AX J1740.2-2903: Optical Period Confirms Intermediate Polar Classification
ATel #2681; J. P. Halpern. E. V. Gotthelf (Columbia U.)
on 18 Jun 2010; 09:04 UT
Credential Certification: Jules Halpern (jules@astro.columbia.edu)
Subjects: Optical, X-ray, Gamma Ray, Binary, Cataclysmic Variable
Following the optical identification of AX J1740.2-2903 reported in ATel #2664,
we obtained time-series photometry in the R-band on 2010 June 17 UT for
2.3 hr, using the 1.3m McGraw-Hill telescope of the MDM Observatory. A strong
periodic modulation is detected in these data at P = 622+/-7 s, which agrees
with the X-ray period of P = 623+/-2 s in XMM-Newton data reported in
ATel #2664. Identified as the spin period of the white dwarf, the optical/X-ray
period confirms the classification of this INTEGRAL detected source (Bird et al. 2010, ApJS, 186, 1)
as a member of the intermediate polar class of cataclysmic variables.
