Happy Christmas to everyone here on the Double Star observing forum!
On Christmas Eve night I set up my William Optics 158 mm f/7 apochromatic refractor and my William Optics 70 mm small apo on a Berlebach Planet altazimuth mount with mirror diagonals fitted to both scopes.
From about 9 pm I was delighted to see Cassiopeia had come down from my zenith. It was time for real action. Sky conditions were extremely good.
As some of you know I have been working through the magnificent "W" constellation for quite a while now.
I had observed NQ Cassiopeiae for the first time.
But before I got to it I was also observing some faint doubles on the way.
1. Stf 16 was my first port of call. I simply thought I would have no problems with this double. Stelle Doppie says that the primary is white (A3) but no spectral class was given for the secondary.
For the record the magnitudes are: A = 7.7. B = 8.8. Sep: 5.9". PA = 41 degrees. I was very happy to see a very slim dark gap at 40X through a 2" eyepiece. It was very nice.
A is white alright. But what about B?
As I increased through 112X, 140X and 167X I was seeing orange or red for the secondary.
When I came indoors at a later stage, I checked Sissy Haas and states A is white; but B is blue white!
I then checked Burnham, and he just says both stars share a common proper motion with an A3 spectrum. Nothing for B.
Guide 9.1 DVD agrees with Sissy Haas. So it is a real personal conundrum.
My next 5 nights are due to be overcast.
But I will have to observe it again at some stage. It's vital I do so.
Maybe I will embarrassed by what I find.
I notice Stf 16 has not been discussed on Cloudy Nights in the past.
2. In the same fov as NQ Cas, ES 42 is positioned as one of the stars shaped like a cross - an asterism for sure.
A = 8.4. B = 9.4. Sep = 7.1". PA = 207 degrees. Split at 112X. ES stands for the Reverend Espin.
3. HDS 44 is even easier. It's below NQ Cas.
A = 9.0. B = 10.3. Sep = 12.3". PA = 38 degrees.
Comments and questions are always welcome.
Kind regards from Aubrey.