4U 0142+61
Abstract
B. Kern and C. Martin, California Institute of Technology, communicate: "We observed the anomalous x-ray pulsar (AXP) 4U 0142+61 on Nov. 16-17 UT with the Palomar 5-m telescope, using an unfiltered CCD observing in a periodic frame-transfer mode, synchronized with the known 8.7-s x-ray period (Gavriil and Kaspi 2001, http://xxx.lanl.gov/abs/astro-ph/?0107422). In 10-phase bins, we find optical pulsations with a 30-percent pulsed fraction. The pulse profile is similar in morphology and agrees within 0.1 in phase with the soft x-ray pulse profile. This is the first detection of optical pulsations in an AXP. Our discovery unambiguously confirms the optical counterpart (Hulleman et al. 2000, Nature 408, 689), and the large pulsed fraction rules out x-ray reprocessing as the source of pulsed optical emission."
- Publication:
-
International Astronomical Union Circular
- Pub Date:
- December 2001
- Bibcode:
- 2001IAUC.7769....2K