6 easy doubles in Cassiopeia.

Hello, Darren.

I hope you are well. I am too, thank God.

I will be printing off that full page from the Australian website.
The next time you are with me at the Sugarloaf I am going to show my 3 books which are called Burnham's Celestial Handbook. In volume 1 there is a complete rundown of Stellar Classifications on page 80.
I never knew about the Colour Index (CI). I find the explanations very interesting.
Burnham uses stellar classifications extensively in his 3 books. Sometimes he gives spectral classes for both stars in double star system. Unfortunately he does not do so for 35 Cassiopeiae.
Over on www.cloudynights.com an Italian astronomer has been in touch and he is very knowledgeable, He has discovered that 35 B Cassiopeiae has a spectral class of M0V. The star is a red dwarf and, remarkably, it is much, much nearer than 35 A. The system is most certainly an optical double star. A is 390.55 parsecs from us; B is 15.43 parsecs away.
Now regarding different M class stars: there are stars with spectral classes M1, M2, M3, M4, M5 and M6. But there are all variable stars. All none variable red stars appear to be labelled M, M0 or M0V.

What we have not yet discovered is the explanation about the number after the initial spectral class - which in this case is M. I don't think the letter after the number is all that important, e.g, V in this case. But I may be wrong on that.

So once again, I thank you very much for providing, not just me, but the rest of us on www.irishastronomy.org with all this wealth of information, Darren.

By the way, I do have a busy day ahead of me. But I am going to do some observing on Saturday night in my back garden. The skies are going to be really clear.

Blessings to you and your family.

Aubrey.

Hi Aubrey,

Very many thanks for your message, and delighted to read you're doing well. All is good this end, a little more sleep would be nice, but as they say 'all clouds have silver linings'. ..more about that later!

I'm looking forward to seeing those handbooks. Also, that's fascinating about the distance of those two stars, hey?

Not sure what is meant by an 'optical double' I'm afraid. Perhaps you could enlighten me about this phenomenon when we next meet.

From reading around stellar classifications this week it seems that the roman numeral after the number has to do with luminosity. Here is one of webapages I found on the topic:

astronomy.swin.edu.au/cosmos/M/Morgan-Keenan+Luminosity+Class

And the number itself (0, 1, 2 etc.), refers to a subclass of stellar classification. For example, this page ( www.star.ucl.ac.uk/~pac/spectral_classification.html ) states that  "A star midway through the range between F0 and G0 would be an F5 type star. The Sun is a G2 type star."

In other words, the number seems to indicate where along the spectrum the star is.  

Best of luck with tonight's session. I've not had had a chance to take the scope out since the little lad arrived. However, the late nights on the sofa have provided me with lots of time to (1) practice with the digital imaging software 'GIMP' to try to enhance my sketches, and (2) to read around the theoretical aspects of astronomy. How much of it I actually understand is a different story : ) 

As always, kindest regards,

Darren.

Hello, Darren and everyone else.

A major discussion has utterly erupted over on www.cloudynights.com regarding our mystery star 35 B Cassiopeiae over the last 2 days.
Serious heavyweights are now heavily involved in sorting out the spectral class of this star. Thankfully it has all been very well tempered.
Serious amateur astronomers from Colorado, Arizona and Oregon (USA), Australia and Milan, Italy have weighed with their opinions.
The Australian amateur thinks the star is somewhat similar in spectral class to Gamma Crucis which is a bright star of magnitude 1.7 to 1.8. That means it is slightly variable after all. Indeed the guy from Arizona has now stated that both stars of 35 Cassiopeiae are variable.

My main man from Colorado has appealed to any spectroscopist on Cloudy Nights to give a professional decision as what is the true spectral class of 35 B Cass. He has also asked for an estimate of the star's distance from Earth. He reckons it is much more further away than it has been alleged from other contributors on the Cloudy Nights website. There seems to be no end of discrepancies on our star.

But I must point out I cannot accept any credit in sorting out this enigmatic star. You see, a previous guy from California asked me specifically to observe 35 Cassiopeiae. He told nothing regarding its colours. I had to check them out myself.
None of us on Cloudy Nights have heard from him since 31st August. Why that is the case I don't understand. He normally is on the website every 2 or 3 days.

But either way, please watch this space. I will bring news to you all as soon as I can.

Kind regards,

Aubrey.

Hi Aubrey,

I was looking forward to hearing from you about 35 Cassiopeiae B. It is incredible to read how the conversation has developed, and it's rather exciting to think where the conversation might go next! Something tells me there will be several more twists and turns in this story. 

Whether you feel you deserve credit or not (and I for one believe you do); you've brought together a team of international astronomers who want to contribute to a discussion. In my eyes that's impressive, and regardless of whether we receive a definitive answer to colour of this wondrous star "It is not the answer that enlightens, but the question.” – Eugene Ionesco. 

For this reason, thank you for asking the question, and for sharing your passion for astronomy with us. 

Clear Skies, 

Darren. 

p.s. I hope everything is OK with your California based astronomer.

Hello, Darren and everyone else.

At last it is official!!!
The spectral class of 35 B Cassiopeiae is: K4i.
The star is otherwise known as SAO 11709.
Its magnitude is 8.6.
That's a little bit fainter that Neptune.

A bloke called Robin from England has a spectrograph.
He used his equipment on our mystery star.
The star is a giant orange star.
Its distance is 700 parsecs.

All that's left for me to say is to update all your literature and label SAO 11709 as having a K4i spectral class.

I have congratulated the man for publishing his findings on Cloudy Nights.
I have also encouraged him to make his discovery known to the professional community.

Many thanks to all from Aubrey.

Robin Leadbetter is well known in the BAA and frequently contributes to spectroscopy discussions. He has published work in professional journals and manages to be both thorough and yet readable. Well done Aubrey on stirring this interesting debate.

Finbarr.