Poster abstract details
Optical and infrared study of enigmatic post-AGB primary and disk shaped secondary in \epsilon Aurigae
Abstract
\epsilon Aurigae is a spectroscopic binary with a period of 27 years which is punctuated by flat bottomed eclipse of 2 year
duration. The system has three components: a F0Ia post-AGB primary star of
mass 2.2M_{\odot}, a B5 type main sequence secondary that is surrounded by a
disk of gas and dust. The disk eclipses the primary. The nature of
the transiting disk and its origin were not known.
From the archival data spanning from UV to far-IR we constructed SED
of this binary star. To constrain the physical and chemical properties
of the disk, we modelled the disk shaped secondary from the SED using a 2D Monte-Carlo radiative transfer code SRCDUST. We investigate
that the grains in the disk are basically silicates and hence the disk was
originated from a mass transfer from the F0Ia post-AGB star
to its companion. The disk
is geometrically thin which is seen nearly edge-on. The grains are mostly
forward scattering with size larger than 10\mu. It is suggested that the disk has a mass smaller than 0.00005M_{\odot}, a diameter of 4AU and a scale height of 0.01 and it doest exhibit a central hole.
We also carried out high resolution (\sim 70000) spectroscopic monitoring of KI, Na,
and H\alpha profiles during the totality phase of the present eclipse of \epsilon
Aurigae using VBT Echelle spectrograph. Results from these observations will be presented.
duration. The system has three components: a F0Ia post-AGB primary star of
mass 2.2M_{\odot}, a B5 type main sequence secondary that is surrounded by a
disk of gas and dust. The disk eclipses the primary. The nature of
the transiting disk and its origin were not known.
From the archival data spanning from UV to far-IR we constructed SED
of this binary star. To constrain the physical and chemical properties
of the disk, we modelled the disk shaped secondary from the SED using a 2D Monte-Carlo radiative transfer code SRCDUST. We investigate
that the grains in the disk are basically silicates and hence the disk was
originated from a mass transfer from the F0Ia post-AGB star
to its companion. The disk
is geometrically thin which is seen nearly edge-on. The grains are mostly
forward scattering with size larger than 10\mu. It is suggested that the disk has a mass smaller than 0.00005M_{\odot}, a diameter of 4AU and a scale height of 0.01 and it doest exhibit a central hole.
We also carried out high resolution (\sim 70000) spectroscopic monitoring of KI, Na,
and H\alpha profiles during the totality phase of the present eclipse of \epsilon
Aurigae using VBT Echelle spectrograph. Results from these observations will be presented.