WR 8: Two Stars and a Nebula
Aka "AB8"

OTA: CDK24
Camera: Moravian 61000Pro
Observatory: Heaven's Mirror
Date of Capture: Mar '24
Date of Processing: Mar '24

Exposures Used:
R: 10 x 120 sec
G: 10 x  "
B: 10 x  "
H: 27 x 1200 sec
O: 43 x   "
Total Exposure time: 18.5 hours
Image Width: 29d 17m

Processing Tools:
1.    Commercial: PixInsight, Topaz, Radiant Photo
2.    Pixinsight Addons: NoiseXTerminator, BlurXTerminator, StarXTerminator
3.    My Scripts: NB_Assistant, AC_Restar, Subframe Weighting Tool (Excel w/ J. Hunt), ColorTweaker

Target Description:
This is how a Wolf-Rayet star behaves! Being hefty, young, and hot, they show instability by casting off their outer shells, often more than once. In this picture, you can readily identify the WR stars in the nebula's center and what appear to be earlier eruptions in the form of concentric arcs toward the lower left. The radial spokes of this WR nebula are not uncommon in WR nebulae, although the morphology of those spokes varies widely.  

WR 8 (aka AB8) is a double star discovered in 1961 by Sanduleak. Its companion star is a massive O-type star; they orbit each other every 16.6 days. Sanduleak thought that WR 8 had no associated planetary nebula. The O star contributes about 70% of the brightness of the pair, which, together, shines at about 25,500x the brightness of the Sun. The destiny of this pair is a pair of supernova explosions. The more massive (61 solar mass) primary star will go first when it suffers a core collapse, estimated to occur within 10,000 years. The secondary star (19 solar mass) will continue to shine before eventually going supernova. (The Wikipedia description is worth reading.)

Processing Description:
This is an HO image (not HOO) in "natural color." I used a code that solves linear equations expressing the relationship between the narrowband and broadband images to extract the Ha and OIII emission lines separated from their continuum backgrounds.


Target Statistics:
Distance: 1.14E+05 km
Apparent DSO Span: 6.2 ly
Pixel Span at Target: 2E14 km

Alex Woronow