Be Shell Star Spectroscopy
Jim Ferreira, Livermore CA  bakerst@comcast.net

Alpy 600, C9
Alpy 600 with off-axis guider and Atik 420M CCD
C9.25 SCT with Moonlite motorized focuser, 
internal mounted 0.63x focal reducer,
Losmandy G11 mount


Be shell star comparison
Shell Stars - Fe II samplings in spectra, Alpy 600
Be shell star comparison, H-alpha


Be Shell Stars -- Veiling of Photospheric Absorption Lines by Emission Lines in Edge-on Circumstellar Decretion Disk
Be shell stars, veiled lines Alpy 600
Be shell stars have rotational axis inclination that provide a line of sight view of their equatorial region through their decretion disk material.  As such, in some cases, photospheric lines - H-Balmer and He I - can appear weak or absent entirely due to a veiling effect by disk material.

Theta CrB is a Be shell star that presently shows little or no indication of a decretion disk, at least in this low resolution spectrum.  Rather that of a normal B type star with H-Balmer and He I photospheric absorption lines -- I include it here as a base line example. 

Spectrum for 28 Tau shows weak emission at H-alpha, indicating the presence of a decretion disk, with strong absorption lines for both photshpheric and decretion disk material. 

Beta Mon A, 59 Cyg and Gamma Cas each show how emission lines in the decretion disk spectrum can 'veil' photosheric absorption lines.  In Gamma Cas, H-Balmer absorption lines are entirely absent due to this veiling effect.



59 Cyg, HD200120, Alpy 600
Shell Star - 59 Cyg, HD200120, BIVe, 4.74mv
59 Cyg, Alpy 600



HD193182, Alpy 600
Shell Star - HD193182, B7e-B8e, 6.57mv
HD193182, Alpy 600



HD183656, V923 Aql, Alpy 600
Shell Star - HD183656, B6e, 6.09mv
HD183656, V923 Aql, Alpy 600



HD179343, Alpy 600
Shell Star - HD179343, B9e, 6.92mv
HD179343, Alpy 600



88 Her, Alpy 600
Shell Star - 88 Her, B6IVe, 6.78mv
88 Her, Alpy 600 spectroscopy



4 Her, Alpy 600 spectrscopy
Shell Star - 4 Her, B7IVe, 5.74
4 Her, Alpy 600 spectroscopy



HD192954, Alpy 600 spectroscopy
Shell Star - HD192954, B6e-B7e, 7.48mv
HD192954, Alpy 600 spectroscopy



1 Del, Alpy 600 Spectroscopy
Shell Star - 1 Del, B8e-B9e, 6.03mv
1 Del, Alpy 600



Theta CrB, Alpy 600
Shell Star - Theta CrB, B6IIIe, 4.14mv
Theta CrB, Alpy 600



28 tau Alpy 600
Shell Star - 28 Tau, B8Ve, 5.09mv
28 Tau, shell star Alpy 600



Beta Mon A, Alpy 600
Shell Star - Beta Mon, B3Ve
Beta Mon A, Alpy 600



Zeta Tau, Alpy 600
Shell Star - Zeta Tau, B2IIIe, 2.88-3.17mv
Zeta Tau, Alpy 600



ew lac hd217050, alpy 600
Shell Star - EW Lac, B3IVe, 5.34mv
ew lac hd217050, alpy 600



gamma cas alpy 600
Shell Star - Gamma Cas, B0.5IVe, 2.47mv
gamma cas alpy 600



omi and alpy 600
Shell Star - Omi And, B6III+A2p, 3.55mv
omi and alpy 600


psi and phi persei alpy 600
Psi Persei, B5Ve and Phi Persei, B1.5Ve    Alpy 600
psi and phi persei alpy 600
Psi Persei     Alpy 600
psi persei, instrument response corrected alpy 600



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