Details

Autor(en) / Beteiligte

• Barlow, B. N.
• Dunlap, B. H.
• Clemens, J. C.
• Reichart, D. E.
• Ivarsen, K. M.
• LaCluyze, A. P.
• Haislip, J. B.
• Nysewander, M. C.

Titel

Fortnightly fluctuations in the O−C diagram of CS 1246

Ist Teil von

• Monthly notices of the Royal Astronomical Society, 2011-07, Vol.414 (4), p.3434-3443

Ort / Verlag

Oxford, UK: Blackwell Publishing Ltd

Erscheinungsjahr

2011

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• Dominated by a single, large-amplitude pulsation mode, the rapidly pulsating hot subdwarf B star CS 1246 is a prime candidate for a long-term O−C diagram study. We collected nearly 400 h of photometry with the 0.41-m Panchromatic Robotic Optical Monitoring and Polarimetry Telescopes over a time-span of 14 months to begin looking for secular variations in the pulse timings. Interestingly, the O−C diagram is dominated by a strong sinusoidal pattern with a period of 14.1 d and an amplitude of 10.7 light-seconds. Underneath this sine wave is a secular trend implying a decrease in the 371.7-s pulsational period of , which we attribute to the evolution of the star through the Hertzsprung-Russell diagram. The sinusoidal variation could be produced by the presence of a low-mass companion, with m sin i≃ 0.12 M⊙, orbiting the subdwarf B star at a distance of 20 R⊙. An analysis of the combined light curve reveals the presence of a low-amplitude first harmonic to the main pulsation mode.