Related papers: Rapid variations of dust colour in comet 41P/Tuttl…

Comet 41P/Tuttle-Giacobini-Kresak (41P), a Jupiter family comet with three discoveries over about 100 years, is in a short-periodic orbit around the Sun with the perihelion close to the Earth distance. The 2017 apparition of 41P offered a…

We present results from our 47-night imaging campaign of Comet 41P/Tuttle-Giacobini-Kresak conducted from Lowell Observatory between 2017 February 16 and July 2. Coma morphology revealed gas jets, whose appearance and motion as a function…

We report observations of color in the inner coma of Comet C/2013 UQ4 (Catalina) with the broadband B and R filters. We find significant temporal variations of the color slope, ranging from -12.67 $\pm$ 8.16 \% per 0.1~$\mu$m up to $35.09…

Cometary outgassing can produce torques that change the spin state of the nucleus, influencing the evolution and lifetimes of comets (1,2). If these torques spin up the rotation to the point that centripetal forces exceed the material…

Thanks to the Rosetta mission, our understanding of comets has greatly improved. A very good opportunity to apply this knowledge appeared in early 2017 with the appearance of the Jupiter family comet 41P/TGK. We performed an observational…

The rotations of cometary nuclei are known to change in response to outgassing torques. The nucleus of comet 41P/Tuttle-Giacobini-Kresak exhibited particularly dramatic rotational changes when near perihelion in 2017 April. Here, we use…

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 report on photometry and high resolution spectroscopy of the chemically peculiar Jupiter-family Comet (hereafter JFC) 21P/Giacobini-Zinner. Comet 21P is a well known member of the carbon-chain depleted family but displays also a…

We report results of polarimetric observations of comet 21P/Giacobini-Zinner made at phase angles, {\alpha}=76-78 deg, between 10 and 17 of September 2018, and compare them with previous measurements. We find significant variations in the…

We report on photometry and imaging of the Jupiter Family Comets 41P/Tuttle-Giacobini-Kresak and 45P/Honda-Mrkos-Pajdusakova with the TRAPPIST-North telescope. We observed 41P on 34 nights from February 16, 2017 to July 27, 2017 pre- and…

We report results from broadband visible images of comet C/2012 S1 (ISON) obtained with the Hubble Space Telescope Wide Field Camera 3 on 2013 April 10. C/ISON's coma brightness follows a 1/{\rho} (where {\rho} is the projected distance…

We analyze jet features found in the coma of Comet 21P/Giacobini-Zinner (21P/GZ) during its 2018 perihelion passage using narrowband CN photometric imaging in order to determine the comet's rotational period, and constrain the CN gas…

We present results of imaging polarimetry of comet 2P/Encke performed on January 23, 2017 at the heliocentric (1.052 au) and geocentric (1.336 au) distances and phase angle 46.8 deg, 46 days before perihelion. Observations were made through…

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.…

We analyze 2-5 micrometre spectroscopic observations of the dust coma of comet 67P/Churyumov-Gerasimenko obtained with the VIRTIS-H instrument onboard Rosetta from 3 June to 29 October 2015 at heliocentric distances r_h = 1.24-1.55 AU. The…

Comet 17P/Holmes underwent a dramatic outburst in October 2007, caused by the sudden fragmentation of its nucleus and the production of a large quantity of grains scattering sunlight. We report on 90 GHz continuum observations carried out…

Most comets are volatile-rich bodies that have recently entered the inner solar system following long-term storage in the Kuiper belt and the Oort cloud reservoirs. These reservoirs feed several distinct, short-lived "small body"…

We present results for Chandra observations of comets, 17P/Holmes (17P) and 8P/Tuttle (8P). 17P was observed for 30 ksec right after its major outburst, on 31 Oct 2007 (10:07 UT) and comet 8P/Tuttle was observed in 2008 January for 47 ksec.…

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…

We report our new spectropolarimetric observations for 67P dust over 4,000--9,000 Angstrom using the ESO/Very Large Telescope in January--March 2016 (phase angle ranging $\sim$26--5 deg) to constrain the properties of the dust particles of…