"Call myself an astronomer" ? Huh!

[Guest]

Well all these years poor old Capella star. Always in the north all year round. Always beckoning me to take a peak through the telescope. But just the occassional glance through binoculars.

  But tonight I thought that it's about time that I read up a little about Capella.

It is a double star, both similar size. The same spectural colour as our Sol. Also a number of small red stars orbiting at a light year. Well I never. More respect to Capella from now on.

I understand that due to a very high internal pressure on both. The nuclear fuel will exhaust much faster. They will become red giants.

Has anyone observed Capella through the telescope? Can it be resolved into the double?

[SilverAstro]

34 minutes ago, Grumpy Martian said:

Well all these years poor old Capella star. Always in the north

due to a very high internal pressure on both. The nuclear fuel will exhaust much faster.

Thanks for that, interesting.

You're right mostly just a signpost to other things! , no I've not looked AT it, thanks for the prompt, I will next time the clouds part.

One of the 'interesting' things nearby is epsilon Auriga, variable, mysteriously fades once every approx 27years ( I've had two of them, doubt if I shall get a third )

Didnt understand the bit about "high internal pressure" if it(they) are similar to Sol ? I feel a google upon me >>>

 

[Moonshane]

It's not listed as a double in any of my books so is presumably too tight to split with garden scopes.

[ronin]

Don't think it can be split, they are a close (very close) pair, the double was determined by spectroscophy.

If I recall they are simialr size but different temperatures, about 400 or 500 degrees different, so the spectrum from each is a little different. When the light gets to us and gets through the atmosphere then some refracting occurs and as the light started out different when refracted the components are a little different and so we get the wider range of colours. The twinkle is that of 2 slightly different coloured stars.

Knowing it is a double, similar size, slightly different temperatures and therefore different refracted colours seen is a good explanation for it on outreach events. Which is where the above in effect came from.

Why is that one twinkling so much? When asked by a 4 year old needs an explanation.

[Stu]

SkySafari lists it's as a Double having separation of 3.7" but the secondary is only Mag 17.10, i.e. pretty tough!

[Dave In Vermont]

Yow! Very interesting, GM, I didn't know it was the same as our star re: spectral-colour. I'd only given it a quick glance over the years. I stand utterly curious now - thank you very much!

Onwards & upwards!

Dave

[Guest]

33 minutes ago, Dave In Vermont said:

Yow! Very interesting, GM, I didn't know it was the same as our star re: spectral-colour. I'd only given it a quick glance over the years. I stand utterly curious now - thank you very much!

Onwards & upwards!

Dave

Hi Dave. Hope you get clear skies to check the eclipse of Sol later. Capella stars are much bigger than Sol though

Going back to the eclipse. We saw the 1999 eclipse in Falmouth UK. It was a bit cloudy. Bit it did not stop us from seeing the shadow of the Moon racing at 500 m.p.h. We could see a thin slither of light from beyond the eclipse shadow looking out to sea.

There was an immediate drop in temperature of approx 2 degrees ,you could feel the drop. Our dog lay down extremely upset. The sea birds took to flight from the cliffs and the cattle could be seen laying down for the night ( but it was not night). So an errie experience.

You will have to post your experienc Dave.

[Guest]

1 hour ago, ronin said:

Don't think it can be split, they are a close (very close) pair, the double was determined by spectroscophy.

If I recall they are simialr size but different temperatures, about 400 or 500 degrees different, so the spectrum from each is a little different. When the light gets to us and gets through the atmosphere then some refracting occurs and as the light started out different when refracted the components are a little different and so we get the wider range of colours. The twinkle is that of 2 slightly different coloured stars.

Knowing it is a double, similar size, slightly different temperatures and therefore different refracted colours seen is a good explanation for it on outreach events. Which is where the above in effect came from.

Why is that one twinkling so much? When asked by a 4 year old needs an explanation.

That's a fantastic point about outreach Ronin. When I was in Dorset last week, a person insisted that Capella was an army helicopter because it was twinkleling so much. Now I know one of the reasons why. I will go back to explain when down there agaun next week.

[Dave In Vermont]

Heya - I'm out of the path of totality - though in 2024 I'm directly under the next show - but I'm doing my part!

I'll be hauling my ST80, which is outfitted as my Solar-Scope w/ Rainbow-Symphony (orange) filter - out to the main lawn here. Right by a busy street in my area. And any takers will be welcome! As for 2024 - I'm thinking of renting 'tent-space' and getting out of town onto a high mountain to my East! Yikes! The whole nation - and 1/2 of yours - is over in the States for this! And now the worst (though most read) news (Yahoo) has written an article saying "There's a huge FIRE in it's path! " Totally false. Some smoke may pass over the path - but this is a BIG nation.

So thanks for the tip on reactions of our four-legged friends back in '99! Fascinating stuff indeed!

Below is our totality for my area up here in Vermont. Thanks for all! Maybe see you in '24!

Dave

If anyone wonders what they may see:

https://www.timeanddate.com/eclipse/in/@4460364

 

 

 

[Pondus]

I always observe Capella without instrumental accompaniment