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CTB1/Abell 85 - HA/OIII Bicolour (and Candidate SNR G117.4 +1.5)


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About this observation
Graeme Coates
Time of observation
30/09/2020 - 00:00
CTB1 / Abell 85
Observing location
Skywatcher Esprit ED80
41hrs total (26hr OIII, 15hr HA)
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Located in Cassiopiea and straddling the 0h RA line, CTB1 (G116.9+0.2) is a large faint supernova remnant with an angular size just larger than that of the full moon. The shell is clearly visible in HA, with some filamentary OIII emission visible on the western edge.

There is a lot of faint gas in this area of sky. In addition to CTB1, there is evidence that some emission is due to the SN remnant G 116.5+1.1 (above and to the left; north-west of CTB1). There is possibility of another remnant shown here as filamentary structure to the left of CTB1 itself, with provisional designation G117.4+1.5 (see Mavromatakis et al. -

To the top right (south-west) is open cluster King 12, and the curious shaped, possible PN We2-262 can be found towards the top of the frame.

Taken from EEYE in Spain in Sep/Oct 2019.
Esprit 80ED, MI250, STF8300.

26hrs with Chroma 3nm OIII
15hrs with Chroma 3nm HA

Image capture: Paul Tribe and Graeme Coates
Processing: Graeme Coates

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