Related papers: Disintegrating In-Bound Long-Period Comet C/2019 J…
Comets, relics from the early solar system, consist of dust and ice. The ice sublimates as comets approach the Sun, ejecting dust from their nuclei seen as activity. Different volatiles sublimate at different Sun-comet distances and eject…
The prime objective is to settle a contradiction between a high nongravitational acceleration affecting the orbital motion of comet C/1995 O1 and its enormous nucleus by modeling it as a compact cluster of boulder-sized fragments held…
Based on millimeter-wavelength continuum observations we suggest that the recent 'spectacle' of comet 17P/Holmes can be explained by a thick, air-tight dust cover and the effects of H2O sublimation, which started when the comet arrived at…
Extensive observations of comet C/2004 Q2 (Machholz) were carried out between August 2004 and May 2005. The images obtained were used to investigate the comet's inner coma features at resolutions between 350 and 1500 km/pixel. A photometric…
Aims. Rotation periods of cometary nuclei are scarce, though important when studying the nature and origin of these objects. Our aim is to derive a rotation period for the nucleus of comet C/2004 Q2 (Machholz). Methods. C/2004 Q2 (Machholz)…
We have developed a 3-step criterion to decide if a comet coming from the Oort Cloud will disintegrate. If we apply this criterion to comet C/2013 US10 we find that the probability of disintegration is 92%. The Secular Light Curve of this…
In early April 2017, five weeks before passing through perihelion, the dust-poor comet C/2015 ER61 was observed to undergo a major outburst, during which its intrinsic brightness increased briefly by about 2 mag. Evidence is presented in…
We present initial observations of the interstellar body 2I/(2019 Q4) Borisov taken to determine its nature prior to the perihelion in 2019 December. Images from the Nordic Optical Telescope show a prominent, morphologically stable dust…
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 the polarimetric results and analysis of comet C/2012 L2 (LINEAR) observed at 31$^\circ$.1 phase angle before perihelion passage. The observations of the comet were carried out using ARIES Imaging Polarimeter (AIMPOL) mounted on…
The solar system is dusty, and would become dustier over time as asteroids collide and comets disintegrate, except that small debris particles in interplanetary space do not last long. They can be ejected from the solar system by Jupiter,…
Previous studies have suggested that Comet 209P/LINEAR may produce strong me- teor activity on Earth on 2014 May 24; however, exact timing and activity level is difficult to estimate due to the limited physical observations of the comet.…
Comet C/2016 R2 PanSTARRS (hereafter C/2016 R2) presents an unusually high N2/CO abundance ratio, as well as a heavy depletion in H2O, making it the only known comet of its kind. Understanding its dynamical history is therefore of essential…
Comet C/1999 S4 (LINEAR) was exceptional in many respects. Its nucleus underwent multiple fragmentations culminating in the complete disruption around July 20, 2000. We present circular polarization measurements along the cuts through the…
Jewitt et al. (2014) recently reported that main belt comet P/2013 R3 experienced a breakup, probably due to rotational disruption, with its components separating on mutually hyperbolic orbits. We propose a technique for constraining…
High entry speed (> 25 km/s) and low density (< 2500 kg/m3) are two factors that lower the chance of a meteoroid to drop meteorites. The 26 g carbonaceous (CM2) meteorite Maribo recovered in Denmark in 2009 was delivered by a superbolide…
We present Hubble Space Telescope observations of active asteroid P/2020 O1 taken to examine its development for a year after perihelion. We find that the mass loss peaks <~1 kg/s in 2020 August and then declines to nearly zero over four…
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…
Previously unknown asteroid P/2010 A2 rose to prominence in 2010 by forming a transient, comet-like tail consisting of ejected dust. The observed dust production was interpreted as either the result of a hypervelocity impact with a smaller…
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…