This past month has certainly been spectacular for astronomical events. Aurorae have graced our skies with tremendous activity, Saturn is back to the early evening, as is Venus, and now a comet. The comet, C/2023 A3 (Tsuchinshan-ATLAS) was noted as being the comet of the century, but reservations must always been taken when making such predictions. This was a good comet, but not nearly as spectacular as NEOWISE (C/2020 F3), Comet McNaught, Hale-Bopp, or Comet Hyakutake (C/1996 B2)… all of which were tremendous and easily seen without optical aid. C/2023 A3 was nice but bright only for a brief few days while it was in the glare of the Sun near sunrise then just after sunset. As of this writing, it is rapidly fading though still viaible with small telescopes.

Our first view of the comet here in southern New Hampshire, was on the early evening of 12 October 2024 as it made its way around the Sun and approached Earth. We were able to see it just after sunset from the tallest building on campus, the Library. Looking west, it was only visible for about 30 minutes, but easily photographed with a telephoto.

By 17th October the comet was up for a longer period but was already fading. We captured a lot of imagery this evening with a group of students and faculty by the Hill Bridge looking back to the southwest over the Field House.

Note that the anti-tail is faintly visible in the above image.

By 18th October the comet was considerably higher in altitude and even fainter. I was unable to see it without a pair of binoculars. The comet was still not visible to the observatory domes. Image below.

On 24th October, the comet had risen enough to be visible in the 0.7m telescope, so we gave it a go and imaged in Lum and RGB for the following close-up images. These are about 25×25 arc-minutes in dimension. Each is a 20 minute total integration comprised of ten, 2-minute integrations. One is summed and shows the stars as a series of points giving a good indication of the comet’s rapid movement relative to the background stars. The other image is a median which removes the stars and allows one to enjoy the comet’s details without distraction.