Masses and Orbital Inclinations of Planets in the PSR B1257+12 System

Maciej Konacki, Alex Wolszczan
2003 Astrophysical Journal  
We present measurements of the true masses and orbital inclinations of the two Earth-mass planets in the PSR B1257+12 system, based on the analysis of their mutual gravitational perturbations detectable as microsecond variations of the arrival times of radio pulses from the pulsar. The 6.2-millisecond pulsar, PSR B1257+12, has been regularly timed with the Arecibo telescope since late 1990. Assuming the standard pulsar mass of 1.4 M_Sun, the derived masses of planets B and C are 4.3 +/- 0.2
more » ... are 4.3 +/- 0.2 M_Earth and 3.9 +/- 0.2 M_Earth, respectively. The corresponding orbital inclinations of 53.4 and 47.3 deg (or 127 and 133 deg) imply that the two orbits are almost coplanar. This result, together with the known near 3:2 resonance between the orbits of the two planets, strongly supports the hypothesis of a disk origin of the PSR B1257+12 planetary system. The system's long-term stability is guaranteed by the low, Earth-like masses of planets B and C.
doi:10.1086/377093 fatcat:lvyvd6lednefpmdivtdioizhmq