Open AccessDetection of 6‐cm radio‐continuum emission from an EB (β‐Lyrae type) variable star – HIP 68718
Author(s) -
Anderson M. W. B.,
Filipović M. D.
Publication year - 2007
Publication title -
monthly notices of the royal astronomical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.058
H-Index - 383
eISSN - 1365-2966
pISSN - 0035-8711
DOI - 10.1111/j.1365-2966.2007.11783.x
Subject(s) - physics , astrophysics , light curve , rosat , sky , astronomy , rr lyrae variable , position angle , variable star , radio spectrum , stars , galaxy , globular cluster
We report the 6‐cm radio‐continuum detection of a previously unknown radio star, HIP 68718, identified by the Hipparcos satellite as an EB or β‐Lyrae type optical variable. Only five prior radio detections of this type are reported in the literature. The radio source (VLA J140402−002145) was detected at the 6σ level, with an associated <1 arcsec position error. The radio‐optical separation is 0.2 arcsec and is well within the position errors. A ROSAT X‐ray source (RXJ 1404.0−0021) is located 4.5 arcsec from the radio position. Based on the component spectral types (F5V + G5V), 1.52 d period, variations in the peak of the light curve and the X‐ray and 6‐cm radio luminosities, we conclude the star is a candidate RS CVn. The binary is in a near‐contact phase based on the asymmetric light curve (O'Connell effect). Evidence of two faint possible companion objects was also found in the J ‐ and K ‐band Two‐Micron All‐Sky Survey images.