Abell 85 / CTB-1 (Cas)

Abell 85 / CTB-1 (Cas)

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Date/Site: 4., 5., 6. and 11. November 2020, remote observatory on the AAR club's site in Presberg
Exposure/
Filter:
R: 15 x 180 seconds,
G: 18 x 180 seconds,
B: 18 x 180 seconds,
L: 32 x 180 seconds
Hα: 53 x 600 seconds,
OIII: 60 x 600 seconds (-20°C)
Camera: Moravian G3-16200 with Astronomik Type II-filters
Optics/
Instrument:
250mm f/4,7 Newton with VIP-3010 Paracorr on 10Micron GM1000 HPS
Guiding: Lodestar attached to a 61mm-finder,
focusing: Microtouch and FocusMax,
data acquired remotely using CCD-Commander and MaximDL 5,
calibration and processing: PixInsight 1.8

In 1966 George Abell included this glowing bowl of gas into his catalogue of planetary nebulae, although it is a supernova-remnant, which was identified as the extended radio source CTB-1 as early as 1960.
A difficult object, the interesting OIII-emission can barely be seen even after several hours of integration.

© Friedhelm Hübner, last revision:  17.01.2021