Pulsar planets are planets that are found orbiting pulsars, or rapidly rotating neutron stars. The first such planets to be discovered were around a millisecond pulsar and were the first extrasolar planet to be confirmed as discovered.
History
Pulsar planets are discovered through pulsar timing measurements, to detect anomalies in the pulsation period. Any bodies orbiting the pulsar will cause regular changes in its pulsation. Since pulsars normally rotate at near-constant speed, any changes can easily be detected with the help of precise timing measurements. The discovery of pulsar planets was unexpected; pulsars or neutron stars have previously gone supernova, and it was thought that any planets orbiting such stars would have been destroyed in the explosion.
In 1991, Andrew G. Lyne announced the first-ever pulsar planet discovered around PSR 1829–10.[1] However, this was later retracted,[2] just before the first real pulsar planets were announced.
In 1992, Aleksander Wolszczan and Dale Frail announced the discovery of a multi-planet planetary system around the millisecond pulsar PSR 1257+12.[3] These were the first two extrasolar planets confirmed to be discovered, and thus the first multi-planet extrasolar planetary system discovered, and the first pulsar planets discovered. There was doubt concerning the discovery because of the retraction of the previous pulsar planet, and questions about how pulsars could have planets. However, the planets proved to be real.[4] Two additional planets of lower mass were later discovered by the same technique, although one has since been retracted.
In 2000, the millisecond pulsar PSR B1620−26 was found to have a circumbinary planet (PSR B1620−26 b) that orbits both it and its companion white dwarf, WD B1620–26. This was announced as the oldest planet ever discovered, at 12.6 billion years old.[5] It is currently believed to have originally been the planet of WD B1620–26 before becoming a circumbinary planet, and therefore, while discovered through the pulsar timing method, it did not form the way that PSR B1257+12's planets are thought to have.
In 2006, the magnetar 4U 0142+61, located 13,000 light-years (1.2×1017 km) from Earth, was found to have a circumstellar disk. The discovery was made by a team led by Deepto Chakrabarty of MIT using the Spitzer Space Telescope.[6] The disk is thought to have formed from metal-rich debris left over from the supernova that formed the pulsar roughly 100,000 years ago and is similar to those seen around Sun-like stars, suggesting it may be capable of forming planets in a similar fashion. Pulsar planets would be unlikely to harbour life as we know it, because the high levels of ionizing radiation emitted by the pulsar and the corresponding paucity of visible light.
In 2011, a planet that is theorized to be the remaining core of a star that orbited a pulsar was announced. It orbits millisecond pulsar PSR J1719−1438, and represents a path to planetary status by evaporation of a star.[7][8] The planet is estimated to have a density of at least 23 times that of water, a diameter of 55,000 km, a mass near that of Jupiter's, and a 2-hour, 10-minute orbital period at 600,000 km. It is thought to be the diamond crystal core remaining from the evaporated white dwarf, with an estimated weight of 2.0×1027 kg (1×1031 carats).[9][10]
There are three types of pulsar planets known so far. The PSR B1257+12 planets were formed out of the debris of a destroyed companion star that used to orbit the pulsar.[11] In PSR J1719-1438, the planet most likely is the companion, or what's left of it after being almost entirely blasted away by the extreme irradiation from the nearby pulsar. PSR B1620–26 b is most likely a captured planet.
List of pulsar planets
Confirmed planets
Pulsar Planetary object Mass Semimajor axis
(AU) Orbital period Discovered
PSR B1620–26 PSR B1620–26 b 2.5 MJ 23 100 years 2003
PSR B1257+12 PSR B1257+12 A 0.020 M⊕ 0.19 25.262±0.003 days 1994
PSR B1257+12 B 4.3 M⊕ 0.36 66.5419±0.0001 days 1992
PSR B1257+12 C 3.90 M⊕ 0.46 98.2114±0.0002 days 1992
PSR B0943+10 PSR B0943+10 b 2.8 MJ 1.8 730 days 2014
PSR B0943+10 c 2.6 MJ 2.9 1460 days 2014
PSR B0329+54 PSR B0329+54 b 1.97 ± 0.19 M⊕ 10.26 ± 0.07 27.76 ± 0.03 years 2017
Candidate planets
Pulsar Planetary object Mass Semimajor axis
(AU) Orbital period Announced
PSR J1719-1438 PSR J1719-1438 b ~1 MJ 0.004 2.176951032 hours 25 August 2011
Doubtful planets
Pulsar Planetary object Mass Semimajor axis
(AU) Orbital period Announced
Geminga Geminga b 1.7 M⊕ 3.3 5.1 years 1997
PSR B0329+54 PSR B0329+54 A 0.3 M⊕ 2.3 1205.358±0.003 days 1979
PSR B1828-10 PSR B1828-10 A 3 M⊕ 0.93 384.3649 days 1992
PSR B1828-10 B 12 M⊕ 1.32 493.077375 days 1992
PSR B1828-10 C 8 M⊕ ? ? 1992
Protoplanetary disks (fallback disks)
Pulsar Protoplanetary disk Discovered
4U 0142+61 debris disk 2006
1E 2259+586 candidate debris disk 2009[12]
Disproven planets
Pulsar Planet Mass
PSR 1829-10 PSR 1829-10 A 10 M⊕
PSR B1257+12 PSR B1257+12 D[13] 0.0004 M⊕
See also
Lists of exoplanets
List of stars with proplyds
Exoplanet
Dale Frail
Andrew Lyne
Aleksander Wolszczan
References
Nature vol.352 no.6333 : A planet orbiting the neutron star PSR1829–10
Nature vol.355 no.6357 : No planet orbiting PS R1829–10
Wolszczan, A.; Frail, D. (1992). "A planetary system around the millisecond pulsar PSR1257 + 12". Nature. 355 (6356): 145–147. Bibcode:1992Natur.355..145W. doi:10.1038/355145a0. S2CID 4260368.
Wolszczan, A. (1994). "Confirmation of Earth Mass Planets Orbiting the Millisecond Pulsar PSR B1257+12". Science. 264 (5158): 538–542. Bibcode:1994Sci...264..538W. doi:10.1126/science.264.5158.538. PMID 17732735. S2CID 19621191.
Britt, Robert Roy. "Primeval Planet: Oldest Known World Conjures Prospect of Ancient Life". Space.com. Retrieved 2020-10-28.
"Scientists crack mystery of planet formation". CNN.com. April 5, 2006. Archived from the original on 2006-04-08. Retrieved 2006-04-05.
Max Planck Institute, "A Planet made of Diamond" Archived 2011-09-14 at the Wayback Machine, 25 August 2011
Reuters, "Astronomers discover planet made of diamond", Ben Hirschler, 25 August 2011
National Geographic, "Diamond" Planet Found; May Be Stripped Star", Andrew Fazekas, 25 August 2011
New Scientist, "Astrophile: The diamond as big as a planet", David Shiga, 25 August 2011
Very long baseline interferometry astrometry of PSR B1257+12, a pulsar with a planetary system
Kaplan, David L.; Chakrabarty, Deepto; Wang, Zhongxiang; Wachter, Stefanie (July 2009). "A Mid-Infrared Counterpart to the Magnetar 1E 2259+586". Astrophysical Journal. 700 (1): 149–154. arXiv:0906.1604. Bibcode:2009ApJ...700..149K. doi:10.1088/0004-637X/700/1/149. ISSN 0004-637X. S2CID 9937378.
Wolszczan, Alex (January 2012). "Discovery of pulsar planets". New Astronomy Reviews. Elsevier. 56 (1): 2–8. Bibcode:2012NewAR..56....2W. doi:10.1016/j.newar.2011.06.002.
vte
Exoplanetology
Planet
Definition
IAU Planetary science
Main topics
Exoplanet Methods of detecting exoplanets Planetary system Planet-hosting stars
PDS 70.jpg
Sizes
and types
Terrestrial
Carbon planet Coreless planet Desert planet Dwarf planet Ice planet Iron planet Lava planet Ocean planet Mega-Earth Sub-Earth Super-Earth
Gaseous
Eccentric Jupiter Gas dwarf Helium planet Hot Jupiter Hot Neptune Ice giant Mini-Neptune Super-Neptune Super-Jupiter Super-puff Ultra-hot Jupiter Ultra-hot Neptune
Other types
Blanet Brown dwarf Chthonian planet Circumbinary planet Disrupted planet Double planet Eyeball planet Giant planet Mesoplanet Planemo Planet/Brown dwarf boundary Planetesimal Protoplanet Pulsar planet Sub-brown dwarf Sub-Neptune Ultra-cool dwarf Ultra-short period planet (USP)
Formation
and evolution
Accretion Accretion disk Asteroid belt Circumplanetary disk Circumstellar disc Circumstellar envelope Cosmic dust Debris disk Detached object Disrupted planet Excretion disk Exozodiacal dust Extraterrestrial materials Extraterrestrial sample curation Giant-impact hypothesis Gravitational collapse Hills cloud Interplanetary dust cloud Interplanetary medium Interplanetary space Interstellar cloud Interstellar dust Interstellar medium Interstellar space Kuiper belt List of interstellar and circumstellar molecules Merging stars Molecular cloud Nebular hypothesis Oort cloud Outer space Planetary migration Planetary system Planetesimal Planet formation Protoplanetary disk Ring system Rubble pile Sample-return mission Scattered disc Star formation
Systems
Exocomet
Interstellar Exomoon
Tidally detached Rogue planet Orbits
Retrograde Trojan Mean-motion resonances Titius–Bode law
Host stars
A B Binary star Brown dwarfs F/Yellow-white dwarfs G/Yellow dwarfs Herbig Ae/Be K/Orange dwarfs M/Red dwarfs Pulsar Red giant Subdwarf B Subgiant T Tauri White dwarfs Yellow giants
Detection
Astrometry Direct imaging
list Microlensing
list Polarimetry Pulsar timing
list Radial velocity
list Transit method
list Transit-timing variation
Habitability
Astrobiology Circumstellar habitable zone Earth analog Extraterrestrial liquid water Habitability of natural satellites Superhabitable planet
Catalogues
Nearby Habitable Systems Exoplanet Data Explorer Extrasolar Planets Encyclopaedia NASA Exoplanet Archive NASA Star and Exoplanet Database
Lists
Exoplanetary systems
Host stars Multiplanetary systems Stars with proto-planetary discs
Exoplanets
Discoveries Extremes Firsts Nearest Largest Heaviest Terrestrial candidates Kepler Potentially habitable Proper names
Discovered exoplanets by year
before 2000 2000–2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020
Other
Carl Sagan Institute Exoplanet naming convention Exoplanet phase curves Exoplanetary Circumstellar Environments and Disk Explorer Extragalactic planet Fulton gap Geodynamics of terrestrial exoplanets Neptunian Desert Nexus for Exoplanet System Science Planets in globular clusters Planets in science fiction Sudarsky's gas giant classification
Planetary (PPNe) Supernova remnants (SNRs)
Hellenica World - Scientific Library
Retrieved from "http://en.wikipedia.org/"
All text is available under the terms of the GNU Free Documentation License
