Related papers: SN 2015bh: NGC 2770's 4th supernova or a luminous …

We present Hubble Space Telescope imaging confirming the optical disappearance of the failed supernova (SN) candidate identified by Gerke et al. (2015). This $\sim 25~M_{\odot}$ red supergiant experienced a weak $\sim 10^{6}~L_{\odot}$…

We present an optical spectropolarimetric observation of the unique Type Ib supernova (SN) 2005bf at 8 days after the second maximum. The data, combined with the polarization spectrum taken at 6 days before the second maximum (Maund et al.…

We report on X-ray spectral evolution of the nearby Type IIn supernova (SN) 2005ip, based on Chandra and Swift observations covering from ~1 to 6 years after the explosion. X-ray spectra in all epochs are well fitted by a thermal emission…

We discuss, in the context of the single star scenario, the nature of the progenitors of Red Supergiants (RSG), of Luminous Blue Variables (LBV) and of Wolf-Rayet (WR) stars. These three different populations correspond to evolved phases of…

We present very early, high-cadence photometric observations of the nearby Type Ia SN 2017cbv. The light curve is unique in that it has a blue bump during the first five days of observations in the U, B, and g bands, which is clearly…

Type IIb Supernova (SN) 2011dh, with conclusive detection of an unprecedented Yellow Supergiant (YSG) progenitor, provides an excellent opportunity to deepen our understanding on the massive star evolution in the final centuries toward the…

In this letter, we present recent observations from the Hubble Space Telescope of the interacting transient, SN 2016jbu, at +5 years. We find no evidence for any additional outburst from SN 2016jbu, and the optical source has now faded…

It remains unclear whether massive star evolution is facilitated by mass loss through stellar winds only, or whether episodic mass loss during an eruptive luminous blue variable (LBV) phase is also significant. LBVs exhibit unique…

Ultraviolet, optical, and near-infrared photometry and optical spectroscopy of the broad-lined Type Ic supernova (SN) 2009bb are presented, following the flux evolution from -10 to +285 days past B-band maximum. Thanks to the very early…

We present spectroscopic and photometric observations of the emission-line star MWC 930 (V446 Sct) during its long-term optical brightening in 2006--2013. Based on our earlier data we suggested that the object has features found in Luminous…

So far the highly unstable phase of luminous blue variables (LBVs) has not been understood well. It is still uncertain why and which massive stars enter this phase. Investigating the variabilities by looking for a possible regular or even…

The most massive evolved stars (above 50 M_sun) undergo a phase of extreme mass loss in which their evolution is reversed from a redward to a blueward motion in the HRD. In this phase the stars are known as Luminous Blue Variables (LBVs)…

We present photometry and spectroscopy of the suspected cataclysmic variable (CV) Lanning 386. We confirm that it is a CV, and observe deep eclipses, from which we determine the orbital period Porb to be 0.1640517 +- 0.0000001 d (= 3.94 h).…

We present photometric and spectroscopic observations of SN Hunt 248, a new supernova (SN) impostor in NGC 5806, which began a multi-stage outburst in 2014 May. The initial '2014a' discovery brightening exhibited an absolute magnitude of…

The nature of the progenitor star (or system) for the Type IIn supernova (SN) subclass remains uncertain. While there are direct imaging constraints on the progenitors of at least four Type IIn supernovae, one of them being SN 2010jl,…

The nature of SN 1961V has been uncertain. Its peculiar optical light curve and slow expansion velocity are similar to those of super-outbursts of luminous blue variables (LBVs), but its nonthermal radio spectral index and declining radio…

Supernova (SN) 2008D/XRT 080109 is considered to be the only direct detection of a shock breakout from a regular SN to date. While a breakout interpretation was favored by several papers, inconsistencies remain between the observations and…

We present extensive optical observations of the normal Type Ic supernova (SN) 2007gr, spanning from about one week before maximum light to more than one year thereafter. The optical light and color curves of SN 2007gr are very similar to…

Van Marle et al. (2005) showed that circumstellar absorption lines in early Type Ib/c supernova and gamma-ray burst afterglow spectra may reveal the progenitor evolution of the exploding Wolf-Rayet star. While the quoted paper deals with…

We present photometric and spectroscopic analysis of the peculiar core-collapse SN 2013gc, spanning seven years of observations. The light curve shows an early maximum followed by a fast decline and a phase of almost constant luminosity. At…