Results 21 to 30 of about 441,928 (76)

Probing the composition of sub-millisecond rotating compact stars by r-modes instability [PDF]

, 2012
We investigate the implications of the r-modes instability on the composition of a compact star rotating at a sub-millisecond period. In particular, the only viable astrophysical scenario for such an object, wich might present inside the Low Mass X-ray ...
Giuseppe Pagliara, Drago, Alessandro, Alessandro Drago, Pagliara, Giuseppe   +3 more
core   +1 more source

X-Ray Polarimetry of Accreting White Dwarfs: A Case Study of EX Hydrae

The Astrophysical Journal
We present the first first X-ray polarization measurements of a white dwarf (WD), the intermediate polar EX Hya. We measured significant polarization only in the 2–3 keV energy band with a polarization degree of 8% at a 3 σ significance.
Sean J. Gunderson, Swati Ravi, Herman L. Marshall, Dustin K. Swarm, Richard Ignace, Yael Nazé, David P. Huenemoerder, Pragati Pradhan   +7 more
doaj   +1 more source

DQ white-dwarf stars with low C abundance: Possible progenitors [PDF]

, 2006
Aims. The present paper focuses on the evolution of hydrogen-deficient white dwarfs with the aim of exploring the consequences of different initial envelope structures on the carbon abundances expected in helium-rich, carbon-contaminated DQ white dwarfs.
Rohrmann, Rene Daniel, R. D. Rohrmann, Rohrmann, René, Scoccola, Claudia Graciela, Althaus, Leandro Gabriel, C. G. Scóccola, A. H. Córsico, A. M. Serenelli, Serenelli, Aldo Marcelo, Corsico, Alejandro Hugo, Serenelli, A. M., L. G. Althaus   +11 more
core   +1 more source

A Multiwavelength Study of the 2025 Low State of the Intermediate Polar BG CMi

The Astrophysical Journal
We present multiwavelength observations of the first recorded low state of the intermediate polar BG CMi. Optical monitoring of the source by members of the American Association of Variable Star Observers reveals a decrease of ∼0.5 mag that lasted ∼50 ...
A. W. Shaw, K. Mukai, C. O. Heinke, C. G. Nixon, D. A. H. Buckley, P. A Dubovský, F.-J. Hambsch, J. Hilburn, K. Petrík, R. M. Plotkin, S. B. Potter, N. Rawat, T. Shahbaz, S. Dufoer, S. Dvorak, D. Messier, G. Myers, P. Nelson, R. Sabo, J. Ulowetz, T. Vanmunster   +20 more
doaj   +1 more source

Indirect imaging of AM Herculis-stars [PDF]

, 2005
AM Herculis stars (or 'polars') are close binaries consisting of a white dwarf with a strong magnetic field and a main sequence star (the 'secondary') which is losing mass to the white dwarf.
Staude, Andreas
core   +1 more source

Broadband X-Ray Observations of the Periodic Optical Source ZTF J185139.81+171430.3 and Its Identification as a Massive Intermediate Polar

The Astrophysical Journal
We present X-ray observations of the periodic optical source ZTF J185139.81+171430.3 (hereafter ZTF J1851) by the XMM-Newton, NICER, and NuSTAR telescopes.
Ren Deng, Kaya Mori, Eric Miao, Gabriel Bridges, Charles J. Hailey, David A. H. Buckley, Gavin Ramsay, Dan Jarvis   +7 more
doaj   +1 more source

A Broadband X-Ray Investigation of Fast-spinning Intermediate Polar CTCV J2056–3014

The Astrophysical Journal
We report on XMM-Newton, NuSTAR, and NICER X-ray observations of CTCV J2056–3014, a cataclysmic variable (CV) with one of the fastest-spinning white dwarfs (WDs) at P = 29.6 s.
Ciro Salcedo, Kaya Mori, Gabriel Bridges, Charles J. Hailey, David A. H. Buckley, Raimundo Lopes de Oliveira, Gavin Ramsay, Anke van Dyk   +7 more
doaj   +1 more source

HST Observations of the Cataclysmic Variable Propeller LAMOST J024048.51+195226.9

The Astrophysical Journal
We present Hubble Space Telescope (HST) far-UV spectra and light curves of the magnetic cataclysmic variable (CV) LAMOST J024048.51+195226.9 (J0240), the second known CV propeller. The five consecutive HST orbits span a full 7.34 hr binary orbital period.
Jordan Tweddale, Peter Garnavich, Colin Littlefield, Paula Szkody   +3 more
doaj   +1 more source

Wide binary stars in the Galactic field : a statistical approach [PDF]

, 2010
This thesis focuses on the statistical properties of wide binary (WB) star systems in the Galactic field. With projected separations larger than 200 AU and, consequently, having very low binding energies, WB are sensitive probes of the Galactic ...
Longhitano, Marco
core   +1 more source

X-Ray Spectroscopy Mass Constraints on V1674 Her: The Fastest Nova does not have a Near-Chandrasekhar White Dwarf

The Astrophysical Journal
V1674 Her (Nova Her 2021) is the fastest classical nova ever recorded, with an optical decline time of t _2  ∼ 1 day, typically interpreted as evidence for a white dwarf mass close to the Chandrasekhar limit.
Tekeba Olbemo, Manel Errando, Andrea Gokus   +2 more
doaj   +1 more source