相关论文: Outbursts of EX Hydrae Revisited
We report the detection of a large amplitude MIR outburst in the white dwarf (WD) 0145+234 in the NEOWISE Survey data. The source had a stable MIR flux before 2018, and was brightened by about 1.0 magnitude in the W1 and W2 bands within…
We present our spectroscopic observations of V455 Andromedae during the 2007 superoutburst. Our observations cover this superoutburst from around the optical peak of the outburst to the post-superoutburst stage. During the early superhump…
(Abridged) We report on the analysis of high-speed photometry of the dwarf nova EX Dra through its outburst cycle with eclipse mapping techniques. The eclipse maps show evidence of the formation of a one-armed spiral structure in the disc…
Dwarf nova outbursts result from enhanced mass transport through the accretion disc of a cataclysmic variable system. We assess the question of whether these outbursts are caused by an enhanced mass transfer from the late-type main sequence…
We study mass ejection from accretion disks formed in the merger of a white dwarf with a neutron star or black hole. These disks are mostly radiatively-inefficient and support nuclear fusion reactions, with ensuing outflows and…
We present a compilation of spectroscopic observations of the sgB[e] star CI Cam. This includes data from before, during, and after its 1998 outburst. The object shows a rich emission line spectrum originating from circumstellar material,…
In early 2008, the young low-mass star EX Lupi, the prototype of the EXor class of eruptive variables, optically brightened by over five magnitudes for a period of 7 months. The previous time a change of such amplitude had been observed in…
We present an analysis of HST STIS data of VW Hyi acquired ~ 14 days after a superoutburst. At the time of the observation the system appears to be going into outburst with the longest wavelengths increasing in flux by a factor of 5, while…
Previous theoretical studies indicate that the inner disk in dwarf novae evaporates into a high-temperature, optically thin, and geometrically thick accretion flow during quiescence, with the inner edge moving toward the white dwarf at the…
The outbursts of black hole X-ray transients can be understood as caused by a limit cycle instability in the accretion disk, similar to dwarf nova outbursts. For adequately low mass overflow rates from the companion star long outburst…
We present the X-ray light curves of the last two outbursts --2014 & 2016-- of the well known accreting millisecond X-ray pulsar (AMXP) Aquila X-1 using the monitor of all sky X-ray image (MAXI) observations in the $2-20$ keV band. After…
EX Lupi, a low-mass young stellar object, went into an accretion-driven outburst in March of 2022. The outburst caused a sudden phase change of ~ 112$^{\circ}$ $\pm$ 5$^{\circ}$ in periodically oscillating multiband lightcurves. Our high…
We present spectroscopy and photometry of the LMC supersoft binary system RX~J0513.9-6951. We derive a refined spectroscopic period of P$=0.761\pm0.004$~d, which is consistent with the value obtained from long term photometric monitoring…
Haro 2 is a blue compact dwarf galaxy and the closest (at 21Mpc) known $Ly\alpha$ emitter. UV and optical observations have found Haro 2 to be immersed in shells of partly ionized gas expanding at $\sim200$km/s. Observations of CO(2-1)…
Analysis of observations of the SU UMa-type dwarf nova, CP Dra, between February 2001 and April 2009 has revealed 15 outbursts, at least eight of which were superoutbursts. The supercycle length is 230+/-56 d. We report photometry of the…
We present a model for the high-low state transition of the X-Ray Nova GS 1124-68 (Nova Muscae 1991) observed by Ginga. The model consists of an advection-dominated accretion flow (ADAF) near the central black hole surrounded by a thin…
Using the disc instability model for dwarf novae and soft X-ray transients, we investigate the stability of accretion discs in long-period binary systems. We simulate outbursts due to this thermal-viscous instability for two symbiotic…
During the 1996/1997 outburst of the X-ray transient GRO J1655-40 the Wide Field Cameras onboard BeppoSAX observed the system with nearly continuous coverage during some stages of this outburst. On two occasions we find clear evidence for…
We show that if the dwarf-nova disc instability model includes the effects of heating by stream impact and tidal torque dissipation in the outer disc, the calculated properties of dwarf-nova outbursts change considerably, and several…
EX Lupi is the prototype for a class of young, pre-main sequence stars which are observed to undergo irregular, presumably accretion-generated, optical outbursts that result in a several magnitude rise of the optical flux. EX Lupi was…