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Hello,
This is just an alert that C/2017 T2 is now about 2 degrees away from the Double Cluster. Those with modest telescopes should be able to visually observe and/or image the conjunction with relative ease.
See Nick James’ observing challenge for more information.
David Swan
A low resolution spectrum from last night. Mainly scattered sunlight but once divided by a nearby G2v solar analogue star spectrum the emission features can be identified. CN at 390nm in the UV is particularly strong.
The raw spectrum image can be seen here
https://britastro.org/node/20453
Cheers
Robin
Very nice, Robin. I was disappointed not to pick up the green outer coma with my OSC cam and Hyperstar last time, particularly with the comet being so nicely placed at the moment. But it is clear in your spectrum.
It’s now close enough that I can fit it in the field of my wide-angle imaging system. This is an image from Chelmsford tonight.
Had an excellent view last night of the comet in the same FOV as the lesser known mag 7.6 OC NGC 957 in Perseus last night. Nucleus of the comet only a 1/3 deg from the OC. Used my 60 cm F4.5 Newtonian with a 21mm Ethos e/p giving x129 and a 3/4 deg FOV. Glorious sight. The tail was at least 1/4 degree long, possibly up to 1/3 degree but always difficult to decide where they end visually, tail in a direction away from the cluster.
As a bonus had a look at C/2018 N2 but that was more difficult, couldn’t see it in the 21mm e/p but in the 13mm Ethos, direct vision, a small fuzzy disc. 8mm (x340) was too much, 10mm (x270) optimum.
Skies were claggy though due to high humidity, SQM 20.9, mag 5 N/E.
Andrew
Andrew. Many thanks for that observation. This is a good opportunity for visual views as well as imaging.
Yes, great to hear you got a good view Andrew. I imagine the high altitude of T2 is really helping evening visual observers.
It was unexpectedly clear for a period this evening. I caught the comet with a 200mm lens: 50 x 10s. 2020/01/21 21:40.
Hi David, yes altitude makes a real difference in these increasingly humid skies here in the UK. I try and avoid observing anything below 30 degrees altitude and travel to the Canaries for lower latitude objects. I often note that cameras seem to punch through the clagg better than visual but they are still affected. Re your excellent image, I note the double cluster is prominent but NGC 957 is barely noticeable as an OC and looks more like just a denser star field whereas in the 24″ it looked a decent cluster. Equally I can’t fit the double cluster in the big scope and need a much smaller scope for that.
Andrew
Have to say I was slightly underwhelmed at T2 on the evening of Jan 20. Although overhead, the background sky is always too bright to appreciate Comets from Birmingham, even fairly bright ones like this. In the 51cm with a 10mm Ethos I could just discern the tail. Ten minutes later, and a degree or so away across the open cluster, I was seeing close to mag 16 in a variable star field with the same eyepiece. My first Comet was Bennett in 1970, and I have loved observing them ever since. However light pollution has virtually ended this aspect of visual observing enjoyment for me.
Gary
Been having a ‘play’ with SLOOH over the past couple of weeks, and managed this image of C/2017 T2 on Jan 4.812 UT with ‘Canary 1’ – (0.5-m). Not keen on displaying images I haven’t taken (I refuse to spend time processing images), but I quite liked this one.
Gary
Gary
T2 is in closest conjunction with the Double Cluster over the next few days. Managed to capture an image this evening during a break in clouds. I’ve finally got the ASI294MC spacing right for my Hyperstar. It has only taken a year’s work, on and off!
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