Optical and infrared photometry of the microquasar GRO J1655-40 in quiescence

Jenny Greene, Charles D. Bailyn, Jerome A. Orosz

Research output: Contribution to journalArticlepeer-review

184 Scopus citations


We present BVIJK photometry of the black hole candidate GRO J1655-40 in full quiescence. We report a refined orbital period of 2.62191 ± 0.00020 days. The light curves are dominated by ellipsoidal variations from the secondary star. We model the light curves with an upgraded code that includes a more accurate treatment of limb darkening. Previous models containing a large cool disk are ruled out, and, indeed, our data can be fitted with a pure ellipsoidal light curve without any disk contribution. In general agreement with previous results, we derive a confidence region of the correlated quantities inclination and mass ratio, centered on an inclination of 70°.2 ± 1°.9 and mass ratio of 2.6 ± 0.3, resulting in a primary mass M1 = 6.3 ± 0.5 M (all 95% confidence). The complex limits and errors on these values and on the possible disk contribution to the light curve are discussed.

Original languageEnglish (US)
Pages (from-to)1290-1297
Number of pages8
JournalAstrophysical Journal
Issue number2 PART 1
StatePublished - Jun 20 2001
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Astronomy and Astrophysics
  • Space and Planetary Science


  • Accretion, accretion disks
  • Binaries: close
  • Black hole physics
  • Stars: individual (GRO J1655-40)
  • X-rays: stars


Dive into the research topics of 'Optical and infrared photometry of the microquasar GRO J1655-40 in quiescence'. Together they form a unique fingerprint.

Cite this