PSR B1257+12 B

Planetbox begin
name = PSR B1257+12BPlanetbox 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 = 0.36
eccentricity = 0.0186 ± 0.0002
period = 66.5419 ± 0.0001
ang_dist = 1.2
long_peri = 250.4 ± 0.6
t_peri = 2,449,768.1 ± 0.1
semi-amp = ?Planetbox character
mass = 0.013
mass_earth = 4.3 ± 0.2 Planetbox discovery
discovery_date = 22 January 1992
discoverers = Aleksander Wolszczan
discovery_method = Pulsar Timing
discovery_site = flag|Poland
discovery_status = Published

PSR B1257+12B is an extrasolar planet approximately 980 light-years away in the constellation of Virgo (the Virgin). PSR B1257+12B was the first planet ever discovered outside the Solar system, and is the second object known to be orbiting the pulsar PSR B1257+12. At a distance of 0.36 AU with an orbital period of approximately 66 days. The planet is over four times as massive as the Earth. Because planet B and planet C orbit rather close to each other, they cause measurable perturbations in each other's orbits. As expected, perturbations were detected confirming that the planets are real. Accurate masses of the two planets, as well as their inclinations, were measured by calculating how much the planets interfere each other.

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.

See also

* PSR B1257+12A
* PSR B1257+12C
* PSR B1257+12D

External links

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