Tuesday, October 30, 2007

Comet Holmes 2

After a frustrating three nights in which I could not observe the comet because of cloud, tonight was finally clear. The comet has moved since I had last observed it on Friday, this time forming an isosceles triangle with Mirfak (Alp Per) at the apex and Del Per at the other side.

The comet had also expanded, It was now obviously non-stellar to the naked eye and looked stunning through binoculars.

The telescope view was fantastic. I roughly estimated the coma to be about 8.5 arcminutes across with the brighter central part slightly off centre. I also observed as the the star TYC 3334-512-1 (I hope I've identified it properly) showed through the coma just outside the brighter central part.

I hope there will be more clear nights to observe the evolution of this object.

Friday, October 26, 2007

Comet Holmes 1


This comet is giving an unexpected show in the autumn sky. On the 24th October, this previously magnitude 17 comet suddenly went through an outburst that made it about a million times brighter taking it to naked eye visibility.

Unfortunately I was clouded out last night. However, this evening notwithstanding very high humidity, a thin veil of high cloud and an almost full moon, I set out to observe the comet. I was not to be disappointed. The object is impossible to miss even with the naked eye, making a right angled triangle with Mirfak (Alpha Persei) and Delta Persei with the right angle at Delta.

With the naked eye the comet looks like a bright star which I made out to be certainly brighter than Delta Persei and brighter even than the 2.9 Gamma Persei. I can't be too certain due to the high cloud.

Through 16x70 binoculars, the comet appeared as a yellowish fuzzy object.

I then got out the 8" Dobsonian. Here the comet could be seen at its most magnificent. The object looks like a large planetary nebula. I observed a bright core surrounded by a large circular coma. I could not see any tail.

Considering that the comet is so far away from the sun (2.44 AU) and 1.63 AU from the Earth, I think that such a bright outburst is amazing.

Due to the haze there was not much else worth observing except the Moon. Here the highlight was the sun setting over the crater Humboldt. This offered a spectacular view of the shadow of the central peak on its Eastern wall.

Above image from the JPL Small-Body Database Browser