Tuesday, July 13, 2010

Quick but fun dark sky session

I went to the Meyer Observatory last night to learn a bit about the operation of the 24-inch telescope.  Unfortunately, the camera shutter wasn't working.  While it was being fixed, I sneaked out and pulled out my 8" F/4 telescope, which I brought along.  I had a rather nice and very fast session under really dark skies--about 20-25 minutes.  Actually, my first impression of the skies was that it was cloudy and the clouds were lit up by city lights.  In particular, Sagittarius looked really clouded over.  What an embarrassing mistake!  The clouds were clouds of stars--the Milky Way!  Unfortunately, I forgot to bring my 30mm 1.25" eyepiece, and the scope only has a 1.25" focuser, so I was stuck with a 13mm, which rather took away the scope's wide-field advantages.

I started with M13, which resolved fairly well, but not as well as in my 13" from brighter sites, though I had a hard time finding Hercules--too many stars in the sky!  I had a nice look at M51.  It had its companion visible, and there definitely was a connection between them.  I got a vague hint of spiralness.

M57 was a nice little donut.  Better than I expected from this very fast scope with a damaged mirror.  I then tried to find M20 and M8.  While trying to point to M20, I hit M8, which was very nice.  In fact, M8 was naked-eye, with a nice dark lane down the middle.  M20 was a little ways up.  I don't think I saw all of its three dark lanes, but I did get an impression of at least two.  I tried for the American Nebula at some point, with no luck, because the field of view was too small.  And I also tried for the Veil Nebula, and did in fact get a nice line, which may have been the broomstick, but it was hard to tell--the image wasn't as sharp as when I used my 13".

Still, it was a very nice session squeezed in a short amount of time.  I rather like a scope that weighs less than 17lbs.  I am looking forward to taking the travel scope by plane to Canada.


  1. Yeah, don't confuse the Milky Way for the clouds, you might miss out, but fortunately you didn't.

    Hercules, for me, is extremely easy to find. My first Messier object was located in Hercules, M13. The easiest way to locate Hercules is to remember it's in the middle of Arcturus and Vega, which are two very bright stars that are easy to locate.

    Hey Alex, (I hope you don't mind me calling you Alex) I have a question. I'm curious about galaxies and the details that can be seen, especially the 'spiralness' you allude to. To see such detail you don't need a long exposure shot, correct? I'm guessing taking a long exposure shot merely increases detail of the 'arms,' but not that's the only way to see the 'spiralness' of galaxies.

    As for as a travel scope you can get the Sky-watcher 70mm. :)- But, you might want something a little bigger, I presume. To my surprise my father came home one day with a telescope: a Celestron StarHopper 4.5". However, I must say I would not spend the money on this scope for full price. I, better yet my dad, was able to get it at a great price with the store trying to get rid of it. He paid $120 for the scope, which easily sells around $200+ for such scopes. Also, it uses an alt/az mount (making it a tabletop scope), and many prefer the EQ mounts (I don't know your taste). The scope also weighs 18 lbs.

    Whatever travel scope you find, I can only hope you get as good of a deal as I got with the Sky-watcher 70mm.

  2. Jarrett:

    Normally, Hercules is really easy to find. But if there are too many stars, the distinctive "square" is obscured by all the other stars. I did end up using Antares, Vega and the Big Dipper.

    My home-made travel scope is an 8" (well, less because the mirror is damaged in one area and blacked-out) Dobsonian. It weighs in at under 17 lbs, and disassembles so the mirror box with primary and secondary can fit in a backpack (this is about half of the weight) and everything else folds pretty flat and can go in a suitcase (or in the backpack if it's a big backpack, I guess). I am pretty happy with it. I got the optics for about $40, and miscellaneous parts probably cost me another $40-80. Plus I bought a bunch of tools (jigsaw, mainly).

    Last time I traveled with a telescope, it was with my home-made 68mm refractor (cost under $20, as I got the lens, with a small chip that I blacked out, for about $17). That scope weighed about 3 lbs, and mounted on a photo tripod. I don't like the stability of the photo tripod, but since there was one at the other end of travel, I didn't have to bring one with me. It's certainly not as nice as a Sky-watcher.

    As for spiralness, it depends. If you're taking photographs, you need either larger aperture or a longer exposure. A small aperture and short exposure and you won't see anything, or just a small blur. But I am not an astrophotographer.

    Visually, you need dark skies, good viewing conditions (transparency), aperture and experience.

    You see more through the same scope in the same conditions with experience. I also find that I see more in an object if I come back to it several times in a session. In effect, this is like a long exposure, with your brain training itself to recognize the details in the object, and putting the data together.

    I had very dark skies when I was observing this time (green, but close to blue boundary, and somewhat elevated), and that compensated for the fact that I was only using an 8" scope. In somewhat brighter skies, I need my 13" to get any hint of spiral structure. Combining the dark skies and aperture is the best: I've had beautiful views of M33 with the 13" at that site.

  3. I realized that my remark at the end of my post about a travel scope was unclear. The 8" F/4 is my travel scope.