View source for Astronomy:RX J0720.4-3125

{{Starbox begin|name=[http://simbad.u-strasbg.fr/simbad/sim-id?Ident=RX%J0720.4-3125 RX J0720.4-3125]}}
<!--{{Starbox image
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{{Starbox observe
  |epoch=1996.7
|equinox=[[Astronomy:J2000.0|J2000.0]]
  |constell=[[Astronomy:Canis Major|Canis Major]]
  |ra={{RA|07|20|24.961}} 
  |dec={{DEC|-31|25|50.21}}
  |appmag_v=~26.6<ref name="Kaplan1"/>
}}
{{Starbox detail
| mass=
| radius_km=~5
| luminosity=
| temperature=
| metal=
| rotation=
| age=  }}
{{Starbox catalog|names=RX&nbsp;J0720.4-3125, 1ES&nbsp;0718-31.3}}
{{Starbox reference |
  Simbad=1ES+0718-31.3 }}
{{Starbox end}}

'''RX J0720.4-3125''' is a [[Astronomy:Neutron star|neutron star]] in the constellation [[Astronomy:Canis Major|Canis Major]]. It was discovered in 1997 in the ROSAT All-sky survey.<ref name="Kaplan1">{{cite journal|author=Kaplan, D.L.|author2=van Kerkwijk, M.H.|author3=Marshall, H.L.|author4=Jacoby, B.A.|author5=Kulkarni, S. R.|author6=Frail, D.A. |date=2002|title=The Nearby Neutron Star RX J0720.4-3125 from Radio to X-rays|journal=The Astrophysical Journal|volume=590|issue=2|url=http://iopscience.iop.org/0004-637X/590/2/1008|doi=10.1086/375052|arxiv = astro-ph/0303126 |bibcode = 2003ApJ...590.1008K }}</ref> Measurement of its parallax leads to an estimate of around 360 parsecs (1174 light-years) for its distance from Earth.<ref name="Kaplan2">{{cite journal|author=Kaplan, D. L.|author2=van Kerkwijk, M. H.|author3=Anderson, J. |title=The Distance to the Isolated Neutron Star RX J0720.4-3125 | journal=The Astrophysical Journal |volume = 660 | issue= 2 |pages= 1428–43 |bibcode=2007ApJ...660.1428K|arxiv = astro-ph/0703343 |doi = 10.1086/513309 }}</ref> It is a member of the [[Astronomy:The Magnificent Seven (neutron stars)|Magnificent Seven]], a group of neutron stars that are relatively near to the [[Astronomy:Solar System|Solar System]]. RX J0720.4-3125 has a radius of around 5&nbsp;km. Its spectrum and temperature appear to be mysteriously changing over several years. The nature of the changes are unclear, but it is possible there was an event such as the star's absorption of an accretion disc.<ref name="Hohle">{{cite journal|display-authors= 4|author= Hohle, M.M.|author2= Haberl, F.|author3= Vink, J.|author4= de Vries, C.P.|author5= Turolla, R.|author6= Zane, S.|author7= Méndez, M. |title = The Continued Spectral and Temporal Evolution of RX J0720.4-3125 | journal = [[Organization:Monthly Notices of the Royal Astronomical Society|Monthly Notices of the Royal Astronomical Society]] |volume = 423 |issue = 2 |pages= 1194–99 |bibcode=2012MNRAS.423.1194H |arxiv = 1203.3708 |doi = 10.1111/j.1365-2966.2012.20946.x }}</ref>

==References==
{{reflist}}

{{Stars of Canis Major}}

[[Category:Canis Major]]
[[Category:Neutron stars]]
[[Category:ROSAT objects]]

{{Sourceattribution|RX J0720.4-3125|1}}