PSR J1719-1438
Observation data
Epoch MJD 55411.0[1]      Equinox J2000
Constellation Serpens
Right ascension 17:19:10.0730(1)[1]
Declination −14:38:00.96(2)[1]
Characteristics
Spectral type millisecond pulsar[1]
Apparent magnitude (R) >25.4[1]
Apparent magnitude (g) >24.1[1]
Apparent magnitude (I) >22.5[1]
Astrometry
Distance~1,200[1] pc
Orbit[1]
PrimaryPSR J1719-1438
CompanionPSR J1719-1438b
Period (P)2 hours 10 minutes 37.0237 ±0.0002 seconds
Semi-major axis (a)0.001819(1) light seconds
Eccentricity (e)<0.06
Periastron epoch (T)MJD 55411.0
Details
Other designations
PSR J1719-14
Database references
SIMBADdata

PSR J1719-1438 is a millisecond pulsar with a spin period of 5.8 ms located about 4,000 ly from Earth in the direction of Serpens Cauda,[1][2] one minute from the border with Ophiuchus. Millisecond pulsars are generally thought to begin as normal pulsars and then spin up by accreting matter from a binary companion.

The location of PSR J1719-1438 (circled in red)

Diamond planet

The PSR J1719-1438 planetary system
Companion
(in order from star)		 Mass Semimajor axis
(AU)		 Orbital period
(hours)		 Eccentricity Inclination Radius
b ~1.02 MJ 0.004 2.176951032 <0.06 — ≤0.4 RJ

PSR J1719-1438 was discovered in 2011 by the High Time Resolution Survey, a radio astronomy search for astronomical objects that rapidly vary in radio brightness, such as pulsars.[1] Timing measurements using the Parkes Telescope and Lovell Telescope showed that it has a low-mass companion: PSR J1719-1438 b.[1] The companion has a mass similar to that of Jupiter, but 40% of the diameter. It orbits the pulsar with a period of 2 hours 10 minutes and 37 seconds, at a distance of around 600,000 km (0.89 solar radii).[1] The companion is likely the remnant of a star whose outer layers were siphoned off by the more massive pulsar. Calculations show the companion has a minimum density of 23 grams per cubic centimeter and is probably an ultra-low-mass carbon–oxygen white dwarf.[1]

Because the companion to PSR J1719-1438 is planet-sized, made primarily of carbon (with an unknown amount of oxygen), and very dense, it may be similar to a large diamond. In the science press, the object has been called the "Diamond Planet".[2][3][4]

A lump of QCD matter

It has been suggested in 2012 that PSR J1719-1438 b may not be the remnant of a white dwarf, but a lump of quark matter with a size of just 1 kilometer and the mass of Jupiter,[5] that would have been born in the collision and merger of two previous quark stars, part of the ejected matter ending orbiting the merger remnant we see as the pulsar PSR J1719-1438.[6]

See also

  • Black Widow Pulsar – Pulsar in the constellation Sagitta
  • EF Eridani, a star system with a compact star and a degraded planetary-mass former star
  • PSR J1544+4937 – Pulsar

References

  1. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 Bailes, M.; Bates, S. D.; Bhalerao, V.; Bhat, N. D. R.; Burgay, M.; Burke-Spolaor, S.; d'Amico, N.; Johnston, S.; et al. (2011). "Transformation of a Star into a Planet in a Millisecond Pulsar Binary". Science. 333 (6050): 1717–20. arXiv:1108.5201. Bibcode:2011Sci...333.1717B. doi:10.1126/science.1208890. PMID 21868629. S2CID 206535504.
  2. 1 2 "Star Transforms into A Diamond Planet". Universe Today. 25 August 2011. Retrieved 26 August 2011.
  3. ↑ "Surprise! Alien Planet Made of Diamond Discovered". Space.com. 25 August 2011. Retrieved 25 August 2011.
  4. ↑ "A Planet made of Diamond". Max Planck Institut for Radio Astronomy. Archived from the original on 14 September 2011. Retrieved 26 August 2011.
  5. ↑ Horvath, J. E. (2012). "The nature of the companion of PSR J1719-1438: a white dwarf or an exotic object?". Research in Astronomy and Astrophysics. 12 (7): 813–816. arXiv:1205.1410. Bibcode:2012RAA....12..813H. doi:10.1088/1674-4527/12/7/009. S2CID 119260648.
  6. ↑ Bauswein, A.; Janka, H. -T.; Oechslin, R.; Pagliara, G.; Sagert, I.; Schaffner-Bielich, J.; Hohle, M. M.; Neuhäuser, R. (2009). "Mass Ejection by Strange Star Mergers and Observational Implications". Physical Review Letters. 103 (1): 011101. arXiv:0812.4248. Bibcode:2009PhRvL.103a1101B. doi:10.1103/PhysRevLett.103.011101. PMID 19659133. S2CID 24542292. 011101.
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