Celestial hemisphere:  Northern  ·  Constellation: Ursa Major (UMa)  ·  Contains:  Bode's nebulae  ·  M 81  ·  M 82  ·  NGC 2976  ·  NGC 3031  ·  NGC 3034  ·  NGC 3077
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Galaxies M81, M82 and the Ultra-Faint Integrated Flux Nebula, Roger Clark
Galaxies M81, M82 and the Ultra-Faint Integrated Flux Nebula
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Galaxies M81, M82 and the Ultra-Faint Integrated Flux Nebula

Getting plate-solving status, please wait...
Galaxies M81, M82 and the Ultra-Faint Integrated Flux Nebula, Roger Clark
Galaxies M81, M82 and the Ultra-Faint Integrated Flux Nebula
Powered byPixInsight

Galaxies M81, M82 and the Ultra-Faint Integrated Flux Nebula

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Description

Galaxies Messier 81 and Messier 82 are two bright galaxies in the constellation Ursa Major and are surrounded by the extremely faint Integrated Flux Nebula, IFN. The IFN surface brightness is fainter than 25 magnitudes per square arc-second. This image reaches to about 27 magnitudes per square arc-second.

This image was obtained with a Canon 7D Mark II 20-megapixel digital camera and 300 mm f/2.8 L IS II lens at f/2.8. Forty seven 60-second exposures at ISO 1600 were added (47 minutes total exposure). No dark frame subtraction, no flat fields. Tracking with an astrotrac and no guiding. This image was obtained on a windy night that challenged the light setup.

Processing: raw conversion in photoshop ACR with lens profiles, following my guide:

http://www.clarkvision.com/articles/astrophotography.image.processing.basics/

Stretched with rnc-color-stretch: http://www.clarkvision.com/articles/astrophotography-rnc-color-stretch/

Daylight white balance to maintain natural color.

The bright parts of the IFN only averaged 0.9 photon per exposure, and fainter parts several times less. To be able to bring out such faint detail shows the impressive uniformity and the excellent in-pixel hardware design of the dark current suppression on the sensor

More info on this image and processing is here:

http://www.clarkvision.com/galleries/gallery.astrophoto-1/web/m81+m82-300mmc12.29.2016.0J6A0804-868av47-a2-rs.e-1783s.html

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Galaxies M81, M82 and the Ultra-Faint Integrated Flux Nebula, Roger Clark