RX J1856.5-3754

RX J1856.5-3754

X-ray image of RX J1856.5-3754
Observation data Epoch 1996.7      Equinox J2000.0[1]
Constellation	Corona Australis
Right ascension	18h 56m 35s[1]
Declination	-37° 54′ 36″[1]
Apparent magnitude (V)	~25.6[1]
Details
Mass	0.9 M☉
Radius	1.9 - 4.1 km R☉
Luminosity	? L☉
Temperature	? K
Metallicity	?
Rotation	?
Age	1 million years
Other designations
RX J185635-3754, 1ES 1853-37.9, 1RXS J185635.1-375433
Database references
SIMBAD	data

RX J1856.5-3754 (also called RX J185635-3754, RX J185635-375, and various other designations) is a nearby neutron star in Corona Australis. It is believed to have been created by a supernova explosion of its companion star about one million years ago and is moving 108 km/s across the sky. It was discovered in 1992, and observations in 1996 appeared to confirm that it was a neutron star, the closest neutron star to Earth yet discovered. It was originally thought to be about 150–200 light-years away, but further observations using the Chandra X-ray Observatory in 2002 appear to show that its distance is greater—about 450 light-years. It was once proposed that RX J1856.5-3754 was too small to be a neutron star and may therefore in fact be a quark star (see also 3C58). However, this theory is not currently considered to have much supporting evidence.^{[citation needed]}

References

• http://jumk.de/astronomie/special-stars/rx-j185635-375.shtml
• Walter, Frederick M.; Lattimer, James M., The Astrophysical Journal, 2002

1. ^ ^{a b c d} RX J185635-3754 - an Isolated Neutron Star, F. M. Walter, web page at the Department of Physics and Astronomy, State University of New York at Stony Brook. Accessed on line June 29, 2007.

External links

• The Mystery of the Lonely Neutron Star, European Southern Observatory press release, September 11, 2000. Accessed online at spaceref.com May 20, 2007.
• Closest Known Neutron Star Races Across Sky (space.com)
• Is RX J185635-375 a Quark Star?
• APOD: 2002 April 14 - RX J185635-375: Candidate Quark Star
• Bare Quark Stars or Naked Neutron Stars? The Case of RX J1856.5-3754
• RX J185635-3754 - an Isolated Neutron Star
• News Release STScI-1997-32: Hubble Sees a Neutron Star Alone in Space

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