相关论文: Prediscovery Observations and Orbit of Comet C/201…

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…

The thermal emission of comet C/2013 A1 (Siding Spring) was observed on March 31, 2013, at a heliocentric distance of 6.48 au using the PACS photometer camera of the Herschel Space Observatory. The comet was clearly active, showing a coma…

We performed a monitoring observation of a Jupiter-Family comet, 17P/Holmes, during its 2014 perihelion passage to investigate its secular change in activity. The comet has drawn the attention of astronomers since its historic outburst in…

Comet 7P/Pons-Winnecke was observed from the Calar Alto Observatory (Spain) for four months during the 2021 inbound apparition. Broad-band visible images were taken between 1.71 and 1.25 AU pre-perihelion, while long-slit spectrophotometric…

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…

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 present the analysis of the polarimetric and spectral data obtained for the dynamically new comet C/2012\,J1 (Catalina) when it was at a distance of 3.17~AU from the Sun. The observations were made at the prime focus of the 6-m BTA…

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…

The main-belt comets occupy dynamically asteroidal orbits in the main asteroid belt. Here we present physical observations of the second-known member of this population, P/2005 U1 (Read), which showed vigorous cometary activity from 2005…

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…

We describe pre-perihelion optical observations of interstellar comet 3I/ATLAS taken during July - September 2025 using the Nordic Optical Telescope. Fixed aperture photometry of the comet is well described by a power law function of…

Comet C/2025 K1 (ATLAS) reached perihelion at 0.33 au on 2025 October 8. Daily monitoring by the LCO Outbursting Objects Key Project revealed a major activity increase between November 2 and 4, accompanied by rapid changes in coma…

We present results of two-year photometric monitoring of Comet C/2011 J2 (LINEAR) that spans the time period from February 2013 through December 2014, before and after perihelion passage. The observations were conducted with broadband R…

To date, at least three comets -- 2I/Borisov, C/2016 R2 (PanSTARRS), and C/2009 P1 (Garradd) -- have been observed to have unusually high CO concentrations compared to water. We attempt to explain these observations by modeling the effect…

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…

In this paper, we present a unique data set of more than one year's worth of regular observations of comet C/2013 A1(Siding Spring) with TRAPPIST in Chile, along with low-resolution spectra obtained with the ESO/VLT FORS 2 instrument. The…

The results of the photometric observations of comet C/2009 P1 (Garradd) performed at the 60-cm Zeiss-600 telescope of the Terskol observatory have been analyzed. During the observations, the comet was at the heliocentric and geocentric…

This comprehensive study of comet C/1995 O1 focuses first on investigating its orbital motion over a period of 17.6 yr (1993-2010). The comet is suggested to have approached Jupiter to 0.005 AU on -2251 November 7, in general conformity…

We report new observations of the active asteroid P/2010 A2 taken when it made its closest approach to the Earth (1.06 au in 2017 January) after its first discovery in 2010. Despite a crucial role of the rotational period in clarifying its…

(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…