Eta Serpentis
  | |
| Observation data Epoch J2000 Equinox J2000 | |
|---|---|
| Constellation | Serpens |
| Right ascension | Template:RA[1] |
| Declination | Template:DEC[1] |
| Apparent magnitude (V) | 3.260[2] |
| Characteristics | |
| Spectral type | K0 III-IV[3] |
| U−B color index | +0.643[2] |
| B−V color index | +0.940[2] |
| Astrometry | |
| Radial velocity (Rv) | +8.4[4] km/s |
| Proper motion (μ) | RA: −547.75[1] mas/yr Dec.: −701.42[1] mas/yr |
| Parallax (π) | 53.93±0.18 mas[1] |
| Distance | Template:Rnd ± Template:Rnd ly (Template:Rnd ± Template:Rnd pc) |
| Absolute magnitude (MV) | +1.87[5] |
| Details | |
| Mass | 1.60±0.20[6] M☉ |
| Radius | 5.92±0.02[7] R☉ |
| Luminosity | 17.85±0.13[7] L☉ |
| Surface gravity (log g) | 2.92±0.04[8] cgs |
| Temperature | 4,875±7[7] K |
| Metallicity [Fe/H] | −0.21±0.01[9] dex |
| Rotational velocity (v sin i) | 2.47±1.00[9] km/s |
| Age | 2.69[10] Gyr |
| Other designations | |
| Template:Odlist[11] | |
| Database references | |
| SIMBAD | data |
Eta Serpentis, Latinized from η Serpentis, is a star in the constellation Serpens. In particular, it lies in Serpens Cauda, the snake's tail, and is the brightest in that part of the constellation. The star has an apparent visual magnitude of 3.260,[2] making it visible to the naked eye. Parallax measurements give a distance estimate of 60.5 light-years (18.5 parsecs) from the Earth.[1]
This star is larger than the Sun, with 1.6 times the mass[6] and almost six times the radius.[7][12] The spectrum matches a stellar classification of K0 III-IV,[3] with the luminosity class of III-IV corresponding to an evolved star that lies between the subgiant and giant stages. The expanded outer envelope star is radiating about 18 times the luminosity of the Sun at an effective temperature of 4,875 K.[7] At this temperature, it has an orange hue typical of a K-type star.[13] Eta Serpentis displays solar-like oscillations with a period of 0.09 of a day.[14]
Eta Serpentis was previously classified as a carbon star, which would have made it the brightest carbon star in the sky, although this classification was since found to be erroneous.[15]
Eta Serpentis is currently 1.6 light-years away from Gliese 710.[citation needed]
Name
In Chinese astronomy, the star is known as Script error: No such module "Lang". (Script error: No such module "Lang".), meaning 'Left Wall of Heavenly Market Enclosure'; the name refers to an asterism that represents eleven old states in China. The leftmost borderline of the enclosure consists of η Serpentis, δ Herculis, λ Herculis, μ Herculis, o Herculis, 112 Herculis, η Ophiuchi, ζ Aquilae, θ1 Serpentis, ν Ophiuchi and ξ Serpentis.[16] Consequently, the Chinese name for η Serpentis itself is Script error: No such module "Lang". (Script error: No such module "Lang"., the Eighth Star of Left Wall of Heavenly Market Enclosure, representing the region of Donghai (東海, lit. meaning 'eastern sea').[17][18]
References
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- ^ a b c d e f Page Module:Citation/CS1/styles.css has no content.van Leeuwen, F. (November 2007), "Validation of the new Hipparcos reduction", Astronomy and Astrophysics, 474 (2): 653–664, arXiv:0708.1752, Bibcode:2007A&A...474..653V, doi:10.1051/0004-6361:20078357, S2CID 18759600
- ^ a b c d Page Module:Citation/CS1/styles.css has no content.Cousins, A. W. J. (1984), "Standardization of Broadband Photometry of Equatorial Standards", South African Astronomical Observatory Circulars, 8: 59, Bibcode:1984SAAOC...8...59C
- ^ a b Page Module:Citation/CS1/styles.css has no content.Frasca, A.; et al. (December 2009), "REM near-IR and optical photometric monitoring of pre-main sequence stars in Orion. Rotation periods and starspot parameters", Astronomy and Astrophysics, 508 (3): 1313–1330, arXiv:0911.0760, Bibcode:2009A&A...508.1313F, doi:10.1051/0004-6361/200913327, S2CID 118361131
- ^ Page Module:Citation/CS1/styles.css has no content.Wielen, R.; et al. (1999), "Sixth Catalogue of Fundamental Stars (FK6). Part I. Basic fundamental stars with direct solutions", Veroeffentlichungen des Astronomischen Rechen-Instituts Heidelberg, 35 (35), Astronomisches Rechen-Institut Heidelberg: 1, Bibcode:1999VeARI..35....1W
- ^ Page Module:Citation/CS1/styles.css has no content.Carney, Bruce W.; et al. (March 2008), "Rotation and Macroturbulence in Metal-Poor Field Red Giant and Red Horizontal Branch Stars", The Astronomical Journal, 135 (3): 892–906, arXiv:0711.4984, Bibcode:2008AJ....135..892C, doi:10.1088/0004-6256/135/3/892, S2CID 2756572
- ^ a b Page Module:Citation/CS1/styles.css has no content.Mosser, B.; Belkacem, K.; Goupil, M.-J.; Miglio, A.; Morel, T.; Barban, C.; Baudin, F.; Hekker, S.; Samadi, R.; Ridder, J. De; Weiss, W.; Auvergne, M.; Baglin, A. (2010-07-01), "Red-giant seismic properties analyzed with CoRoT", Astronomy & Astrophysics, 517: A22, arXiv:1004.0449, Bibcode:2010A&A...517A..22M, doi:10.1051/0004-6361/201014036, ISSN 0004-6361
- ^ a b c d e Page Module:Citation/CS1/styles.css has no content.Baines, Ellyn K.; Armstrong, J. Thomas; Schmitt, Henrique R.; Benson, James A.; Zavala, R. T.; van Belle, Gerard T. (2014-01-13), "Navy Precision Optical Interferometer Measurements of 10 Stellar Oscillators", The Astrophysical Journal, 781 (2): 90, arXiv:1401.3342, Bibcode:2014ApJ...781...90B, doi:10.1088/0004-637x/781/2/90, ISSN 0004-637X
- ^ Page Module:Citation/CS1/styles.css has no content.Soubiran, C.; Creevey, O. L.; Lagarde, N.; Brouillet, N.; Jofré, P.; Casamiquela, L.; Heiter, U.; Aguilera-Gómez, C.; Vitali, S.; Worley, C.; de Brito Silva, D. (2024-02-01), "Gaia FGK benchmark stars: Fundamental Teff and log g of the third version", Astronomy and Astrophysics, 682: A145, arXiv:2310.11302, Bibcode:2024A&A...682A.145S, doi:10.1051/0004-6361/202347136, ISSN 0004-6361
- ^ a b Page Module:Citation/CS1/styles.css has no content.Deka-Szymankiewicz, B.; Niedzielski, A.; Adamczyk, M.; Adamów, M.; Nowak, G.; Wolszczan, A. (2018-07-01), "The Penn State - Toruń Centre for Astronomy Planet Search stars. IV. Dwarfs and the complete sample", Astronomy and Astrophysics, 615: A31, arXiv:1801.02899, Bibcode:2018A&A...615A..31D, doi:10.1051/0004-6361/201731696, ISSN 0004-6361
- ^ Page Module:Citation/CS1/styles.css has no content.Luck, R. Earle (2017-01-01). "Abundances in the Local Region II: F, G, and K Dwarfs and Subgiants". The Astronomical Journal. 153 (1): 21. arXiv:1611.02897. Bibcode:2017AJ....153...21L. doi:10.3847/1538-3881/153/1/21. ISSN 0004-6256.
- ^ Page Module:Citation/CS1/styles.css has no content."eta Ser -- Variable Star", SIMBAD, Centre de Données astronomiques de Strasbourg, retrieved 2012-01-19
- ^ Page Module:Citation/CS1/styles.css has no content.Mérand, A.; et al. (July 2010), "Interferometric radius and limb darkening of the asteroseismic red giant η Serpentis with the CHARA Array", Astronomy and Astrophysics, 517: A64, Bibcode:2010A&A...517A..64M, doi:10.1051/0004-6361/200912103
- ^ Page Module:Citation/CS1/styles.css has no content."The Colour of Stars", Australia Telescope, Outreach and Education, Commonwealth Scientific and Industrial Research Organisation, December 21, 2004, archived from the original on 2012-03-18, retrieved 2012-01-16
- ^ Page Module:Citation/CS1/styles.css has no content.Tabur, V.; et al. (December 2010), "Period-luminosity relations of pulsating M giants in the solar neighbourhood and the Magellanic Clouds", Monthly Notices of the Royal Astronomical Society, 409 (2): 777–788, arXiv:1007.2974, Bibcode:2010MNRAS.409..777T, doi:10.1111/j.1365-2966.2010.17341.x, S2CID 118411237
- ^ Page Module:Citation/CS1/styles.css has no content.Antipova, L. I.; Boyarchuk, A. A. (2001). "The chemical composition of the red giant η Ser". Astronomy Reports. 45 (9): 700. Bibcode:2001ARep...45..700A. doi:10.1134/1.1398919. S2CID 62893990.
- ^ Template:In lang 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, Template:ISBN.
- ^ Template:In lang AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 6 月 23 日 Script error: No such module "webarchive".
- ^ Template:In lang English-Chinese Glossary of Chinese Star Regions, Asterisms and Star Name Script error: No such module "webarchive"., Hong Kong Space Museum. Accessed on line November 23, 2010.
