2 00 7 Follow - up observations of pulsating subdwarf B stars : Multisite campaigns on PG 1618 + 563 B and PG 0048 + 091
نویسنده
چکیده
We present follow-up observations of pulsating subdwarf B (sdB) stars as part of our efforts to resolve the pulsation spectra for use in asteroseismological analyses. This paper reports on multisite campaigns of the pulsating sdB stars PG 1618+563B and PG 0048+091. Data were obtained from observatories placed around the globe for coverage from all longitudes. For PG 1618+563B, our five-site campaign uncovered a dichotomy of pulsation states: Early during the campaign the amplitudes and phases (and perhaps frequencies) were quite
منابع مشابه
PG 1618 + 563 B : A new bright pulsating sdB star ?
The results of two runs of time-series photometry made at the Nordic Optical Telescope clearly show that the sdB star PG 1618+563B is a new member of the EC 14026 class of sdB pulsators. Its power spectrum shows a doublet of frequencies at about 6.95 and 7.18 mHz (P ∼ 144 and 139 s respectively), which produce a modulation effect in the light curve with a beat period of about 1.2 hours. The amp...
متن کاملAn evolutionary study of the pulsating subdwarf B eclipsing binary PG 1336−018 (NY Vir)
Context. The formation of subdwarf B (sdB) stars is not well understood within the current framework of stellar single and binary evolution. Aims. In this study, we focus on the formation and evolution of the pulsating sdB star in the very short-period eclipsing binary PG 1336−018. We aim at refining the formation scenario of this unique system, so that it can be confronted with observations. M...
متن کاملSynthetic photometry for non-radial pulsations in subdwarf B stars
We describe a method for computing theoretical photometric amplitude ratios for a number of modes of nonradially pulsating subdwarf B stars in both SDSS and UBVR systems. In order to avoid costly solutions of the non-adiabatic nonradial pulsation equations, we have adopted the adiabatic approximation. We argue that this is a valid approach, at least for the V361 Hya stars, because observations ...
متن کاملThe Potential of Multi - Colour Photometry for Pulsating
We investigate the potential of multi-colour photometry for partial mode identification in both long-and short-period variable subdwarf B stars. The technique presented is based on the fact that the frequency dependence of an oscillation's amplitude and phase bears the signature of the mode's degree index l, among other things. Unknown contributing factors can be eliminated through the evaluati...
متن کاملTime resolved spectroscopy of the multiperiodic pulsating subdwarf B star PG 1605 + 072
We present results for the 2m spectroscopic part of the Multi-Site Spectroscopic Telescope campaign, which took place in May/June 2002. In order to perform an asteroseismological analysis on the multiperiodic pulsating subdwarf B star PG 1605+072 we used over 150 hours of time resolved spec-troscopy in order to search for and analyse line profile variations by using phase binning. We succeeded ...
متن کامل