And XXX / Cass II - a dwarf Spheroidal satellite galaxy of M31 (Wim van Berlo)

And XXX / Cass II - a dwarf Spheroidal satellite galaxy of M31

A month ago, I decided to image a faint Andromeda dwarf satellite galaxy, And XXX / Cass II. This galaxy was discovered as late as 2013 during a deep sky survey of the Andromeda galaxy region (PAndAS, Pan Andromeda Archaeological Survey). At the time that I posted my attempt, I had collected 40 minutes of Luminance data that showed no trace of this small companion to M31.One month and 30 imaging hours later, I may have caught something.And XXX / Cass II is the thirtiest satellite galaxy to M31. It is situated just north of and somewhat inbetween ngc 185 and ngc 147, two other satellite galaxies of M31. It has diameter of only approximately 1600 ly (540 pc). The galaxy was discovered and characterised based on only 8 (!) of its member stars. Although the galaxy has an absolute magnitude of -8, its surface brightness is only 26 mag/arcsec2, making it almost impossible to detect.I believe that this image is the first obtained by an amateur astronomer.
I applied the 2DPlot script in PixInsight to a cropped version of the luminance master.
First I applied a "linear stretch", by bringing in the black point and the white point to such a level that the ifn and the probable galaxy became just visible. I then created a line profile accross a horizontal line. The marked section of the profile coincides with the location and approximate size of the dwarf galaxy.. The slight increase in pixel values indicates that I indeed captured this very faint satellite galaxy.

Final
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B

Description: inverted luminance

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C

Description: Annotated version

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D

Title: with 2D pixel value profile

Description: I applied the PixInsight 2DPlot script to a crop of the original luminance master.

Uploaded: ...

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Status	Basic success
Started	...
Astrometry.net job	6513980
PixInsight job	n/a
PixInsight queue size	n/a
PixInsight stage	n/a

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And XXX / Cass II - a dwarf Spheroidal satellite galaxy of M31

And XXX / Cass II - a dwarf Spheroidal satellite galaxy of M31

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And XXX / Cass II - a dwarf Spheroidal satellite galaxy of M31

And XXX / Cass II - a dwarf Spheroidal satellite galaxy of M31

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