Help a newb astronomer see Comet Lulin from Maryland!

February 23, 2009 6:49 AM

I am going crazy trying to get a sighting of Comet Lulin, and I don't want to blow the best chance tonight! I live east of Rockville, MD, and there is a fair amount of light pollution in the area. I just got a 6" Dobsonian Telescope (Orion XT6), but know very little about finding my way around the sky.

I'm sure I'm looking in the right place, as I've consulted sky charts from spaceweather.com. In early February, I tried waking up around 4am a few times to get a view of the comet in the south-east of Virgo, with no success. Last night I tried at 1am, the current recommended time. I found Saturn and looked a few degrees down and east. Through my binoculars I can see a very, very faint patch of gas, so dim I would pass right over it if I didn't know I was looking for a comet. Through my telescope I see nothing, though. I had a hard time finding focus because I don't know whether that faint patch was really the comet.

Is the core obvious? Will it really look green? I'm not seeing anything like the pictures that are posted on spaceweather. Can anyone give me an idea of what the comet will look like to my eyes through the telescope? Has anyone successfully seen it from a location like mine? Any other generic viewing/finding/focusing tips? I have a Orion XT6 Dobsonian with 25mm and 10mm eyepieces. Can you help a newbie astronomer?

posted by RobotNinja to sports, hobbies, & recreation (7 comments total)

Download stellarium, and then follow this guide

http://www.astronomylog.co.uk/2009/02/10/find-comet-lulin-in-stellarium/

Sorted!
posted by zeoslap at 7:29 AM on February 23

(Well sorted to confirm location at least, can't help you with the rest of it)
posted by zeoslap at 7:30 AM on February 23

If you have moderate light pollution, a "very, very faint patch of gas" would be all to expect. Even under Mauna Kea conditions, you won't see anything like the photographs that are posted online. The human eye just isn't as sensitive as a CCD imager, especially when it comes to color.

I'm going out to view Lulin for the first time tonight. I'll post back around midnight EST if we have clear sky here and let you know what I see.

As for your equipment, the 10mm Plössl that comes with the XT6 is likely too much magnification for this comet under moderate conditions. Your best bet is likely the 6in/25mm or 10x-15x binoculars. With a 2° separation with Saturn tonight, you should be able to hop from comet to planet easily with your 25mm (which has a 1° FOV on the XT6). Also, try using averted vision to make out more of the comet.
posted by joe vrrr at 7:59 AM on February 23

If you have moderate light pollution, a "very, very faint patch of gas" would be all to expect.

Can I expect to see any kind of structure, like a central core or any of the tail? I'm pretty sure that the "blob" I saw through my 8x40 binoculars was Lulin, but I'm wondering if there's "more" to see through a telescope.
posted by RobotNinja at 8:33 AM on February 23

The big factor in viewing comets is contrast. For a better view, he only thing you can do is get to darker skies, so the comet stands out more. There's no moon for the next few nights, so that's good. Binoculars are your best bet because they show enough surrounding sky to allow the comet to stand out. A telescope won't show much more because it's sort of like a blown-up view of what is essentially a fractal pattern. The telescopic view of a glowing smudge that fades to the edges is still a glowing smudge that fades to the edges.

Darker skies will give you more background stars to use to adjust your focus as well.
posted by bonobothegreat at 8:59 AM on February 23

I'm taking a look now, and indeed the comet is a faint fuzzy. Lulin is much smaller than I expected. Under moderately light-polluted skies, my best views so far are with an 8" reflector and a 18mm eyepiece.

I'm not able to make out any structure or tail, but I do notice a distinct oblong shape to the comet with averted vision. I've also noticed its speed. In the last hour I've been able to gauge its movement by comparison to background stars.
posted by joe vrrr at 8:19 PM on February 23

At time like this I wish I lived in the country..and a it farther south.
posted by bonobothegreat at 12:21 AM on February 24