Related papers: Multiple Outbursts of Asteroid (6478) Gault

NGC1566 is a changing-look active galaxy that exhibited an outburst during 2017-2018 with a peak in June 2018. We triggered AstroSat observations of NGC 1566 twice in August and October 2018 during its declining phase. Using the AstroSat…

We report the discovery in our HST ACS B, V, and I images of NGC 4449 of a globular cluster (GC) which appears associated with two tails of blue stars. The cluster is massive (M~1.7x10^6 M_sun) and highly flattened (\epsilon~0.24). From the…

The unique inner-belt asteroid 311P/PANSTARRS (formerly P/2013 P5) is notable for its sporadic, comet-like ejection of dust in nine distinct epochs spread over $\sim$250 days in 2013. This curious behavior has been interpreted as the…

MUSE observations of the cluster of galaxies CGr32 ($M_{200}$ $\simeq$ 2 $\times$ 10$^{14}$ M$_{\odot}$) at $z$ = 0.73 reveal the presence of two massive star forming galaxies with extended tails of diffuse gas detected in the…

Galactic black hole candidate (BHC) GX~339-4 underwent several outbursting phases in the past two and a half decades at irregular intervals of $2-3$ years. Nature of these outbursts in terms of the duration, number of peaks, maximum peak…

We present a spectral and timing study of the NuSTAR and Swift observations of the black hole candidate IGR J17091-3624 in the hard state during its outburst in 2016. Disk reflection is detected in each of the NuSTAR spectra taken in three…

We present Hubble Space Telescope Observations of (596) Scheila during its recent dust outburst. The nucleus remained point-like with absolute magnitude V(1,1,0) = 8.85+/-0.02 in our data, equal to the pre-outburst value, with no secondary…

We present the timing and spectral studies of the Be/X-ray binary XTE J1946+274 during its 2018 and 2021 giant outbursts using observations with the SXT and the LAXPC instruments on the AstroSat satellite. Unlike the 1998 and 2010…

On 3 July 2016, several instruments on board ESA's Rosetta spacecraft detected signs of an outburst event on comet 67P, at a heliocentric distance of 3.32 AU from the sun, outbound from perihelion. We here report on the inferred properties…

Symbiotic binary AG~Draconis (AG~Dra) has an well-established outburst behavior based on an extensive observational history. Usually, the system undergoes a 9--15~yr period of quiescence with a constant average energy emitted, during which…

From Jan. 6, 2019 to Feb. 18, 2019, OSIRIS-REx observed asteroid (101955) Bennu ejecting 11 plumes of dust, of which part is escaping and another part is re-captured by the asteroid. The relative magnitudes of the typical forces acting on…

We present spectroscopy of the accreting X-ray binary and millisecond pulsar SAX J1808.4-3658. These observations are the first to be obtained during a reflaring phase. We collected spectroscopic data during the beginning of reflaring of…

We describe the physical and orbital properties of C/2011 W3. After surviving perihelion, the comet underwent major changes (permanent loss of nuclear condensation, formation of spine tail). The process of disintegration culminated with an…

Gaia19fct is one of the Gaia-alerted eruptive young stars that has undergone several brightening events. We conducted monitoring observations using multi-filter optical and near-infrared photometry, as well as near-infrared spectroscopy, to…

Asteroid collisions are one of the main processes responsible for the evolution of bodies in the main belt. Using observations of the Dimorphos impact by the DART spacecraft, we estimate how asteroid collisions in the main belt may look in…

Outflows are a key element in the baryon cycle of galaxies, and their properties provide a fundamental test for our models of how star formation quenches in galaxies. Here we report the detection of outflowing gas in two recently quenched,…

We report high-resolution spectroscopic observations of WD 1145+017 -- a white dwarf that recently has been found to be transitted by multiple asteroid-sized objects within its tidal radius. We have discovered numerous circumstellar…

Cometary outbursts offer a valuable window into the composition of comet nuclei with their forceful ejection of dust and volatiles in explosive events, revealing the interior components of the comet. Understanding how different types of…

Outbursts are known to begin with a sudden appearance and steep brightening of a "stellar nucleus" --- an unresolved image of a plume of material on its way from the comet's surface and an initial stage of an expanding halo of ejecta. Since…

We present a preliminary analysis of comet P/2019 LM$_4$ (Palomar) as observed by the Zwicky Transient Facility (ZTF) survey in 2019 and 2020. We find that the discovery of the comet in 2019 and the recovery in 2020 is largely attributed to…