A Young Brown Dwarf Companion to DH Tauri
Kobayashi, Naoto; Usuda, Tomonori; Pyo, Tae-Soo; Tamura, Motohide; Hayashi, Masahiko; Fukagawa, Misato; Ando, Hiroyasu; Itoh, Yoichi; Mayama, Satoshi; Hayashi, Saeko S.; Ishii, Miki; Suto, Hiroshi; Takato, Naruhisa; Oasa, Yumiko; Naoi, Takahiro; Tsuji, Takashi; Morino, Jun-ichi; Yamashita, Takuya; Nishikawa, Takayuki; Murakawa, Koji; Oya, Shin; Miyama, Shoken M.; Kaifu, Norio
Japan, United States
Abstract
We present the detection of a young brown dwarf companion, DH Tau B, associated with the classical T Tauri star DH Tau. Near-infrared coronagraphic observations with CIAO on the Subaru Telescope have revealed DH Tau B with H=15 mag located 2.3" (330 AU) away from the primary, DH Tau A. Comparing its position with a Hubble Space Telescope archive image, we confirmed that DH Tau A and B share a common proper motion, suggesting that they are physically associated with each other. The near-infrared color of DH Tau B is consistent with those of young stellar objects. The near-infrared spectra of DH Tau B show deep water absorption bands, a strong K I absorption line, and a moderate Na I absorption line. We derived its effective temperature and surface gravity of Teff=2700-2800 K and logg=4.0-4.5, respectively, by comparing the observed spectra with synthesized spectra of low-mass objects. The location of DH Tau B on the H-R diagram gives its mass of 30MJ-50MJ.
Based on data collected at the Subaru Telescope, which is operated by the National Astronomical Observatory of Japan.