Double star challenges around Caph

[Nik271]

Caph (Beta Cas) is the westernmost star of the 'W 'of Cassiopeia and rises  high in the sky in autumn and winter.

As the full moon approaches I was looking for some double star challenges and with the help of some excellent books I made this list.

All of them except the last should be doable in theory with a good scope of 4 inches of aperture or above. I have seen some of them with a 5 inch Mak, of course larger aperture will make it easier. 

Here is a star chart:

 

1: Caph itself. It's an optical double with very wide separation, more than 1' (minute!) west, however the primary is 2.3 and the secondary is 12.4. You need good transparency if you have small aperture.

 

Southwest of Caph are two 6-th magnitide stars, and they are both challenging doubles: STF 3057 and STF 3062

2: STF 3057 (mag 6.7 and 9.3 separattion 3.9'') has a dim secondary which makes it a challenge.

3: STF 3062 (mag 6.4 and 7.3 separation 1.5'')  is a close double, on the limits of a 4inch aperture. This is a physical double with a period of 106 years. the pair is sarting to close again and by 2050 will be only .5'' apart

 

4:   Sigma Cas (mag 5 and 7.2, separation 3''). Again the challenge for this one is the dim secondary.

5:  6 Cas (mag 5.6 and 8, separation 1.5'') This one is the most challenging I've seen myself from this list. It's both close and with magnitude difference, reminds me of Zeta Herc. I used a 7 inch Mak for the split.

6:  9 Cas (mag 5.9 and 12.6, separation 82'') This one is very similar to Caph. Optical double of course.

Every list has to have one impossible/improbable challenge so here it is. Not for the 4 inch aperture, more likley for a 20 incher on top of a mountain and the observer with the eyes of an eagle.

7: Bu 1224 (mag 6.7 and 13.7 separation 3.5''). One of Burnham's discoveries. Never seen it myself. I had a look last night, no chance.

 

Clear skies!

 

Nik

 

 

[RobertI]

Nice selection of doubles Nik. I shall add these to my current list of targets for Oct/Nov. 👍

[chiltonstar]

Some more for when/if the cloud ever lifts.....

Chris

[Dave scutt]

Nice list of doubles thanks.

[wookie1965]

Great list I will check if I have done any of these and write ones down I haven't thanks. 

[cotterless45]

These are stars within one degree of Caph. A lovely project to keep you busy , Nick.

[Stu]

Nice post @Nik271 must have a wander around some of those when I next get a chance.

[Hayduke27]

I'm adding some of these to my observation list, thanks Nik!