Search Publications
δ Scuti pulsations in the bright Pleiades eclipsing binary HD 23642
Southworth, John; Murphy, S. J.; Pavlovski, K.
We announce the discovery of pulsations in HD 23642, the only bright eclipsing system in the Pleiades, based on light curves from the Transiting Exoplanet Survey Satellite (TESS). We measure 46 pulsation frequencies and attribute them to δ Scuti pulsations in the secondary component. We find four ℓ = 1 doublets, three of which have frequency split…
An eclipsing 47 min double white dwarf binary at 400 pc
Kepler, S. O.; Hermes, J. J.; Dhillon, V. S. +20 more
We present the discovery of the eclipsing double white dwarf (WD) binary WDJ 022558.21-692025.38 that has an orbital period of 47.19 min. Following identification with the Transiting Exoplanet Survey Satellite, we obtained time series ground based spectroscopy and high-speed multiband ULTRACAM photometry which indicate a primary DA WD of mass $0.4…
Hot white dwarfs and pre-white dwarfs discovered with SALT
Werner, K.; Jeffery, C. S.; Miszalski, B. +3 more
The Southern African Large Telescope survey of helium-rich hot subdwarfs aims to explore evolutionary pathways among groups of highly evolved stars. The selection criteria mean that several hot white dwarfs and related objects have also been included. This paper reports the discovery and analysis of eight new very hot white dwarf and pre-white dwa…
A systematic validation of hot Neptunes in TESS data
Bieryla, Allyson; Howell, Steve B.; Ziegler, Carl +26 more
We statistically validated a sample of hot Neptune candidates applying a two-step vetting technique using DAVE and TRICERATOPS. We performed a systematic validation of 250 transit-like events in the Transiting Exoplanet Survey Satellite archive in the parameter region defined by $P\le 4\, \text{d}$ and $3\, {\rm R}_{\oplus }\le R \le 5\, {\rm R}_{…
Comprehensive coverage of particle acceleration and kinetic feedback from the stellar mass black hole V404 Cygni
Motta, S. E.; Miller-Jones, J. C. A.; Williams, D. R. A. +8 more
We present analysis of comprehensive radio observations of the black hole V404 Cyg during its 2015 outburst. These data represent the best ever coverage of jet production and particle acceleration from any black hole. We report for the first time a clear and near-linear flux-rms correlation in the radio flux densities. Investigation of individual …
Sub-second infrared variability from the archetypal accreting neutron star 4U 1728-34
Stella, L.; Díaz Trigo, M.; Altamirano, D. +23 more
We report on the first simultaneous high-time resolution X-ray and infrared (IR) observations of a neutron star low mass X-ray binary in its hard state. We performed $\approx 2\,$ h of simultaneous observations of 4U 1728-34 using HAWK-I@VLT, XMM-Newton, and NuSTAR. The source displayed significant X-ray and IR variability down to sub-second time-…
An ALMA Survey of M-dwarfs in the Beta Pictoris Moving Group with two new debris disc detections
Kral, Quentin; Wyatt, Mark C.; Lestrade, Jean-François +4 more
Previous surveys in the far-infrared have found very few, if any, M-dwarf debris discs among their samples. It has been questioned whether M-dwarf discs are simply less common than earlier types, or whether the low detection rate derives from the wavelengths and sensitivities available to those studies. The highly sensitive, long-wavelength Atacam…
H I filaments as potential compass needles? Comparing the magnetic field structure of the Small Magellanic Cloud to the orientation of GASKAP-H I filaments
Lee, M. -Y.; McClure-Griffiths, N. M.; van Loon, J. Th +12 more
High-spatial-resolution H I observations have led to the realization that the nearby (within few hundreds of parsecs) Galactic atomic filamentary structures are aligned with the ambient magnetic field. Enabled by the high-quality data from the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope for the Galactic ASKAP H I survey, w…
A new redback pulsar candidate 4FGL J2054.2+6904
Karpova, A. V.; Gilfanov, M. R.; Zyuzin, D. A. +1 more
The Fermi catalogue contains about 2000 unassociated γ-ray sources. Some of them were recently identified as pulsars, including so-called redbacks and black widows, which are millisecond pulsars in tight binary systems with non- and partially-degenerate low-mass stellar companions irradiated by the pulsar wind. We study a likely optical and X-ray …
Mapping the kinematic parameters of the Galaxy from the Gaia EDR3 red giants and sub-giants
Akhmetov, V. S.; Fedorov, P. N.; Velichko, A. B. +2 more
We present the results of a kinematic analysis of red giants and sub-giants whose centroids are in the plane of our Galaxy. For this, the positions, parallaxes, proper motions, and radial velocities of these stars from the Gaia EDR3 catalogue were used. We applied two approaches to obtain kinematic parameters. The first approach - solving the equa…