SEEDS DIRECT IMAGING OF THE RV-DETECTED COMPANION TO V450 ANDROMEDAE, AND CHARACTERIZATION OF THE SYSTEM
AuthorHełminiak, K. G.
Brandt, T. D.
Carson, J. C.
Grady, C. A.
Hayashi, S. S.
Hodapp, K. W.
Knapp, G. R.
McElwain, M. W.
Takahashi, Y. H.
Turner, E. L.
AffiliationUniv Arizona, Steward Observ
stars: imaging; stars: individual (V450 And)
MetadataShow full item record
PublisherIOP PUBLISHING LTD
CitationSEEDS DIRECT IMAGING OF THE RV-DETECTED COMPANION TO V450 ANDROMEDAE, AND CHARACTERIZATION OF THE SYSTEM 2016, 832 (1):33 The Astrophysical Journal
JournalThe Astrophysical Journal
Rights© 2016. The American Astronomical Society. All rights reserved.
Collection InformationThis item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at email@example.com.
AbstractWe report the direct imaging detection of a low-mass companion to a young, moderately active star V450. And, that was previously identified with the radial velocity (RV) method. The companion was found in high-contrast images obtained with the Subaru Telescope equipped with the HiCIAO camera and AO188 adaptive optics system. From the public ELODIE and SOPHIE archives we extracted available high-resolution spectra and RV measurements, along with RVs from the Lick planet search program. We combined our multi-epoch astrometry with these archival, partially unpublished RVs, and found that the companion is a low-mass star, not a brown dwarf, as previously suggested. We found the best-fitting dynamical masses to be m(1) = 1.141(-0.091)(+0.037)and m(2) = 0.279(-0.020)(+0.023) M-circle dot. We also performed spectral analysis of the SOPHIE spectra with the iSpec code. Hipparcos time-series photometry shows a periodicity of P = 5.743 day, which is also seen in the SOPHIE spectra as an RV modulation of the star A. We interpret it as being caused by spots on the stellar surface, and the star to be rotating with the given period. From the rotation and level of activity, we found that the system is 380(-100)(+220) Myr old, consistent with an isochrone analysis (220(-90)(+2120) Myr). This work may serve as a test case for future studies of low-mass stars, brown dwarfs, and exoplanets by combination of RV and direct imaging data.
VersionFinal published version
SponsorsNational Astronomical Observatory of Japan as Subaru Astronomical Research Fellow; Japan Society for Promotion of Science (JSPS) Fellowship for Research; Mitsubishi Corporation International Student Scholarship; NASA through the Sagan Fellowship Program; NAOJ Fellowship, Inoue Science Research Award; JSPS KAKENHI ; U.S. National Science Foundation ; JSPS KAKENHI Grant [25247026, 15H02063]; [25-8826]