The Invisible Monster Has Two Faces: Observations of Epsilon Aurigae with the Herschel Space Observatory

Abstract

We present Herschel Space Observatory photometric observations of the unique, long-period eclipsing binary star Epsilon Aurigae. Its extended spectral energy distribution is consistent with our previously published cool (550 K) dust disk model. We also present an archival infrared spectral energy distribution of the side of the disk facing the bright F-type star in the binary, which is consistent with a warmer (1150 K) disk model. The lack of strong molecular emission features in the Herschel bands suggests that the disk has a low gas-to-dust ratio. The spectral energy distribution and Herschel images imply that the 250 GHz radio detection reported by Altenhoff et al. is likely contaminated by infrared-bright, extended background emission associated with a nearby nebular region and should be considered an upper limit to the true flux density of Epsilon Aur.

5 pages, 2 figures; to be published in Astrophysical Journal Letters

References in corpus (5)

• Herschel Space Observatory - An ESA facility for far-infrared and submillimetre astronomy
• The Herschel-SPIRE instrument and its in-flight performance
• In the Shadow of the Transiting Disk: Imaging epsilon Aurigae in Eclipse
• Spectral and photometric analysis of the eclipsing binary epsilon Aurigae prior to and during the 2009-2011 eclipse
• Effects of dust on light-curves of εAur type stars

Cited by in corpus (6)

• Discovery of an unusual bright eclipsing binary with the longest known period: TYC 2505-672-1 / MASTER OT J095310.04+335352.8
• Interferometry of $\epsilon$ Aurigae: Characterization of the asymmetric eclipsing disk
• Physical properties of beta Lyr A and its opaque accretion disk
• Novalike Cataclysmic Variables in the Infrared
• 2D Monte-Carlo Radiative transfer modeling of the disk shaped secondary of Epsilon Aurigae
• K I 7699 Å and related shell lines during the recent eclipse of $\epsilon$ Aurigae