|Discovered by||Grigory Neujmin|
|Discovery date||August 2, 1929|
|1929 III; 1;|
|Orbital characteristics A|
|Epoch||March 6, 2006|
|Semi-major axis||4.858 AU|
|Orbital period||10.71 a|
|Last perihelion||April 8, 2015|
July 15, 2004
|Next perihelion||January 14, 2026|
276P/Vorobjov (previously P/2012 T7 (VOROBJOV)) is a Jupiter-family comet discovered on 15 October 2012 by Tomáš Vorobjov on three 120-s images taken remotely using the 0.81-m f/7 Ritchey-Chretien Schulman Telescope located at the Mt. Lemmon SkyCenter via the Sierra Stars Observatory Network in the course of a minor-planet search survey undertaken as part of the International Astronomical Search Collaboration (IASC) school campaigns. After posting on the Minor Planet Center's NEOCP webpage, other observers have commented on the object's cometary appearance. The discovery was announced by the Minor Planet Center on 18 October, three days after the discovery.41P/Tuttle–Giacobini–Kresák
41P/Tuttle–Giacobini–Kresák is a periodic comet in the Solar System. The comet nucleus is estimated to be 1.4 kilometers in diameter.Discovered by Horace Parnell Tuttle on May 3, 1858, and re-discovered independently by Michel Giacobini and Ľubor Kresák in 1907 and 1951 respectively, it is a member of the Jupiter family of comets.43P/Wolf–Harrington
43P/Wolf–Harrington is a periodic comet discovered on December 22, 1924, by Max Wolf in Heidelberg, Germany. In 2019 it will pass within 0.065 AU (9,700,000 km; 6,000,000 mi) of Jupiter, which will lift the perihelion point and increase the orbital period to 9 years.During the 1997 apparition the comet reached an apparent magnitude a little bit brighter than 12.The comet had an unfavorable apparition in 2010, because during perihelion (closest approach to the Sun), the comet was only 10 degrees from the Sun as seen from Earth. The comet was not more favorably positioned in the sky until mid October 2010.
The comet nucleus is estimated to be 3.6 kilometers in diameter.53P/Van Biesbroeck
53P/Van Biesbroeck is a periodic comet 7 km in diameter.This comet and 42P/Neujmin are fragments of a parent comet that split around March 1845. The orbit of 53P/Van Biesbroeck has a Jupiter Minimum orbit intersection distance (MOID) of only 0.009 AU (1,300,000 km; 840,000 mi). The next perihelion passage is on Christmas Eve 24 December 2028. The comet is expected to brighten to about apparent magnitude 14.C/2012 E2 (SWAN)
Comet C/2012 E2 (SWAN) was a Kreutz group sungrazing comet discovered by Vladimir Bezugly in publicly available images taken by the SWAN instrument (Solar Wind ANisotropies) on board the SOHO spacecraft. It is recognized for being the first Kreutz sungrazer observed in SWAN imagery.C/2015 F3
Comet C/2015 F3 (SWAN) was discovered in March 2015 by Rob Matson, Vladimir Bezugly and Michael Matiazzo in near real time images taken by the SWAN instrument aboard the SOHO spacecraft. At discovery the comet was already shining at around 10th magnitude as it was already near perihelion
. Orbital studies revealed C/2015 F3 to be a related fragment to long periodic comets C/1988 A1 (Liller) and C/1996 Q1 (Tabur), which were already thought to have broken off each other at a previous perihelion passage. As of May 2015, Comet SWAN was fading rapidly, as both C/1988 A1 and C/1996 Q1 ultimately did. .C/2015 F5 (SWAN-XingMing)
Comet C/2015 F5 (SWAN-XingMing) was discovered on March 29, 2015 in near real time SWAN images of the SOHO spacecraft, by Szymon Liwo and Worachate Boonplod. It was also independently discovered on April 4, 2015 by Guoyou Sun and Gao Xing at the XingMing observatory near Ürümqi, China. At discovery, the comet had just passed perihelion and was only 0,35 AU from the Sun, shining at about +10 mag. As of May 2015 the comet had faded below mag +13. The comet is periodic with an orbital period of about 61 years .Comet
A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena are due to the effects of solar radiation and the solar wind acting upon the nucleus of the comet. Comet nuclei range from a few hundred metres to tens of kilometres across and are composed of loose collections of ice, dust, and small rocky particles. The coma may be up to 15 times the Earth's diameter, while the tail may stretch one astronomical unit. If sufficiently bright, a comet may be seen from the Earth without the aid of a telescope and may subtend an arc of 30° (60 Moons) across the sky. Comets have been observed and recorded since ancient times by many cultures.
Comets usually have highly eccentric elliptical orbits, and they have a wide range of orbital periods, ranging from several years to potentially several millions of years. Short-period comets originate in the Kuiper belt or its associated scattered disc, which lie beyond the orbit of Neptune. Long-period comets are thought to originate in the Oort cloud, a spherical cloud of icy bodies extending from outside the Kuiper belt to halfway to the nearest star. Long-period comets are set in motion towards the Sun from the Oort cloud by gravitational perturbations caused by passing stars and the galactic tide. Hyperbolic comets may pass once through the inner Solar System before being flung to interstellar space. The appearance of a comet is called an apparition.
Comets are distinguished from asteroids by the presence of an extended, gravitationally unbound atmosphere surrounding their central nucleus. This atmosphere has parts termed the coma (the central part immediately surrounding the nucleus) and the tail (a typically linear section consisting of dust or gas blown out from the coma by the Sun's light pressure or outstreaming solar wind plasma). However, extinct comets that have passed close to the Sun many times have lost nearly all of their volatile ices and dust and may come to resemble small asteroids. Asteroids are thought to have a different origin from comets, having formed inside the orbit of Jupiter rather than in the outer Solar System. The discovery of main-belt comets and active centaur minor planets has blurred the distinction between asteroids and comets. In the early 21st century, the discovery of some minor bodies with long-period comet orbits, but characteristics of inner solar system asteroids, were called Manx comets. They are still classified as comets, such as C/2014 S3 (PANSTARRS). 27 Manx comets were found from 2013 to 2017.As of July 2018 there are 6,339 known comets, a number that is steadily increasing as they are discovered. However, this represents only a tiny fraction of the total potential comet population, as the reservoir of comet-like bodies in the outer Solar System (in the Oort cloud) is estimated to be one trillion. Roughly one comet per year is visible to the naked eye, though many of those are faint and unspectacular. Particularly bright examples are called "great comets". Comets have been visited by unmanned probes such as the European Space Agency's Rosetta, which became the first ever to land a robotic spacecraft on a comet, and NASA's Deep Impact, which blasted a crater on Comet Tempel 1 to study its interior.Comet nucleus
The nucleus is the solid, central part of a comet, popularly termed a dirty snowball or an icy dirtball. A cometary nucleus is composed of rock, dust, and frozen gases. When heated by the Sun, the gases sublimate and produce an atmosphere surrounding the nucleus known as the coma. The force exerted on the coma by the Sun's radiation pressure and solar wind cause an enormous tail to form, which points away from the Sun. A typical comet nucleus has an albedo of 0.04. This is blacker than coal, and may be caused by a covering of dust.Results from the Rosetta and Philae spacecraft show that the nucleus of 67P/Churyumov–Gerasimenko has no magnetic field, which suggests that magnetism may not have played a role in the early formation of planetesimals. Further, the ALICE spectrograph on Rosetta determined that electrons (within 1 km (0.62 mi) above the comet nucleus) produced from photoionization of water molecules by solar radiation, and not photons from the Sun as thought earlier, are responsible for the degradation of water and carbon dioxide molecules released from the comet nucleus into its coma. On 30 July 2015, scientists reported that the Philae spacecraft, that landed on comet 67P/Churyumov-Gerasimenko in November 2014, detected at least 16 organic compounds, of which four (including acetamide, acetone, methyl isocyanate and propionaldehyde) were detected for the first time on a comet.Grigory Neujmin
Grigory Nikolayevich Neujmin (Russian: Григорий Николаевич Неуймин; January 3, 1886 [O.S. December 22, 1885]–December 17, 1946) was a Georgian–Russian astronomer, native of Tbilisi in Georgia, and a discoverer of numerous minor planets as well as 6 periodic and a hyperbolic comet at the Pulkovo and Simeiz Observatories during the first half of the 20th century.List of numbered comets
This is a list of periodic comets that were numbered by the Minor Planet Center after having been observed on at least two occasions. As of October 2018 there are 375 numbered comets (1P–375P), most of them being members of the Jupiter-family (JFC). There are also 27 Encke-type comets (ETCs), 14 Halley-type comets (HTCs), 4 Chiron-type comets (CTCs), and one long-period comet (i.e. 153P). Many of these bodies are also near-Earth comets (NECs). In addition, 8 numbered comets are principally classified as minor planets – five main-belt comets, two centaurs (CEN), and one Apollo asteroid – and display characteristics of both an asteroid and a comet.
Occasionally, comets will break up into multiple chunks, as volatiles coming off the comet may cause it to break into two or more pieces. An extreme example of this is 73P/Schwassmann–Wachmann, which broke into over 50 pieces during its 1995 perihelion.
For a larger list of periodic Jupiter-family and Halley-type comets including unnumbered bodies, see list of periodic comets.