Related papers: Hubble Space Telescope Observations of Active Aste…

Observations of active asteroid P/2017 S5 when near perihelion reveal the ejection of large (0.1 to 10 mm) particles at 0.2 to 2 m/s speeds, with estimated mass-loss rates of a few kg/s. The protracted nature of the mass loss (continuous…

We present Hubble Space Telescope observations of active asteroid 313P/Gibbs (formerly P/2014 S4) taken over the five month interval from 2014 October to 2015 March. This object has been recurrently active near perihelion (at 2.4 AU) in two…

Hubble Space Telescope observations of active asteroid 324P/La Sagra near perihelion show continued mass loss consistent with the sublimation of near-surface ice. Isophotes of the coma measured from a vantage point below the orbital plane…

We present observations and models of the dust environment of activated asteroid P/2013 P5 (PANSTARRS). The object displayed a complex morphology during the observations, with the presence of multiple tails. We combined our own…

We examine the development of the active asteroid 311P/PANSTARRS (formerly, 2013 P5) in the period from 2013 September to 2014 February using high resolution images from the Hubble Space Telescope. This multi-tailed object is characterized…

We present initial observations of the newly-discovered active asteroid 313P/Gibbs (formerly P/2014 S4), taken to characterize its nucleus and comet-like activity. The central object has a radius $\sim$0.5 km (geometric albedo 0.05…

Some asteroids eject dust, unexpectedly producing transient, comet-like comae and tails. First ascribed to the sublimation of near-surface water ice, mass losing asteroids (also called "main-belt comets") can in fact be driven by a…

We present a study of comet C/2017 K2 (PANSTARRS) using prediscovery archival data taken from 2013 to 2017. Our measurements show that the comet has been marginally increasing in activity since at least 2013 May (heliocentric distance of…

We present deep imaging observations of activated asteroid P/2016 G1 (PANSTARRS) using the 10.4m Gran Telescopio Canarias (GTC) from late April to early June 2016. The images are best interpreted as the result of a relatively short-duration…

Active asteroids show (typically transient) cometary activity, driven by a range of processes. A sub-set, sometimes called main-belt comets, may be driven by sublimation and so could be useful for tracing the present-day distribution of…

We present a photometric and astrometric study of the split active asteroid P/2016 J1 (PANSTARRS). The two components (hereafter J1-A and J1-B) separated either $\sim$1500 days (2012 May to June) or 2300 days (2010 April) prior to the…

We report on the characterisation of the dust activity and dynamical evolution of two faint active asteroids, P/2019 A4, and P/2021 A5, observed with the 10.4m GTC using both imaging and spectroscopy. Asteroid P/2019 A4 activity is found to…

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…

We report on the catastrophic disintegration of P/2016 G1 (PANSTARRS), an active asteroid, in April 2016. Deep images over three months show that object is constituted by a central concentration of fragments surrounded by an elongated coma,…

We present observations and dust tail models of activated asteroid P/2015 X6 from deep imaging data acquired at the 10.4m Gran Telescopio Canarias (GTC) from mid-December 2015 to late January 2016. The results of the modeling indicate that…

While having a comet-like appearance, P/2012 F5 (Gibbs) has an orbit native to the Main Asteroid Belt, and physically is a km-sized asteroid which recently (mid 2011) experienced an impulsive mass ejection event. Here we report new…

We present visible and mid-infrared imagery and photometry of temporary Jovian co-orbital comet P/2019 LD$_2$ taken with HST/WFC3, Spitzer/IRAC, the GROWTH telescope network, visible spectroscopy from Keck/LRIS and archival ZTF observations…

We present deep imaging observations, orbital dynamics, and dust tail model analyses of the double-component asteroid P/2016 J1 (J1-A and J1-B). The observations were acquired at the Gran Telescopio Canarias (GTC) and the…

We present initial results from observations and numerical analyses aimed at characterizing main-belt comet P/2012 T1 (PANSTARRS). Optical monitoring observations were made between October 2012 and February 2013 using the University of…

We report new observations of the prototype main-belt comet (active asteroid) 133P/Elst-Pizarro taken at high angular resolution using the Hubble Space Telescope. The object has three main components; a) a point-like nucleus, b) a long,…