Tuesday, January 12, 2010

1/11/10 Observing Log

First observing session of 2010. I've now had the telescope a little over a year, so it is back to observing the winter constellations again. I've now viewed most of the non-galaxy winter Messier objects visible in the first half of the night, so almost everything viewed this evening I've seen before. But it gives me a chance to see how the seeing is different than in previous times.

Plus, tonight was the first time I've really seen Mars well, and the first time I've seen it through my Orion 8" scope.

Observed these objects tonight:

  • M41 - Took a quick look at M41 since I can find it within a few seconds if I have the green laser pointer running, since it is so easy to find between Sirius and Adhara.

  • NGC 2204 - Happened to see this listed in my Pocket Sky Atlas, near Mirzam in Canis Major. I was quite disappointed. Nothing really to see here. Move along.

  • M79 - I've gotten to the point now where I can estimate the seeing/light pollution of my observing location in my back yard by seeing how easily I can see all the stars of Lepus with the naked eye, which is the quadrilateral shape below Orion. Alpha Leporis (Arneb) is magnitude 2.58, Beta Leporis (Nihal) in 2.84, Epsilon Leporis is 3.19 and Mu Leporis is 3.29. I could barely make out Mu Leporis, so my backyard naked-eye limiting magnitude is probably around 3.50, which gives you an idea of how bad the light pollution is here. Anyway, I found M79 fairly easily compared to last year. If you extend the line from Alpha to Beta and intersect it with a line perpendicular to a line between Beta and Mu, you should find it quickly. M79 is a globular cluster - one of the few you can see during the winter - and is a faint circular smudge in my scope.

  • M42, M43 (Orion Nebula) - Spent some time looking at the Orion Nebula with various eyepieces and filters. Tonight, I think the Oxygen III filter brought out more detail than the UltraBlock. Popped in the 8mm Stratus to get a good view of the Trapezium.

  • Canopus - As I was looking around the sky for the next thing to observe, I happened to notice a bright star far in the southern sky, just above the neighborhood tree line. At first I thought it was a distant plane! I watched it for a few moments and it didn't move, so I got out my iPhone and brought up Starmap and quickly determined it was Canopus! This was interesting simply because back where I grew up, in northern Indiana, you can never see Canopus since it is always below the horizon. Canopus is the second brightest star in the sky after Sirius. No wonder it looked like a plane. I took a quick look at it through the scope. Canopus is in the constellation Carina, which got me thinking about Eta Carinae. I determined from a bit of research later that I probably won't be able to see Eta Carinae from Austin. Even if I could somehow see it, it would probably be totally washed out by all the horizon haze here. Time for a trip to South Padre!

  • NGC 2360 - Decided I wanted to check out M47 and M46 again, so I star-hopped to them from Sirius, and passed NGC 2360 along the way. Not a bad little open cluster.

  • M47 - M47 is a bright open cluster, but generally isn't as visually interesting to me as M46.

  • M46 - I always find M46 interesting. It is also a good way to determine how good your seeing is and how dark it is. I have seen M46 as hundreds of faint orangish stars on nights with excellent seeing, but tonight most of the color was washed out, so the cluster looked grey and less stars were visible than in my other sightings last year. A bit disappointing.

  • Mars - By now Mars was quite high in the sky (shortly after midnight on 1/12/10). This was my first viewing of Mars through my Orion telescope, and really my first-ever good look at Mars under high magnification. The lower power 19mm and 16mm Edge-On eyepieces just showed a small bright whitish disk (Mars is at magnitude -1.0, which is bright enough to affect your night vision!), so I moved up to the 13mm, 8mm and 5mm Stratus, and then added the Barlow to the 5mm to get Mars magnified to 480x. While this necessitated moving the Dob frequently, I was clearly able to see the intense white of the South Polar Cap; it contrasted well with the rest of the orangish hue of the planet. I also observed a prominent dark Y-shaped feature which I later researched to be Syrtis Major (the lower part of the Y) and Noachis Terra / Terra Cimmeria (the arms of the Y). This map of the prominent features of Mars shows all of those locations. The whole experience of seeing Mars for the first time under high mag was extremely cool. I can see how the eye can play tricks on you, since the image changes a lot as it gets affected by the atmosphere. If you look at it long enough, you might start seeing some canals as well, just like Percival Lowell!

  • Saturn - By this time Saturn had risen enough for me to move my scope around the yard a bit and take a look. The rings are no longer edge-on like they were in September, but they are still quite narrrow. I could see the shadow of the rings on the Saturnian surface, and I could also see Titan nearby. Saturn is also an orangish color in my scope, similar to Mars.

All in all, a nice hour and a half of viewing tonight. I finally "knowingly" saw Canopus, and I had my first real view of Mars. Even though the light pollution seemed high tonight, I was pretty pleased with the overall outcome.

I ordered a better green laser pointer earlier this week, since my current green laser is very powerful but stops working well when it gets cold. I have to spend 3-5 minutes heating it up with the warmth my hand before it starts shooting a long beam again. The new one is from Orion Telescopes and is supposedly able to handle colder temperatures. We'll see.