Related papers: The Hamburg Meteorite Fall: Fireball trajectory, o…
Numerous decameter-sized asteroids have been observed impacting Earth as fireballs. These objects can have impact energies equivalent to hundreds of kilotons of TNT, posing a hazard if they impact populated areas. Previous estimates of…
An explosion on comet 17P/Holmes occurred on 2007 Oct 23, projecting particulate debris of a wide range of sizes into the interplanetary medium. We observed the comet using the Spitzer spectrograph on 2007 Nov 10 and 2008 Feb 27, and the…
On 7th August 2019, an impact flash lasting $\sim1$s was observed on Jupiter. The video of this event was analysed to obtain the lightcurve and determine the energy release and initial mass. We find that the impactor released a total energy…
To better estimate which luminous efficiency ($\tau$) value is compatible with contemporary values of the ionization coefficient ($\beta$), we report a series of simultaneous optical and specular echo radar measurements of low speed…
The population of Earth-impacting meteoroids and its size-dependent orbital elements are key to understanding the origin of meteorites and informing on planetary defence efforts. Outstanding questions include the role of collisions in…
Apollo meteoroid 2018 LA has become only the third natural object ever to be discovered prior to causing a meteor airburst and just the second one to have its meteorites recovered (at Botswana's Central Kalahari Game Reserve). Here, we use…
The near-Earth asteroid (99942) Apophis is a potentially hazardous asteroid. We obtained far-infrared observations of this asteroid with the Herschel Space Observatory's PACS instrument at 70, 100, and 160 micron. These were taken at two…
The Andromedid meteor shower underwent spectacular outbursts in 1872 and 1885, producing thousands of visual meteors per hour and described as `stars fell like rain' in Chinese records of the time. The shower originates from comet 3D/Biela…
This paper reports on the detection of a likely explosive outflow in the high-mass star-forming complex G34.26+0.15, adding to the small number (six) of explosive outflows detected so far. ALMA CO(2-1) and SiO(5-4) archival observations…
We present the analysis of the atmospheric trajectory and orbital data of four bright bolides observed over Spain, one of which is a potential meteorite dropping event. Their absolute magnitude ranges from -10 to -11. Two of these are of…
We analysed Rossi X-ray Timing Explorer observations of the accretion-powered 401 Hz pulsar SAX J1808.4-3658, in order to precisely determine the source distance. While the fluences for the five transient outbursts observed from 1996 were…
We measure the metallicity of the unusual hypervelocity star HE 0437-5439 from high resolution spectroscopy to be half-solar. We determine a spectral type of B2 IV-III for the star and derive an effective temperature Teff= 21,500 +/- 1,000…
Herschel/HIFI observations have revealed the presence of widespread absorption by hydrogen fluoride (HF) J = 1-0 rotational transition, toward a number of Galactic sources. We present observations of HF J = 1-0 toward the high-mass…
An exploding primordial black-hole (PBH) may produce a single pulse of electromagnetic radiation detectable at the low-frequency end of the radio spectrum. Furthermore, a radio transient from an exploding PBH could be a signature of an…
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,…
We investigate the orbital stability close to the unique L4-point Jupiter binary Trojan asteroid 624 Hektor. The gravitational potential of 624 Hektor is calculated using the polyhedron model with observational data of 2038 faces and 1021…
The $\sim$4 km diameter main belt asteroid 6478 Gault has ejected dust intermittently since at least 2013. The character of the emission, including its episodic nature and the low speed of the ejected particles ($V \sim $ 0.15 m s$^{-1}$),…
We report new observations of the active asteroid P/2010 A2 taken when it made its closest approach to the Earth (1.06 au in 2017 January) after its first discovery in 2010. Despite a crucial role of the rotational period in clarifying its…
A bright fireball with an absolute magnitude of -10.5 $\pm$ 0.5 was recorded over the South of Spain on August 15, 2012. The atmospheric trajectory, radiant and heliocentric orbit of this event are calculated. These data show that the…
The near-Earth asteroid (196256) 2003 EH1 has been suggested to have a dynamical association with the Quadrantid meteoroid stream. We present photometric observations taken to investigate the physical character of this body and to explore…