Van Maanen's star

Starbox begin
name= [http://simbad.u-strasbg.fr/simbad/sim-id?Ident=NAME%20VAN%20MAANEN'S%20STAR Van Maanen's star] Starbox observe
epoch=J2000.0 (ICRS)
constell=Pisces
ra=RA|00|49|09.8992SIMBAD link|NAME+VAN+MAANEN'S+STAR|NAME VAN MAANEN'S STAR -- White Dwarf, entry, SIMBAD. Accessed on line July 9, 2008.]
dec=DEC|+05|23|19.007
appmag_v=12.36 Starbox character
class=DZ7 [ [http://webviz.u-strasbg.fr/viz-bin/VizieR-S?WD%200046%2b051 WD 0046+051] , database entry, Spectroscopically Identified White Dwarfs (4th edition, v.2), G. P. McCook and E. M. Sion, CDS ID [http://vizier.u-strasbg.fr/viz-bin/Cat?III/210 III/210] .]
b-v=0.56
u-b=0.02
v-r=0.5
r-i=0.4
variable=None Starbox astrometry
radial_v=+6 ± 15 [http://adsabs.harvard.edu/abs/1974AJ.....79..815G Astrometric determination of the gravitational redshift of van Maanen 2 (EG 5)] , George Gatewood and Jane Russell, "Astronomical Journal" 79, #7 (July 1974), pp. 815–818. See §III for adopted values of mass, radius and gravity.]
prop_mo_ra=1231.72
prop_mo_dec=-2707.67
parallax=231.88
p_error=1.79
parallax_footnote=Entry, [http://nstars.nau.edu/index.cfm?fuseaction=singleSearch.astrometry&SystemID=0049p0523 0049+0523] , astrometry, NStars database. Accessed on line July 9, 2008.]
absmag_v=14.1 [From parallax and apparent magnitude.] Starbox detail
mass=0.7 ± 0.3
radius=0.013 ± 0.002
gravity=8.0 ± 0.3
luminosity=<0.0002
temperature=6750Mid-Infrared Observations of van Maanen 2: No Substellar Companion, J. Farihi and E. E. Becklin, "Astrophysical Journal Letters" 608 (June 20, 2004), pp. L109&ndash;L112, bibcode|2004ApJ...608L.109F, doi|10.1086/422502.]
age=~4&times;10⁹Starbox catalog
names=van Maanen 2, G 001-027, Gliese 35, GCTP 160.00, HIP 3829, LFT 76, LHS 7, LTT 10292, WD 0046+051Starbox reference
Simbad=HIP+3829

Van Maanen's star is a white dwarf star. Out of the white dwarfs known, it is the third closest to the Sun, after Sirius B and Procyon B, in that order, and the closest known solitary white dwarf. [http://www.chara.gsu.edu/~thenry/RECONS/TOP100.posted.htm The One Hundred Nearest Star Systems] , RECONS, January 1, 2008; accessed online July 9, 2008.] Discovered in 1917 by Adriaan van Maanen [ [http://adsabs.harvard.edu/abs/1917PASP...29..258V Two Faint Stars with Large Proper Motion] , A. van Maanen, "Publications of the Astronomical Society of the Pacific" 29 (#172), December 1917, pp. 258&ndash;259.] , Van Maanen's star was the third white dwarf identified, after 40 Eridani B and Sirius B."White Dwarfs", E. Schatzman, Amsterdam: North-Holland, 1958.] ^{, p. 2}

Characteristics

Van Maanen's star is located 14.1 light years from the Sun in the constellation Pisces, and has a relatively high proper motion of 2.98" annually. It is far too faint to be seen with the naked eye. Its mass has been estimated to be about 70% of the Sun's, with a diameter roughly 1% of the Sun's. It is under 2/10,000 times as luminous as the Sun. [http://www.solstation.com/stars/v-maanen.htm Van Maanen's Star] , solstation.com, accessed on line July 12, 2008.] It has a relatively cool temperature of approximately 6750 K. As white dwarfs cool with time, this can be used to estimate the age of the star, thought to be around 4 billion years.

Possible Companion

The possible existence of a substellar companion has been controversial for over 30 years, with various detections and negations. As recently as 2004, there was one paper confirming and one denying its detection. [See Makarov, "A Substellar Companion to van Maanen 2" (Astrophys. J., 600, L71-L73 (2004), bibcode|2004ApJ...600L..71M), and Farihi et al., and "Mid-infrared observations of Van Maanen 2: no substellar companion" (Astrophys. J., 608, L109-L112 (2004), bibcode|2004ApJ...608L.109F.)]

ee also

* List of nearest stars
* List of stars named after people
* Van Maanen's star in fiction

References

External links

* http://www.richweb.f9.co.uk/astro/nearby_stars.htm