Close Companions to the T Tauri Stars CVSO 109 and CVSO 165 Observed by the HST ULLYSES Program

Abstract

The Hubble Space Telescope (HST) Ultraviolet Legacy Library of Young Stars as Essential Standards (ULLYSES) program is a HST Director s Discretionary program that is in the process of obtaining a large library of ultraviolet spectroscopic observations of young stars of both high and low masses. We present information on close companions to the T Tauri stars CVSO 109 and CVSO 165 in Orion that were observed with the HST as part of this program. CVSO 109 has a fainter companion at an angular separation ρ\u2009=\u20090.″64 near PA\u2009=\u2009218° and Δ(F28X50LP)\u2009≈\u20090.6\u2009 mag, while the CVSO 165 companion is at ρ\u2009=\u20090.″30 near PA\u2009=\u2009326° with Δ(F28X50LP)\u2009≈\u20091.7\u2009 mag. Both components of CVSO 165 appear to be active stars with strong emission features, while the CVSO 109 companion shows only modest indications of stellar activity. Extracted spectra for each of these components will be included in ULLYSES Data Release 2.