Three Comets

[Bill S]

Three comets snapshotted the other night.

I was looking for (1)Ceres, which will have a close encounter with Aldebaran in early November and then spotted the comets on the Cartes du Ciel chart.

Comet 67P Churyumov–Gerasimenko is familiar enough as the comet that was visited by the Rosetta mission and landed on by Philae and later the Rosetta spacecraft itself. It’s nice to have a look and say hello. At a magnitude of ~10.5 it was about 0.49 au from Earth and 1.26 au from the Sun. It’s in an elliptical orbit that goes out to roughly the distance of Jupiter and comes round every 6.4 years.

Also in the Taurus / Auriga area, 29P Schwassmann-Wachmann is of particular interest at the moment because it has been undergoing a series of outbursts. Normally it’s around magnitude 16 but the series of four outbursts have caused it to brighten to around 11. It is about 5.4 au from the Earth and 5.9 au from the Sun. Its coma makes it look rather like a planetary nebula. Perhaps someone should produce an anti-Messier catalogue of comets that can be mistaken for DSOs. The outbursts could be due to unstable material undergoing phase changes causing material to expand outwards. It is at its brightest for 40 years. The comet has a fairly circular orbit beyond Jupiter and goes around the Sun in 14.6 years.  See for example https://britastro.org/node/26242

C/2019 L3 (ATLAS) was the BAA’s comet of the month for September. (ATLAS = Asteroid Terrestrial-Impact Last Alert System) I viewed the comet in Lynx. It had a magnitude of about 10.5 and about 3.6 au from both Earth and the Sun.  More information about this brightening comet is on the BAA website https://britastro.org/node/26218

 Looking forward to another clear night before long - I hope.

 

Bill S

 

 

[fwm891]

Great report must have look too

[Martin Meredith]

Great to see some comets. 

67P has quite a tail. Is that also the stub of a tail in 29P or perhaps it is moving sufficiently quickly to produce a slight egg shape?

For C/2019 L3 it is easy to see why Messier felt it necessary to produce his catalogue...

Martin

[Mike JW]

Well done Bill. I knew these three were well worth observing having had the heads up from Andrew but I could not face the late hour - good for you for being out there in the small hours.

Mike

[Paul M]

Very impressive collection. I was wanting to grab some comets on my last outing but a bright Moon put me off comet hunting. I did get a very grainy image  of C/2021 A1 Leonard, forecast to become comet of the year... maybe

29P is one of those comets that's been there all my stargazing life but I've never seen it nor really looked for it but your capture has piqued my interest. Gotta have a look for it now.

[Bill S]

I had another look at 29P last night before the clouds came over and the coma seems to have expanded somewhat compared with how it looked on 4 October - posted earlier.

 

Could be worth keeping an eye on.

 

Bill

 

[Mike JW]

Hi Bill,

At last I got to take a look at 29P. I was amazed at how extensive the halo has become. It also appears to have a double nucleus -  which I assume is a star it is about to crash into!!!

Mike

PS and here is a better shot 24hrs later. The nucleus looks elongated, inner and outer halo. Also there is a sliver of brightness coming off the nucleus (to the right and up)

 

Edited October 31, 2021 by Mike JW
another image

[AKB]

Here's my stab at 29P from last night (Nov 4) in Aurega.

The many stacks don't add much after the first few minutes, but I wanted to see if I could detect motion.  Indeed, looking at the individual frames there is a small shift over the whole 15 minute stack, but not enough to make a significant track visible here.

Tony.

 

[AKB]

Another opportunity to view two of these last night:

• 29P – in Aurega (I think) with an L-shaped flare perhaps visible from the nucleus
• 2019L3 – in Lynx, very close to the 'Intergalactic Wanderer'  NGC 241

Tony

 

 

 

[Mike JW]

Excellent shots and great to have L3 added as well.

Mike