PSR B1257 + 12 b , also known under the designation PSR B1257 + 12 A and the name Draugr ( English Draugr ) - exoplanet , located approximately 2300 light years in the constellation Virgo [1] . The planet closest to the pulsar PSR B1257 + 12 . Its mass is approximately two times the mass of the moon . It is currently the smallest known planet (of all whose mass is measured), including the planets of the solar system [3]
| PSR B1257 + 12 b | |
|---|---|
| Exoplanet | |
 Comparison of the sizes of Draugra and the Earth | |
| Parent star | |
| Star | PSR B1257 + 12 |
| Constellation | Virgo |
| Right Ascension ( α ) | 13 h 00 m 01 s |
| Declination ( δ ) | + 12 ° 40 ′ 57 ″ |
| Distance | 2,300 ± 100 [1] St. years old ( 710 ± 40 [1] pc ) |
| Spectral class | Pulsar |
| Age | 0.8 billion years |
| Elements of the orbit | |
| Semimajor axis ( a ) | 0.19 [2] a. e. |
| Eccentricity ( e ) | 0.0 [2] |
| Orbital Period ( P ) | 25.262 ± 0.003 [2] d. |
| Inclination ( i ) | 50 [2] ° |
| Pericenter Time ( T 0 ) | 2,449,765.6 ± 0.2 [2] JD |
| physical characteristics | |
| Weight ( m ) | 0.020 ± 0.002 [2] M ⊕ |
| Radius ( r ) | ~ 0.00002 R J |
| Discovery Information | |
| opening date | April 22, 1994 |
| Discoverer (s) |
|
| Detection method | periodic pulsation method |
| Opening place |  [3] |
Title
After discovery, the planet received the designation PSR 1257 + 12, and then PSR B1257 + 12 A. Later it became known as PSR B1257 + 12 b.
In July 2014, the International Astronomical Union organized a competition for the selection of names for a number of exoplanets and their maternal stars. [4] In December 2015, the International Astronomical Union announced the results according to which the planet PSR 1257 + 12 b received the name “Draugr” [5] . A proposal for this name came from Italy. Draugr is a creature from Scandinavian mythology , a living dead, close to vampires .
Notes
- Wolszczan, A. Confirmation of Earth Mass Planets Orbiting the Millisecond Pulsar PSR B1257 + 12 (Eng.) // Science : journal. - 1994. - Vol. 264 , no. 5158 . - P. 538-542 . - DOI : 10.1126 / science.264.5158.538 . - . - PMID 17732735 . Archived July 20, 2011.
- ↑ 1 2 3 Yan, Zhen; Shen, Zhi-Qiang; Yuan, Jian-Ping; Wang, Na; Rottmann, Helge; Alef, Walter. Very long baseline interferometry astrometry of PSR B1257 + 12, a pulsar with a planetary system (Eng.) // Monthly Notices of the Royal Astronomical Society : journal. - Oxford University Press , 2013 .-- Vol. 433 . - P. 162-169 . - DOI : 10.1093 / mnras / stt712 . - .
- ↑ 1 2 3 4 5 6 Konacki, M .; Wolszczan, A. Masses and Orbital Inclinations of Planets in the PSR B1257 + 12 System // The Astrophysical Journal : journal. - IOP Publishing 2003. - Vol. 591 , no. 2 . - P. L147 — L150 . - DOI : 10.1086 / 377093 . - . - arXiv : astro-ph / 0305536 .
- ↑ 1 2 Dumé, Belle Astronomers find smallest exoplanet . PhysicsWeb (February 11, 2005).
- ↑ NameExoWorlds: An IAU Worldwide Contest to Name Exoplanets and their Host Stars . IAU.org (July 9, 2014).
- ↑ Final Results of NameExoWorlds Public Vote Released . IAU.org (December 15, 2015).