Related papers: Comet C/2017 K2 (PANSTARRS): dynamically old or ne…

The interstellar traveler, 2I/Borisov, is the first clearly active extrasolar comet, ever detected in our Solar system. We obtained high-resolution interferometric observations of 2I/Borisov with the Atacama Large Millimeter/submillimeter…

A previous spectroscopic study identified the very massive O2 III star VFTS 16 in the Tarantula Nebula as a runaway star based on its peculiar line-of-sight velocity. We use the Gaia DR2 catalog to measure the relative proper motion of VFTS…

An object called G2 was recently discovered moving towards the supermassive black hole in the Galactic Center. G2 emits infrared (IR) lines and continuum, which allows constraining its properties. The question is still unresolved whether G2…

We present optical and near-infrared adaptive optics (AO) imaging and spectroscopy of 13 ultracool (>M6) companions to late-type stars (K7-M4.5), most of which have recently been identified as candidate members of nearby young moving groups…

Since 2017, two macroscopic interstellar objects have been discovered in the inner Solar System, both of which are distinct in nature. The first interstellar object, 1I/`Oumuamua, passed within $\sim63$ lunar distances of the Earth,…

(60558) 174P/Echeclus is an unusual object that belongs to a class of minor planets called Centaurs, which may be intermediate between Kuiper Belt Objects and Jupiter Family comets. It is sporadically active throughout its orbit at…

Orbits of 44 close and fast visual binaries are computed using the latest speckle observations; 23 orbits are determined for the first time, the rest are revisions, some quite substantial. Six combined orbits use radial velocities. The…

Comet C/2002 S2, a member of the Kreutz family of Sungrazing comets, was discovered in white light images of the SOHO/LASCO coronagraph on 2002 September 18 and observed in \hi\, \lya\, emission by the SOHO/UVCS instrument at four different…

We used the UltraViolet-Optical Telescope on board Swift to systematically follow the dynamically new comet C/2013 A1 (Siding Spring) on its approach to the Sun. The comet was observed from a heliocentric distance of 4.5 AU pre-perihelion…

We report new photometric and spectroscopic observations of the K2-99 planetary system. Asteroseismic analysis of the short-cadence light curve from K2's Campaign 17 allows us to refine the stellar properties. We find K2-99 to be…

Main belt asteroid (300163) 2006 VW139 (later designated P/2006 VW139) was discovered to exhibit comet-like activity by the Pan-STARRS1 survey telescope using automated point-spread-function analyses performed by PS1's Moving Object…

The interstellar comet 3I/ATLAS is only the third interstellar object to be discovered. Pre-perihelion measurements provide a unique opportunity to study its activity and composition, which may alter as it is heated in the coming months. We…

We analyze findings of the Stardust mission that brought to the Earth dust from the 81P/Wild 2 coma. Just as the data of the Deep Impact mission to 9P/Tempel 1, they are at odds with the widely accepted condensation/sublimation comet…

We present the kinematic analysis of $246$ stars within $4\mbox{$^\prime$}$ from the center of Orion Nebula Cluster (ONC), the closest massive star cluster with active star formation across the full mass range, which provides valuable…

It is well known that some Main Belt asteroids show comet-like features. A representative example is the first known Main Belt comet 133P/(7968) Elst-Pizarro. If the mechanisms causing this activity are too weak to develop visually evident…

The outer Solar System is believed to host a vast reservoir of long-period comets (LPCs), but our understanding of their spatial distribution and dynamical history remains limited due to observational biases and uncertainties in orbital…

Photometric and spectroscopic observations of five nearly parabolic comets with eccentricity larger than 0.99 at heliocentric distances greater than 4 AU were performed. No molecular emission was observed for any studied comet and the…

We present our results for comet (ISON). Our results were obtained with amateur telescopes observing from the ground, before and after the comet had passed conjunction with the Sun in August 2013. We measured a mean radius of 830 +- 245 m,…

Here, we explore some peculiar orbital features of the recently discovered asteroid A/2017 U1, which is a clear outlier when considering the average value of the eccentricity of known hyperbolic comets. As for the orientation of its orbit…

Context. Theories of the formation and evolution of small bodies in planetary systems predict that they may escape into interstellar space at any time. After having characterized just two such interlopers -1I/2017 U1 (Oumuamua) and…