View source for Astronomy:PSR J1719-1438 b

{{Planetbox begin 
| name = PSR J1719-1438 b
}}
{{Planetbox star
| star = [[Astronomy:PSR J1719-1438|PSR J1719-1438]]
| constell = [[Astronomy:Serpens|Serpens]]
| RA = {{RA|17|19|10}}
| DEC = {{DEC|−14|38|01}}
| dist_ly =  ~3900
| dist_pc = ~1200
| class = [[Astronomy:Pulsar|Pulsar]]
| mass = ~1.4
| radius = 
| age = >12.5
}}
{{Planetbox orbit 
| semimajor = 0.004
| eccentricity = < 0.06
| period = 0.090706293
| period_hour = 2.176951032
| arg_peri = 
| t_peri = 2,455,235.51652439
| inclination = 
}}
{{Planetbox character
| mass = ~1.02
| mass_earth = ~330
| radius = ≤0.4
| radius_earth = ≤4
| density_cgs = ≥23
}} 
{{Planetbox discovery 
| discovery_date = 25 August 2011
| discoverers = Matthew Bailes et al.
| discovery_method = Pulsar timing
| discovery_site = [[Astronomy:Parkes Observatory|Parkes Observatory]], Australia
| discovery_status = Confirmed
}}
{{Planetbox reference
| star = PSR+1719-14
| planet = b
}}

'''PSR J1719-1438 b''' is an extrasolar planet that was discovered on August 25, 2011 in orbit around [[Astronomy:PSR J1719-1438|PSR J1719-1438]], a [[Astronomy:Millisecond pulsar|millisecond pulsar]]. The [[Astronomy:Pulsar planet|pulsar planet]] is most likely composed largely of crystalline carbon, but with a [[Physics:Density|density]] far greater than [[Chemistry:Diamond|diamond]].<ref name=Reuters /><ref name="Bailes2011">{{cite journal |doi=10.1126/science.1208890 |title=Transformation of a Star into a Planet in a Millisecond Pulsar Binary |year=2011 |last1=Bailes |first1=M. |last2=Bates |first2=S. D. |last3=Bhalerao |first3=V. |last4=Bhat |first4=N. D. R. |last5=Burgay |first5=M. |last6=Burke-Spolaor |first6=S. |last7=d'Amico |first7=N. |last8=Johnston |first8=S. |last9=Keith |first9=M. J. |journal=Science |url=http://www.swinburne.edu.au/chancellery/mediacentre/resources/Diamond-planet-Science.pdf|bibcode = 2011Sci...333.1717B |pmid=21868629 |volume=333 |issue=6050 |pages=1717–20|arxiv = 1108.5201 |display-authors=9 |last10=Kramer |first10=M. |last11=Kulkarni |first11=S. R. |last12=Levin |first12=L. |last13=Lyne |first13=A. G. |last14=Milia |first14=S. |last15=Possenti |first15=A. |last16=Spitler |first16=L. |last17=Stappers |first17=B. |last18=Van Straten |first18=W. }}</ref> PSR J1719-1438 b orbits so closely to its host star, the planet's orbit would fit inside the [[Astronomy:Sun|Sun]]. The existence of such [[Astronomy:Carbon planet|carbon planet]]s had been theoretically postulated.

==Observational history==

PSR J1719-1438 was first observed in 2009 by a team headed by Matthew Bailes of Swinburne University of Technology in Melbourne, Australia. The orbiting planet was published in the journal ''Science'' on August 25, 2011.<ref name=Space/> The planet was confirmed through pulsar timing, in which small modulations detected in the highly regular pulsar signature are measured and extrapolated.<ref name=PC/> Observatories in Britain, Hawaii, and Australia were used to confirm these observations.<ref name=Reuters />

==Host star==
{{main|Astronomy:PSR J1719-1438}}
PSR J1719-1438 is a pulsar some 4,000 [[Light year|light year]]s away from Earth in the Serpens Cauda constellation, approximately one minute from the border with Ophiuchus. The pulsar completes more than 10,000 rotations a minute. It is approximately 12 miles across, but has a mass that is 1.4 [[Astronomy:Solar mass|solar mass]]es.<ref name=Space />

==Characteristics==

PSR J1719-1438 b was, at the time of its August 25, 2011 discovery, the densest planet ever discovered, at nearly 20 times the density of Jupiter (about 23 times the density of water).<ref name=Reuters /> It is slightly more massive than Jupiter.<ref name=Reuters /> It is thought to be composed of oxygen and carbon (as opposed to hydrogen and helium, the main components of [[Astronomy:Gas giant|gas giant]]s like Jupiter and Saturn).

The oxygen is most likely on the surface of the planet, with increasingly higher quantities of carbon deeper inside the planet. The intense pressure acting upon the planet suggests that the carbon is crystallized, much like [[Chemistry:Diamond|diamond]] is.<ref name=Reuters />

PSR J1719-1438 b orbits its host star with a period of 2.177 hours and at a distance of a little bit less than one (0.89) solar radius.<ref name=Reuters />

==See also==
* [[Astronomy:WASP-12b|WASP-12b]], a carbon planet
* [[Astronomy:BPM 37093|BPM 37093]], a carbon star
* [[Astronomy:EF Eridani|EF Eridani]], a star system with a compact star and a degraded planetary-mass former star

==References==
{{reflist|refs=

<ref name=Space>{{cite news |url=http://www.space.com/12731-diamond-alien-planet-discovered-neutron-star.html |title=Surprise! Alien Planet Made of Diamond Discovered |first=Nola Taylor |last=Redd |date=25 August 2011 |publisher=TechMediaNetwork |accessdate=25 August 2011}}</ref>
<ref name=Reuters>{{cite news |url=https://www.reuters.com/article/2011/08/25/us-planet-diamond-idUSTRE77O69A20110825 |title=Astronomers discover planet made of diamond |first=Ben |last=Hirschler |date=25 August 2011 |agency={{wipe|Reuters}} |accessdate=25 August 2011}}</ref>
<ref name=PC>{{cite news |url=https://www.pcmag.com/article2/0,2817,2391879,00.asp |title=Scientists Discover 'Diamond Planet' Orbiting Pulsar |first=Mark |last=Hachman |date=25 August 2011 |publisher=Ziff Davis |accessdate=25 August 2011}}</ref>

}}

==Further reading==
*{{cite journal |doi=10.1126/science.1208890 |title=Transformation of a Star into a Planet in a Millisecond Pulsar Binary |year=2011 |last1=Bailes |first1=M. |last2=Bates |first2=S. D. |last3=Bhalerao |first3=V. |last4=Bhat |first4=N. D. R. |last5=Burgay |first5=M. |last6=Burke-Spolaor |first6=S. |last7=d'Amico |first7=N. |last8=Johnston |first8=S. |last9=Keith |first9=M. J. |journal=Science |url=http://www.swinburne.edu.au/chancellery/mediacentre/resources/Diamond-planet-Science.pdf|bibcode = 2011Sci...333.1717B |pmid=21868629 |volume=333 |issue=6050 |pages=1717–20|arxiv = 1108.5201 |display-authors=9 |last10=Kramer |first10=M. |last11=Kulkarni |first11=S. R. |last12=Levin |first12=L. |last13=Lyne |first13=A. G. |last14=Milia |first14=S. |last15=Possenti |first15=A. |last16=Spitler |first16=L. |last17=Stappers |first17=B. |last18=Van Straten |first18=W. }}
*{{cite press release|title=A Planet made of Diamond |publisher=[[Organization:Max Planck Institute for Radio Astronomy|Max Planck Institute for Radio Astronomy]] |date=August 25, 2011 |url=http://www.mpifr-bonn.mpg.de/public/pr/pr-pulsar-august2011-en.html |accessdate=August 26, 2011 |deadurl=yes |archiveurl=https://web.archive.org/web/20110914234539/http://www.mpifr-bonn.mpg.de/public/pr/pr-pulsar-august2011-en.html |archivedate=September 14, 2011 |df= }}
*{{cite journal |doi=10.1073/pnas.0510489103 |title=Carbon under extreme conditions: Phase boundaries and electronic properties from first-principles theory |year=2006 |last1=Correa |first1=Alfredo A. |first2=Stanimir A. |last2=Bonev |first3=Giulia |last3=Galli |journal=Proceedings of the National Academy of Sciences |volume=103 |issue=5 |pmid=16432191 |pages=1204–8 |pmc=1345714|bibcode = 2006PNAS..103.1204C }}

{{s-start}}
{{s-bef|before=[[Astronomy:Kepler-10b|Kepler-10b]]}}
{{s-ttl|title=Most dense planet|years=2011&nbsp;—2015}}
{{s-aft|after=[[Astronomy:K2-22b|K2-22b]]}}
{{s-end}}

[[Category:Pulsar planets]]
[[Category:Serpens (constellation)]]

{{Sourceattribution|PSR J1719-1438 b|1}}