Gliese 581

Ukuran Matahari (kiri) dan Gliese 581 (kanan).
Data pengamatan Epos J2000.0      Ekuinoks J2000.0
Rasi bintang	Libra[1]
Asensio rekta	15j 19m 26.8269d[2]
Deklinasi	−07° 43′ 20.189″[2]
Magnitudo tampak (V)	10.56 to 10.58[note 1]
Ciri-ciri
Kelas spektrum	M3V[5]
Indeks warna B−V	1.61[6]
Jenis variabel	BY Dra[7][note 2]
Astrometri
Kecepatan radial (Rv)	−9.5 ± 0.5[6] km/s
Gerak diri (μ)	RA: −1 221.289 ± 0.160[2] mdb/thn Dek.: −97.237 ± 0.105[2] mdb/thn
Paralaks (π)	158,64±0,35[2] mdb
Jarak	20,56 ± 0,05 tc (6,30 ± 0,01 pc)
Magnitudo mutlak (MV)	11.6[11]
Detail
Massa	0.31[12] M☉
Radius	0,299±0,010[13] R☉
Luminositas (bolometrik)	0.013[5] L☉
Luminositas (visual, LV)	0.002[note 3] L☉
Gravitasi permukaan (log g)	4,92±0,10[14]
Suhu	3,480 ± 48[14] K
Metalisitas [Fe/H]	−0.33 ± 0.12[14]
Rotasi	132,5±6,3 h[15]
Usia	7 to 11[12][16] gigatahun
Penamaan lain
HO Librae, HO Lib, BD−07°4003, GJ 581, HIP 74995, LFT 1195, LHS 394, LPM 564, LTT 6112, NLTT 39886, TYC 5594-1093-1, Wolf 562.[6][17]
Referensi basis data
SIMBAD	The star
	e
	b
	c
	d
	f (artifact)
	g

Gliese 581 (pengucapan: /ˈgliːzə/) atau HO Librae adalah bintang katai merah dengan tipe spektrum M3V, terletak sejauh 20.3 tahun cahaya dari Bumi. Observasi menunjukan bahwa bintang ini diorbit oleh sedikitnya empat planet, yaitu Gliese 581 b, c, d, dan e. Bintang ini mendapat perhatian setelah Gliese 581 c, eksoplanet yang ditemukan terletak di dekat zona laik hidup bintang ini pada April 2007.

Pada akhir September 2010. telah dketemukan lagi dua planet yang mengelilingi bintang ini, yaitu Gliese 581 f dan g.

Referensi

Pranala luar

Wikinews bahasa Inggris memberitakan: First earthlike planet outside solar system discovered

• "SPACE.com - Major Discovery: New Planet Could Harbor Water and Life". Space.com. Diarsipkan dari asli tanggal 2010-12-24. Diakses tanggal 2008-10-20.
• "Gliese 581 / HO Librae". Solstation.com. Diarsipkan dari asli tanggal 2008-10-10. Diakses tanggal 2008-10-20.
• "CTV.ca | Earth-like planet found that may support life". Ctv.ca. Updated Wed. April 25 2007 11:05 AM ET. Diarsipkan dari asli tanggal 2007-10-23. Diakses tanggal 2008-10-20. ;
• Extrasolar Planets Encyclopaedia: Gl 581 Diarsipkan 2012-05-10 di Wayback Machine.
• Do your own simulation of radio communications to or from Gliese 581 Diarsipkan 2008-12-23 di Wayback Machine.
• All Wet? Astronomers Claim Discovery of Earth-like Planet Diarsipkan 2007-10-13 di Wayback Machine., Scientific American
• Position of Gliese 581 marked on local space. Diarsipkan 2010-06-04 di UK Government Web Archive (Top right corner)
• Photo of Constellation Libra with Gliese 581 Diarsipkan 2009-02-06 di Wayback Machine.
• Artist conceptions of planets of Gliese 581 Diarsipkan 2011-09-28 di Wayback Machine.
• Speculation about geology/geochemistry of Gliese 581c Diarsipkan 2007-06-17 di Wayback Machine. The Geochemical Society Diarsipkan 2009-04-11 di Wayback Machine.
• Computer models suggest planetary and extrasolar planet atmospheres - A gas, gas, gas Washington University in St. Louis Diarsipkan 2008-07-05 di Wayback Machine.
• Extrasolar Planet Interactions Diarsipkan 2016-05-05 di Wayback Machine. by Rory Barnes & Richard Greenberg, Lunar and Planetary Lab, University of Arizona

Artikel bertopik bintang ini adalah sebuah rintisan. Anda dapat membantu Wikipedia dengan mengembangkannya.

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1. ↑ Gliese 581 is classified as a BY Draconis variable in the General Catalogue of Variable Stars.^[3] This catalog gives a maximum magnitude of 10.56 and minimum of magnitude 10.58 for a relatively low 20 mmag (0.020 magnitudes) variability.^[4] For full data see data description and "The combined table of GCVS Vols I-III and NL 67-78 with improved coordinates, General Catalogue of Variable Stars". Sternberg Astronomical Institute. Diarsipkan dari asli tanggal 2017-06-20. Diakses tanggal 2009-04-27.
2. ↑ In 1994 Edward Weis concluded that Gliese 581, like half the 43 dwarf M stars he studied over a multi-year period, showed long term variability (and page 1137, Fig 1 shows Gliese 581 had magnitude 10.58 in 1982 and between 10.57 and 10.56 from 1985 to 1990).^[8] Bonfils noted in 2005 that Gliese 581 "has been classified as a variable star (HO Lib), but its variability (Weis 1994) is only marginally significant. If real it would be on a time scale of several years, with short term variability being at most ∼0.006 mag."^[9] Measurements by MOST showed short term variability of about 5 mmag (half a percent) over a period of a few weeks.^[10]
3. ↑