Related papers: The planet-hosting subdwarf B star V391 Pegasi is …

Among the competing evolution theories for subdwarf-B (sdB) stars is the binary evolution scenario. EC~20117-4014 (=V4640~Sgr) is a spectroscopic binary system consisting of a pulsating sdB star and a late F main-sequence companion…

The principal aim of this project is to determine the structural parameters of the rapidly pulsating subdwarf B star PG 0911+456 from asteroseismology. Our work forms part of an ongoing programme to constrain the internal characteristics of…

We present the discovery of nonradial pulsations in a hot subdwarf B star based on 30.5 days of nearly continuous time-series photometry using the \emph{Kepler} spacecraft. KIC 010139564 is found to be a short-period pulsator of the V361…

A review is presented on the properties, origin and evolutionary links of hot subluminous stars which are generally believed to be extreme Horizontal Branch stars or closely related objects. Amongst the field stars a large fraction of sdBs…

We present key sample results of a systematic survey of the pulsation properties of models of hot B subdwarfs. We use equilibrium structures taken from detailed evolutionary sequences of solar metallicity (Z = 0.02) supplemented by grids of…

We obtain time-series spectrophotometry observations at the VLT with the aim of partially identifying the dominant oscillation modes in the rapidly pulsating subdwarf B star EC 20338-1925 on the basis of monochromatic amplitude and phase…

In this paper we describe a new class of pulsating stars, the prototype of which is the bright, early, F-type dwarf, Gamma Doradus. These stars typically have between 1 and 5 periods ranging from 0.4 to 3 days with photometric amplitudes up…

We continue our program of single-site observations of pulsating subdwarf B (sdB) stars and present the results of extensive time series photometry of HS 0039+4302 and HS 0444+0458. Both were observed at MDM Observatory during the fall of…

We report the discovery of a long-period g-mode oscillation in the previously known short-period p-mode sdB pulsator HS 0702+6043. This makes this star an extraordinary object, unique as a member of the family of sdB pulsators, and one of…

We present results from the first two quarters of a survey to search for pulsations in compact stellar objects with the Kepler spacecraft. The survey sample and the various methods applied in its compilation are described, and spectroscopic…

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…

We report the detection of nonradial g-mode oscillations in the DA white dwarfs HS1039+4112 (B=15.9) and HE1429-0343 (B=15.8) from time-series photometry made at the Loiano 1.5 m telescope. The two stars were previously selected as probable…

Ground-based optical photometry of the counterparts of High-Mass X-ray Binaries (HMXBs) has revealed the presence of periodic modulations on timescales of ~0.3-0.5 d. More recent space-based observations Corot and TESS of OB and Be stars…

K2, the two-wheel mission of the Kepler space telescope, observed the pulsating subdwarf B star EQ Psc during engineering tests in 2014 February. In addition to a rich spectrum of g-mode pulsation frequencies, the observations demonstrate a…

Hot subdwarf B (sdB) stars are evolved, subluminous, helium-burning stars, most likely formed when red-giant stars lose their hydrogen envelope via interactions with close companions. They play an important role in our understanding of…

PSR J1744-3922 is a binary pulsar exhibiting highly variable pulsed radio emission. We report on a statistical multi-frequency study of the pulsed radio flux variability which suggests that this phenomenon is extrinsic to the pulsar and…

Hot subdwarf B stars (sdBs) are evolved, core helium-burning objects located on the extreme horizontal branch. Their formation history is still puzzling as the sdB progenitors must lose nearly all of their hydrogen envelope during the…

We analyse the pulsating behaviour of TIC 308396022 observed by the TESS mission. The star is a high-amplitude $\delta$ Sct star (HADS) that shows a very rich amplitude spectrum using the 3-yr light curve. Among these frequencies, the…

I present detailed analysis of the near infrared spectrum of HD 3651B, a faint, co-moving wide companion to the nearby planet-hosting star HD 3651. These data confirm the companion as a brown dwarf with spectral type T8, consistent with the…

Subdwarf B (sdB) stars are thought to be core helium burning stars with low mass hydrogen envelopes. In recent years it has become clear that many sdB stars lose their hydrogen through interaction with a binary companion and continue to…