Epsilon Eridani

ε Eridani
	; Lokasi bintang ε Eridani (dilingkari)
Data pengamatan; Epos J2000.0 Ekuinoks J2000.0
Rasi bintang	Eridanus
Asensio rekta	03j 32m 55.84496d
Deklinasi	−09° 27′ 29.7312″
Magnitudo tampak (V)	3.736
Ciri-ciri
Kelas spektrum	K2V
Magnitudo semu (B)	4.61
Magnitudo semu (V)	3.73
Magnitudo semu (J)	2.228 ±0.298
Magnitudo semu (H)	1.880 ± 0.276
Magnitudo semu (K)	1.776 ± 0.286
Indeks warna U−B	+0.571
Indeks warna B−V	+0.887
Jenis variabel	BY Dra
Astrometri
Kecepatan radial (Rv)	+15.5 ± 0.9 km/s
Gerak diri (μ)	RA: −975.17 mdb/thn ; Dek.: 19.49 mdb/thn
Paralaks (π)	311,37±0,1 mdb
Jarak	10,475 ± 0,003 tc ; (3,212 ± 0,001 pc)
Magnitudo mutlak (MV)	6.19
Detail
Massa	0.82 ± 0.02 M☉
Radius	0.735 ± 0.005 R☉
Luminositas	0.34 L☉
Gravitasi permukaan (log g)	4.30 ± 0.08
Suhu	5,084 ± 5.9 K
Metalisitas	−0.13 ± 0.04 dex
Rotasi	11.2 hari
Kecepatan rotasi (v sin i)	2.4 ± 0.5 km/s
Usia	400–800 juta tahun
Penamaan lain
	Ran, 18 Eridani, BD -09°697, GCTP 742.00, GJ 144, HD 22049, HIP 16537, HR 1084, LHS 1557, SAO 130564, WDS 03330-0928.
Referensi basis data
SIMBAD	The star
	planet b
	planet c

Epsilon Eridani (ε Eridani, disingkat Epsilon Eri, ε Eri), lebih dikenal dengan nama Ran /ˈrɑːn/,^[18] adalah bintang deret-utama dengan kelas spektrum K2. Berjarak sekitar 10.5 tahun cahaya dari Matahari, merupakan rasi bintang Eridanus, serta bintang terdekat ketiga yang dapat dilihat dengan mata telanjang. Usianya diperkirakan setidaknya kurang dari satu miliar tahun. Dikarenakan masih relatif muda, Epsilon Eridani memiliki aktivitas magnetik yang lebih tinggi dari Matahari, dengan angin surya 30 kali lebih kuat. Periode rotasinya relatif cepat 11.1 hari.

Epsilon Eridani diperkirakan memiliki 85% dari masa Matahari^[9] dan radiusnya 84% dari radius Matahari,^[19] tetapi memiliki hanya 28% tingkat luminositas dibanding Matahari. Bintang ini merupakan bintang K dengan kelas spektrum terdekat, setelah Alpha Centauri B.^[9] kandungan metallisitas atau zat-zat yang lebih berat dari helium sedikit lebih rendah dari Matahari, dengan tingkat kromosferik besi diperkirakan 74% dari Matahari.^[15]

Etimologi

Bintang ini memiliki nama tradisional Sadira atau Al Sadirah, berasal dari bahasa Arab yang berarti "burung unta yang lari dari air". Nama lainnya untuk bintang ini adalah:

nama lain	asal bahasa	arti
天苑三 / Tiānyuànsān	China	bintang ketiga pada rasi Padang Rumput di Langit^[20]

Selain rasi Eridanus,bintang ini juga merupakan anggota dari berbagai rasi, asterisma atau kelompok berikut:

nama lain	asal bahasa	arti	anggota lain
天苑 / Tiānyuán	China	Padang Rumput di Langit	γ Eri, π Eri, δ Eri, ζ Eri, π Cet, η Eri, τ¹ Eri, τ² Eri, τ³ Eri, τ⁴ Eri, τ⁵ Eri, τ⁶ Eri, τ⁷ Eri, τ⁸ Eri, τ⁹ Eri
Cītlalmazātl	Aztec	rusa	γ Eri, δ Eri, υ⁴ Eri+, φ Eri, χ Eri+, τ⁴ Eri+, υ² Eri+, η Eri, 43 Eri+, τ³ Eri+, τ⁶ Eri+, τ⁵ Eri+, τ¹ Eri+, τ² Eri, τ⁹ Eri+, α For, β For, κ For+, χ² For+, χ¹ For+, χ³ For+

+ berkemungkinan merupakan anggota

Referensi

^ ^a ^b ^c ^d van Leeuwen, Floor (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752v1 , Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. Note: see VizieR catalogue I/311.
^ ^a ^b ^c Cousins, A. W. J. (1984), "Standardization of Broadband Photometry of Equatorial Standards", South African Astronomical Observatory Circulars, 8: 59, Bibcode:1984SAAOC...8...59C.
^ Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770 , Bibcode:2006AJ....132..161G, doi:10.1086/504637.
^ ^a ^b ^c ^d "V* eps Eri – variable of BY Dra type", SIMBAD, Centre de Données astronomiques de Strasbourg, diakses tanggal November 5, 2010.
^ ^a ^b ^c Cutri, R. M.; et al. (June 2003), "The IRSA 2MASS all-sky point source catalog, NASA/IPAC infrared science archive", The IRSA 2MASS All-Sky Point Source Catalog, Bibcode:2003tmc..book.....C.
^ "GCVS query=eps Eri", General Catalog of Variable Stars, Sternberg Astronomical Institute, Moscow, Russia, diakses tanggal May 20, 2009.
^ Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick, ed., "The revision of the general catalogue of radial velocities", Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, University of Toronto: International Astronomical Union, 30, hlm. 57, Bibcode:1967IAUS...30...57E.
^ Benedict, G. Fritz; et al. (November 2006), "The extrasolar planet e Eridani b – orbit and mass", The Astronomical Journal, 132 (5): 2206–2218, arXiv:astro-ph/0610247 , Bibcode:2006AJ....132.2206B, doi:10.1086/508323.
^ ^a ^b ^c Staff (June 8, 2007), The one hundred nearest star systems, Research Consortium on Nearby Stars, diakses tanggal November 29, 2007
^ ^a ^b Gonzalez, G.; Carlson, M. K.; Tobin, R. W. (April 2010), "Parent stars of extrasolar planets – X. Lithium abundances and v sini revisited", Monthly Notices of the Royal Astronomical Society, 403 (3): 1368–1380, arXiv:0912.1621 , Bibcode:2010MNRAS.403.1368G, doi:10.1111/j.1365-2966.2009.16195.x. See table 3.
^ Baines, Ellyn K.; Armstrong, J. Thomas (2011), "Confirming Fundamental Parameters of the Exoplanet Host Star epsilon Eridani Using the Navy Optical Interferometer", The Astrophysical Journal, 748: 72, arXiv:1112.0447 , Bibcode:2012ApJ...748...72B, doi:10.1088/0004-637X/748/1/72.
^ Demory, B.-O.; et al. (October 2009), "Mass-radius relation of low and very low-mass stars revisited with the VLTI", Astronomy and Astrophysics, 505 (1): 205–215, arXiv:0906.0602 , Bibcode:2009A&A...505..205D, doi:10.1051/0004-6361/200911976. See Table B.1
^ Saumon, D.; et al. (April 1996), "A theory of extrasolar giant planets", The Astrophysical Journal, 460: 993, arXiv:astro-ph/9510046 , Bibcode:1996ApJ...460..993S, doi:10.1086/177027. See Table A1, p. 21.
^ Kovtyukh, V. V.; et al. (December 2003), "High precision effective temperatures for 181 F-K dwarfs from line-depth ratios", Astronomy and Astrophysics, 411 (3): 559–564, arXiv:astro-ph/0308429 , Bibcode:2003A&A...411..559K, doi:10.1051/0004-6361:20031378.
^ ^a ^b Santos, N. C.; Israelian, G.; Mayor, M. (March 2004), "Spectroscopic [Fe/H] for 98 extra-solar planet-host stars: Exploring the probability of planet formation", Astronomy and Astrophysics, 415 (3): 1153–1166, arXiv:astro-ph/0311541 , Bibcode:2004A&A...415.1153S, doi:10.1051/0004-6361:20034469. —the percentage of iron is given by ${\begin{smallmatrix}10^{-0.13}=0.74\end{smallmatrix}}$ , or 74%
^ ^a ^b Fröhlich, H.-E. (December 2007), "The differential rotation of Epsilon Eri from MOST data", Astronomische Nachrichten, 328 (10): 1037–1039, arXiv:0711.0806 , Bibcode:2007AN....328.1037F, doi:10.1002/asna.200710876.
^ Janson, Markus; et al. (February 2015), "High-contrast imaging with Spitzer: deep observations of Vega, Fomalhaut, and ε Eridani", Astronomy & Astrophysics, 574: 10, arXiv:1412.4816 , Bibcode:2015A&A...574A.120J, doi:10.1051/0004-6361/201424944, A120.
^ "IAU Catalog of Star Names". Diakses tanggal July 28, 2016.
^ Kesalahan pengutipan: Tag <ref> tidak sah; tidak ditemukan teks untuk ref bernama apjss53
^ salah satu rasi bintang menurut bangsa Cina

Pranala luar

"Astronomers discover a nearby star system just like our own Solar System". JAC/UCLA. Diarsipkan dari versi asli tanggal 2006-05-03. Diakses tanggal 24 March 2005.
Bruce Campbell, G.A.H. Walker, S. Yang (1988). "A search for substellar companions to solar-type stars". Astrophysical Journal. 331 (Part 1): 902 – 921. doi:10.1086/166608.
Sean Moran, Marc Kuchner, and Matthew Holman (2004). "The Dynamical Influence of a Planet at Semimajor Axis 3.4 AU on the Dust around ε Eridani". The Astrophysical Journal. 612: 1163 – 1170. doi:10.1086/422796.
"Epsilon Eridani". SolStation. Diakses tanggal 13 April 2006.

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

[aaa474_2_653-1] van Leeuwen, Floor (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752v1 , Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357. Note: see VizieR catalogue I/311.

[saaoc8_59-2] Cousins, A. W. J. (1984), "Standardization of Broadband Photometry of Equatorial Standards", South African Astronomical Observatory Circulars, 8: 59, Bibcode:1984SAAOC...8...59C.

[aj132_1_161-3] Gray, R. O.; et al. (July 2006), "Contributions to the Nearby Stars (NStars) Project: spectroscopy of stars earlier than M0 within 40 pc-The Southern Sample", The Astronomical Journal, 132 (1): 161–170, arXiv:astro-ph/0603770 , Bibcode:2006AJ....132..161G, doi:10.1086/504637.

[SIMBAD-4] "V* eps Eri – variable of BY Dra type", SIMBAD, Centre de Données astronomiques de Strasbourg, diakses tanggal November 5, 2010.

[cutri2003-5] Cutri, R. M.; et al. (June 2003), "The IRSA 2MASS all-sky point source catalog, NASA/IPAC infrared science archive", The IRSA 2MASS All-Sky Point Source Catalog, Bibcode:2003tmc..book.....C.

[gcvs-6] "GCVS query=eps Eri", General Catalog of Variable Stars, Sternberg Astronomical Institute, Moscow, Russia, diakses tanggal May 20, 2009.

[rgcrv66-7] Evans, D. S. (June 20–24, 1966), Batten, Alan Henry; Heard, John Frederick, ed., "The revision of the general catalogue of radial velocities", Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30, University of Toronto: International Astronomical Union, 30, hlm. 57, Bibcode:1967IAUS...30...57E.

[aj132_2206-8] Benedict, G. Fritz; et al. (November 2006), "The extrasolar planet e Eridani b – orbit and mass", The Astronomical Journal, 132 (5): 2206–2218, arXiv:astro-ph/0610247 , Bibcode:2006AJ....132.2206B, doi:10.1086/508323.

[RECONS-9] Staff (June 8, 2007), The one hundred nearest star systems, Research Consortium on Nearby Stars, diakses tanggal November 29, 2007

[mnras403_3_1368-10] Gonzalez, G.; Carlson, M. K.; Tobin, R. W. (April 2010), "Parent stars of extrasolar planets – X. Lithium abundances and v sini revisited", Monthly Notices of the Royal Astronomical Society, 403 (3): 1368–1380, arXiv:0912.1621 , Bibcode:2010MNRAS.403.1368G, doi:10.1111/j.1365-2966.2009.16195.x. See table 3.

[Baines-11] Baines, Ellyn K.; Armstrong, J. Thomas (2011), "Confirming Fundamental Parameters of the Exoplanet Host Star epsilon Eridani Using the Navy Optical Interferometer", The Astrophysical Journal, 748: 72, arXiv:1112.0447 , Bibcode:2012ApJ...748...72B, doi:10.1088/0004-637X/748/1/72.

[aaa505_1_205-12] Demory, B.-O.; et al. (October 2009), "Mass-radius relation of low and very low-mass stars revisited with the VLTI", Astronomy and Astrophysics, 505 (1): 205–215, arXiv:0906.0602 , Bibcode:2009A&A...505..205D, doi:10.1051/0004-6361/200911976. See Table B.1

[apj460_993-13] Saumon, D.; et al. (April 1996), "A theory of extrasolar giant planets", The Astrophysical Journal, 460: 993, arXiv:astro-ph/9510046 , Bibcode:1996ApJ...460..993S, doi:10.1086/177027. See Table A1, p. 21.

[aaa411_3_559-14] Kovtyukh, V. V.; et al. (December 2003), "High precision effective temperatures for 181 F-K dwarfs from line-depth ratios", Astronomy and Astrophysics, 411 (3): 559–564, arXiv:astro-ph/0308429 , Bibcode:2003A&A...411..559K, doi:10.1051/0004-6361:20031378.

[aaa415-15] Santos, N. C.; Israelian, G.; Mayor, M. (March 2004), "Spectroscopic [Fe/H] for 98 extra-solar planet-host stars: Exploring the probability of planet formation", Astronomy and Astrophysics, 415 (3): 1153–1166, arXiv:astro-ph/0311541 , Bibcode:2004A&A...415.1153S, doi:10.1051/0004-6361:20034469. —the percentage of iron is given by ${\begin{smallmatrix}10^{-0.13}=0.74\end{smallmatrix}}$ , or 74%

[an328_10-16] Fröhlich, H.-E. (December 2007), "The differential rotation of Epsilon Eri from MOST data", Astronomische Nachrichten, 328 (10): 1037–1039, arXiv:0711.0806 , Bibcode:2007AN....328.1037F, doi:10.1002/asna.200710876.

[Janson2015-17] Janson, Markus; et al. (February 2015), "High-contrast imaging with Spitzer: deep observations of Vega, Fomalhaut, and ε Eridani", Astronomy & Astrophysics, 574: 10, arXiv:1412.4816 , Bibcode:2015A&A...574A.120J, doi:10.1051/0004-6361/201424944, A120.

[IAU-CSN-18] "IAU Catalog of Star Names". Diakses tanggal July 28, 2016.

[apjss53-19] Kesalahan pengutipan: Tag <ref> tidak sah; tidak ditemukan teks untuk ref bernama apjss53

[20] salah satu rasi bintang menurut bangsa Cina

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