Changes

| image          =Barnardstar2006.jpg

| image          =Barnardstar2006.jpg

| designation    =Gliese 699<br/>V2500 Ophiuchi

| designation    =Gliese 699<br/>V2500 Ophiuchi

| rightascension  =17^h 57^m 48.5^s

| rightascension  =17^h 57^m 48.49803^s<ref name=hipp>van Leeuwen, F. (2007). Validation of the new Hipparcos reduction. ''Astronomy & Astrophysics'', 474(2), pp.653-664. [https://arxiv.org/abs/0708.1752 arXiv:0708.1752]</ref><ref name=simbad>[http://simbad.u-strasbg.fr/simbad/sim-id?Ident=Barnard%27s+star&NbIdent=1&Radius=2&Radius.unit=arcmin&submit=submit+id Barnard's Star] from the [http://simbad.u-strasbg.fr/simbad SIMBAD Astronomical Database]</ref>

| declination    =+04^o 41′ 36″

| declination    =+04° 41′ 36.2072″<ref name=hipp/>

| distance        =5.98 ly

| distance        =5.98 ly

| constellation  =Ophiuchus

| constellation  =Ophiuchus

| type            =Star

| type            =Red dwarf

| dimensions      =

| dimensions      =

| magnitude      =Apparent Mag: 9.54<br />Absolute Mag: 13.22  

| magnitude      =Apparent Mag: 9.54<ref>Koen, C., Kilkenny, D., van Wyk, F. and Marang, F. (2010). UBV(RI)C JHKobservations of Hipparcos-selected nearby stars. ''Monthly Notices of the Royal Astronomical Society'', 403(4), pp.1949-1968.</ref><br/>Absolute Mag: 13.22<ref>From definition of absolute magnitude, using apparent magnitude (+9.511) and distance (5.98 ly) given here.</ref>

| redshift        =

| redshift        =

| radvelocity    =<nowiki>-106.8 km/s</nowiki>

| radvelocity    =-110.5±0.1 km/s<ref>Nidever, D., Marcy, G., Butler, R., Fischer, D. and Vogt, S. (2002). Radial Velocities for 889 Late‐Type Stars. ''The Astrophysical Journal Supplement Series'', 141(2), pp.503-522. [https://arxiv.org/abs/astro-ph/0112477 arXiv:astro-ph/0112477]</ref>

| propmotion      =RA: -798.71 mas/yr<br/>Dec.: 10337.77[1] mas/yr

| propmotion      =RA: -798.71 mas/yr<ref name=hipp/><br/>Dec.: 10337.77 mas/yr<ref name=hipp/>

| parallax        =545.4 ± 0.3 mas

| parallax        =548.31±1.51 mas<ref name=hipp/>

}}

}}

'''Barnard's Star''' is a very cool and dim star that is the third closest star to our [[solar system]] after [[Proxima Centauri]] and [[Alpha Centauri|Alpha Centauri AB]] respectively, located some 6 [[light year]]s from Sol in the constellation of [[Ophiuchus]].<ref>http://www.chara.gsu.edu/RECONS/TOP100.posted.htm</ref>  

'''Barnard's Star''' is a very cool and dim star that is the third closest star to our [[solar system]] after [[Proxima Centauri]] and [[Alpha Centauri|Alpha Centauri AB]] respectively, located some 6 [[light year]]s from Sol in the constellation of [[Ophiuchus]].<ref>[https://www.britannica.com/place/Barnards-star Barnard's Star] from britanica.com</ref>  

The star was first discovered in 1916 by and then named after American astronomer E. E. Barnard, and like [[Proxima Centauri]] is too dim to be viewed by the unaided eye. Barnard noticed in his observations, that the star has the largest known proper motion of all known stars. This is due to the star's closeness to our own [[Solar System]] and actual travel speed through space.<ref>http://adsabs.harvard.edu/cgi-bin/nph-bib_query?bibcode=1916AJ.....29..181B</ref> Barnard's Star is approaching our own system at the speed of 140 kilometers per second and will approach as close as 3.8 light years (making it the closest star) around 11,800 A.D. before receding.  

The star was first discovered in 1916 by and then named after American astronomer E. E. Barnard, and like [[Proxima Centauri]] is too dim to be viewed by the unaided eye. Barnard noticed in his observations, that the star has the largest known proper motion of all known stars, moving around 10 arcsecond per year.<ref name=hipp/> This is due to the star's closeness to our own [[Solar System]] and actual travel speed through space.<ref>Barnard, E. (1916). A small star with large proper-motion. ''The Astronomical Journal'', 29, p.181. [http://adsabs.harvard.edu/abs/1916AJ.....29..181B Online]</ref> Barnard's Star is approaching our own system at the speed of 140 kilometers per second and will approach as close as 3.8 light years (making it the closest star) around 11,800 A.D. before receding.  

Barnard's Star is classified as a spectral type M4.0Ve red dwarf, with only 17 percent of Sol's mass, some 15 to 20 percent of its diameter, but only estimated to have .04% of the luminosity of our star. If the Earth orbited Barnard's Star at the same distance as we orbit the sun, the star would be only 100 times more bright then the full moon.<ref>http://www.solstation.com/stars/barnards.htm</ref> The star is relativity inactive, and has a rotation period of only 130.4 days, typical for an older [[red dwarf]] star. Barnard's Star however isn't completely inactive, but in 1998 a flare was observed, which scientists believed would be unlikely on such an old star.   

Barnard's Star is classified as a spectral type M4.0Ve red dwarf, with only 17 percent of Sol's mass, some 15 to 20 percent of its diameter, but only estimated to have 0.04% of the luminosity of our star. If the Earth orbited Barnard's Star at the same distance as we orbit the sun, the star would be only 100 times more bright then the full moon.<ref>[http://www.solstation.com/stars/barnards.htm Barnard's Star] from solstation.com</ref> The star is relatively inactive, and has a rotation period of only 130.4 days, typical for an older [[red dwarf]] star. Barnard's Star however isn't completely inactive, but in 1998 a [[solar flare|flare]] was observed, which scientists believed would be unlikely on such an old star.   

In recent history there has been much speculation to whither or not Barnard's Star has any planetary companions.   During the late 1960s, astronomer Peter van de Kamp announced the detection of possibly two planets that revolved around each other, however his claim could never be verified, and recent observations have thus far failed to locate any evidence of planetary companions around the star. In order for an Earth-type world to have liquid water at the surface, it would have to be located very close to Barnard's Star, at only around 0.034 to 0.082 AU. Such a world would be tidally locked to the star.

In recent history there has been much speculation to whither or not Barnard's Star has any planetary companions. During the late 1960s, astronomer Peter van de Kamp announced the detection of possibly two [[planet]]s that revolved around each other, however his claim could never be verified, and recent observations have thus far failed to locate any evidence of planetary companions around the star. In order for an Earth-type world to have liquid water at the surface, it would have to be located very close to Barnard's Star, at only around 0.034 to 0.082 AU. Such a world would be tidally locked to the star.

 

==References==

==References==

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