Molecules in the Circumstellar Disk Orbiting BP Piscium

Abstract

BP Psc is a puzzling late-type, emission-line field star with large infrared excess. The star is encircled and enshrouded by a nearly edge-on, dust circumstellar disk, and displays an extensive jet system similar to those associated with pre-main sequence (pre-MS) stars. We conducted a mm-wave molecular line survey of BP Psc with the 30 m telescope of the Institut de Radio Astronomie Millimetrique (IRAM). We detected lines of 12CO and 13CO and, possibly, very weak emission from HCO+ and CN; HCN, H2CO, and SiO are not detected. The CO line profiles of BP Psc are well fit by a model invoking a disk in Keplerian rotation. The mimumum disk gas mass, inferred from the 12CO line intensity and 13CO/12CO line ratio, is ~0.1 Jupiter masses. The weakness of HCO+ and CN (relative to 13CO) stands in sharp contrast to the strong HCO+ and CN emission that characterizes most low-mass, pre-main sequence stars that have been the subjects of molecular emission-line surveys, and is suggestive of a very low level of X-ray-induced molecular ionization within the BP Psc disk. These results lend some support to the notion that BP Psc is an evolved star whose circumstellar disk has its origins in a catastrophic interaction with a close companion.

6 pages, 4 figures; to appear in Astronomy & Astrophysics

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Cited by in corpus (8)

• Imaging the Molecular Disk Orbiting the Twin Young Suns of V4046 Sgr
• Molecules in the disk orbiting the twin young suns of V4046 Sgr
• Shocks and a Giant Planet in the Disk Orbiting BP Piscium?
• Detection of a Molecular Disk Orbiting the Nearby, "Old," Classical T Tauri Star MP Mus
• An ALMA Survey for Disks Orbiting Low-Mass Stars in the TW Hya Association
• Is the Young Star RZ Piscium Consuming Its Own (Planetary) Offspring?
• A single-dish survey of the HCO+, HCN, and CN emission toward the T Tauri disk population in Taurus
• Chandra X-ray Detection of the Enigmatic Field Star BP Psc