Related papers: M31N 2007-11d: A Slowly-Rising, Luminous Nova in M…

The nova T Pyx was observed with high resolution spectroscopy (R ~ 65000) spectroscopy, beginning 1 day after discovery of the outburst and continuing through the last visibility of the star at the end of May 2011. The interstellar…

We present multi-band photometric and optical spectroscopic observations of SN2007ax, the faintest and reddest Type Ia supernova (SNIa) yet observed. With M_B = -15.9 and (B-V)max = 1.2, this SN is over half a magnitude fainter at maximum…

We report unfiltered photometry during the first confirmed superoutburst of the recently discovered dwarf nova, SDSS J073208.11+413008.7 and conclude that it is a member of the SU UMa family. At its brightest, the star was magnitude 15.7.…

The Type Ia supernova (SN Ia) 2013dy in NGC 7250 (d ~ 13.7 Mpc) was discovered by the Lick Observatory Supernova Search. Combined with a prediscovery detection by the Italian Supernova Search Project, we are able to constrain the…

We present observations of the Type Ic supernova (SN Ic) 2011bm spanning a period of about one year. The data establish that SN 2011bm is a spectroscopically normal SN Ic with moderately low ejecta velocities and with a very slow…

We present optical photometry and spectra for the Type Ia supernova (SN Ia) 2007gi in the nearby galaxy NGC 4036. SN 2007gi is characterized by extremely high-velocity (HV) features of the intermediate-mass elements (Si, Ca, and S), with…

Nova Her 2021 (V1674 Her), which erupted on 2021 June 12, reached naked-eye brightness and has been detected from radio to $\gamma$-rays. An extremely fast optical decline of 2 magnitudes in 1.2 days and strong Ne lines imply a high-mass…

We performed extensive, multi-wavelength observations of the prototypical symbiotic star Z Andromedae between 2000 and 2003, during a large eruption. The rise to optical maximum occurred in three distinct stages. During the first stage, the…

M31-RV was an extraordinarily luminous (~10^6 Lsun) eruptive variable, displaying very cool temperatures (roughly 1000 Kelvins) as it faded. The photometric behavior of M31-RV (and several other very red novae, i.e. luminous eruptive red…

We study the spectroscopic evolution of superluminous supernovae (SLSNe) later than 100 days after maximum light. We present new data for Gaia16apd and SN2017egm, and analyse these with a larger sample comprising 41 spectra of 12 events.…

The reported positions of 964 suspected nova eruptions in M31 recorded through the end of calendar year 2013 have been compared in order to identify recurrent nova candidates. To pass the initial screen and qualify as a recurrent nova…

We present observations of SN 2015bn (= PS15ae = CSS141223-113342+004332 = MLS150211-113342+004333), a Type I superluminous supernova (SLSN) at redshift $z=0.1136$. As well as being one of the closest SLSNe I yet discovered, it is…

Classical novae (CNe) have recently been reported to represent the major class of supersoft X-ray sources (SSSs) in the central area of our neighbouring galaxy M 31. This paper presents a review of results from recent X-ray observations of…

We present BVRI photometry of supernova 2011fe in M101 from 2.9 to 182 days after the explosion. The light curves and color evolution show that SN 2011fe belongs to the "normal" subset of type Ia supernovae, with $\Delta m_{15}(B) = 1.21…

We present the results of a study of the variability of X-ray sources in the central 30' of the nearby Andromeda Galaxy (M31) based on XMM Performance Verification observations. Two observations of this field, with a total exposure time of…

We present a re-analysis of the H$\alpha$ and [OIII] flux data from the only comprehensive study of the luminosity evolution of nova shells, undertaken almost two decades ago. We use newly available distances and extinction values, and…

The Type~Ia supernova (SN~Ia) 2016coj in NGC 4125 (redshift $z=0.004523$) was discovered by the Lick Observatory Supernova Search 4.9 days after the fitted first-light time (FFLT; 11.1 days before $B$-band maximum). Our first detection…

The recurrent nova RS Oph underwent a new outburst on August 8, 2021, reaching a visible brightness of V = 4.8 mag. Observations of the 2021 outburst made with the high resolution UVES spectrograph at the Kueyen-UT2 telescope of ESO-VLT in…

We performed optical spectroscopy and photometry of SN 2006gy at late time, ~400 days after the explosion, with the Subaru/FOCAS in a good seeing condition. We found that the SN faded by ~3 mag from ~200 to ~400 days after the explosion…

We present the results of our photometric and spectroscopic follow-up of the intermediate-luminosity optical transient AT 2017jfs. At peak, the object reaches an absolute magnitude of Mg=-15.46+-0.15 mag and a bolometric luminosity of…