Sunday afternoon, 19th of December of 2021 17:40h UTC, I had a clear night, zero clouds, and a great opportunity to capture a telescopic image of the C/2021 A1 (Leonard) comet from my backyard observatory (Astrocat) here in Prades (Tarragona).

Comet was around 5º above the horizon. Moon at 100%. I estimated the apparent magnitude for the core of the comet around m=5.50 to m=6.50 as I compared it with its nearby stars.

This image is an RGB composition with 3 single 60″ exposures (60″ for each channel). No calibration images were applied.




Image Details

3 single 60″ images with R, G, B filters

RGB: (1,1, 1) x 60″ bin1

Not calibrated images


Total exposure: 180″


Moon at 100%

Image resolution: 1.46”/pixel

FOV: 2.54ºx1.7º

Date: 19th of December 2021.

Time: 17:40h UTC

Location: Astrocat Observatory (Tarragona, Catalonia – Spain).



FSQ85 + ASI294MM + SHO LRGB Baader filters – with ZWO EFW 7 pos

Mesu200 mount

Guiding with ASI120MM and ZWO Mini Guide Scope



Aleix Roig – Prades (Tarragona, Spain), December 2021.


Full HD image on Astrobin:




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