Comet Nishimura

C/2023 P1 (Nishimura) is a long-period comet discovered by Hideo Nishimura on 12 August 2023.

Comet Nishimura on September 7, 2023, with 200mm focal length.

At the beginning of September 2023, the comet was visible in the morning, just before sunrise, very low on the horizon and in the sun glare.

Crop of the above image.

This has been a very challenging target for acquisition (high air mass, very short observation time between the object rising and the sun rising, roof in the frame,), but I managed to get a few images, both with Moana, in LRGB, and with the short focal length (200mm) piggy back, in bayered color. The piggy back is a Borg 200, and the optical quality is far from perfection at the edge of the field (coma).

Since the acquisition was so challenged, I had to use a full bag of tricks to process to an acceptable image. No photoshop, mind you (all in Pixinsight), but very heavy handed on masks, denoise, pattern removal and statistical filtering in the stack.

On September 9 I tried acquistion again but there was too much sun glare for the comet to be visible.

Also here is a link on one of the newest star removal technic for comet processing using StarXterminator batch.

Borg 200mm dataset (no calibration at this point):

Nishimura, starless from Moana.

The Moana data is much cleaner and much, much easier to process than the Borg data! The above image is processed using the standard comet workflow.

Also see the discussion on the flake event regarding the new flats.

Starless image above, need to generate the image with stars.

And the Moana dataset, shot in parallel: