This object was brought to my attention by Tim Schaeffer as something that really hasn't been imaged in HSO (RGB map) using a fairly large aperture.
The object is described well by Gary Imm at
https://www.astrobin.com/r5vzcl/Adam Block captured a nice HaRGB at
https://www.adamblockphotos.com/webo-1.htmlFrom Gary...
"This object, also known as PN G135.6+01.0, is a rarely imaged planetary nebula located 5000 light years away in the constellation of Cassiopeia at a declination of +61 degrees. The PN is about 1 arc-minute long in our apparent view, which corresponds to a length of 1.5 light years.
Most of the information below is from the 2002 paper "WeBo 1: A Young Barium Star Surrounded by a Ringlike Planetary Nebula" by Bond, Pollacco, and Webbink. Two of these authors, Weebink & Bond, first identified this PN in 1996 on DSS sky survey images and are the namesake for it.
Three things are surprising about this PN - the circular ring shape (instead of a sphere), the transparent inner region, and the orange-colored central star (instead of blue or white). We are viewing the PN from almost an edge-on perspective (at an angle of 70 degrees), so the circular ring looks elliptical to our view. The rim is slightly deformed, probably from interaction with the ISM.
This star has been determined spectroscopically to be a cool barium star. The view is that this star is the binary companion of a more massive asymptotic giant branch (AGB) star. The AGB star has now become a white dwarf and is no longer not visible to us. This binary system has a 5 day rotation period. This rotation led to the HII gas being preferentially ejected in an orbital plane, resulting in the ring shape."
Comments