PSR B1257 + 12 c

The planet is 0.36 a from the parent star . e. The circulation period is about 66 days . The pulsar planet is four times more massive than the Earth. Since the planet PSR B1257 +12 c and the planet PSR B1257 +12 d (formerly C) are close in mass and their orbits are close to each other, they cause measurable in each other's orbits. As expected, the disturbances found confirmed that the planets were real. The exact masses of the two planets, as well as the inclinations of their orbits, were measured by calculating how much the planets affect each other. The surface temperature of PSR B1257 + 12 s is estimated from 51 to 652 Kelvin.

The planets of PSR 1257 + 12 are designated from A to D (sorted by increasing distance). The reason these planets have names different from other exoplanets is because the naming convention was different at the time of their discovery. Being the first planet ever discovered and discovered around a pulsar , the planet received the capital letter "B" in the designation, and the next - "C". The third open planet was assigned the letter “A”, as it was closer to the star.

Subsequently, when renaming according to new agreements and to avoid confusion in accordance with the modern exoplanet naming system, the planet was assigned the letter “c”, leaving “a” for the star.

In July 2014, the International Astronomical Union launched the process of assigning proper names for some exoplanets and their stars. Among them was the name for the planet PSR B1257 + 12 c, chosen in an open competition and announced in December 2015. It became the word "Poltergeist", proposed by the employees of the Planetarium Südtirol Alto Adige ( Cornedo al Isarco , South Tyrol, Italy ) ^{[3] [4]} . The pulsar PSR B1257 + 12 itself was then called the “Lich”. Continuing the terminology of mythological otherworldly forces and undead, the other two companions were designated as Draugr (the living dead in Scandinavian mythology ) and Phobetor (the deity of nightmares in the ancient tradition ).

In 1991, the Polish radio astronomer Alexander Volshchan , studying the pulsar PSR 1257 + 12 discovered by him at the Arecibo Observatory in 1990 , noticed a periodic change in the frequency of arrival of pulses. Canadian astronomer Dale Freil confirmed this discovery by observing on another radio telescope. In 1992, they jointly published the results of studies in which the detected periodic changes in frequency were explained by the influence of two planets with a mass four times that of the Earth (now known as PSR B1257 + 12 c and PSR B1257 + 12 d ) ^[5] . Later, another planet was discovered with a mass twice that of the moon (PSR B1257 + 12 b), 50 times lighter than the Earth. Thus, the existence of the first open extrasolar planetary system was proved.

The planetary conditions at PSR B1257 + 12 are quite extreme. Two of them, including PSR B1257 + 12 c, are comparable with the Earth, but are very close to the pulsar. The magnetic field of a neutron star is a source of microwave radiation . In addition, the magnetic field accelerates elementary particles. The planet is constantly falling heavy rain of ions. Such conditions are deadly to humans, but even on Earth there are more radiation-resistant organisms like the bacteria Deinococcus radiodurans .

In a 2017 article for the Astronomy and Astrophysics magazine, astrophysicists Alessandro Patruno and Michel Kama from Leiden University (Netherlands) admitted that suitable planets can also be located around neutron stars, citing just the super-earths PSR B1257 + 12 c and PSR as an example B1257 + 12 d ^[6] . They used special software to analyze images of the PSR B1257 + 12 system taken in 2007 by the Chandra X-ray orbital x-ray observatory, as well as earlier data for 2005. Thus, they found that the temperature on the surface of PSR B1257 + 12 reaches 1.1 million Kelvin, and that a dust fragment fragment disk can rotate around the star, the hypothesis of the existence of which was put forward ten years ago by a group of George Pavlov, Oleg Kargaltsev, J.P. Garmir and Alexander Wolshchan ^[7] .

Although the habitability zone PSR B1257 + 12 is incomparably smaller than that of the stars of the main sequence , if a number of conditions are met, the planets c and d will be potentially inhabited. To do this, they must first of all have a powerful and dense atmosphere . If the gas shells are wide enough, then the dangerous x-ray and gamma radiation, which threatens the potential habitability of these planets, will not reach the surface of the planet ^[8] . At the same time, neutron star radiation and a pulsar wind can transfer enough heat to planets to maintain temperatures compatible with the existence of liquid water for billions of years in a row ^[9] .

• List of the first exoplanets
• PSR B1620-26 b
• PSR J1719-1438 b

• Wolszczan, A., Frail, D. A planetary system around the millisecond pulsar PSR1257 + 12 (Eng.) // Nature : journal. - 1992. - Vol. 355 , no. 6356 . - P. 145-147 . - DOI : 10.1038 / 355145a0 . - .

•   Wikimedia Commons has media related to PSR B1257 + 12 c
• Pulsar Planets (unopened) (link not available) . Archived December 30, 2005.
• PSR 1257 + 12c in the encyclopedia of extrasolar planets
• PSR 1257 + 12c in the SIMBAD database

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