Tuesday, February 24, 2009

Comet Lulin Update

Just about six hours ago I was standing in my backyard freezing and looking at Comet Lulin!

I wrote about Comet Lulin last week.

This morning I got up a little before 3 a.m. and I pulled on a pair of jeans over the warm-up pants I sleep in. I put on a scarf and jacket and took my binoculars out into the backyard.

I had worked out a plan.

I knew from the finder chart I posted last week that last night Comet Lulin should be somewhere close to Saturn. Saturn is easy to find in the sky, and right now Saturn is just north of Sigma Leonis. The combination of Saturn and Sigma Leonis is great because the two objects so close together let you orient yourself in the sky to the directions in the finder chart, and also to the distances in the finder chart.

My plan was simply to start with a field of view around Saturn and Sigma Leonis and then check three ways: Down and to the left, straight down and down and to the right. Comet Lulin should have been visible just about two or three times the distance away from Sigma Leonis that Sigma Leonis is away from Saturn.

With my binoculars I saw nothing. It was very cold outside so I didn’t stand around long enough for my eyes to dark-adapt. Also I kept my binoculars hand-held.

But I didn’t give up.

I haven’t blogged about this, but around Christmas I bought myself a present. I bought myself a very inexpensive 4" refractor. This one. Of course it’s achromatic not apochromatic (apochromatic refractors typically cost a thousand dollars per inch of aperture!) and I have it mounted on a light tripod, but at 102mm it gathers more than four times the light of my binoculars and more than three times the light of my 2.4" refractor. Also it has an image erector, so up/down/left/right are all in the ‘proper’ directions.

So, after I didn’t see anything with my binoculars I tried my new f/5 4" refractor.

I checked south and to the east of Saturn and Sigma Leonis and saw nothing. Then I checked straight south along the line of Saturn to Sigma Leonis and there it was, Comet Lulin!

It was very dim. Under these skies south of Chicago I saw the comet as a colorless, indistinct smudge. But I did see it!

It reminded me a lot of what M13 in Hercules looks like under our awful skies. And, of course, that’s why Charles Messier made his catalogue in the first place, so that he wouldn’t mistake things like M13 for new comets.

I didn’t stay outside long in the cold, but I wish I had observed longer. I had already packed up my 2.4" telescope getting ready to move. I wish I had taken the time to unpack my old telescope and check out Comet Lulin with the 2.4". If it looks like the skies will be clear tonight, I might unpack my old telescope and check out Comet Lulin again tomorrow.

Comet Lulin is now speeding away from Saturn and Sigma Leonis toward Regulus. For the next few days, the combination of Regulus and Rho Leonis should make a good pair of objects to orient against. Comet Lulin will be passing directly south of Rho Leonis.

I’m not generally a big fan of Microsoft products, but I want to say that Microsoft’s Worldwide Telescope helped me prepare a little bit for tracking down Comet Lulin. Yesterday afternoon I plotted Saturn and Sigma Leonis using the WWT software. Then I zoomed out so that I could see Spica to the east. That gave me a very realistic image of the sky to study before heading out under the real thing.

I’m pretty sure there must be a way to download the orbital elements of Comet Lulin into the WWT, but I haven’t looked around. Once you do that, you can just plot the comet itself.

So, the year is starting out pretty cool, from an astronomy point of view. It’s been more than ten years since I’ve seen a comet. Comet Lulin is pretty dim, but it’s still a new comet!

(I’ve got a new bug post to do, too, but I’m not sure when I’ll get to it. I didn’t expect any bug posts during the winter, but I had a very interesting encounter outside with the insect world a few days ago. And speaking of new and unexpected things, just yesterday I heard a cool new conspiracy theory about thrift stores. I may get to that tomorrow, or I may wait and do that along with an Andy Warhol comment on thrift stores. I’m not sure.)

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