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
Originally catalogued by George Abell as a planetary
nebula, it soon became evident that it was actually
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
who contributed 9.5 hours of material in H-Alpha and
[OIII] with his Takahashi FSQ85 and Atik 460 Exm
Object: Abell 85 / CTB1
Date of exposures: 25.10.2017, 02.11.2017,
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
Camera: Atik 490Exm
Guiding: Off Axis Guider, Lodestar