The Orbit and Position of the X‐Ray Pulsar XTE J1855−026: an Eclipsing Supergiant System
Author(s) -
R. H. D. Corbet,
K. Mukai
Publication year - 2002
Publication title -
the astrophysical journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.376
H-Index - 489
eISSN - 1538-4357
pISSN - 0004-637X
DOI - 10.1086/342244
Subject(s) - physics , eclipse , astrophysics , supergiant , astronomy , orbital period , orbit (dynamics) , orbital eccentricity , pulsar , proportional counter , light curve , orbital elements , satellite , x ray pulsar , sky , orbital inclination , binary number , stars , detector , optics , arithmetic , mathematics , engineering , aerospace engineering
A pulse timing orbit has been obtained for the X-ray binary XTE J1855-026using observations made with the Proportional Counter Array on board the RossiX-ray Timing Explorer. The mass function obtained of ~16Mo together with thedetection of an extended near-total eclipse confirm that the primary star is asupergiant as predicted. The orbital eccentricity is found to be very low witha best fit value of 0.04 +/- 0.02. The orbital period is also refined to be6.0724 +/- 0.0009 days using an improved and extended light curve obtained withRXTE's All Sky Monitor. Observations with the ASCA satellite provide animproved source location of R.A. = 18h 55m 31.3s}, decl. = -02o 36' 24.0"(2000) with an estimated systematic uncertainty of less than 12". Aserendipitous new source, AX J1855.4-0232, was also discovered during the ASCAobservations.Comment: Accepted for publication in the Astrophysical Journa
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