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HD 184061, a possible Be star?

PostPosted: Mon Oct 19, 2015 6:32 pm
by Paolo Berardi
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

Re: HD 184061, a possible Be star?

PostPosted: Mon Oct 19, 2015 9:50 pm
by Hubert Boussier
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

Re: HD 184061, a possible Be star?

PostPosted: Mon Oct 19, 2015 10:44 pm
by Paolo Berardi
Thanks a lot for your confirmation Hubert!

Merci beaucoup et bonne nuit a vous aussi.

Paolo

Re: HD 184061, a possible Be star?

PostPosted: Tue Oct 20, 2015 10:19 am
by Hubert Boussier
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

Re: HD 184061, a possible Be star?

PostPosted: Wed Oct 21, 2015 1:31 pm
by Andrew Smith
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

Re: HD 184061, a possible Be star?

PostPosted: Wed Oct 21, 2015 9:23 pm
by Paolo Berardi
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

Re: HD 184061, a possible Be star?

PostPosted: Sat Oct 24, 2015 6:28 pm
by Thierry Lemoult
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

Re: HD 184061, a possible Be star?

PostPosted: Sun Oct 25, 2015 7:12 pm
by Paolo Berardi
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.

Re: HD 184061, a possible Be star?

PostPosted: Sun Oct 25, 2015 9:38 pm
by Andrew Smith
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