RS Cygni
Star name: RS Cygni
Other names:
Constellation: Cygnus
Other ID: SAO 69636, HIP 99653, PPM 84477, HD 192443, B+38 3957
Magnitude: 7.1 to 8.5
Absolute magnitude: -0.77
+/- 0.92
Luminosity, Sun = 1: 170 +/- 140
R.A. 2000: 20hr 13min 23.662sec
Dec 2000: 38deg 43min 44.47sec
Spectral type: C5II
Temperature:
Mass, solar masses:
Radius, solar radii:
Distance in light-years: 1550 +/- 650
This Carbon star lies very close to the Crescent nebula (NGC6888, an emission nebula formed from the Wolf-Rayet star HD 192163) in the constellation Cygnus. The mean period of the variability of RS Cygni is 434.1 days.
I’m a very new astrophotographer and took the time this weekend (Aug 13th 2017) to try and image NGC6888 with my 8inch reflector.
Despite a bright moon and annoying random clouds, I managed 13 two minute exposures of the crescent nebular and surrounding area with a Canon 1100D and Explore Scientific UHC filter.
Whilst viewing the live images on the camera I was quite surprised to find a remarkably bright red spot above the nebular. I initially thought the spot was a “hot pixle” but noticed that it was in every frame and looked just like a star!
When I eventually processed the images I found to my surprise that it is indeed a star, RS Cygni to be exact.
Unfortunately, I’ve never herd of ‘carbon stars’ so I never actually looked through the scope to view it, but now I know it’s there my next observing session with address that!
Carbon Stars – Rubies of the night sky 🙂