Related papers: An unusually brilliant transient in the galaxy Mes…

We report on continued monitoring observations of the Galactic center carried out by the X-ray telescope aboard the Swift satellite in 2008 and 2009. This campaign revealed activity of the five known X-ray transients AX J1745.6-2901, CXOGC…

Very faint X-ray transients (VFXTs) are a group of X-ray binaries with low luminosities, the peak X-ray luminosities during their outbursts being only 10$^{34}$--10$^{36}$ erg\,s$^{-1}$. Using the $\gamma$-ray data obtained with the Large…

A new x-ray transient, designated XTE J1739-302, was discovered with the Proportional Counter Array (PCA) on the Rossi X-ray Timing Explorer (RXTE) in data from 12 August 1997. Although it was the brightest source in the Galactic Center…

A search of the first Data Release of the VISTA Variables in the Via Lactea (VVV) Survey discovered the exceptionally red transient VVV-WIT-01 ($H-K_s=5.2$). It peaked before March 2010, then faded by $\sim$9.5 mag over the following two…

Some classes of stars, including supernovae and novae, undergo explosive outbursts that eject stellar material into space. In 2002, the previously unknown variable star V838 Monocerotis brightened suddenly by a factor of about 10^4. Unlike…

Very fast novae are novae which evolve exceptionally quickly (on timescales of only days). Due to their rapid evolution, very fast novae are challenging to detect and study, especially at early times. Here we report the discovery, which was…

We present a multi-wavelenght study of the recently discovered Ultraluminous X-ray transient XMMUJ004243.6+412519 (ULX2 hereafter) in M31, based on Swift data and the 1.8-m Copernico Telescope in Asiago (Italy). Undetected until January…

We report the discovery of an unusual emission line galaxy at redshift z=1.68 found from near-IR imaging and spectroscopic observations with ISAAC/VLT of a faint gravitationally lensed R-band drop-out behind the lensing cluster Abell 1835.…

We report the discovery and follow-up observations of VT 1137-0337: an unusual radio transient found in our systematic search for extragalactic explosions in the VLA Sky Survey (VLASS). VT 1137-0337 is located in the brightest region of a…

We report the discovery of a bright transient X-ray source, CXOU J132518.2-430304, towards Centaurus A (Cen A) using six new Chandra X-Ray Observatory observations in 2007 March--May. Between 2003 and 2007, its flux has increased by a…

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…

We have examined a probable soft X-ray transient source in the M31 bulge at R.A.=0:42:41.814 +/- 0.08", Dec. = 41:16:35.86 +/- 0.07". On the three occasions we observed the source, its spectrum was soft (kT_{in} ~1 keV). The brightest…

We present our analysis of the Type II supernova DLT16am (SN~2016ija). The object was discovered during the ongoing $\rm{D}<40\,\rm{Mpc}$ (DLT40) one day cadence supernova search at $r\sim20.1\,\rm{mag}$ in the `edge-on' nearby…

Wide-field optical surveys have begun to uncover large samples of fast (t_rise < 5d), luminous (M_peak < -18), blue transients. While commonly attributed to the breakout of a supernova shock into a dense wind, the great distances to the…

M85 is a peculiar S0 galaxy in Virgo and is a well-known merger remnant. In this paper, we present the first spectroscopic study of globular clusters (GCs) in M85. We obtain spectra for 21 GC candidates and the nucleus of M85 using the…

Mergers of neutron stars (NS+NS) or neutron stars and stellar mass black holes (NS+BS) eject a small fraction of matter with a sub-relativistic velocity. Upon rapid decompression nuclear density medium condenses into neutron rich nuclei,…

We present the discovery and extensive follow-up of a remarkable fast-evolving optical transient, AT2022aedm, detected by the Asteroid Terrestrial impact Last Alert Survey (ATLAS). AT2022aedm exhibited a rise time of $9\pm1$ days in the…

We present the analysis of the planetary microlensing event OGLE-2014-BLG-1760, which shows a strong light curve signal due to the presence of a Jupiter mass-ratio planet. One unusual feature of this event is that the source star is quite…

We report the discovery of a bright X-ray transient object, XMMU J174554.4-285456, observed in outburst with XMM-Newton on October 3, 2002,and located at 6.3' from SgrA*, the supermassive black hole at the Galactic center.This object…

During a search for X-ray transients in the XMM-Newton archive within the EXTraS project, we discovered a new X-ray source that is detected only during a ~5 min interval of a ~21 h-long observation performed on 2011 June 21 (EXMM…