Related papers: FBS 0107-082: A Symbiotic Binary in a Rare Prolong…
We report on observations of the {\gamma}-ray and optical photopolarimetric behavior of the radio-loud, narrow line type-1 Seyfert galaxy PMN J0948+0022 over a twenty seven month period. As this object has recently been suggested to…
We present the detection of a rare case of dramatic strengthening in the UV absorption profiles in the spectrum of the quasar J115122.14+020426.3 between observations ~2.86 years apart in the quasar rest-frame. A 2001 spectrum from the…
Despite being bright ($V=12$) and nearby ($d=212$ pc) ASAS J071404+7004.3 has only recently been identified as a nova-like cataclysmic variable. We present time-resolved optical spectroscopy obtained at the Isaac Newton Telescope together…
We present optical photometric and spectroscopic observations of the likely stellar counterpart to the unassociated \emph{Fermi}-Large Area Telescope (LAT) $\gamma$-ray source 2FGL J0846.0+2820, selected for study based on positional…
We present deep spatially-resolved optical spectroscopy of the NW companion galaxy of the quasar BR 1202-0725 at $z=4.7$. Its rest-frame UV spectrum shows star-forming activity in the nuclear region. The Ly$\alpha$ emission profile is…
We report on FORS2 optical spectroscopy of the black hole X-ray binary V404 Cygni, performed at the very beginning of its 2015 outburst decay, complemented by quasi-simultaneous $Swift$ X-ray and ultra-violet as well as REM near-infrared…
We describe the first results from a program of multi-wavelength monitoring of symbiotic binary stars in outburst. The prototypical symbiotic star Z Andromedae was observed extensively at radio, optical, far-UV, and X-ray wavelengths during…
As a class of compact binaries with large binding energy, cataclysmic variables formed through close encounters play an important role in the dynamical evolution of globular clusters. As part of a systematic search for CVs undergoing dwarf…
We report the discovery of a new bright (V$\sim$12.6) cataclysmic variable star identified with the ROSAT X-ray source RX J1643.7+3402. Spectroscopic and photometric observations show it to be a novalike variable sharing some of the…
We present the results of photometric observations of SDSS J080434.20+510349.2 in its low state and during an outburst and spectroscopy during the outburst. We found such peculiarities as a long-term outburst with amplitude probably not…
We present high speed photometric observations of 20 faint cataclysmic variables, selected from the Sloan Digital Sky Survey and Catalina catalogues. Measurements are given of 15 new directly measured orbital periods, including four…
FS CMa type stars are a group of Galactic objects with the B[e] phenomenon. They exhibit strong emission-line spectra and infrared excesses, which are most likely due to recently formed circumstellar dust. The group content and…
Our observations of the first reported outburst of SDSS J081321.91+452809.4 during 2008 April show that this cataclysmic variable is a dwarf nova. The outburst amplitude was at least 3.1 magnitudes and the outburst appears to have been…
The twelve-year light curve of the nova-like cataclysmic variable HS 0506+7725 between 2006 April and 2018 November is presented. This shows that the star spends most of the time in a normal state at magnitude ~14.7, but multiple excursions…
We present photometric and spectral monitoring of the symbiotic system HM Sge, which consists of a Mira variable with a dust shell and a hot white dwarf ionizing the surrounding gaseous nebula. The system underwent a nova-like outburst in…
The 2008 optical transient in NGC 300 is one of a growing class of intermediate-luminosity transients that brighten several orders of magnitude from a previously optically obscured state. The origin of their eruptions is not understood. Our…
High and low resolution $IUE$ spectra of V838 Her in the early outburst stages exhibit a strong absorption feature shortward of $\lambda$3130. We discuss the nature of this spectral feature and provide convincing evidence that it…
We report the discovery of a new cataclysmic variable in MASTER database which is identical to the faint ROSAT X-ray source 1RXS J015017.0+375614. The object was observed in outbursts to 14.9m on 2012 Nov. 28 and to 14.3m on 2013 Jan. 07,…
We report on observations of the optical variability of the radio-loud, narrow-line Seyfert 1 galaxy J0948+0022 on time scales ranging from minutes to years. Implications regarding recent suggestions that the object may constitute a…
We report the discovery of a large amplitude (factor of $\sim$100) X-ray transient (IC 10 X-2, CXOU J002020.99+591758.6) in the nearby dwarf starburst galaxy IC10 during our Chandra monitoring project. Based on the X-ray timing and spectral…