sky. One other trick I may try is using a cloth over my head (like the old fashioned photographers used to do). I say this because when I first looked at M51 I saw nothing. As my eye became used to the darkness M51 and it's companion literally popped into view! If I hadn't been so patient I wouldn't have found this pair. The cloth over the head trick should cut out stray ambient light and have the effect of making your environment a little darker. I also noticed that a lot of light reflects of the white tube of my telescope! To counteract this I've got another piece of black cloth with a hole cut in it (for the focuser and finder scope to pass through) so it will sit over the tube and stop the light reflection!
Update April 2001
I've found M81 (mag 6.9) and M82 (mag 8.4) - at last! The moon was out and was practically full at 86% of its current phase! The sky was very bright but I could easily make out the galaxies.
I read a report on Neale Monks web site on how he tracked the pair down. I followed his advice and WOW there they were! Here's how I found them. I followed a line up from Dubhe until I reached the star 23 UMa mag 3.67, I then moved to the left until I came across a small group of stars forming a triangle (8 rho UMa mag 4.76, 11 Sig1 UMa mag 5.14 and 13 Sig2 UMa mag 4.8). Following a line down from 11 Sig1 through 13 Sig2 I came across M81 and M82 in my 32mm eyepiece. They are bright and I'm not sure which I saw first - they were 'just there!'.
M82 impressed me the most. It has a very distinctive elongated shape and I was surprised at how bright this mag 8.4 object actually was even with the Moon washing out the sky! Moving down from M82 I found M81. It appears much larger in size and has a more oval / rounded shape with a distinctive central core. After viewing this object for some time I could make out faint hazy outer layers of the galaxy. I'll be back to visit this pair the next time the moon is out of the way. Both galaxies stood up well to high magnification but didn't show up any extra detail.
