Related papers: Outburst activity of symbiotic system AGDra

A report is made on the luminosity and pulse-period evolution of the Be binary X-ray pulsar, GX 304$-$1, during a series of outbursts from 2009 to 2013 observed by MAXI/GSC, RXTE/PCA, and Fermi/GBM. In total, twelve outbursts repeated by…

Symbiotic systems often include an asymptotic giant branch (AGB) star and a hot compact companion, such as a white dwarf, that are in close interaction. Due to the intense ultraviolet emission from the hot companion, the molecular content…

Red Giant Branch (RGB) stars are overwhelmingly observed to rotate very slowly compared to main-sequence stars, but a few percent of them show rapid rotation and high activity, often as a result of tidal synchronizationn or other angular…

Stellar activity cycles reveal continuous relaxation and induction of magnetic fields. The activity cycle is typically traced through the observation of cyclic variations in total brightness or Ca H&K emission flux of stars, as well as…

We present a timing and spectral analysis of the variable X-ray source 3A 1954+319. Our analysis is mainly based on an outburst serendipitously observed during INTEGRAL Key Program observations of the Cygnus region in 2008 fall and on the…

We describe observational evidence for a new kind of interacting-binary-star outburst that involves both an accretion instability and an increase in thermonuclear shell burning on the surface of an accreting white dwarf. We refer to this…

The star ASAS J174600-2321.3 was found to exhibit peculiar photometric variability (conspicuous brightening of about 4 magnitudes (V), fast luminosity declines, intrinsic pulsations). It was rejected as an RCB candidate in recent…

Multiwavelength observations are reported here of the Be/X-ray binary pulsar system GRO J1008-57. Over ten years worth of data are gathered together to show that the periodic X-ray outbursts are dependant on both the binary motion and the…

CCD photometric observations of the dwarf nova V1006 Cyg were carried out in 2015-2017 with 11 telescopes located at 7 observatories. They covered the 2015 superoutburst with rebrightening, five normal outbursts of ~4-day duration and one…

We present and analyze optical photometry and high resolution SALT spectra of the symbiotic recurrent nova V3890 Sgr at quiescence. The orbital period, P=747.6 days has been derived from both photometric and spectroscopic data. Our…

The modeling of UV and optical spectra emitted from the symbiotic system AG Draconis, adopting collision of the winds, predicts soft X-ray bremsstrahlung from nebulae downstream of the reverse shock with velocities > 150 km/s and…

White dwarfs with a F, G or K type companion represent the last common ancestor for a plethora of exotic systems throughout the galaxy, though to this point very few of them have been fully characterised in terms of orbital period and…

Accretion of mass onto a white dwarf (WD) in a binary system can lead to stellar explosions. If a WD accretes from stellar wind of a distant evolved giant in a symbiotic binary, it can undergo occasional outbursts in which it brightens by…

We present recent contemporaneous X-ray and optical observations of the Be/X-ray binary system A\,0535+26 with the \textit{Fermi}/Gamma-ray Burst Monitor (GBM) and several ground-based observatories. These new observations are put into the…

SDSS J080434.20+510349.2 is the WZ type binary that displayed rare outburst in 2006 (Pavlenko et al., 2007). During the long-lasting tail of the late stage of the outburst binary shown the two-humped or four-humped profile of the orbital…

During the British Astronomical Association (BAA) 2022 campaign, 27436 photometric observations of the dwarf nova (DN) CG Draconis were made, with 106 eclipses recorded. This work summarizes the new data available and provides updated…

R Aqr is a symbiotic binary system consisting of a Mira variable with a pulsation period of 387 days and a hot companion which is presumably a white dwarf with an accretion disk. This binary system is the source of a prominent bipolar…

We report the discovery of a one magnitude increase in the optical brightness of the 59.63 minute orbital period AM CVn binary SDSS J113732.32+405458.3. Public $g$, $r$, and $i$ band data from the Zwicky Transient Facility (ZTF) exhibit a…

The multi-site photometric observations of MN Dra were made over 77 nights in August-November, 2009. The total exposure was 433 hours. During this time the binary underwent two superoutbursts and five normal outbursts. During the course of…

We report on multi-wavelength observations during quiescence and of the first detected outburst of the ~60 min orbital period AM CVn SDSS J113732+405458. Using X-ray and UV observations we determined an upper limit duration of the event of…