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Related papers: Identifying modes in a pulsating sdB (EC14026) sta…

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We report the discovery of the second and third pulsating extremely low mass white dwarfs (WDs), SDSS J111215.82+111745.0 (hereafter J1112) and SDSS J151826.68+065813.2 (hereafter J1518). Both have masses < 0.25 Msun and effective…

2M1938+4603 (KIC 9472174) displays a spectacular light curve dominated by a strong reflection effect and rather shallow, grazing eclipses. The orbital period is 0.126 days, the second longest period yet found for an eclipsing sdB+dM, but…

We suggest that the recently discovered, enigmatic pulsar with a period of 18.18 minutes, GLEAM-X J162759.5-523504.3, is most likely a hot subdwarf (proto white dwarf). A magnetic dipole model explains the observed period and…

Solar and Stellar Astrophysics · Physics 2022-02-11 Abraham Loeb , Dan Maoz

The Parkes multibeam pulsar survey has led to the discovery of more than 700 pulsars. In this paper, we provide timing solutions, flux densities and pulse profiles for 180 of these new discoveries. Two pulsars, PSRs J1736-2843 and…

We report the discovery of an eclipsing X-ray binary with a 3.62-hr period within 24" of the center of the dwarf starburst galaxy NGC 4214. The orbital period places interesting constraints on the nature of the binary, and allows for a few…

Blue large-amplitude pulsators (BLAPs) form a small group of hot objects pulsating in a fundamental radial mode with periods of the order of 30 minutes. Proposed evolutionary scenarios explain them as evolved low-mass stars: either ~0.3…

Solar and Stellar Astrophysics · Physics 2022-07-13 A. Pigulski , K. Kotysz , P. A. Kolaczek-Szymanski

We report the discovery of an eclipsing binary -- PTF1 J072456$+$125301-- composed of a subdwarf B (sdB) star ($g'=17.2^m$) with a faint companion. Subdwarf B stars are core helium-burning stars, which can be found on the extreme horizontal…

Solar and Stellar Astrophysics · Physics 2015-08-19 M. Schindewolf , D. Levitan , U. Heber , H. Drechsel , V. Schaffenroth , T. Kuper , T. Prince

AQ Col (EC 05217-3914) is one of the first detected pulsating subdwarf B (sdB) stars and has been considered to be a single star. Photometric monitoring of AQ Col reveals a pulsation timing variation with a period of 486 days, interpreted…

Solar and Stellar Astrophysics · Physics 2022-02-16 T. Otani , A. E. Lynas-Gray , D. Kilkenny , C. Koen , T. von Hippel , M. Uzundag , M. Vuckovic , C. M. Pennock , R. Silvotti

We have found that the white dwarf PG 1101+364 is a double-lined white dwarf/white dwarf binary with an orbital period of 3.47 hours. PG 1101+364 is the shortest period detached double-degenerate yet found and gravitational radiation will…

Astrophysics · Physics 2016-06-08 T. R. Marsh

We present results of a Transiting Exoplanet Survey Satellite (TESS) search for short-period pulsations in compact stellar objects observed in years 1 and 3 of the TESS mission, during which the southern ecliptic hemisphere was targeted. We…

Solar and Stellar Astrophysics · Physics 2023-01-11 A. S. Baran , V. Van Grootel , R. H. Ostensen , H. L. Worters , S. K. Sahoo , S. Sanjayan , S. Charpinet , P. Nemeth , J. H. Telting , D. Kilkenny

We present lightcurves of four binary subdwarf B stars, Ton 245, Feige 11, PG1432+159 and PG1017-086. We also present new spectroscopic data for PG1017-086 from which we derive its orbital period, P=0.073d, and the mass function, f_m =…

Astrophysics · Physics 2009-11-07 P. F. L. Maxted , T. R. Marsh , U. Heber , L. Morales-Rueda , R. C. North , W. A. Lawson

We report the discovery of oscillations in the hot subdwarf B star JL 166 from time-series photometry using the Goodman Spectrograph on the 4.1-m Southern Astrophysical Research Telescope. Previous spectroscopic and photometric observations…

Solar and Stellar Astrophysics · Physics 2015-05-13 B. N Barlow , B. H. Dunlap , A. E. Lynas-Gray , J. C. Clemens

We announce the discovery of a new eclipsing hot subdwarf B + M dwarf binary, EC 10246-2707, and present multi-colour photometric and spectroscopic observations of this system. Similar to other HW Vir-type binaries, the light curve shows…

We present optical time series spectroscopy of the pulsating white dwarf star G29-38 taken at the Very Large Telescope (VLT). By measuring the variations in brightness, Doppler shift, and line shape of each spectrum, we explore the physics…

Astrophysics · Physics 2009-11-13 Susan E. Thompson , M. H. van Kerkwijk , J. C. Clemens

B-type stars are promising targets for asteroseismic modelling, since their frequency spectrum is relatively simple. We deduce and summarise observational constraints for the hybrid pulsator, HD50230, earlier reported to have deviations…

We have discovered both intermediate-order gravity mode and low-order pressure mode pulsation in the same star, HD 209295. It is therefore both a Gamma Doradus and a Delta Scuti star, which makes it the first pulsating star to be a member…

We report our discovery of an extremely rare, low mass, quadruple-lined spectroscopic binary BD-22 5866 (=NLTT 53279, integrated spectral type = M0 V), found during an ongoing search for the youngest M dwarfs in the solar neighborhood. From…

We report the discovery of the first variable extreme horizontal branch star in a globular cluster (omega Cen). The oscillation uncovered has a period of 114 s and an amplitude of 32 mmags. A comparison between horizontal branch models and…

Astrophysics · Physics 2009-11-13 S. K. Randall , A. Calamida , G. Bono

We present the recent discovery of a new subdwarf B variable (sdBV), with an exceptionally low surface gravity. Our spectroscopy of J20136+0928 places it at Teff = 32100 +/- 500, log(g) = 5.15 +/- 0.10, and log(He/H) = -2.8 +/- 0.1. With a…

HD 202850 is a late B-type supergiant. It is known that photospheric lines of such stars vary. Due to macroturbulence the lines are much wider than expected. Macroturbulence has been linked to stellar pulsations. It has been reported that…

Solar and Stellar Astrophysics · Physics 2014-03-07 Sanja Tomic , Michaela Kraus , Mary Oksala
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