Home News About Us Contact Contributors Disclaimer Privacy Policy Help FAQ

Quick Search
My eDoc
Session History
Support Wiki
Direct access to
document ID:

          Institute: MPI für Astronomie     Collection: Publikationen_mpia     Display Documents

ID: 730187.0, MPI für Astronomie / Publikationen_mpia
The coolest `stars' are free-floating planets
Authors:Joergens, V.; Bonnefoy, M.; Liu, Y.; Bayo, A.; Wolf, S.; Harris, H. C.
Place of Publication:Flagstaff
Publisher:Lowell Observatory
Date of Publication (YYYY-MM-DD):2015-01
Audience:Not Specified
Abstract / Description:We show that the coolest known object that is probably formed in a star-like mode is a free-floating planet. We discovered recently that the free-floating planetary mass object OTS 44 (M9.5, ˜12 Jupiter masses, age ˜2 Myr) has significant accretion and a substantial disk. This demonstrates that the processes that characterize the canonical star-like mode of formation apply to isolated objects down to a few Jupiter masses. We detected in VLT/SINFONI spectra that OTS 44 has strong, broad, and variable Paschen β emission. This is the first evidence for active accretion of a free-floating planet. The object allows us to study accretion and disk physics at the extreme and can be seen as free-floating analog of accreting planets that orbit stars. Our analysis of OTS 44 shows that the mass-accretion rate decreases continuously from stars of several solar masses down to free-floating planets. We determined, furthermore, the disk mass (10 Earth masses) and further disk properties of OTS 44 through modeling its SED including Herschel far-IR data. We find that objects between 14 and 0.01 solar masses have the same ratio of the disk-to-central-mass of about 1%. Our results suggest that OTS 44 is formed like a star and that the increasing number of young free-floating planets and ultra-cool T and Y field dwarfs are the low-mass extension of the stellar population.
External Publication Status:published
Document Type:Other
Communicated by:N. N.
Affiliations:MPI für Astronomie
The scope and number of records on eDoc is subject to the collection policies defined by each institute - see "info" button in the collection browse view.