Comet C/2023 A3 Tsuchinshan-ATLAS

[Nicola Fletcher]

I had a second look at it last night. It was much smaller and dimmer than Monday night but I could still see it naked eye and it was still very impressive through binoculars. I tried to take some photos with my 70-300mm zoom but it was so windy it was very difficult. Here is a single image that wasn’t too bad - I prefer the wide angle image from Monday which I processed a bit in Lightroom to bring out the details.

Last night:

Monday night:

I would have thought it qualified as a great comet on Monday night. It was really an incredible sight from my dark sky location before the moon put in an appearance.

[bish]

Tried to see it last night with 9x60 bins. Was in the right area but couldn't see it. I think a thin layer of cloud appeared at the wrong time.

[SuburbanMak]

Finally some clear skies over Hampshire - I drove West of Winchester’s lights to Farley Mount & set up as the sun went down.  A lovely still autumn evening and quite a crowd gathered (well, 8 or 9 people it’s normally deserted when I go up there to observe).  
I took the Tak FS 60 in CB mode with a 30mm Stella Lyra UFF and Canon 10x42 IS Bin’s and joined the waiting watchers. 
I was unflatteringly pleased to be the first to pick up the comet in the bins around 7 pm and after some sweeping got the scope on to it too.  Fainter than expected but still impressive with gradation in the tail, a bright nucleus and at times the anti tail showing with AV.  Just visible naked eye as the dark gathered and before the moon got well above the horizon. 
Overall though I’d say the view was best in the binoculars with more context and the whole tail showing (which I estimated at about 3 degrees). 
I was able to give quite a few folk a view through the Tak. 
We watched until gathering mist irradiated by a rising full moon gradually obliterated views of the setting comet. 
That moon made for an atmospheric walk back to the car. A great and surprisingly social session. 
Took a hit and hope snap which won’t win prizes…
 

Edited Friday at 08:21 by SuburbanMak

[Gfamily]

15 hours ago, Geoff Lister said:

It looks like the anti-tail is genuine, and not a ghost reflection in the optics.

It's heavier material thrown out from the comet, so is less affected by the solar radiation pressure, so travels with the comet. It becomes visible when we pass through the plane of the comet's orbit. 

Edited Friday at 13:36 by Gfamily
Correct why the material stays around the coma

[johnturley]

Got my first glimpse of the comet last night, having been clouded out on all previous evening.

Conditions were not great, as some high cloud about, but managed to get a snap through the 14in using my Canon EOS 6D, before it disappeared behind the neighbouring houses.

It was fainter than I was expecting, not a patch on Neowise, I estimated the magnitude at around +3, which is consisted with Seiichi Yoshida's page on the BAA Comet Section's website. I could not make it out with the naked eye, but it was clearly visible through my 16 x 80 finder.

Edited Friday at 10:03 by johnturley

[Arcturus-]

Last night the conditions were finally good enough for me to see/photo the comet on my 7th or 8th attempt. I think It was just about visible to the naked eye with averted vision when I was able to block some of the moonlight, definitely good when seen through 10x50 binoculars though.

 

[andrew63]

A colour image from last night. Comet A3 became obscured behind the tress shortly after the B/W image I took. So made a short walk with a better view below the mountain - taken just before 8 pm. 

 

Edited Friday at 13:41 by andrew63
info

[Nicola Fletcher]

2 hours ago, johnturley said:

Got my first glimpse of the comet last night, having been clouded out on all previous evening.

Conditions were not great, as some high cloud about, but managed to get a snap through the 14in using my Canon EOS 6D, before it disappeared behind the neighbouring houses.

It was fainter than I was expecting, not a patch on Neowise, I estimated the magnitude at around +3, which is consisted with Seiichi Yoshida's page on the BAA Comet Section's website. I could not make it out with the naked eye, but it was clearly visible through my 16 x 80 finder.

I’d be interested to know how it compared earlier in the week with Neowise. There was a big difference between it yesterday and Monday. Yesterday I could just about make it out naked eye, whereas on Monday I could understand how ancient peoples must have thought the end of the world was coming when they saw great comets! 

Edited Friday at 12:03 by Nicola Fletcher

[scotty1]

Sods law the moon was full when this comet was visible. 

[geoflewis]

Here's another look at Comet C/2023 A3 (Tsuchinshan-ATLAS) whilst it is still around. This was captured from my back garden around 8pm (UT) on 17 Oct 2024, with the 18mm-200mm lens on my Nikon D90 camera fully zoomed in at 200mm. It's a stack of 11x20sec exposures, so nearly 4m total exposure, for better signal. This time I used the Star Adventurer mount, rather than the previous fixed tripod, so that I could shoot longer exposures without trailing. Unfortunately there were some clouds around, plus the comet was rapidly setting towards the tree tops.

[Gfamily]

19 hours ago, geoflewis said:

Here's another look at Comet C/2023 A3 (Tsuchinshan-ATLAS) whilst it is still around. 

I think that's the first 'wide angle' shot I've seen that shows the anti-tail quite clearly.

Impressed!

[Geoff Lister]

I tried this evening (19th) with my 10x50s but no sign through the thin cloud layer. Even my S50 had a lot of samples with "too-few-stars", and, at times, even Arcturus was hidden from view; but I did manage a long-ish stacking session with some gaps, and with the counter holding at 11 minutes for over 3 minutes, I stopped the recording. The anit-tail seems to have gone, but the comet is speeding through the star-field. I wanted to capture more of the tail, so offset the aiming point, and lost the comet title in the final stacked image.

To give an idea of brightness, in the 4-star bow to the left of the tail, Stellarium lists the 2nd star from the bottom as visually magnitude 9.28.

Geoff