Related papers: How peculiar is the "peculiar variable" DZ Crucis …

T Pyx is a recurrent nova which has undergone eruptions on an almost regular basis every 20 years until reaching a long lasting quiescence between 1967 and 2011. We observed the long awaited 2011 explosion in the optical and near infrared…

Extremely luminous, red eruptive variables like RV in M31 are being suggested as exemplars of a new class of astrophysical object. Our greatly extended series of nova simulations shows that classical nova models can produce very red,…

L and M band observations of the nova-like variable V4332 Sgr are presented. Two significant results are obtained viz. the unusual detection of water ice at 3.05 microns and the fundamental band of 12CO at 4.67 microns in emission. The ice…

U Sco is a recurrent nova which showed recorded outbursts in 1863, 1906, 1936, 1979, 1987, and most recently in 1999. The eclipsing nature of the object was discovered after the 1987 outburst. We examined our time-series photographic…

Aiming to perform a study of the warm dust and gas in the luminous blue variable star G79.29+0.46 and its associated nebula, we present infrared Spitzer imaging and spectroscopy, and new CO J=2-->1 and 4-->3 maps obtained with the IRAM 30m…

We present optical observations of the enigmatic nova-like variable V4332 Sgr. The importance of this object should not be understated since it is considered to be the possible prototype of a new class of eruptive variables. These objects…

We present photometric and spectroscopic observations of SN 2000ch, an unusual and extremely luminous variable star located in the galaxy NGC 3432. The object was discovered on 2000 May 3.2 during the course of the Lick Observatory…

We present a new luminous star in M33 located in the nuclear region. The star shows strong FeII and [FeII] forest, hydrogen emissions in the spectrum, as well as nebular lines. TiII and SiII lines were detected in absorption, their radial…

A CCD photometric study of the dense galactic open cluster M37 is presented and discussed. The majority of the analysed data are time-series measurements obtained through an R_C filter. The observations were carried out on seven nights…

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…

The standard model for Type II supernovae explosion, confirmed by the detection of the neutrinos emitted during the supernova explosion, predicts the formation of a compact object, usually assumed to be a neutron star. However, the lack of…

We report an analysis of photometric behaviour of DI UMa, an extremely active dwarf nova. The observational campaign (completed in 2007) covers five superoutbursts and four normal outbursts. We examined principal parameters of the system to…

The search was performed for cataclysmic variable stars with outlying infrared magnitudes in USNO-B1.0 catalog. The selection was limited to objects in the Northern hemisphere with (B1-R1) < 1 and (R2-I) > 3.5. The search method is…

We present near-infrared spectroscopic and photometric observations of nova V5584 Sgr taken during the first 12 days following its discovery on Oct. 26.439 UT 2009. The evolution of the spectra is shown from the initial P Cygni phase to an…

Synoptic spectroscopic observations of the U Sco 2010 outburst from maximum light to quiescence as well as a contemporaneous X-ray observation are presented and analyzed. The X-ray spectrum 52 days after outburst indicates a hot source…

Despite decades-old predictions of the expected presence of dozens of cataclysmic variables in the cores of globular clusters, the number of irrefutable, out-bursting candidates is still barely a handful. Using multi-wavelength, multi-epoch…

We present near-infrared spectroscopic and photometric observations of the nova V5579 Sgr during the maximum and early decline phase. The spectra follow the evolution of the nova from peak brightness when the lines had strong P Cygni…

BZ UMa is a cataclysmic variable star whose specific classification has eluded researchers since its discovery in 1968. It has outburst and spectral properties consistent with both U Gem class dwarf novae and intermediate polars. We present…

The upper main sequence stars CU Virginis is the most enigmatic object among magnetic chemically peculiar (mCP) stars. It is an unusually fast rotator showing strictly periodic light variations in all regions of the electromagnetic…

V4444 Sgr (Nova Sgr 1999) has been recently suggested to be a possible recurrent nova based on the detection of the preexisting dust, which may have been formed in a previous outburst. We examined this possibility using the available…