相关论文: The Impending Demise of Comet C/2012 S1 ISON

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 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…

Comet C/2012 S1 (ISON) shows strange photometric behavior compared to many past comets. Shortly after its discovery, majority of astronomers expected its surviving until perihelion passage. Unprecedented evolution of its photometric…

On 2013 November 28 Comet ISON (C/2012 S1) will pass by the Sun with a perihelion distance of 2.7 solar radii. Understanding the possible outcomes for the comet's response to such a close passage by the Sun is important for planning…

To gain a greater insight into the impending evolution of the physical behavior of comet C/2012 S1, its light curve and orbital properties are compared with those for C/1962 C1 (Seki-Lines) and C/2002 O4 (Hoenig). All three are likely Oort…

We present photometric and morphological analysis of the behavior of sungrazing comet C/2012 S1 ISON in SOHO and STEREO images around its perihelion on 2013 November 28.779 UT. ISON brightened gradually November 20-26 with a superimposed…

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 introduce a parameter, X, to predict the changes in the rotational period of a comet in terms of the rotational period itself, the nuclear radius, and the orbital characteristics. We show that X should be a constant if the bulk densities…

We plot the Secular Light Curves (SLCs) of comets C/2011 L4 Panstarrs and C/2012 S1 ISON. The brightness of C/2011 L4 Panstarrs and C/2012 S1 ISON increase steeply after discovery but both decrease in slope sharply at ~4-5 AU, 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 observed dynamically new sungrazing comet ISON (C/2012 S1) extensively at Lowell Observatory throughout 2013 in order to characterize its behavior prior to perihelion. ISON had "typical" abundances for an Oort Cloud comet. Its dust…

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…

Previously proposed mechanisms have difficulty explaining the disruption of Comet C/2012 S1 (ISON) as it approached the Sun. We describe a novel cometary disruption mechanism whereby comet nuclei fragment and disperse through dynamic…

We present our results for comet (ISON). Our results were obtained with amateur telescopes observing from the ground, before and after the comet had passed conjunction with the Sun in August 2013. We measured a mean radius of 830 +- 245 m,…

We have used the unique far-UV imaging capability offered by a sounding rocket borne instrument to acquire observations of C/2012 S1 (ISON) when its angular separation with respect to the sun was 26.3deg, on 2013 November 20.49. At the time…

We make the following predictions: (1) Comet 67P/Churyumov-Gerasimenko. The Secular Light Curve (SLC) of this comet exhibits a photometric anomaly in magnitude that is present in 1982, 1996, 2002 and 2009. Thus it must be real. We interpret…

We report photometric observations for comet C/2012 S1 (ISON) obtained during the time period immediately after discovery (r=6.28 AU) until it moved into solar conjunction in mid-2013 June using the UH2.2m, and Gemini North 8-m telescopes…

We present an analysis of the photometric and spectroscopic data of the comet C/2012 S1 (ISON) observed at the heliocentric distances of 6.21\div 4.81 AU. The photometric observations were made with the 60-cm Zeiss-600 telescope (ICAMER,…

We present imaging observations of the disintegrating long-period comet C/2021 A1 (Leonard). High resolution observations with Hubble Space Telescope show no evidence for surviving fragments, and place a 3 sigma upper limit to their…

We present molecular observations carried out with the IRAM 30m telescope at wavelengths around 1.15 mm towards the Oort cloud comets C/2012 S1 (ISON) and C/2013 R1 (Lovejoy) when they were at 0.6 and 1 au, respectively, from the Sun. We…