Hello, everyone here who is interested in carbon stars.
On Friday night 30th October 2020 I set up my Williams Optics 158 mm F/7 apochromatic refractor in my Bortle 9 back garden.
There was the problem of an almost Full Moon to contend with.
Sunset occurred at 4.55 pm.
The air temperatures dropped from 4 degrees to 2 degrees Celsius during my time of observation.
But the sky was very clear and no wind between 5 and 7 pm over Dublin, Ireland.
I very much required those conditions because the particular carbon star was going to prove a very faint one.
You see, [I81] C 8 is seriously faint.
Simbad says the magnitude is 11.5, and then adds the ~ symbol which suggests it is variable.
My Guide 9.1 DVD gives 14.0. But I reckon neither of these sources have it fully correct.
I agree 100% with our friends on AAVSO which state its magnitude is +12.9.
[I81] C 8 is in Cassiopeia right next to TYC 4018 1946 whose magnitude is 11.5.
[I81] C 8 is not a strong orange carbon star although it still has a spectral class of C.
There is another orange star very close by which has the designation 3UC307-007505.
Its magnitude is +12.3.
Therefore if you have the desire to hunt down [I81] C 8, please be careful that you do see both stars.
I know some of you like the designations which start with the letters GSC.
[I81] C 8 is also called GSC 04018-00410.
The right ascension is: 00 hours 15 minutes and 01.46 seconds.
The declination is +63 degrees 12 minutes and 09.8 seconds.
Another question I was asking was: what does [I81] refer to or who?
Simbad helped out very well.
It refers to Takashi Ichikawa who is a Japanese astronomer.
I presume he is still alive and well.
To successfully observe GSC 04018-00410 I had to use my most powerful eyepiece - a Radian 3 mm.
It gives my scope 374X.
But I have to state I only once saw this carbon star directly.
I kept seeing it with averted vision and especially as I gave the scope very slight side to side movements.
Still I am greatly relived to say I saw the star!
GSC 04018-00410 or [I81] C 8 is the 15th carbon star I have observed in Cassiopeia and my 92nd overall.
Thank you for reading my latest report
Comments, corrections and especially images are very welcome.
Clear skies from Aubrey.