Користувач:UkrainianCossack/Чернетка/Дельта Лебедя
UkrainianCossack/Чернетка/Дельта Лебедя
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| Дані дослідження Епоха {{{епоха}}} | |
|---|---|
| Сузір'я | {{{сузір’я}}} |
| Пряме піднесення | {{{пр_сходж}}} |
| Схилення | {{{схилення}}} |
| Видима величина (V) | {{{вид_вел}}} |
| Характеристики | |
| Спектральний клас | {{{клас}}} |
| показник кольору U−B | –0.10[1] |
| показник кольору B−V | –0.02[1] |
| Тип змінності | {{{змінна}}} |
| Астрометрія | |
| Власний рух (μ) | за пр. піднес.: {{{пс}}} мас/рік |
| Відстань | {{{відстань_ср}}} світлових років {{{відстань_пс}}} парсек |
| Компоненти орбіти | |
| Другий компонент | B |
| Період (P) | 780.27 років |
| Велика піввісь (a) | 3.0" |
| Ексцентриситет (e) | 0.4670 |
| нахил (i) | ° |
| Вузол (Ω) | {{{node}}}° |
| Епоха периастру (T) | {{{periastron}}} |
| Подробиці | |
| Маса | {{{маса}}} M☉ |
| Інші позначення | |
{{{назви}}}
| |
| Посилання | |
| SIMBAD | дані для del+Cyg |
Дельта Л́ебедя (δ Cygni, аббревіатура Delta Cyg, δ Cyg) — це подвійна зірка, третя за яскравість у сузір'ї Лебідь (Cygnus ). Також є частинною Північного Хреста астеризма, де найяскравіша зірка Денеб. Based upon parallax measurements obtained during the Hipparcos mission, Delta Cygni is located roughly 165 св. р. (51 пк) distant from the Sun.[2]
Delta Cygni's two components are designated Delta Cygni A (officially named Fawaris [fəˈwɛərɪs])[3] and B. More widely separated is a faint third component, a 12th magnitude star that is moving along with the others. Together they form a triple star system.[4]
Nomenclature[ред. | ред. код]
δ Cygni (Latinised to Delta Cygni) is the binary's Bayer designation. The designations of the two components as Delta Cygni A and B derive from the convention used by the Washington Multiplicity Catalog (WMC) for multiple star systems, and adopted by the International Astronomical Union (IAU).[5]
Traditionally, Delta Cygni had no proper name.[4] It belonged to the Arabic asterism al-Fawāris (الفوارس), meaning "the Riders" in indigenous Arabic,[6] together with Zeta, Epsilon, and Gamma Cygni, the transverse of the Northern Cross. In 2016, the IAU organized a Working Group on Star Names (WGSN)[7] to catalog and standardize proper names for stars. The WGSN decided to attribute proper names to individual stars rather than entire multiple systems.[8] It approved the name Fawaris for the component Delta Cygni A on 1 June 2018 and it is now so included in the List of IAU-approved Star Names.[3]
In Chinese, 天津 (Tiān Jīn), meaning Celestial Ford, refers to an asterism consisting of Delta Cygni, Gamma Cygni, 30 Cygni, Alpha Cygni (Deneb) and Nu, Tau, Upsilon, Zeta and Epsilon Cygni.[9] Consequently, the Chinese name for Delta Cygni itself is 天津二 (Tiān Jīn èr, англ. the Second Star of Celestial Ford).[10]
Properties[ред. | ред. код]
The primary, Delta Cygni A, is a blue-white giant star of spectral class B9,[11] with a temperature of 10,500 K. It is nearing the end of its main-sequence life stage with a luminosity 155 times that of the Sun, a radius of 5.13 solar radii, and a mass approximately 2.93 solar masses. Like many hot stars, it spins rapidly, at least 135 kilometers per second at the equator, about 60 times that of the Sun.[12]
The close companion Delta Cygni B is a yellow-white class F of the sixth magnitude (6.33) with a luminosity about 6 times that of the Sun, and a mass about 1.5 times the Sun's. The two stars orbit each other at an average distance of 157 AU and a period of 780 years.[4]
The much more distant third companion is an orange (class K) twelfth magnitude star, and only two thirds as massive.[4]
The two main stars together appear with a spectral type of A0 IV.[13] As seen from Earth, the entire triple star system of Delta Cygni shines at a combined apparent magnitude of 2.87.[14]
Pole Star[ред. | ред. код]
Delta Cygni is a visible star located within 3° of the precessional path traced across the celestial sphere by the Earth's North pole. For at least four centuries around 11,250 AD it will probably be considered a pole star, a title currently held by Polaris which is just 0.5° off of the precessional path.
| Preceded by | Pole Star | Succeeded by |
|---|---|---|
| Deneb | ~11,000 AD to ~11,500 AD |
Vega |
Suspected variability[ред. | ред. код]
Both δ Cygni A and B have been suspected to vary in brightness. δ Cygni A was reported in 1951 as varying between magnitudes 2.85 and 2.89, and δ Cygni B was reported in 1837 to vary between magnitudes 6.3 and 8.5. The variability of the stars has not been confirmed.[15]
References[ред. | ред. код]
- ↑ а б Johnson, H. L. та ін. (1966), UBVRIJKL photometry of the bright stars, Communications of the Lunar and Planetary Laboratory, 4 (99): 99, Bibcode:1966CoLPL...4...99J
- ↑ 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
- ↑ а б Naming Stars. IAU.org. Процитовано 18 June 2018.
- ↑ а б в г Kaler, James B., Delta Cygni, Stars, University of Illinois, процитовано 3 жовтня 2018
- ↑ Hessman, F. V.; Dhillon, V. S.; Winget, D. E.; Schreiber, M. R.; Horne, K.; Marsh, T. R.; Guenther, E.; Schwope, A.; Heber, U. (2010). On the naming convention used for multiple star systems and extrasolar planets. arXiv:1012.0707 [astro-ph.SR].
- ↑ Allen, R. H. (1963). Star Names: Their Lore and Meaning (вид. Reprint). New York, NY: Dover Publications Inc. с. 193, 197. ISBN 978-0-486-21079-7.
- ↑ IAU Working Group on Star Names (WGSN). Процитовано 22 May 2016.
- ↑ WG Triennial Report (2015-2018) - Star Names (PDF). с. 5. Процитовано 14 липня 2018.
- ↑ (кит.) 中國星座神話, written by 陳久金. Published by 台灣書房出版有限公司, 2005, ISBN 978-986-7332-25-7.
- ↑ (кит.) AEEA (Activities of Exhibition and Education in Astronomy) 天文教育資訊網 2006 年 7 月 4 日
- ↑ Edwards, T. W. (April 1976), MK classification for visual binary components, Astronomical Journal, 81: 245—249, Bibcode:1976AJ.....81..245E, doi:10.1086/111879
- ↑ Challouf, M. та ін. (2014), Improving the surface brightness-color relation for early-type stars using optical interferometry⋆, Astronomy & Astrophysics, 570: A104, arXiv:1409.1351, Bibcode:2014A&A...570A.104C, doi:10.1051/0004-6361/201423772.
- ↑ . Bibcode:2009A&A...501..297Z.
{{cite journal}}: Пропущений або порожній|title=(довідка) - ↑ Malagnini, M. L.; Morossi, C. (November 1990), Accurate absolute luminosities, effective temperatures, radii, masses and surface gravities for a selected sample of field stars, Astronomy and Astrophysics Supplement Series, 85 (3): 1015—1019, Bibcode:1990A&AS...85.1015M
- ↑ Samus, N. N.; Durlevich, O. V. та ін. (2009). VizieR Online Data Catalog: General Catalogue of Variable Stars (Samus+ 2007-2013). VizieR On-line Data Catalog: B/gcvs. Originally Published in: 2009yCat....102025S. 1: B/gcvs. Bibcode:2009yCat....102025S.
Помилка цитування: Тег <ref> з назвою "Anderson2012", визначений у <references>, не використовується в попередньому тексті.
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<ref> з назвою "malkov", визначений у <references>, не використовується в попередньому тексті.External links[ред. | ред. код]
- James B. "Jim" Kaler, DELTA CYG (Delta Cygni) - STARS
- Alan M. MacRobert, Understanding Celestial Coordinates - Sky & Telescope
- Richard Powell, The Brightest Stars - An Atlas of The Universe
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