In:
Astronomy & Astrophysics, EDP Sciences, Vol. 615 ( 2018-7), p. A160-
Kurzfassung:
We report the discovery of a bright, brown dwarf companion to the star HIP 64892, imaged with VLT/SPHERE during the SHINE exoplanet survey. The host is a B9.5V member of the Lower-Centaurus-Crux subgroup of the Scorpius Centaurus OB association. The measured angular separation of the companion (1.2705 ± 0.0023 ” ) corresponds to a projected distance of 159 ± 12 AU. We observed the target with the dual-band imaging and long-slit spectroscopy modes of the IRDIS imager to obtain its spectral energy distribution (SED) and astrometry. In addition, we reprocessed archival NACO L -band data, from which we also recover the companion. Its SED is consistent with a young ( 〈 30 Myr), low surface gravity object with a spectral type of M9 γ ± 1. From comparison with the BT-Settl atmospheric models we estimate an effective temperature of T eff = 2600 ± 100 K, and comparison of the companion photometry to the COND evolutionary models yields a mass of ~29−37 M J at the estimated age of 16 −7 +15 Myr for the system. The star HIP 64892 is a rare example of an extreme-mass ratio system ( q ~ 0.01) and will be useful for testing models relating to the formation and evolution of such low-mass objects.
Materialart:
Online-Ressource
ISSN:
0004-6361
,
1432-0746
DOI:
10.1051/0004-6361/201832650
Sprache:
Englisch
Verlag:
EDP Sciences
Publikationsdatum:
2018
ZDB Id:
1458466-9
SSG:
16,12
