HD 184061, a possible Be star?

HD 184061, a possible Be star?

Postby Paolo Berardi » Mon Oct 19, 2015 6:32 pm

Hi all, yesterday I had the opportunity to observe the bright star HD 184061 in Aquila (Hipparcos catalog 96092), finding an H-alpha profile type often exhibited by Be stars (central emission on a photospheric large absorption).

Image

On Simbad the object type is 'Star', with spectral type A0 and no luminosity class reported. The Catalogue of Stellar Spectral Classifications (Skiff, 2009-2014) reports only one entry with spectral type B9.5IV-V and no note about an emission line status. The star seems not included in BeSS stars list.

Firstly, I would like to ask a confirmation of its peculiarity or not. Eventually, could anybody take a new spectrum? Just to exclude a mistake in my observation.

If real, might it be classified as Be Star, taking into account the star properties?

The star field:
Image

Paolo
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Re: HD 184061, a possible Be star?

Postby Hubert Boussier » Mon Oct 19, 2015 9:50 pm

Buonasera Paolo,

Ho guardato HD184061, Paolo hai ragione c'è una righa d'èmissione nella righa di assorbimento Halpha.
Pero sul Simbad il classo spettralo é A0

Buona notte

Hubert
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Re: HD 184061, a possible Be star?

Postby Paolo Berardi » Mon Oct 19, 2015 10:44 pm

Thanks a lot for your confirmation Hubert!

Merci beaucoup et bonne nuit a vous aussi.

Paolo
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Re: HD 184061, a possible Be star?

Postby Hubert Boussier » Tue Oct 20, 2015 10:19 am

Bonjour,

Le spectre basse résolution de l'étoile HD184061 pour laquelle Paolo a détecté un raie Halpha en émission.

Le spectre global LISA – Atik 460EX 2x2, C11 Edge f/D 0,7 15x15s:

Image

La raie Halpha Image



Hubert
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Re: HD 184061, a possible Be star?

Postby Andrew Smith » Wed Oct 21, 2015 1:31 pm

Hi Paolo, well done were you looking for Be type stars specifically?

Can you and Herbert send your FITS file to Thierry Lemoult for adding to his database here http://www.astrosurf.com/aras/be_candid ... idate.html

Regards Andrew
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Re: HD 184061, a possible Be star?

Postby Paolo Berardi » Wed Oct 21, 2015 9:23 pm

Very nice spectrum, Hubert. The h-alpha profile is well-resolved.

Andrew, thank you for reminding me the excellent job of data collection carried out by Thierry. I just sent him my spectrum.

It would be very useful a specialist opinion.

I wasn't following a Be search plan, the observation was by chance enough...

Paolo
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Re: HD 184061, a possible Be star?

Postby Thierry Lemoult » Sat Oct 24, 2015 6:28 pm

Hello
Nice finding Paolo. I just updated the page http://www.astrosurf.com/aras/be_candidate/auto-be-candidate.html with this new possible Be star.
Thierry
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Re: HD 184061, a possible Be star?

Postby Paolo Berardi » Sun Oct 25, 2015 7:12 pm

Thierry, Andrew, I read "To Be or not to Be" section, you are doing a great job.

For HD184061, also the H-K color seems ok, being equal to +0.03. The luminosity class value is missing on Simbad (but an old paper reports IV-V), so I tried to observe the star in a spectral region with sensible lines. Luminosity effect is shown on "A Digital Spectral Classification Atlas" by R. O. Gray:

https://ned.ipac.caltech.edu/level5/Gra ... tents.html

Luminosity effect at A0 (Gray page) and, below, the same spectral region for HD 184061 and Vega observed with Lhires III and 1200 l/mm grating:

Image

Image

From these spectra (but consider my untrained eye!), the star HD 184061 seems to fall between III and V class. Supergiants class association should be excluded because of the low metal lines strength and broadened Balmer lines (if that is a density effect).

Yesterday I took an R~6000 spectrum of H-alpha line:

Image

Paolo

PS: Thierry, I'm sending you the profiles for the database.
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Re: HD 184061, a possible Be star?

Postby Andrew Smith » Sun Oct 25, 2015 9:38 pm

Paolo - Skiff's (2009 -2014) Catalogue of Stellar Classification here http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=B/mk has it as B9.5IV-V so a good candidate for a Be star.

Regards Andrew
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