dimanche 31 octobre 2021

Comets Hitting the Sun

 







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Oct. 31, 2021

There are many comets that approach the Sun as close as possible, sometimes up to perihelion distances of only a few hundred thousand kilometers. Small comets during such encounters completely burn out, and comets with large nuclei (more than 3 km) can withstand even several close flights. Therefore, such comets are called circumsolar comets or comets touching the Sun (eng. Sungrazing comets), but close flyby of even large objects near the Sun due to the action of tidal forces often leads to their disintegration.


The first comet discovered to orbit extremely close to the Sun was the Great Comet in 1680. She flew at a distance of only 200,000 km from the surface of our star. Until the second half of the 19th century, it was believed that flyby of all bright comets is the return of the same circumsolar comet, observed in 1106.


In 1843, another circumsolar comet appeared. Calculations of its orbit showed that the orbital period was no more than two hundred years. This fact suggested that this was the return of a comet in 1680. However, the flyby of the brightest comets in 1880 and 1882 somewhat puzzled astronomers.


It was only in 1888 that an end was put in these disputes after the work of the German astronomer Heinrich Kreutz, in which he proved that the bright comets of 1843, 1880 and 1882 are fragments of one long-destroyed giant comet, and the comet of 1680 has nothing to do with them. This is how a whole family of circumsolar comets arose, named after Heinrich Kreutz, who proved their relationship.


With the launch of the Solar and Heliospheric Observatory (SOHO) spacecraft in 1995, it became possible to observe comets passing near the Sun at any time of the year. Hundreds of circumsolar comets have been discovered with SOHO. Most of them, according to experts, belong to the Kreutz family. The rest are usually called "random" circumsolar comets.

Source: Moscow Planetarium.

Related links:

ROSCOSMOS Press Release: https://www.roscosmos.ru/33175/

Moscow Planetarium: https://www.roscosmos.ru/tag/moskovskiy-planetariy/

Comet: https://www.roscosmos.ru/tag/kometa/

Images, Text, Credits: ROSCOSMOS/Moscow Planetarium/NASA - ESA/SOHO/Orbiter.ch Aerospace/Roland Berga.

Best regards, Orbiter.ch