Editing Teegarden's Star (section)

== Properties ==
[[File:Nearby Stars (14ly Radius).svg|thumb|left|Teegarden's Star (top, center) is the 25th-nearest known star (system) to the [[Solar System]].<ref name="Reylé2021"/>]]
Teegarden's Star is classified as a [[red dwarf]] as its approximate calculated mass of just over 0.09 times that of the Sun is narrowly above the limit of [[brown dwarf]]s.<ref name="Schweitzer2019"/> The inherently low temperature of such objects explains why it was not discovered earlier,<ref name=reid2013/> since it has an [[apparent magnitude]] of only 15.1<ref name=lepine /> (and an [[absolute magnitude]] of 17.22<ref name=aj132_6_2360 />). Like most red and brown dwarfs it emits most of its energy in the [[infrared]] spectrum.<ref name=kaler2011/>

The [[parallax]] was initially measured as 0.43 ± 0.13 arcseconds. This would have placed its distance at only 7.50 [[light-year]]s, making Teegarden's Star only the [[List of nearest stars and brown dwarfs|third star system in order of distance]] from the [[Sun]], ranking between [[Barnard's Star]] and [[Wolf 359]].<ref name=disc /> However, even at that time the anomalously low luminosity (the absolute magnitude would have been 18.5) and high uncertainty in the parallax suggested that it was in fact somewhat farther away, still one of the Sun's nearest neighbors but not nearly as high in the ranking in order of distance. A more accurate parallax measurement of 0.2593 arcseconds was made by [[George Gatewood]] in 2009, yielding a distance of 12.578 light-years,<ref name=gatewood/> very close to the value now accepted.<ref name="CARMENES" />

Teegarden's Star is inactive compared to stars of similar spectrum and mass. It still shows some [[stellar flare]]s with strengths comparable to the largest solar flares. Two of these flares were observed by a study, and one of them shows clear signatures of the [[Neupert effect]].<ref name=Fuhrmeister2025/>