Related papers: Comet 162P/Siding Spring: A Surprisingly Large Nuc…

Comet C/2017 K2 (PANSTARRS) was discovered by the Pan-STARRS1 (PS1) Survey on 2017 May 21 at a distance 16.09 au from the Sun, the second most distant discovery of an active comet. Pre-discovery images in the PS1 archive back to 2014 and…

We present analyses of Spitzer observations of 29P/Schwassmann-Wachmann 1 using 16 $\mu$m IRS "blue" peak-up (PU) and 24 $\mu$m and 70 $\mu$m MIPS images obtained on UT 2003 November 23 and 24 that characterize the Centaur's large-grain…

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 report Spitzer Space Telescope observations of comet 67P/Churyumov-Gerasimenko at 5.5 and 4.3 AU from the Sun, post-aphelion. Comet 67P is the primary target of the European Space Agency's Rosetta mission. The Rosetta spacecraft will…

We present spectral and spatial information for major volatile species in Comet 10P/Tempel 2, based on high-dispersion infrared spectra acquired on UT 2010 July 26 (heliocentric distance Rh = 1.44 AU) and September 18 (Rh = 1.62 AU),…

We present infrared images and spectra of comets 2P/Encke, 67P/Churyumov-Gerasimenko, and C/2001 HT50 (LINEAR-NEAT) as part of a larger program to observe comets inside of 5 AU from the sun with the Spitzer Space Telescope. The nucleus of…

We summarize the collective knowledge of physical and surface properties of comet nuclei, focusing on those that are obtained from remote observations. We now have measurements or constraints on effective radius for over 200 comets,…

We observed Comet C/Siding Spring using the Hubble Space Telescope (HST) during its close approach to Mars. The high spatial resolution images obtained through the F689M, F775W, and F845M filters reveal the characteristics of the dust coma.…

The close encounter of Comet C/2013 A1 (Siding Spring) with Mars on October 19, 2014 presented an extremely rare opportunity to obtain the first flyby quality data of the nucleus and inner coma of a dynamically new comet. However, the…

We present a physical characterization of main-belt comet 176P/LINEAR. Observations show the object exhibiting a fan-shaped tail in late 2005, but then becoming inactive in early 2006. Using data from 2007 when the object was observed to be…

We present results from CCD observations of comet 2P/Encke acquired at Steward Observatory's 2.3m Bok Telescope on Kitt Peak obtained in Oct. 2002, when the comet was near aphelion. Rotational lightcurves in B, V and R-filters were acquired…

We present time-resolved photometric observations of Jupiter family comet 17P/Holmes during its dramatic outburst of 2007. The observations, from the orbiting Solar Mass Ejection Imager (SMEI), provide the most complete measure of the…

The release of volatiles from comets is usually from direct sublimation of ices on the nucleus, but for very or hyper-active comets other sources have to be considered to account for the total production rates. In this work, we present new…

We observed near-Sun comet 323P/SOHO for the first time using ground and space telescopes. In late December 2020, the object was recovered at Subaru showing no cometary features on its way to perihelion. However, in our postperihelion…

Images and low-resolution spectra of the near-Earth Jupiter family comet (JFC) 249P/LINEAR in the visible range obtained with the instrument OSIRIS in the 10.4m Gran Telescopio Canarias on January 3, 4, 6 and February 6, 2016 are presented,…

We investigated the physical properties of the comet-like objects 107P/(4015) Wilson--Harrington (4015WH) and P/2006 HR30 (Siding Spring; HR30) by applying a simple thermophysical model (TPM) to the near-infrared spectroscopy and 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…

We present observations of main-belt comet 358P/PANSTARRS (P/2012 T1) obtained using the Gemini South telescope from 2017 July to 2017 December, as the object approached perihelion for the first time since its discovery. We find best-fit…

Little is known about the physical properties of the nuclei of Oort cloud comets. Measuring the thermal emission of a nucleus is one of the few means for deriving its size and constraining some of its thermal properties. We attempted to…

The Near-Earth Comet P/2016 BA$_{14}$ (PanSTARRS) is a slow-rotatating nearly-dormant object, a likely dynamical twin of 252P/LINEAR, and was recently shown to have a mid-infrared spectrum very dissimilar to other comets. BA$_{14}$ also…