XTE J1855-026 is a supergiant X-ray binary
ATel #1876; I. Negueruela (Alicante), J. Casares (IAC), F. Verrecchia (ASDC), P. Blay (Valencia), G. L. Israel (INAF-OA Roma), S. Covino (INAF-OA Milan)
on 16 Dec 2008; 21:23 UT
Credential Certification: Ignacio Negueruela (ignacio@dfists.ua.es)
Subjects: Optical, Binary, Pulsar
Referred to by ATel #: 2482
The eclipsing X-ray pulsar XTE J1855-026 (Corbet & Mukai 2002, ApJ 577, 923) has been unambiguously identified by a recent Swift observation (Romano et al., ATel #1875) with the reddened early-type star proposed as candidate counterpart by Verrecchia et al. (ATel #102).
High-quality spectra of the counterpart taken in August 2003 with the 4.2-m WHT (La Palma) show it to be a B0 Iaep luminous supergiant. Preliminary analysis of its radial velocity curve, based on observations taken with the 2.5-m INT (La Palma) during Aug 2005, recovers the 6-d period found from the X-ray pulsations. Further work to determine a full orbital solution is in progress.
