PSR J1719-1438b

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PSR J1719-1438b is an extrasolar planet that was discovered on August 25, 2011 in an extremely tight orbit around PSR J1719-1438 , a millisecond pulsar .

Due to the presumed origin of this object from a white dwarf, there is disagreement as to whether it should be called an (exo) planet, or more generally as an object of planetary mass , or more specifically e.g. B. as a " charcoal white dwarf of ultra-low mass".

character

PSR J1719-1438b has a diameter of 60,000 km (about half the size of Jupiter ) with a minimum density of 23 grams per cubic centimeter. Its mass is approximately 1.02 masses of Jupiter . The central pulsar planet is almost certainly made up largely of crystalline carbon or diamond . PSR J1719 -1438 b and PSR J1719 -1438 were presumably two stars in an ultra-compact low-mass X-ray binary (UC LMXB) binary star system . After PSR J1719 -1438 had exploded as a supernova and became a slowly rotating pulsar, PSR J1719 -1438 b first went into a red giant phase. The continuous transfer of matter to the pulsar shrank it to a white dwarf, of which only the “naked” core remained, while the pulsar picked up angular momentum due to the constant incidence of matter and accelerated it to a millisecond pulsar.

Due to the extreme conditions of the system, the white dwarf converted into a planet, which is mainly composed of heavy elements such as carbon and oxygen. PSR J1719 -1438 b orbits its central star at a distance of 600,000 km, this is so close that the orbit of the planet would fit into the sun. Furthermore, the planet only takes 2 hours, 10 minutes and 37.0237 seconds (mean error: 20 microseconds) to orbit PSR J1719-1438.

The existence of such diamond planets was postulated theoretically.

See also

Individual evidence

  1. ↑ M. Bailes et al., Transformation of a Star into a Planet in a Millisecond Pulsar Binary , Science 2011, doi : 10.1126 / science.1208890
  2. ↑ Bailes M., Bates, SD, Bhalerao, VB, Bhat, NDR, Burgay M., Burke-Spolaor S., D'Amico N., Johnston S., Keith, MJ, Kramer M., Kulkarni, SR, Levin L., Lyne, AG, Milia S., Possenti A., Spitler L., Stappers B., van Straten W., Transformation of a Star into a Planet in a Millisecond Pulsar Binary , Science 2011, 333 , p. 1717– 1720 doi : 10.1126 / science.1208890 speaks of an "ultralow-mass carbon white dwarf"
  3. ^ Diamonds in the sky, M. Kramer (MPI Bonn) in SuW from 11/2011, page 21