Bad Astronomy

I just spotted Comet Lulin

I went outside just now (11:00 p.m.) to check for something, and saw a big old hole in the clouds almost perfectly centered in Saturn… and Comet Lulin! So I grabbed my binoculars and took a look.

Wow! It’s huge! I estimate its size through my 15x70 binoculars at about 1/3 - 1/2 a degree, or roughly the size of the full Moon on the sky. It’s pretty bright, though it’s so spread out it’s probably very difficult to see naked eye except from dark sites (though I may be off there; I was only seeing 3rd magnitude stars due to light pollution and clouds). The tail was not obvious exactly, but I could see this wasn’t just a ball; it was elongated in an east/west direction. Also, the comet’s green color was pretty obvious. It’s an eerie faint green, like a planetary nebula (for those of you who have seen them through telescopes). In fact, they’re both green for roughly the same reason: nebulae are green due to fluorescing oxygen, and the comet from fluorescing molecules of carbon and CN (a radical that may come from hydrogen cyanide that is broken down by UV sunlight).

From my location and time (Boulder Colorado at 11:00 p.m. local time) it was “below and to the right” of Saturn. Your mileage may vary with your own location and time, and especially date as the comet is zipping along right now. Check Sky and Telescope for updates on its position.

All in all, a very spectacular sight, and one that I think will photograph well. Give it a shot!