Understanding sub-stellar populations using wide-field infrared surveys by Pinfield, D. J., Day-Jones, A. C., Burningham, B., Leggett, S. K., Beaumont, H., Tamura, M., Tinney, C. G., Liu, M. C., Homeier, Derek, Lodieu, N., Deacon, N. R., West, A. A., Huelamo, N., Dupuy, Trent J., Mortlock, D. J., Warren, S. J., Jones, H. R. A., Lucas, P. W., Ishi, M., McMahon, R. G., Hewett, P., Zapatero-Osorio, M. R., Martin, E. L., Venemans, B. P., Barrado, D., Zhang, Z., Morales-Calderon, M., West, A. A.

“…We also present some exciting results from our ongoing search for wide companions to this sample, that has so far revealed an M4-T8.5 binary system at ∼12 parsecs and also the first ever Tdwarf-white dwarf binary system. The T dwarfs in these binaries have their properties constrained by the primary object and are thus benchmark objects that are already testing the predictions of theoretical model atmospheres.…”
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The progenitors of type Ia supernovae: what can we learn from the circumstellar medium around single degenerate systems? by Booth, R, Richard Booth

“…<p>While the progenitors of Type Ia supernovae (SNe Ia) have long been thought to be thermonuclear explosions of white dwarf stars, what triggers the explosion are still a topic of debate. …”

Evolution of intermediate-mass X-ray binaries driven by magnetic braking of Ap/Bp stars: I. Ultracompact X-ray binaries by Chen, W, Podsiadlowski, P

“…It is generally believed that ultracompact X-ray binaries (UCXBs) evolved from binaries consisting of a neutron star accreting from a low-mass white dwarf(WD) or helium star where mass transfer is driven by gravitational radiation. …”

Global finite-energy solutions of the compressible Euler–Poisson equations for general pressure laws with large initial data of spherical symmetry by Chen, G-QG, Huang, F, Li, T, Wang, W, Wang, Y

“…We are concerned with global finite-energy solutions of the three-dimensional compressible Euler–Poisson equations with gravitational potential and general pressure law, especially including the constitutive equation of white dwarf stars. In this paper, we construct global finite-energy solutions of the Cauchy problem for the Euler– Poisson equations with large initial data of spherical symmetry as the inviscid limit of the solutions of the corresponding Cauchy problem for the compressible Navier– Stokes–Poisson equations. …”

A New 626 s Periodic X-ray Source in the Direction of the Galactic Center by Farrell, SA, Gosling, A, Webb, N, Barret, D, Rosen, SR, Sakano, M, Pancrazi, B

“…In the latter case, the modulation would be the spin period of a magnetic white dwarf. However, we find no evidence for absorption dips over the 626 s period, a low temperature black body spectral component, or Fe Kalpha emission lines. …”

Tidal disruption events and gravitational waves from intermediate-mass black holes in evolving globular clusters across space and time by Fragione, G, Leigh, NWC, Ginsburg, I, Kocsis, B

“…We compute the fraction of GCs still hosting intermediate-mass black holes (IMBHs) at a given redshift in early and late -type galaxies of different masses and sizes, and the corresponding rate of tidal disruption events (TDEs), both main-sequence (MS) and white dwarf (WD) stars. We find that the integrated TDE rate for the entire GC population can exceed the corresponding rate in a given galactic nucleus and that ~90% of the TDEs reside in GCs within a maximum radius of ~2–15 kpc from the host galaxy's center. …”

Bow-shocks, nova shells, disc winds and tilted discs: the Nova-Like V341 Ara Has It All by Castro Segura, N, Knigge, C, Acosta-Pulido, JA, Fender, R, Ponomareva, A, Williams, D

“…Their radial velocities suggest a high mass ratio, which in turn implies an unusually low white-dwarf mass. We also constrain the wind mass-loss rate of the system from the spatially resolved [O III] emission produced in the bow shock; this can be used to test and calibrate accretion disc wind models. …”

High-velocity features: a ubiquitous property of Type Ia Supernovae by Mazzali, P, Benetti, S, Altavilla, G, Blanc, G, Cappellaro, E, Elias-Rosa, N, Garavini, G, Goobar, A, Harutyunyan, A, Kotak, R, Leibundgut, B, Lundqvist, P, Mattila, S, Mendez, J, Nobili, S, Pain, R, Pastorello, A, Patat, F, Pignata, G, Podsiadlowski, P, Ruiz-Lapuente, P, Salvo, M, Schmidt, B, Sollerman, J, Stanishev, V, Stehle, M, Tout, C, Turatto, M, Hillebrandt, W

“…In this scenario, the high incidence of HVFs suggests that a thick disk and/or a high-density companion wind surrounds the exploding white dwarf, as may be the case in single degenerate systems. …”

Discovery of jets launched by classical nova eruptions by McLoughlin, D

“…Classical novae are stellar explosions that occur on the surface of white dwarfs in close binary systems. This thesis presents time-domain spec- troscopy of four recent eruptions in the Milky Way, carried out by the Global Jet Watch telescopes. …”

Simplified 3D GCM modelling of the irradiated brown dwarf WD 0137−349B by Lee, GKH, Casewell, SL, Chubb, KL, Hammond, M, Tan, X, Tsai, S-M, Pierrehumbert, RT

“…White dwarf–brown dwarf short-period binaries (Porb ≲ 2 h) are some of the most extreme irradiated atmospheric environments known. …”

New hot subdwarf variables from the EC survey by Kilkenny, D, Worters, H, Lynas-Gray, A

“…The sdOV star, EC 03089–6421 is found to have Teff = 52 000 ± 3000 K and log g = 5.6 ± 0.2, and with a mass ∼0.1 M could be a progenitor to an extremely low-mass white dwarf.…”

A statistical analysis of circumstellar material in Type Ia supernovae by Maguire, K, Sullivan, M, Patat, F, Gal-Yam, A, Hook, I, Dhawan, S, Howell, D, Mazzali, P, Nugent, P, Pan, Y, Podsiadlowski, P, Simon, J, Sternberg, A, Valenti, S, Baltay, C, Bersier, D, Blagorodnova, N, Chen, T, Ellman, N, Feindt, U, Förster, F, Fraser, M, González-Gaitán, S, Graham, M, Gutiérrez, C

“…The origin of this material is controversial, but the simplest explanation is that it results from previous mass loss in a system containing a white dwarf and a non-degenerate companion star. We present new single-epoch intermediate-resolution spectra of 17 low-redshift SNe Ia taken with XShooter on the ESO Very Large Telescope. …”

The high energy X-ray probe (HEX-P): Resolving the nature of Sgr A* flares, compact object binaries and diffuse X-ray emission in the Galactic center and beyond by Kaya Mori, Gabriele Ponti, Gabriele Ponti, Matteo Bachetti, Arash Bodaghee, Jonathan Grindlay, Jaesub Hong, Roman Krivonos, Ekaterina Kuznetsova, Shifra Mandel, Antonio Rodriguez, Giovanni Stel, Shuo Zhang, Tong Bao, Franz Bauer, Maïca Clavel, Benjamin Coughenour, Javier A. García, Julian Gerber, Brian Grefenstette, Amruta Jaodand, Bret Lehmer, Kristin Madsen, Melania Nynka, Peter Predehl, Ciro Salcedo, Daniel Stern, John Tomsick

“…HEX-P will be uniquely equipped to explore a variety of major topics in Galactic astrophysics, allowing us to 1) investigate broad-band properties of X-ray flares emitted from the supermassive black hole (BH) at Sgr A* and probe the associated particle acceleration and emission mechanisms; 2) identify hard X-ray sources detected by NuSTAR and determine X-ray point source populations in different regions and luminosity ranges; 3) determine the distribution of compact object binaries in the nuclear star cluster and the composition of the Galactic Ridge X-ray emission; 4) identify X-ray transients and measure fundamental parameters such as black hole spin; 5) find hidden pulsars in the Galactic Center; 6) search for BH–OB binaries and hard X-ray flares from young stellar objects in young massive clusters; 7) measure white dwarf (WD) masses of magnetic CVs to deepen our understanding of CV evolution and the origin of white dwarf magnetic fields; 8) explore primary particle accelerators in the GC in synergy with future TeV and neutrino observatories; 9) map out cosmic-ray distributions by observing non-thermal X-ray filaments; 10) explore past X-ray outbursts from Sgr A* through X-ray reflection components from giant molecular clouds.…”
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The Missing Symbiotic Stars: A Joint Analysis with Gaia, GALEX, and XMM-Newton Data by Xiao-jie Xu, Yong Shao, Xiang-Dong Li

“…The existence of a population of low-accretion-rate symbiotic stars (SySts), consisting of a giant star and a compact companion (usually a white dwarf), has been proposed recently. However, their population has not been fully understood. …”
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On Variation Mechanisms in Recurrent Nova IM Normae by R. E. Wilson

“…One way is as alternating eclipses of and by the disk that surrounds this cataclysmic variable’s accreting white dwarf, rather than purely a succession of disk-by-star eclipses. …”
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How does the carbon fusion reaction happen in stars? by X. Tang, B. Bucher, X. Fang, M. Notani, W. P. Tan, Y. Li, P. Mooney, H. Esbensen, C. L. Jiang, K. E. Rehm, C. J. Lin, E. Brown

“…Due to its compli-cated reaction mechanism, there is great uncertainty in the reaction rate which limits our understanding of vari-ous stellar objects, such as explosions on the surface of neutron stars, white dwarf (type Ia) supernovae, and massive stellar evolution. …”
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Hunting for Cold Exoplanets via Microlensing by Beaulieu, Jean-Philippe

“…Microlensing has discovered the first cold super-Earth, and the first Jupiter planet orbiting a white dwarf. It also detected a number of Earth, Super-Earth, Neptune, Saturn, Jupiter, super-Jupiter orbiting main sequence stars in the mass range $0.08-1 M_\odot $. …”
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Multifilter Time-series Observations of Eleven Blue Short-period ATLAS Variable Stars by C. Koen, V. Schaffenroth, A. Kniazev

“…In two of these latter systems, the primary stars are also sdB stars, while two have white-dwarf components. In all eight of these binaries the companion stars are probably M dwarfs. …”
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NICER Discovery of Millisecond X-Ray Pulsations and an Ultracompact Orbit in IGR J17494-3030 by Ng, Mason, Ray, Paul S, Bult, Peter, Chakrabarty, Deepto, Jaisawal, Gaurava K, Malacaria, Christian, Altamirano, Diego, Arzoumanian, Zaven, Gendreau, Keith C, Güver, Tolga, Kerr, Matthew, Strohmayer, Tod E, Wadiasingh, Zorawar, Wolff, Michael T

“…The mass donor is most likely a ≃0.02M⊙ finiteentropy white dwarf composed of He or C/O. The fractional rms pulsed amplitude is 7.4%, and the soft (1-3 keV) X-ray pulse profile contains a significant second harmonic. …”
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NICER Discovery of Millisecond X-Ray Pulsations and an Ultracompact Orbit in IGR J17494-3030 by Ng, Mason, Ray, Paul S., Bult, Peter, Chakrabarty, Deepto, Jaisawal, Gaurava K., Malacaria, Christian, Altamirano, Diego, Arzoumanian, Zaven, Gendreau, Keith C., Güver, Tolga, Kerr, Matthew, Strohmayer, Tod E., Wadiasingh, Zorawar, Wolff, Michael T.

“…The mass donor is most likely a ≃0.02M⊙ finiteentropy white dwarf composed of He or C/O. The fractional rms pulsed amplitude is 7.4%, and the soft (1-3 keV) X-ray pulse profile contains a significant second harmonic. …”
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