Supernova remnant in Cassiopeia.
Abell 85, aka CTB 1 is a large supernova remnant (SNR) located in Cassiopeia. The southern portion of the supernova remnant bubble also made it to Lynds bright nebula catalog as LBN 576. Originally catalogued by George Abell as a planetary nebula, it soon became evident that it was actually a SNR.
|Object:||Abell 85 / CTB1|
|Date of exposures:||25.10.2017, 02.11.2017, 05.11.2017, 06.11.2017|
|Exposures:||Ha: 22 x 1200 sec., OIII: 12 x 1200 sec., RGB: 36 x 300 sec, sum: 14,0 hrs.|
|Telescope:||Takahashi Epsilon 130D|
|Focal length:||430 mm|
|Filter:||Astrodon H-Alpha 5nm, OIII 3nm, RGB E-Series|
|Guiding:||Off Axis Guider, Lodestar|
It was also recognized as a radio source and acquired the alternative designation CTB 1. The right side of the field includes a small reflection nebulae (GN 23.50.6.03), which is not clearly visible in this image, and a small possible planetary nebula (We 2-262).
Abell 85 has relatively weak [OIII] and H-Beta emission compared to the "traditional" supernova-remnant lines of H-alpha, [NII], and [SII]. In fact, this object is often considered as one of the most challenging for visual observation and remains a big challenge for CCD photography. North is up in this image.
The picture is a cooperation project with Jürgen Beißer, Lilienthal, who contributed 9.5 hours of material in H-Alpha and [OIII] with his Takahashi FSQ85 and Atik 460 Exm camera.