beta Lyra profile!

[Gasman]

Hi

I took this spectrum of beta Lyra the other night and found conflicting spectral designations for it with various catalogues. My deepsky planner 6 has it listed as an A8 type star so I corrected my profile using an A7V (the nearest in the library) and wondering why I have emission lines for He and Ha where the reference star shows absorption lines??. Anyone throw any light (sorry ;-)) on why this would be please?

Thanks

Steve

[the rev]

Hi Steve, interesting spectrum. I have beta lyrae as a B6-8II star with a B type secondary, if that's any help.

Kate

[Merlin66]

Shelyak, Beta Lyr is a bright Be emission star.

http://www.shelyak.com/dossier.php?id_dossier=61

(Follow the link through to the Be star section)

Simbad is the best source to use:

http://simbad.u-strasbg.fr/simbad/sim-id?Ident=beta+lyra&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id

Quotes Beta Lyr as a B8II-III ep star.

[Gasman]

Thanks Kate and Ken for the info!

Just done a comparison with a B8I and still wondering about the discrepancies with the profile?

Maybe its an anomaly to do with its eclipse?

Steve

[Merlin66]

I think the calibration may be out slightly...but at lo-res it's difficult to draw any meaning comparisons.

Have you looked at the results in the BeSS database for suitable references?

[robin_astro]

Hi

I took this spectrum of beta Lyra the other night and found conflicting spectral designations for it with various catalogues. My deepsky planner 6 has it listed as an A8 type star so I corrected my profile using an A7V (the nearest in the library) and wondering why I have emission lines for He and Ha where the reference star shows absorption lines??. Anyone throw any light (sorry ;-)) on why this would be please?

Thanks

Steve

Hi Steve,

Instead of looking up the star and trying to "make you spectrum look right" , why not calibrate it using an instrument response generated from a spectrum of a known reference star? Then you will have fully calibrated spectrum of your new target to investigate. If you do this you will find that the shape of the continuum suggests that it is a hot (most likely A or star with H and He emission.

Beta Lyrae (Shelyak) is a very interesting rather complex binary system with complex changes in its spectrum at high resolution, the reason the company making the LHIRES spectrograph used it as its name. More here

http://www.shelyak.com/dossier.php?id_dossier=2

http://stars.astro.illinois.edu/sow/sheliak.html

For reliable accumulated knowledge of spectral type for any star the best reference is Brian Skiff's labour of love, an accumulation of everything that has been published here.

http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/mk

Cheers

Robin

[robin_astro]

Hi Steve,

Instead of looking up the star and trying to "make you spectrum look right" , why not calibrate it using an instrument response generated from a spectrum of a known reference star? Then you will have fully calibrated spectrum of your new target to investigate. If you do this you will find that the shape of the continuum suggests that it is a hot (most likely A or star with H and He emission.

Beta Lyrae (Shelyak) is a very interesting rather complex binary system with complex changes in its spectrum at high resolution, the reason the company making the LHIRES spectrograph used it as its name. More here

http://www.shelyak.c...hp?id_dossier=2

http://stars.astro.i...ow/sheliak.html

For reliable accumulated knowledge of spectral type for any star the best reference is Brian Skiff's labour of love, an accumulation of everything that has been published here.

http://vizier.u-stra...eR?-source=B/mk

Cheers

Robin

What ! predictive smileys now? !!

I actually wrote

(most likely A or B star with H and He emission.)

Robin

[Gasman]

Cheers Robin, that feels like my wrists have been well and truly slapped Seriously though I did calibrate the beta Lyra profile using a previously produced curve but I think I did something wrong with the BASS software I use, am now writing a hundred times `I must not produce inaccurate profiles, I must not produce inaccurate profiles............................`

Steve

[robin_astro]

Sorry Steve,

Reading my post back I can see what you mean! My wife has been telling me recently that I am turning into a "Grumpy Old Man" and it looks like you got the brunt of it this time

Best Wishes

Robin