Aircraft inteference

[Jack Martin]

The picture of Gamma Cas speaks for itself.

Jack

[twotter]

It might be speaking but I'm not hearing What are we looking at here?

[Telrad]

It might be speaking but I'm not hearing What are we looking at here?

Spectra through a Rainbow Optics Star Spectroscope I think?

Thanks for sharing this Jack

[Jack Martin]

twotter,

The two lights either side of the spectrum of Gamma Cas is an aircraft crossing the field of view.

Regards,

Jack

[Jack Martin]

Telrad,

Yes.

Regards,

Jack

[Telrad]

Telrad,

Yes.

Regards,

Jack

[twotter]

twotter,

The two lights either side of the spectrum of Gamma Cas is an aircraft crossing the field of view.

Regards,

Jack

Ah, thank you

[jsandse]

Nice spectra Jack you can see the Halpha emission nicely in the spectra. I took a spectra of gamma cas a few months ago here it is:

[Telrad]

Interesting spectra jsandse. Has Gamma Cas been studied by X-ray spectroscopy?

[jsandse]

Yes loads.....

See following paper for details and some example X-ray spectra from Gamma Cass:

http://arxiv.org/PS_cache/arxiv/pdf/0903/0903.2600v2.pdf

[Telrad]

Thank you for the link

[Jack Martin]

jsandse,

Thats a nice profile of the H alpha emission line what is the dip in the peak around 6565A?

Regards,

Jack

[moflaher]

Are the strange absorption line in your spectra associated with the element BEERILIUM and possibly AWFULONBOARDMEALIUM?

[jsandse]

Very funny Moflaher

Jack in answer to your question nearly all the lines - including the one you mentioned close to 6565 are tellurics. For those that don't know what telluric lines are - they are absorption lines caused by water in the earths atmosphere. See below my spectra in blue with a sample telluric spectrum overlaid on it in green. You can see how the lines match up.

Interestingly there is a small absorption feature in the middle of the broad emission line exactly where the Hydrogen alpha line is - I have marked it by a red line in the spectra. It would be interesting to know where this line originated from. My guess is that it is what is left of the absorption line from the photosphere of the star. Anyone else have any ideas?

cheers

John

[jsandse]

Converting the x-axis unit from angstroms to kmpersec choosing 0 at the Halpha line we can then estimate the terminal velocity of the wind for gamma cass by seeing what the velocity is where the emission line hits the continuum on the blue edge of the line. I estimate around 700km per sec give or take 150km per sec or so...

[Jack Martin]

jsandse,

Thanks for answering my query I now understand the profile better fascanating stuff you can get so much out of spectroscopy.

Regards.

Jack

[Jack Martin]

jsandse,

I have no idea what the small absorption feature in the middle of the broad emission line is but it needs further investigation can I copy and paste this on to one or two professionals who might know?

Regards,

Jack

[jsandse]

of course

[jsandse]

if you go to the BeSS database - database of Be star spectra at BeSS Database - and search for the gamma cass spectra you can see that spectra taken by other amateurs around the same time as me have the same absorption feature at Halpha...

cheers

John

[Jack Martin]

jsandse,

Will do.

Jack

[Photosbykev]

does anyone else hear the whooshing sound as this goes straight over their head?

I need to get educated lol

[Merlin66]

"Spectroscopy - the final frontier....to boldly go where few amateurs have gone before"

More than 80% of all the facts and information we have about the Universe was obtained from those little bits of coloured images!

Seriously, if you take your time and think it through, spectroscopy isn't that difficult and can be very, very challenging and satisfying.

Give it a go - you'll love it.

Onwards & Upwards

( Kev- I only have three passions in my life - My wife, my spectroscopy and my solar observing!)

[Photosbykev]

( Kev- I only have three passions in my life - My wife, my spectroscopy and my solar observing!)

I have two passions; my photography, in all its forms, and my dog.

PLEASE do not tell the wife

[Jack Martin]

Merlin66,

And I only have one passion Spectroscopy.

Jack

[Jack Martin]

jsandse,

I put your question two 2 professionals so far one has answered as follows;

'As for your question, indeed it is a shell star and you see variations

in the Ha from the stars photosphere as the star increases and

decreases in magnitude. This line varies quite a bit and is very

interesting. '

It will be interesting to read the other answer.

Regards,

Jack