Potter, Dan

Contact Email: potter@ifa.hawaii.edu
Institute: University of Hawaii, Institute for Astronomy
First Coauthor: Mike Cushing
Institute: U. of Hawaii, IFA
Second Coauthor: Ralph Neuhauser
Institute: MPI Extraterrestrische Phsik
Research URL:http://ifa.hawaii.edu/~ao
Subject Area: Brown Dwarfs & Extrasolar Planets
Waveband: Infrared
Technique: Imaging (Direct)
Presentation:
Title: The Discovery of a low mass Binary Companion to the young solar analog Star HD130948
Abstract: As a part of a survey for low mass companions using the Hokupa'a adaptive optics system mounted on the Gemini North 8m telescope, we report the discovery of a low mass binary system with a separation of 120 mas which is  8 magnitudes fainter in the H-band and 2.6 arcseconds away from the G1V star HD130948. We have confirmed the binary system to have the same proper motion as HD130948. A comparison of the obtained JHK colors with theoretical models places the binary companions at the substellar border. We also present low resolution near-IR spectra obtained with "SpeX" mounted on the NASA infrared Telescope Facility of the combined light of the companion stars. These spectra show CO bandhead and water absorption features indicative of late-M to early-L spectral classification. As the system is only 17.9 pc away, the 2.2 AU on sky separation of the binary pair would give an orbital period on the order of 10-15 years, a measure of which provides a mass estimate independent of theoretical models. Combined with the independent age estimates of HD130948, the system will be valuable in constraining the evolutionary models of such objects.