Astrophysics, abstract
astro-ph/0511358

From: William T. Reach [view email]

Date (v1): Fri, 11 Nov 2005 16:32:59 GMT (59kb)
Date (revised v2): Thu, 17 Nov 2005 07:43:56 GMT (0kb,I)
Date (revised v3): Thu, 17 Nov 2005 21:57:35 GMT (0kb,I)
Date (revised v4): Fri, 13 Jan 2006 18:04:39 GMT (59kb)

The Dust cloud around the White Dwarf G 29-38

Authors: William T. Reach, Marc J. Kuchner, Ted von Hippel, Adam Burrows, Fergal Mullally, Mukremin Kilic, D. E. Winget

Comments: accepted for publication in the Astrophysical Journal Letters

Journal-ref: 2005, Astrophysical Journal Letters, volume 635, page L161

We present new observations of the white dwarf G 29-38 with the camera (4.5 and 8 microns), photometer (24 microns), and spectrograph (5.5-14 microns) of the Spitzer Space Telescope. This star has an exceptionally large infrared excess amounting to 3% of the bolometric luminosity. The spectral energy distribution has a continuum peak around 4.5 micros and a 9-11 micron emission feature 1.25 times brighter than the continuum. A mixture of amorphous olivine and a small amount of forsterite in an emitting region 1-5 Rsun from the star can reproduce the shape of the 9-11 micron feature. The spectral energy distribution also appears to require amorphous carbon to explain the hot continuum. Our new measurements support the idea that a relatively recent disruption of a comet or asteroid created the cloud.

http://arxiv.org/abs/astro-ph/0511358