Peter 229
Double star Gliese 229 |
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left: Discovery of GJ 229 B at the Palomar Observatory right: image from the Hubble Space Telescope (NASA) |
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Observation dates equinox : J2000.0 , epoch : J2000.0 |
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AladinLite | ||||||||||||||||||||
Constellation | Hare | |||||||||||||||||||
Right ascension | 06 h 10 m 34.6 s | |||||||||||||||||||
declination | −21 ° 51 ′ 52.7 ″ | |||||||||||||||||||
Apparent brightness | 8.12 likes | |||||||||||||||||||
Known exoplanets |
2 |
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Position of the attendant ( JD 2450398) | ||||||||||||||||||||
Angular distance | 7 ", 674 ± 0", 007 | |||||||||||||||||||
Position angle | 163 °, 91 ± 0 °, 10 | |||||||||||||||||||
Astrometry | ||||||||||||||||||||
parallax | (173.70 ± 0.05) mas | |||||||||||||||||||
distance | (18.77 ± 0.01) ly (5.76 ± 0.01 pc ) |
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Individual data | ||||||||||||||||||||
Names | A ; B. | |||||||||||||||||||
Observation data: | ||||||||||||||||||||
Apparent brightness | A. | 8.13 mag | ||||||||||||||||||
B. | ||||||||||||||||||||
Typing: | ||||||||||||||||||||
Spectral class | A. | M1 V | ||||||||||||||||||
B. | T6.5 | |||||||||||||||||||
B − V color index | A. | (1.19) | ||||||||||||||||||
U − B color index | A. | (1.48) | ||||||||||||||||||
Physical Properties: | ||||||||||||||||||||
Absolute vis. Brightness M vis |
A. | +9.3 mag | ||||||||||||||||||
B. | ||||||||||||||||||||
Dimensions | A. | (0.563 ± 0.042) M ☉ | ||||||||||||||||||
B. | 0.03 M ☉ | |||||||||||||||||||
radius | A. | (0.547 ± 0.044) R ☉ | ||||||||||||||||||
B. | ||||||||||||||||||||
Luminosity | A. | 0.03 L ☉ | ||||||||||||||||||
B. | ||||||||||||||||||||
Effective temperature | A. | 3560 K | ||||||||||||||||||
B. | ~ 850 K | |||||||||||||||||||
Other names and catalog entries |
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Gliese 229 (Gl 229, GJ 229) is a star in the constellation Rabbit . It is a double system 18.8 light years away.
Gliese 229 A is a red dwarf of the spectral type M1, while Gliese 229 B is a brown dwarf of the spectral class T6 with 20 to 50 times the mass of Jupiter and a surface temperature of around 850 Kelvin. The distance between the two components is approximately 50 astronomical units .
Gliese 229 B is the first unequivocally proven brown dwarf (Nakajima et al., 1995).
In 2014, an exoplanet was discovered around Gliese 229 A (Gliese 229 A b) and another in 2020.
table
Planet (order from the star) |
Discovered |
Mass ( earth masses ) |
Major semiaxis of the railway ( AU ) |
Rotation time ( days ) |
eccentricity |
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Gliese 229 A c | 2020 | 7.93 +2.39−3.44 | 0.339 +0.024−0.029 | 122.0 ± 0.4 | 0.29 +0.06−0.26 |
Gliese 229 A b | 2014 | 10.02 +3.35−6.10 | 0.896 +0.069−0.073 | 523.2 +13.0−7.0 | 0.17 +0.07−0.17 |
Web links
Commons : Gliese 229 - Collection of images, videos and audio files
- scinexx.de: The first clear brown dwarf: Gliese 229b May 7, 2010
Individual evidence
- ↑ a b c d e f HD 42581. In: SIMBAD . Center de Données astronomiques de Strasbourg , accessed December 6, 2018 .
- ↑ HD 42581 B. In: SIMBAD. Center de Données astronomiques de Strasbourg, accessed December 6, 2018 .
- ↑ a b P. E. Kervella, F. Arenou, F. Mignard, F. Thévenin: Stellar and substellar companions of nearby stars from Gaia DR2. Binarity from proper motion anomaly . In: Astronomy & Astrophysics . 623, p. A72. arxiv : 1811.08902 . bibcode : 2019A & A ... 623A..72K . doi : 10.1051 / 0004-6361 / 201834371 .
- ^ GJ 229 B. In: Extrasolar Planets Encyclopaedia . Retrieved December 6, 2018 .
- ↑ a b c M. Tuomi et al .: Bayesian search for low-mass planets around nearby M dwarfs - estimates for occurrence rate based on global detectability statistics . In: MNRAS . 441, No. 2, pp. 1545-1569. arxiv : 1403.0430 . bibcode : 2014MNRAS.441.1545T . doi : 10.1093 / mnras / stu358 .
- ↑ T. Nakajima, T. Tsuji, Y. Takeda: Physical Properties of Gliese 229B Based on Newly Determined Carbon and Oxygen Abundances of Gliese 229A . In: The Astronomical Journal . 150, No. 2. arxiv : 1506.03178 . bibcode : 2015AJ .... 150 ... 53N . doi : 10.1088 / 0004-6256 / 150/2/53 .
- ^ T. Nakajima et al .: Discovery of a cool brown dwarf . In: Nature . 378, No. 6556, 1995, pp. 463-465. bibcode : 1995Natur.378..463N . doi : 10.1038 / 378463a0 .
- ↑ a b Fabo Feng et al .: Search for Nearby Earth Analogs II. detection of five new planets, eight planet candidates, and confirmation of three planets around within nearby M dwarfs ∗ . In: The Astrophysical Journal Supplement Series . 246, No. 1, August. arxiv : 2001.02577 . bibcode : 2020ApJS..246 ... 11F . doi : 10.3847 / 1538-4365 / ab5e7c .