Related papers: Where are the Mini Kreutz-family Comets?
Encke-type comet 332P/Ikeya-Murakami is experiencing cascading fragmentation events during its 2016 apparition. It is likely the first splitting Encke-type comet ever being observed. A nongravitational solution to the astrometry reveals a…
Sungrazing comets have always captured a lot of interest and curiosity among the general public as well as scientists since ancient times. The perihelion passage of comet C/2012 S1 (ISON) at the end of this year (on 2013 November 28) is an…
We investigate the brightening behavior of long-period comets as a function of dynamical age, defined by the original reciprocal semimajor axis, $1/a_0$. Our goal is to test long-standing claims about comet behavior using a large number of…
We present the detection of new cometary X-ray emission lines in the 1.0 to 2.0 keV range using a sample of comets observed with the Chandra X-ray observatory and ACIS spectrometer. We have selected 5 comets from the Chandra sample with…
We report a new imaging spectroscopic observation of Oort-cloud comet C/2017 K2 (hereafter K2) on its way to perihelion at 2.53 au, around a heliocentric distance where H2O ice begins to play a key role in comet activation. Normalized…
Jupiter family comet 17P/Holmes underwent a remarkable outburst on UT 2007 Oct. 24, in which the integrated brightness abruptly increased by about a factor of a million.We obtained near infrared (0.8 - 4.2 micron) spectra of 17P/Holmes on…
We present the first results from the COSINE (Cometary Object Study Investigating their Nature and Evolution) project, based on a uniformly processed dataset of 484 comets observed over the full 15-year duration of the WISE/NEOWISE mission.…
Hyperactive comet activity typically becomes evident beyond the frost line (3 to 4 au) where it becomes too cold for water-ice to sublimate. If carbon monoxide (CO) and carbon dioxide (CO2) are the species that drive activity at…
Core-collapse Supernovae (CC-SNe) descend from progenitors more massive than about 8 Msun. Because of the young age of the progenitors, the ejecta may eventually interact with the circumstellar medium (CSM) via highly energetic processes…
[Abridged] Sun-grazing comets almost never re-emerge, but their sublimative destruction near the sun has only recently been observed directly, while chromospheric impacts have not yet been seen, nor impact theory developed. Employing simple…
Comets can be divided into two groups: type I, characterized by high gas/dust ratio, low polarization, and a weak or absent 10 micron silicate feature, and type II, for which a low gas/dust ratio, high polarization, and strong silicate…
Abridged. We have performed an ecliptic survey of the Kuiper belt, with an areal coverage of 8.9 square degrees to a 50% limiting magnitude of r'=24.7, and have detected 88 Kuiper belt objects, roughly half of which received follow-up one…
Jupiter Family comets (JFCs) are short period comets which have recently entered the inner solar system, having previously orbited in the Kuiper Belt since the formation of the planets. We used two nights on the 3.6m New Technology…
We examine the rise and sudden demise of comet C/2010 X1 (Elenin) on its approach to perihelion. Discovered inbound at 4.2 AU, this long-period comet was predicted to become very bright when near perihelion, at 0.48 AU on 2011 September 10.…
The Kuiper belt objects, the Centaurs, and the Jupiter-family comets form an evolutionary continuum of small outer Solar System objects, and their study allows us to gain insight into the history and evolution of the Solar System. Broadband…
We report results of intensive time-resolved imaging photometry and synoptic deep imaging of the comet C/2012 S1 (ISON) performed in February 2013. The data were obtained at the Wise Observatory in Israel (WO), at the Himalayan Chandra…
As an Oort Cloud object with a record small perihelion distance of 2.7 Rsun and discovered more than a year before its encounter with the Sun, comet C/2012 S1 is a subject of considerable scientific interest. Its activity along the orbit's…
A numerical simulation of the Oort cloud is used to explain the observed orbital distributions and numbers of Jupiter-family and Halley-type short-period comets. Comets are given initial orbits with perihelion distances between 5 and 36 AU,…
Comets are icy objects that orbitally evolve from the trans-Neptunian region (the Kuiper belt and beyond) into the inner Solar System, where they are heated by solar radiation and become active due to sublimation of water ice. Here we…
Ultraviolet spectra of Comet 96/P Machholz were obtained during its 2002 perihelion with the UVCS instrument aboard the SOHO satellite. Emission from H I, C II, C III, and O I, is detected near the nucleus. The outgassing rate is in line…