II Zw 40 -- the cometary galaxy with two tails

[Steve Gottlieb]

I thought discussing a "cometary galaxy" might be a appropriate theme as I had my first view of PANSTARRS from the Berkeley hills today.

II Zw 40 = UGCA 116 is a very strange object. The UGCA calls it "intergalactic nebulosity?" It's been described as a prototypical H II galaxy or BCDG (Blue Compact Dwarf Galaxy) by Sargent & Searle in 1970. The nucleus of II Zw 40 is dominated by one large H II region and fans or tails extend to the south and southeast, suggesting the merger of two galaxies.

I took a look last Saturday night with my 24" and found a fairly faint, round glow, perhaps 18" diameter. A relatively bright stellar knot appeared to be at the northwest edge, though it was difficult to pinpoint the location. I didn't see any sign of the two tails and I'm guessing they would require more aperture.

Has anyone else observed this interesting galaxy? Check out the blue starburst nucleus on the SDSS image and the dual tails!

II Zw 40
05 55 42.6 +03 23 32
V ~ 14.7

II Zw 40.jpg

[Jimi Lowrey]

I revisited this small unusual galaxy last night the blue starburst nucleus looked like a fairly bright fuzzy star at 488X the brighter tail to the south was obvious and extended with AV the other tail was hard to see and only popped a couple of times in moments of good seeing.

This is a really cool galaxy.