Quiescent X-ray/optical counterparts of the black hole transient H 1705-250

Y. J. Yang, A. K.H. Kong, D. M. Russell, F. Lewis, R. Wijnands

Research output: Contribution to journalArticlepeer-review


We report the result of a new Chandra observation of the black hole X-ray transient H 1705-250 in quiescence. H 1705-250 was barely detected in the new ~50 ks Chandra observation. With five detected counts, we estimate the source quiescent luminosity to be LX ~ 9.1 × 1030 erg s-1 in the 0.5-10 keV band (adopting a distance of 8.6 kpc). This value is in line with the quiescent luminosities found among other black hole X-ray binaries with similar orbital periods. By using images taken with the Faulkes Telescope North, we derive a refined position of H 1705-250. We also present the long-term light curve of the optical counterpart from 2006 to 2012, and show evidence for variability in quiescence.

Original languageEnglish (US)
Pages (from-to)2876-2880
Number of pages5
JournalMonthly Notices of the Royal Astronomical Society
Issue number4
StatePublished - Dec 21 2012


  • Binaries
  • X-rays

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science


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