Teegarden's star

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Red dwarf or brown dwarf
Teegarden's star
Constellation Aries
Position
equinox : J2000.0
Right ascension 02h 53m 00.901s
declination + 16 ° 52 ′ 52.642 ″
Further data
Brightness  (visual)

15.40 mag

Brightness  (B-band)

17.21 likes

distance

(12.49 ± 0.01) ly

Spectral class

M7.0 V

parallax

(261.01 ± 0.27) mas

V-radial

(63 ± 5) km / s

Proper movement in right ascension

(3429.53 ± 0.33) mas / a

Proper movement in declination

(−3806.16 ± 0.31) mas / a

Absolute brightness M V ≈ +17.21 mag
Dimensions 0.08 M ☉
history
Catalog names
GAT 1370, LSPM J0253 + 1652, SO 025300.5 + 165258, SO 0253 + 1652
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Teegarden's star (catalog names including LSPM J0253 + 1652 or SO 025300.5 + 165258 , SO 0253 + 1652 for short ) is an M dwarf ( brown dwarf or red dwarf ) in the constellation Aries , around 12.5 light years from the sun . Initial measurements led to the assumption that it could be the third closest star to the Sun.

discovery

The object was discovered in 2003 by a group of scientists through the evaluation of multi-year recordings of the NEAT program for the detection of asteroids . In addition, it could also be identified on photo plates from the Palomar Observatory Sky Survey from 1951.

The object by Bonnard Teegarden from J. was named Goddard Space Flight Center of NASA , head of the discovery team.

properties

Teegarden's star with 0.08 solar masses is probably just above the upper mass limit of brown dwarfs. Like all brown and red dwarfs, it radiates most of its energy in the infrared spectrum . The effective temperature is probably below 3000 Kelvin and the star is believed to be more than 8 billion years old.

distance

The parallax was initially determined to be 0.43 ± 0.13 arc seconds, with which the distance from Teegarden's star to the sun would have been only 7.5 light years. The object would have been the third closest known star at this point in time. The unusually low luminosity and high uncertainty in determining the parallax led to the assumption that Teegarden's star must actually be further away, even if it was still in the vicinity of the sun. In 2009, the American astronomer George Gatewood determined the parallax to be 0.2593 arc seconds, which resulted in a distance of 12.578 light years. In the Gaia DR2 catalog , the parallax is given with high accuracy as 0.2610 arc seconds, which corresponds to 12.49 light years.

Planetary system

In 2010, Teegarden's star was examined for exoplanets orbiting it using the radial velocity method . Although changes in radial velocity were detected, there was insufficient data to confirm the existence of a planet.

Teegarden's star was studied for three more years as part of the CARMENES project at the Calar Alto observatory . Based on the evaluation of the data collected, the existence of two roughly Earth-sized (1.1 to 1.3 Earth masses) exoplanets was announced in June 2019. Both planets orbiting the star in its habitable zone were classified as potentially life-friendly in an initial assessment, as Teegarden's star is considered relatively calm due to observations and its old age.

See also

Web links

Individual evidence

  1. ↑ a b c d e f GAT 1370. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed on November 10, 2018 .
  2. ^ A b Cassy L. Davison, RJ White, TJ Henry, AR Riedel, W.-C. Jao, JI Bailey, SN Quinn, JR Cantrell, JP Subasavage, JG Winters: A 3D Search for Companions to 12 Nearby M Dwarfs . In: The Astronomical Journal . 149, No. 3, 2015, p. 106. arxiv : 1501.05012 . bibcode : 2015AJ .... 149..106D . doi : 10.1088 / 0004-6256 / 149/3/106 .
  3. ↑ astronews of May 21, 2003: Possible new neighbor of the sun discovered. Retrieved April 1, 2015 .
  4. ↑ a b c B. J. Teegarden, SH Pravdo, M. Hicks, SB Shaklan, K. Covey, O. Fraser, SL Hawley, T. McGlynn, IN Reid: Discovery of a New Nearby Star . arxiv : astro-ph / 0302206 .
  5. ↑ a b The CARMENES search for exoplanets around M dwarfs - Two temperate Earth-mass planet candidates around Teegarden's Star . In: Astronomy & Astrophysics . 2019. doi : 10.1051 / 0004-6361 / 201935460 .
  6. ↑ Gatewood, George; Coban, Louis: Allegheny Observatory Parallaxes for Late M Dwarfs and White Dwarfs . bibcode : 2009AJ .... 137..402G .
  7. ↑ JR Barnes, JS Jenkins, HRA Jones, P. Rojo, P. Arriagada, A. Jordan, D. Minniti, M. Tuomi, SV Jeffers, D. Pinfield: ROPS: A New Search for Habitable Earths in the Southern Sky . bibcode : 2009AJ .... 137..402G .
  8. ↑ Two potentially life-friendly planets found orbiting a nearby star National Geographic