Results 31 to 40 of about 441,928 (76)

Evolution of the Inner Accretion Flow and the White Dwarf Spin Pulse during the 2023 Outburst in GK Persei

The Astrophysical Journal
We present our X-ray and optical observations performed by NICER, NuSTAR, and Tomo-e Gozen during the 2023 outburst in the intermediate polar GK Persei. The X-ray spectrum consisted of three components: blackbody (BB) emission of several tens of eVs from
Mariko Kimura, Takayuki Hayashi, Yuuki Wada, Wataru Iwakiri, Shigeyuki Sako, Martina Veresvarska, Simone Scaringi, Noel Castro-Segura, Christian Knigge, Keith C. Gendreau, Zaven Arzoumanian   +10 more
doaj   +1 more source

Identification of DQ Serpentis and DT Serpentis as symbiotic stars

, 1997
Optical and near infrared spectroscopy of the stars DQ Ser and DT Ser are presented. DQ Ser shows a late-type continuum (M3 - M5) with emission lines of Balmer series, HeI, HeII, [OIII], OI and CaII triplet while DT Ser presents a earlier spectral type ...
F. Elizalde, M. G. Pereira, J. E. Steiner, D. Cieslinski   +3 more
core   +1 more source

Classifying Optical (Out)bursts in Cataclysmic Variables: The Distinct Observational Characteristics of Dwarf Novae, Micronovae, Stellar Flares, and Magnetic Gating

The Astrophysical Journal Letters
Cataclysmic variables can experience short optical brightenings, which are commonly attributed to phenomena such as dwarf novae outbursts, micronovae, donor flares, or magnetic gating bursts.
Krystian Iłkiewicz, Simone Scaringi, Martina Veresvarska, Domitilla De Martino, Colin Littlefield, Christian Knigge, John A. Paice, Anwesha Sahu   +7 more
doaj   +1 more source

Tracing the Orbital Motion of the Accreting White Dwarf in EX Hydrae with XRISM/Resolve

The Astrophysical Journal Letters
Measuring the masses of accreting white dwarfs (WDs) is crucial for understanding their evolution and the physics of accretion. High-resolution X-ray spectroscopy can trace the WD motion through Doppler shifts of emission lines formed close to the WD. We
Yuken Ohshiro, Yukikatsu Terada, Taichi Ichikawa, Yugo Motogami, Manabu Ishida, Koji Mukai, Masayoshi Nobukawa, Takayuki Hayashi, Mariko Kimura, Mai Takeo   +9 more
doaj   +1 more source

Stochastic Optical Variability and an rms–Flux Relation in the Intermediate Polar EP240309a

The Astrophysical Journal Supplement Series
Magnetic cataclysmic variables provide a natural laboratory for studying how accretion interacts with compact-object magnetospheres and generates stochastic variability.
S.-Y. Wu, Y.-D. Hu, I. Pérez-García, A. J. Castro-Tirado, M. Gritsevich, E. J. Fernández-García, M. D. Caballero-García, S. Guziy, G. García-Segura, R. Sánchez-Ramírez, C. D. Kilpatrick, C. R. Bom, L. Santana, A. Santos, P. J. Meintjes, H. J. van Heerden, A. Martín-Carrillo, L. Hanlon, A. Maury, D.-R. Xiong, B.-B. Zhang   +20 more
doaj   +1 more source

Discovery of Spin-pulse Correlated Magnetic Gating Bursts in the Long-period Intermediate Polar PBC J0801.2–4625

The Astrophysical Journal
We present the first discovery of small-amplitude (tens of millimagnitudes), short-duration (several hours) episodic brightenings in the Transiting Exoplanet Survey Satellite (TESS) light curve of the intermediate polar PBC J0801.2–4625 that are strongly
Vishal Joshi, Akash Sundriyal
doaj   +1 more source

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

, 2019
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, René, Althaus, Leandro Gabriel, Serenelli, Aldo Marcelo, Córsico, Alejandro Hugo, Scóccola, Claudia Graciela   +4 more
core  

New periodic variable stars coincident with ROSAT sources discovered using SuperWASP [PDF]

, 2007
We present optical lightcurves of 428 periodic variable stars coincident with ROSAT X-ray sources, detected using the first run of the SuperWASP photometric survey. Only 68 of these were previously recognised as periodic variables.
West, Richard G., Pollacco, Don, M. Gallaway, Street, R. A., Horne, K. (Keith), Kane, S. R., Christian, Damian Joseph, D. J. Christian (7603835), Hellier, Coel, Enoch, B., Nicholas, J. P., D. Pollacco (7603205), Irwin, J., Skillen, I., B. Enoch (7603838), West, R. G., R. A. Street, D. J. Christian, T. A. Lister (7603856), Irwin, Jonathan, K. Horne, Ryans, R., C. A. Haswell, D. M. Wilson (2428792), Wilson, D. M., Christian, D. J., J. P. Nicholas (7614728), S. R. Kane (7603853), S. R. Kane, Haswell, C. A., J. P. Nicholas, B. Enoch, C. Hellier (7603562), Norton, A. J., W. I. Clarkson, R. G. West, Lister, T. A., W. I. Clarkson (7612619), West, R .G., J. Irwin, Gallaway, M., T. A. Lister, Collier Cameron A (7614731), Pollacco, D., Parley, N., K. Horne (7603850), R. Ryans, C. A. Haswell (7603844), P. J. Wheatley (7590065), Hellier, C., Norton, Andrew J., R. Ryans (7612838), N. Parley, D. M. Wilson, Parley, N. R., I. Skillen (7601975), A. J. Norton (7603859), Horne, Keith Douglas, Horne, K. D., I. Skillen, R. G. West (7602272), A. Collier Cameron, J. Irwin (7606340), P. J. Wheatley, C. Hellier, R. A. Street (7603868), M. Gallaway (7614725), N. Parley (7603862), Cameron, Andrew Collier, Collier Cameron, A., Clarkson, W. I., Kane, Sharad R., Wheatley, P. J., A. J. Norton, Wilson, D. M. (David M.), D. Pollacco   +75 more
core   +1 more source

A study of U Aquarii and the nucleosynthesis of neutrons and S-process elements in evolved stars of low mass [PDF]

, 2014
The origin of the extreme hydrogen deficiency observed in the R Coronae Borealis (RCrB) stars remains poorly understood. A likely mechanism for producing this deficiency is one whereby the original hydrogen envelope of the star is engulfed and ...
Malaney, Robert A.
core   +2 more sources

The Origin of Soft X-rays in DQ Herculis

, 2002
DQ Herculis (Nova Herculis 1934) is a deeply eclipsing cataclysmic variable containing a magnetic white dwarf primary. The accretion disk is thought to block our line of sight to the white dwarf at all orbital phases due to its extreme inclination angle.
Still, M., Ringwald, F. A., White, Nicholas E., Mukai, K.   +3 more
core