Simultaneous five colour photometry of the double period optical pulsar H 2254 -033.
Abstract
Fast photometry of the optical counterpart of the pulsating X-ray source H 2254-033 performed simultaneously in the five passbands of the Walraven system ranging from 3200 to 5500 A confirms the presence of the two reported optical periodicities at 805 and 859 sec and of a modulation with a 3.6-hour orbital period. The amplitudes of the two pulsations are comparable in the UV, whereas the 859-sec pulsation strongly dominates in the visual. Energy spectra show that the source of the 805-sec optical pulsation is beamed in the same direction as the X-rays and has a spectrum consistent with a Rayleigh-Jeans tail of a hot blackbody, whereas the orbital modulation and the 959-sec light source have spectra consistent with light produced by X-ray heating of the companion's stellar atmosphere; this confirms that X-ray heating is the source of the orbital modulation.
- Publication:
-
Astronomy and Astrophysics
- Pub Date:
- September 1981
- Bibcode:
- 1981A&A...101L...9M
- Keywords:
-
- Binary Stars;
- Pulsars;
- Stellar Spectrophotometry;
- X Ray Sources;
- Color;
- Continuous Spectra;
- Energy Spectra;
- Stellar Atmospheres;
- Stellar Spectra;
- X Ray Spectra;
- Astronomy