학술논문
Discovery of a brown dwarf companion to the star HIP 64892
Document Type
Working Paper
Author
Cheetham, A.; Bonnefoy, M.; Desidera, S.; Langlois, M.; Vigan, A.; Schmidt, T.; Olofsson, J.; Chauvin, G.; Klahr, H.; Gratton, R.; D'Orazi, V.; Henning, T.; Janson, M.; Biller, B.; Peretti, S.; Hagelberg, J.; Ségransan, D.; Udry, S.; Mesa, D.; Sissa, E.; Kral, Q.; Schlieder, J.; Maire, A. -L.; Mordasini, C.; Menard, F.; Zurlo, A.; Beuzit, J. -L.; Feldt, M.; Mouillet, D.; Meyer, M.; Lagrange, A. -M.; Boccaletti, A.; Keppler, M.; Kopytova, T.; Ligi, R.; Rouan, D.; Coroller, H. Le; Dominik, C.; Lagadec, E.; Turatto, M.; Abe, L.; Antichi, J.; Baruffolo, A.; Baudoz, P.; Blanchard, P.; Buey, T.; Carbillet, M.; Carle, M.; Cascone, E.; Claudi, R.; Costille, A.; Delboulbé, A.; De Caprio, V.; Dohlen, K.; Fantinel, D.; Feautrier, P.; Fusco, T.; Giro, E.; Gluck, L.; Hubin, N.; Hugot, E.; Jaquet, M.; Kasper, M.; Llored, M.; Madec, F.; Magnard, Y.; Martinez, P.; Maurel, D.; Mignant, D. Le; Möller-Nilsson, O.; Moulin, T.; Origné, A.; Pavlov, A.; Perret, D.; Petit, C.; Pragt, J.; Puget, P.; Rabou, P.; Ramos, J.; Rigal, F.; Rochat, S.; Roelfsema, R.; Rousset, G.; Roux, A.; Salasnich, B.; Sauvage, J. -F.; Sevin, A.; Soenke, C.; Stadler, E.; Suarez, M.; Weber, L.; Wildi, F.
Source
A&A 615, A160 (2018)
Subject
Language
Abstract
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 ($1.2705\pm0.0023$") corresponds to a projected distance of $159\pm12$ AU. We observed the target with the dual-band imaging and long-slit spectroscopy modes of the IRDIS imager to obtain its 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$_{\gamma}\pm1$. From comparison with the BT-Settl atmospheric models we estimate an effective temperature of $T_{\textrm{eff}}=2600 \pm 100$ K, and comparison of the companion photometry to the COND evolutionary models yields a mass of $\sim29-37$ M$_{\text{J}}$ at the estimated age of $16^{+15}_{-7}$ Myr for the system. HIP 64892 is a rare example of an extreme-mass ratio system ($q\sim0.01$) and will be useful for testing models relating to the formation and evolution of such low-mass objects.
Comment: 12 pages, 11 figures, accepted for publication in A&A
Comment: 12 pages, 11 figures, accepted for publication in A&A