HS0702+6043 – A new large amplitude sdB variable at the cool end of the instability region

Schuh, S.; Deetjen, J. L.; Edelmann, H.; Heber, U.

doi:10.1051/0004-6361:20020200

Cited by 30 publications

(32 citation statements)

References 27 publications

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“…All of our stars will be observed for light variations. Up to June 2002, about 70 HQS sdB stars had been observed and nine (HS 0039+4302, HS 0444+0408, HS 0702+6043, HS 0815+4243, HS 1824+5745, HS 2149+0847, HS 2151+0857, HS 2201+2610, and HS 2303+0152) were found to be pulsating (Østensen et al 2000a,b;Dreizler et al 2002;Silvotti et al 2002). This represents about one pulsator in ten sdB stars.…”

Section: Discussionmentioning

confidence: 99%

Spectral analysis of sdB stars from the Hamburg Quasar Survey

Edelmann¹,

Heber²,

Hagen

et al. 2003

A&A

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147

191

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Abstract. We present the results of a spectral analysis of a large sample of subdwarf B stars selected from follow-up observations of candidates from the Hamburg Quasar Survey. Fundamental parameters (effective temperature, gravity, and helium abundance) were determined by matching synthetic line profiles calculated from model atmospheres to all hydrogen and helium absorption lines present in the observed optical spectra. The derived helium abundances are compared with the atmospheric parameters to search for possible trends. We discovered a correlation between the helium abundance and the effective temperature: the larger the temperature, the larger the photospheric helium content of sdB stars. Additionally, a separation into two sequences of sdB stars in the effective temperature -helium abundance plane is detected. We compared our analysis results with data from the literature. The stars from our sample are found to be somewhat more luminous. This can only partly be explained by NLTE effects. Three apparently normal B stars were discovered, which could be massive stars far away from the galactic plane (7-19 kpc). Radial velocities were measured for 23 stars from which we discovered a new radial velocity variable sdB star.

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Section: Discussionmentioning

confidence: 99%

Spectral analysis of sdB stars from the Hamburg Quasar Survey

Edelmann¹,

Heber²,

Hagen

et al. 2003

A&A

Self Cite

147

191

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“…Our determinations of T eff and log g do not include NLTE effects or mixed compositions, so they serve only as a rough indicator. Stars with 6.5 > log g > 5.0 and T eff < 20 000 K were labelled ELM-DAs, as they lay below the ZAHB (Dreizler et al 2002;Althaus, Miller Bertolami, & Córsico 2013;Gianninas et al 2014). Of the 647 sds, we classified 262 sdOs and 375 sdBs.…”

Section: Subdwarfsmentioning

confidence: 99%

New white dwarf stars in the Sloan Digital Sky Survey Data Release 10

Kepler

Pelisoli

Koester

et al. 2014

Monthly Notices of the Royal Astronomical Society

239

186

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We report the discovery of 9 089 new spectroscopically confirmed white dwarfs and subdwarfs in the Sloan Digital Sky Survey Data Release 10. We obtain T eff , log g and mass for hydrogen atmosphere white dwarf stars (DAs) and helium atmosphere white dwarf stars (DBs), and estimate the calcium/helium abundances for the white dwarf stars with metallic lines (DZs) and carbon/helium for carbon dominated spectra DQs. We found 1 central star of a planetary nebula, 2 new oxygen spectra on helium atmosphere white dwarfs, 71 DQs, 42 hot DO/PG1159s, 171 white dwarf+main sequence star binaries, 206 magnetic DAHs, 327 continuum dominated DCs, 397 metal polluted white dwarfs, 450 helium dominated white dwarfs, 647 subdwarfs and 6888 new hydrogen dominated white dwarf stars.

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“…Presently data on 31 sdB pulsators are known: 28 are summarized in the review by Kilkenny (2002); additional discoveries are from Dreizler et al (2002) and Silvotti et al (2002). For three of them, PB 8783 , PG 1605+072 (Kilkenny et al 1999) and PG 1336-018 (Reed et al 2000), large time-series campaigns have permitted to reach a frequency resolution of the order of 1 µHz, which is typically needed for seismological analysis.…”

Section: Introductionmentioning

confidence: 99%