Gas and dust associated with the strange, isolated star BP piscium

Zuckerman, B.; Melis, C.; Song, Inseok; Meier, David S.; Perrin, Marshall D.; Macintosh, Bruce; Marois, Christian; Weinberger, Alycia J.; Rhee, Joseph H.; Graham, James R.; Kastner, Joel H.; Palmer, Patrick; Forveille, T.; Becklin, E. E.; Wilner, D. J.; Barman, T. S.; Marcy, G. W.; Bessell, M. S.
2008
ASTROPHYSICAL JOURNAL
We have carried out a multiwavelength observational campaign demonstrating some of the remarkable properties of the infrared-bright variable star BP Psc. Surrounded by a compact dusty, gaseous disk, this little-studied late G ( or early K) type star emits about 75% of its detected energy flux at infrared wavelengths. Evidence for accretion of gas in conjunction with narrow bipolar jets and Herbig-Haro objects is apparently consistent with classification of BP Psc as a pre-main-sequence star, as postulated in most previous studies. If young, then BP Psc would be one of the nearest and oldest known classical T Tauri stars. However, such an evolutionary classification encounters various problems that are absent or much less severe if BP Psc is instead a luminosity class III post-main-sequence star. In this case, it would be the first known example of a first-ascent giant surrounded by a massive molecular disk with accompanying rapid gas accretion and prominent jets and HH objects. In this model, the genesis of the massive dusty gaseous disk could be a consequence of the envelopment of a low-mass companion star. Properties in the disk may be conducive to the current formation of planets, a gigayear or more after the formation of BP Psc itself.