Orwell Astronomical Society (Ipswich)

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Comet C/2018 Y1 (Iwamoto), 26 February 2019

On 18 December 2018, Japanese astronomer Masayuki Iwamoto discovered a comet, designated C/2018 Y1 (Iwamoto). The body originated in the Oort Cloud and was approaching the Sun for the first time in over 1,000 years. On 12 February 2019, the comet passed Earth at 45 million km and was visible in binoculars. Its motion was easily detectable over a period of some tens of minutes.

In early 2020, I found on my PC a directory of unprocessed images. I knew when they were taken (26 February 2019), but not the subject matter, other than that it was a clearly unimpressive comet.

So what next? I created a median image and fed it into an online astrometry site https://nova.astrometry.net/. It did not take long before it replied with the coordinates of the image (in Auriga) along with image scale and orientation. I learned that I had imaged comet C/2018 Y1 (Iwamoto). The ability of the astrometry website to identify an unknown picture of the sky, with no additional information as to scale, field-of-view or orientation, is very impressive!

Equipment used: 200 mm, f/10 Celestron Edge HD Schmidt-Cassegrain instrument and SBIG 8300 camera using 2x2 binning.


Nigel Evans