Related papers: Nova Scorpius 1437 A.D. is now a dwarf nova, age-d…

We report on the observations of five recent galactic classical novae, performed with XMM-Newton. Some of them show emission in the whole range from 0.2 to 8.0 keV, up to 3 years after the explosion. Nova Oph 1998 shows clear evidence of…

We present high-speed optical photometric observations, spanning ~2 years, of the recently-discovered white dwarf pulsar AR Scorpii. The amplitudes of the orbital, spin and beat modulations appear to be remarkably stable and repeatable over…

We report the discovery of a previously unknown eruption of the recurrent nova M31N 2017-01e that took place on 11 January 2012. The earlier eruption was detected by Pan-STARRS and occurred 1847 days (5.06 yr) prior to the eruption on 31…

We have observed the fast nova V5583 Sagittarii with five B, V, y, R_C, and I_C bands, and found that these multi-band light curves are almost identical with those of V382 Vel 1999 until at least 100 days after outburst. A supersoft X-ray…

V4643 Sagittarii or Nova Sagittarii 2001 was discovered in outburst at 7.7 mag. on 2001 February 24. Here, we present near-infrared results of this fast classical nova obtained in the early decline phase in 2001 March followed by optical…

The metallicity of a star affects its evolution in a variety of ways, changing stellar radii, luminosities, lifetimes, and remnant properties. In this work, we use the population synthesis code binary_c to study how metallicity affects…

We report the discovery of three low-mass double-lined eclipsing binaries in the pre-main sequence Upper Scorpius association, revealed by $K2$ photometric monitoring of the region over $\sim$ 78 days. The orbital periods of all three…

Only one certain classical nova eruption has ever been detected inside a globular cluster - nova 1860 A.D. (T Sco) in M80. During a survey of M87 we have detected an erupting star coincident (to within 0.08 pixels) with a globular cluster…

SDSS J080434.20+510349.2 is the 13th dwarf nova containing a pulsating white dwarf. Among the accreting pulsators that have experienced a dwarf novae outburst, SDSS J0804 has the most dramatic history of events within a short time scale:…

Classical novae occur on the surface of an accreting white dwarf in a binary system. After ejection of a fraction of the envelope and when the expanding shell becomes optically thin to X-rays, a bright source of supersoft X-rays arises,…

We report photometry and spectroscopy of the evolution of Nova Sagittarii 1994 #1 (V4332 Sagittarii) during outburst. We compare the photometric and spectral evolution of this outburst to known classes of outbursts -- including classical…

We present simulations of dwarf nova outbursts taking into account realistic variations of the mass loss rate from the secondary. The mass transfer variation has been derived from 20 years of visual monitoring and from X-ray observations…

The luminosity, light curve, post--maximum spectrum, and lack of a progenitor on deep pre-outburst images suggest that SN 2010U was a luminous, fast nova. Its outburst magnitude is consistent with that for a fast nova using the Maximum…

We report here a new result extracted from the Fermi Large Area Telescope observation of the classical nova ASASSN-16ma that exhibits coherent gamma-ray pulsations at 544.84(7) seconds during its outburst in 2016. Considering the number of…

We present extensive spectroscopy and photometry of the dwarf nova V630 Cassiopeiae. A late-type (K4-5) absorption spectrum is easily detectable, from which we derive the orbital parameters. We find a spectroscopic period of P=2.56387 +/-…

The existence of a vast nova shell surrounding the prototypical dwarf nova Z Camelopardalis (Z Cam) proves that some old novae undergo metamorphosis to appear as dwarf novae thousands of years after a nova eruption. The expansion rates of…

We report a photometric study of the WZ Sagittae-type dwarf nova PQ Andromedae. The light curve shows strong (0.05 mag full amplitude) signals with periods of 1263(1) and 634(1) s, and a likely double-humped signal with P=80.6(2) min. We…

The recurrent symbiotic nova V745 Sco exploded on 2014 February 6 and was observed on February 22 and 23 by the Chandra X-ray Observatory Transmission Grating Spectrometers. By that time the supersoft source phase had already ended and…

The supernova explosion of 1054 AD, which originated the Crab Nebula and Pulsar, is probably the astronomical event which has been most deeply studied by means of historical sources. However, many mysteries and inconsistencies, both among…

We have detected 2 circumbinary planets around the close binary system NN Serpentis using the orbital time delay effect measured via the sharp eclipses of the white dwarf primary. The present pre-cataclysmic binary was formed when the…