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Comet C/2020 R4 (ATLAS) Passes by the Hockey Stick and Whale Galaxies APOD 5/13/2021 | by TransientAstronomer
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Comet C/2020 R4 (ATLAS) Passes by the Hockey Stick and Whale Galaxies APOD 5/13/2021

In this image Comet C/2020 R4 (ATLAS) cruises by the Whale Galaxy NGC 4631 and the Hockey Stick Galaxies NGC 4656 & 4657 from our perspective here on Earth. This image was captured at Grand Mesa Observatory and processed by Terry Hancock and Tom Masterson.


Using two telescope systems last week this image was captured over two nights, 5/5 and 5/6. The first night, Wednesday 5/5 we used System 1 which has a Takahashi 130 telescope capturing images with the monochrome QHY 600 and System 4 where a Takahashi E180 telescope is used and images are captured on a QHY410 color camera. On Thursday night 5/6 only System 1 was used, on this night we focused on capturing more data to get a better background image of the galaxies since by this time Comet C/2020 R4 had moved out of this field of view.


Total Integration Time 7.75 hours


Both systems are available to subscribe to or request data from at Grand Mesa Observatory. If you would like to know more, please visit


APOD Info:


Technical Info:


Location: Purdy Mesa, Colorado

Date of capture: May 5th, 6th 2021

System 1

Lum 136 x 60 sec

RGB 60 x 60 sec

System 2

149 x 60 sec

Camera System 4a: QHY410C Back Illuminated Full Frame Color CMOS

Camera System 1: QHY600 Mono CMOS Photographic version

Optics System 4a: Takahashi E-180 Astrograph

Optics System 1: Takahashi FSQ 130 APO Refractor @ F5

Image Acquisition software Maxim DL6

Pre-Processed in Pixinsight

Post Processed in Photoshop


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Uploaded on May 10, 2021