COMETARY-LIKE BODIES IN THE PROTOPLANETARY DISK AROUND BETA-PICTORIS

Citation
H. Beust et al., COMETARY-LIKE BODIES IN THE PROTOPLANETARY DISK AROUND BETA-PICTORIS, Astrophysics and space science, 212(1-2), 1994, pp. 147-157
Citations number
21
Categorie Soggetti
Astronomy & Astrophysics
ISSN journal
0004640X
Volume
212
Issue
1-2
Year of publication
1994
Pages
147 - 157
Database
ISI
SICI code
0004-640X(1994)212:1-2<147:CBITPD>2.0.ZU;2-W
Abstract
Repeated spectroscopic observations of beta Pictoris have been perform ed since 1985 and revealed the presence, in many metallic lines like C a II, Mg II, Fe II, ..., of strong sporadic circumstellar absorption, redshifted by tens to hundreds of km s-1 with respect to the star and highly time-variable (time-scales of days or hours). We have tentative ly interpreted these variable events as the spectral signature of infa lling cometary-like bodies, when evaporating in the vicinity of the st ar. This scenario has been furthermore theoretically studied, and we s howed that it could indeed explain correctly the observations with the ir peculiar characteristics, like (1) the behavior difference between visible and UV lines, (2) the unusual line ratios, (3) the surprising presence of Al III absorption lines. Constraints deduced from both obs ervational data and theoretical study allowed us to suggest that a pla net within the disk could be responsible, by perturbations, of this hi gh rate infall of small bodies towards the star (> 100 per year).