7 doubles and 1 more Carbon in Cassiopeia

4 weeks 3 hours ago - 4 weeks 3 hours ago #109486 by flt158
Good evening, everyone.

On Saturday night 26th September 2020 I had my 60th observing session in 2020 using my William Optics 158 mm F/7 in my back garden between 9 and 11 pm. Once again I filled a page of my diary as I sought out these 7 doubles plus one more carbon star all near STTA 254 which includes the very famous carbon star WZ Cassiopeiae. It's always a super sight to behold this optical quadruple star at a mere 40X.
The temperature was 3 degrees.
All figures can be checked out on www.stelledoppie.it

1. BU 1337 is very near the previously observed optical double star ARG 47. Except BU 1337 is a true binary. Magnitudes: A = 9. B = 11.7. Sep = 12.9". PA = 248 degrees. I managed to see B at 112X. It was very tough to see it at that power. Then I discovered the companion could easily disappear at 140X and 167X. So I went up to 225X and 280X just to be certain I had it. It was soon discovered that my sky conditions were not all that great. But I am recording the observation as a success all the same

2. Straight down from BU 1337 is the carbon star Case 270. It is less than 30 arc minutes from another carbon star - WZ Cassiopeiae and is right next to SAO 35999 which in turn has a magnitude of +8.8. SAO 35999 is the A component BU 1337. Case 270 was very difficult to find. You see, its magnitude is +12.8 and I don't believe it varies at all. According to Guide 9.1 DVD it has another designation which is 3UC-001081. Simbad has other designations, but I won't mention them here as they are not well known. Its spectral class is C4. And at a magnification of 280X I could just about see Case 270. My eyepiece is a William Optics Uwan 4 mm which has a true field of view of 17.5 arc minutes. Case 270's colour through my apo was orange at that power. I could not see the star at 225X at all. It is my 11th observed carbon star in Cassiopeia - and my 88th overall.
Therefore if any of you do wish to seek out Case 270 you will most likely need a good aperture telescope and a very clear sky with no wind. I was utterly delighted to fit in ARG 47, BU 1337 and Case 270 at 280X using my 280X eyepiece.

3. About 1 degrees east of ARG 47 we have another optical binary from the same man Friedrich Argelander (1799 - 1875). ARG 1 clearly is his first entry of his catalogue. Magnitudes: A = 9.7. B = 9.8. Sep = 26". PA = 329 degrees. Of course I had a very easy split at 40X. But to admire the colours I increased up to 112X. A is definitely orange as it is a K class star. But I also reckon B is orange too. That ought not to be the case as its spectral class is A2. A lesser orange granted but that's the way I saw it.

4. BU 254 is an uncertain double. Magnitudes: A = 7.9. B = 11.9. Sep = 7.5". PA = 238 degrees. Nice split at 112X. The colours are yellow and white. BU stands for Sherburne Burnham (1838 - 1921)

5. HJ 1008 is an optical double. Magnitudes: A = 8.1. B = 11.3. Sep = 21.8". PA = 125 degrees. I found this double quite boring to look at. Both stars are white. I was just content to tick it off my list. The separation was too great. HJ stands for John Herschel (1792 - 1871).

6. On the other hand the optical double HJ 1010 was a bit more enjoyable. Magnitudes: A = 10.3. B = 11.3. Sep = 20.5". PA = 118 degrees. The colours are blue-white and white. Fairly close at 40X. Nice at 112X too.

7. HJ 1012 may be an optical double; but what a real treat it is!. Magnitudes: A = 11.3. B = 11.7. Sep = 14.5". PA = 348 degrees. The 2 very faint stars were sitting side by side at 112X. They looked so delightful through my Pentax 10 mm eyepiece I refused to go higher. It most certainly is one of my faintest doubles.

8. Finally I thought this uncertain double was going to be reasonably easy. KR 4 has a separation of 2.2". PA = 180 degrees. What a toughie it proved to be. www.stelledoppie.it states that A has a magnitude of 8.2 and B is 9.4. However A has the designation V377 Cassiopeiae and has a spectral class of F0. Therefore it must be a variable star. Over on www.aavso.org they state that V377 Cas does not vary much at all. And that it is relatively fixed at 7.8 or 7.85 in visual magnitude. I don't think Stelle Doppie has it right this time.But never mind. It was no wonder I was having great difficulty splitting KR 4 with that delta magnitude of 1.6. I required 225X and 280X so see the tiniest black gap between the 2 stars. Component A was yellow-white alright. KR stands for Adalbert Kruger (1832 - 1896).

Thank you for reading.

Contributions are very welcome.

Clear skies from Aubrey.
The following user(s) said Thank You: michael_murphy, Kinch, Until_then-Goodnight!

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3 weeks 6 days ago - 3 weeks 6 days ago #109489 by Until_then-Goodnight!
Replied by Until_then-Goodnight! on topic 7 doubles and 1 more Carbon in Cassiopeia
Another Brilliant report on the stars in and around Cassiopeia Aubrey - very well done!

Also, congratulations on observing your 88th Carbon star, and HJ 1012. By the sounds of it, it was no easy task observing both of these stars.

Although the seeing may not have been great you were still able to push the magnification on Saturday. Goes to show how the quality of your instruments and one's skill make all difference.

Clear skies,

Darren.
The following user(s) said Thank You: flt158, scfahy

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