Related papers: Expected Fragment Distribution from the First Inte…
In the absence of dense photometry for a large population of Near Earth Objects (NEOs), the best method of obtaining a shape distribution comes from sparse photometry and partial lightcurves. We have used 867 partial lightcurves obtained by…
We present a dynamical analysis of the fragmented active asteroid 331P/Gibbs. Using archival images taken by the Hubble Space Telescope from 2015 to 2018, we measured the astrometry of the primary and the three brightest (presumably the…
On July 28, 2006 the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences recorded the spectrum of a faint meteor. We confidently identify the lines of FeI and MgI, OI, NI and molecular-nitrogen N_2…
Crucial information on the mass accretion-ejection in young stars can be obtained from high spatial resolution images of jets in sources with recurrent accretion outbursts. Using the SPHERE/ZIMPOL instrument, we observed the young binary Z…
The distribution of meteor magnitudes is usually supposed to be described by power-laws. However, this relationship is not able to model the whole data set, and the parameters are considered to be dependent on the magnitude intervals. We…
We report the detection of FRB20191107B with the UTMOST radio telescope at a dispersion measure (DM) of 714.9 ${\rm pc~cm^{-3}}$. The burst consists of three components, the brightest of which has an intrinsic width of only 11.3 $\mu$s and…
We show for the first time that different types of suprathermal ion distributions may exist upstream of a single interplanetary shock. ACE and the two ARTEMIS satellites observed a shock on 8 October 2013. The ARTEMIS P1 and P2 spacecraft…
Data on perihelion fragmentation of the Great September Comet of 1882 (C/1882 R1), a prominent member of the Kreutz sungrazer system, are employed to estimate the size of the nucleus along the radius vector at the time of splitting. The…
Milliarcsecond VLBI maps of regions containing 6.7 GHz methanol maser emission have lead to the recent discovery of ring-like distributions of maser spots and the plausible hypothesis that they may be tracing circumstellar disks around…
We investigate metal pollution onto the surface of low-mass population III stars (Pop. III survivors) via interstellar objects floating in the Galactic interstellar medium. Only recently, Tanikawa et al. analytically estimated how much…
We describe 2016 January to April observations of the fragments of 332P/Ikeya-Murakami, a comet earlier observed in a 2010 October outburst (Ishiguro et al 2014). We present photometry of the fragments, and perform simulations to infer the…
Asteroid discoveries are essential for planetary-defense efforts aiming to prevent impacts with Earth, including the more frequent megaton explosions from decameter impactors. While large asteroids ($\geq$100 km) have remained in the main…
We present multi-point in situ observations of a complex sequence of coronal mass ejections (CMEs) which may serve as a benchmark event for numerical and empirical space weather prediction models. On 2010 August 1, instruments on various…
The gravitational instability model of planet/brown dwarf formation proposes that protostellar discs can fragment into objects with masses above a few Jupiter masses at large semimajor axis. Tidal downsizing may reduce both the object mass…
Iron meteorite falls are rare compared to stony meteorites, and until recently no iron meteorite had a reliably determined pre-atmospheric orbit. This changed on 2020 November 7, when a bright fireball was observed across Sweden and…
I call attention to extraordinary features displayed by the genetically related long-period comet pair of C/1844 Y1 (Great Comet) and C/2019 Y4 (ATLAS). The issue addressed most extensively is the fragmentation and disintegration of the…
Aims: We resolve the length-scales for filament formation and fragmentation (res. <=0.1pc), in particular the Jeans length and cylinder fragmentation scale. Methods: We observed the prototypical high-mass star-forming filament IRDC18223…
Our study attempts to understand the collision characteristics of two coronal mass ejections (CMEs) launched successively from the Sun on 2013 October 25. The estimated kinematics, from three-dimensional (3D) reconstruction techniques…
Free electrons in the Galactic interstellar medium (ISM) disperse and scatter coherent radio waves, by amounts that depend on the distance to the radio source. Models of the Galactic electron density are thus widely used to predict…
We evaluate the reliability of CNEOS-derived ephemerides of fireball events given the absence of the underlying data. We analyzed 18 events that have both (i) sufficient satellite information to derive orbits and (ii) ground-based…