PSR B1257+12 A

Planetbox begin
name = PSR B1257+12APlanetbox image


caption = An artist's impression of the radiated
surface of PSR B1257+12A.Planetbox star
star = PSR B1257+12
constell = Virgo
RA = RA|13|00|01
DEC = DEC|+12|40|57
dist_ly = 980
dist_pc = 300
class = PulsarPlanetbox orbit
semimajor = 0.19
eccentricity = 0.00
period = 25.262 ± 0.003
ang_dist = 0.633
long_peri = 0
t_peri = 2,449,765.6 ± 0.2
semi-amp = ?Planetbox character
mass = 7e-05
mass_earth = 0.025 Planetbox discovery
discovery_date = 23 September 1994
discoverers = Aleksander Wolszczan
discovery_method = Pulsar Timing
discovery_site = flag|Poland
discovery_status = Published

PSR B1257+12A is an extrasolar planet approximately 980 light-years away in the constellation of Virgo (the Virgin). The planet is the innermost object orbiting the pulsar PSR B1257+12, making the planet a pulsar planet. In 1997, it was claimed that this planet was in fact an artifact caused by solar wind, but this claim has since been disproved. It is about twice as massive as Earth's Moon.

Name

It should be noted that the planets of PSR B1257+12 are designated from A to D (ordered by increasing distance). The reason that these planets are not named the same as other extrasolar planets is mainly because of time. Being the first "ever" planets discovered, and being discovered around a pulsar, the planets were given the uppercase letters "B" and "C" (like other planets). When a third planet was discovered around the system (in a closer orbit then the other two), the name "A" was commonly used. 51 Pegasi b (the first planet found around a Sun-like star), paved the way of naming planets. Though these pulsar planets were not renamed, some have taken the liberty to do it themselves. PSR B1257+12A is cataloged as "PSR 1257+12b" on the Extrasolar Planets Encyclopaedia. [http://exoplanet.eu/star.php?st=PSR+1257%2B12]

See also

* PSR B1257+12B
* PSR B1257+12C
* PSR B1257+12D

External links

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* [http://www.astro.psu.edu/users/alex/pulsar_planets.htm Pulsar Planets]