Related papers: V4332 Sgr in 'Quiescence'

The eruptive variable V838 Monocerotis gained notoriety in 2002 when it brightened nine magnitudes in a series of three outbursts and then rapidly evolved into an extremely cool supergiant. We present optical, near-IR, and mid-IR…

We present new radio observations of the supernova SN 1979C made with the VLA at 20, 6, 3.6, and 2 cm from 1991 July to 1998 October, which extend our previously published observations (Weiler et al.1986, 1991), beginning 8 days after…

We report on time series of CCD photometry of V4140 Sgr between 1991 and 2001. The analysis reveals that the object was in the decline from an outburst in 1992 and again in outburst in 2001. The historical light curve collected by amateur…

As one of the closest supernovae (SNe) in the last decade, SN 2023ixf is an unprecedented target to investigate the progenitor star that exploded. However, there is still significant uncertainty in the reported progenitor properties. In…

The bright, nearby, recently discovered supernova SN2010jl is a member of the rare class of relatively luminous Type~IIn events. Here we report archival HST observations of its host galaxy UGC5189A taken roughly 10yr prior to explosion, as…

The Soft Gamma Repeater SGR 1900+14 entered a remarkable phase of activity during the summer of 1998. This activity peaked on August 27, 1998 when a giant periodic gamma-ray flare resembling the famous March 5, 1979 event from SGR 0526-66…

This study sums up a major part of the red giant V449 Cygni measurements for the years 1974 through 2022, obtained by visual and CCD GEOS observers, the Unione Astrofili Italiani, and various automatized telescopes. It appears that the…

We present spectroscopic and photometric observations of the peculiar Type II supernova (SN) 1998A. The light curves and spectra closely resemble those of SN 1987A, suggesting that the SN 1998A progenitor exploded when it was a compact blue…

Since the discovery of SN (supernova) 1987A, the number of Type II-peculiar SNe has grown, revealing a rich diversity in photometric and spectroscopic properties. In this study, using a single 15Msun low-metallicity progenitor that dies as…

CCD UBVRi photometry of the final helium flash object V4334 Sgr (Sakurai's Object), carried out during 1997 - 1999, is presented, and the light curve from its pre-discovery rise to the dust obscuration phase is constructed. The optical…

Understanding the nature of the instabilities of LBVs is important to understand the late evolutionary stages of very massive stars. We investigate the long term, S Dor-type variability of the luminous blue variable GR290 (Romano's star) in…

Observational evidence points to a red supergiant (RSG) progenitor for SN 2023ixf. The progenitor candidate has been detected in archival images at wavelengths (>0.6 micron) where RSGs typically emit profusely. This object is distinctly…

We revisit a notable AGN known as `Sharov21', seen to undergo a dramatic outburst in 1992, brightening by a factor of thirty over a period of approximately one year. A simple microlensing model fit to the event lightcurve provides a…

In 2002, V838 Monocerotis (V838 Mon) erupted in a red novae event which has been interpreted to be a stellar merger. Soon after reaching peak luminosity, it began to cool, and its spectrum evolved to later spectral types. Dust was also…

During the last two years we have used the Palomar Testbed Interferometer to observe several explosive variable stars, including V838 Monocerotis, V1663 Aquilae and recently RS Ophiuchi. We observed V838 Monocerotis approximately 34 months…

Many past studies of cosmological gamma-ray bursts (GRBs) have been limited because of the large distance to typical GRBs, resulting in faint afterglows. There has long been a recognition that a nearby GRB would shed light on the origin of…

We report on the progress of our on-going campaign to monitor the evolution of the VLTP objects V4334 Sgr and V605 Aql, as well as the suspected (V)LTP object CK Vul. V4334 Sgr does not show signs of increased ionization compared to our…

We have observed the fast nova V5583 Sagittarii with five B, V, y, R_C, and I_C bands, and found that these multi-band light curves are almost identical with those of V382 Vel 1999 until at least 100 days after outburst. A supersoft X-ray…

We report the serendipitous detection with the Rossi X-ray Timing Explorer of a long and peculiar X-ray burst whose localization is consistent with one known X-ray burster (GRS 1747-312) and which occurred when that source was otherwise…

We present pre-explosion optical and infrared (IR) imaging at the site of the type II supernova (SN II) 2023ixf in Messier 101 at 6.9 Mpc. We astrometrically registered a ground-based image of SN 2023ixf to archival Hubble Space Telescope…