PSR 1257 + 12 (Leach) (PSR B1257 + 12) is a pulsar whose planetary system was the first to be discovered outside the solar system .
| PSR 1257 + 12 (Leach) | |||
|---|---|---|---|
| Star | |||
 Planetary system PSR 1257 + 12 as presented by the artist. | |||
| Research history | |||
| Discoverer | |||
| opening date | |||
| Observational data ( Age J2000.0 ) | |||
| Type of | Millisecond pulsar | ||
| Right ascension | |||
| Declination | |||
| Distance | 2300 St. years (700 pc ) | ||
| Constellation | |||
| Astrometry | |||
| Own movement (μ) | RA: Dec: | ||
| Parallax (π) | |||
| Characteristics | |||
| Spectral class | Pulsar | ||
| physical characteristics | |||
| Weight | 1.5 M ☉ | ||
| Radius | ≈0.00002 R ☉ | ||
| Age | 8⋅10 8 years | ||
| Rotation | 0.006219 sec | ||
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| Database Information | |||
| SIMBAD | |||
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 [2] . Later, another planet was discovered with a mass twice the mass of the moon.
By the ratio of the periods of the planet resemble Mercury , Venus and the Earth . Their origin is not entirely clear. Inner planets could not survive the supernova explosion. Perhaps they formed after the explosion of a substance flowing onto the pulsar from the second component of the system, later lost. Despite the accuracy of the method used, systems of this type were not found in other pulsars.
Content
- 1 Physical characteristics
- 2 Planetary system
- 2.1 Planet b (formerly A) (also Draugr)
- 2.2 Planet c (formerly B) (also Poltergeist)
- 2.3 Planet d (formerly C) (also Phobetor)
- 2.4 Unconfirmed dwarf planet (formerly D)
- 3 The possibility of the existence of life
- 4 Additional data
- 4.1 Disproved data on the gas giant
- 4.2 Names of the planets
- 5 See also
- 6 notes
- 7 References
Physical Characteristics
A pulsar with a frequency of 160.8 Hertz is located at a distance of ≈2300 light years from the Sun.
Planet System
Planet b (formerly A) (also Draugr)
The circulation period is 25.262 days, the semimajor axis of the orbit is 0.19 a. e. , the orbit is circular ( eccentricity 0,0). Mass 0.025 earth .
Planet c (formerly B) (also Poltergeist)
The circulation period is 66.5419 days, the semimajor axis of the orbit is 0.36 a. e., the orbit is circular (eccentricity 0.0186). Mass 4.3 earth.
Planet d (formerly C) (also Phobetor)
The circulation period is 98.2114 ± 0.0002 days, the semimajor axis of the orbit is 0.46 a. e., the orbit is circular (eccentricity 0.0252). Mass 3.9 ± 0.2 terrestrial.
Unconfirmed dwarf planet (formerly D)
The existence of this hypothetical dwarf planet was suspected in 2002 [3] . The circulation period is about 3.5 years, the semi-major axis of the orbit is about 2.6 a. e. Mass <0.0004 terrestrial (less than 0.2 mass of Pluto ). So far, the existence of a dwarf planet has not been confirmed.
| Planet | Weight ( M E ) | Radius | Circulation period ( days ) | Semimajor axis orbits ( a.u. ) | Eccentricity orbits |
|---|---|---|---|---|---|
| b (A) | 0,025 | ? | 25,262 | 0.19 | 0,0 |
| c (B) | 4.3 | ? | 66,542 | 0.36 | 0.01 |
| d (C) | 3.9 | ? | 98,211 | 0.46 | 0.02 |
| (D) (unconfirmed dwarf planet) | 0,0004 | ?? | 1270 | 2.6 | ? |
The possibility of the existence of life
The conditions on the planets are very exotic. Two of them have a mass similar to the mass of the Earth, and are very close to a pulsar. The magnetic field of a neutron star is a source of microwave radiation. In addition, the magnetic field accelerates elementary particles like an accelerator. The planet is constantly falling heavy rain of ions. Such conditions will be fatal to humans. But life can exist in the depths of the ocean under a protective layer of water or ice. Even on the surface, organisms can extract energy from this radiation. But DNA molecules in such conditions will be destroyed very quickly. On Earth, the bacterium Deinococcus radiodurans can survive without any damage to life, receiving a dose of radiation 500 times more than necessary to kill a person. Such great resistance to radiation by the forms of life known to us allows us to hope that evolution on other planets can create organisms capable of survival even in the pulsar rays.
Additional data
Disproved data on the gas giant
In 1996, the discovery of the fourth planet was announced - the gas giant with a circulation period of 170 years and an orbit radius of 40 a. e. and weighing about 100 Earth masses, but subsequently these data were disproved.
Planet Names
The names of the planets of the pulsar PSR 1257 + 12 initially differed from what is usually called open exoplanets at the present time. The fact is that after the discovery of the 51 Pegasus system in 1995, exoplanets began to be called differently (lowercase Latin letters). But the first exoplanets discovered at the pulsar PSR 1257 + 12 were named in capital letters PSR 1257 + 12 B and PSR 1257 + 12 C. In addition, after the discovery of a new planet closer to the star, it was named PSR 1257 + 12 A , and not D (although now the letter “a” is not used, having reserved it for the central body of the system).
Subsequently, the planets were renamed to avoid confusion according to the modern exoplanet naming system.
See also
- Pulsar planet
- List of Virgo constellation stars
Notes
- ↑ 1 2 3 4 5 6 7 Yan Z., Shen Z., Yuan J. et al. Very long baseline interferometry astrometry of PSR B1257 + 12, a pulsar with a planetary system // Mon. Not. R. Astron. Soc. / D. Flower - OUP , 2013 .-- Vol. 433, Iss. 1. - P. 162–169. - ISSN 0035-8711 ; 1365-2966 - doi: 10.1093 / mnras / stt712
- ↑ A planetary system around the millisecond pulsar PSR1257 + 12 by Wolszczan, A., Frail, D. // Nature, 355 (1992)
- ↑ A dwarf planet orbiting a pulsar? (inaccessible link) . Date of treatment August 14, 2006. Archived May 10, 2006. by Daniel Fischer // The Cosmic Mirror 244 (2002)