Alphard α Hya α Hydrae Alfa Hydrae Hydra takımyıldızında yer alan bir yıldızdır Alphard Hydra takımyıldızın

Name: Alphard
Creator: www.wikipedia.tr-tr.nina.az
Published: 2024-06-29T16:13:46+00:00
License: https://creativecommons.org/licenses/by/4.0/

Alphard (α Hya, α Hydrae, Alfa Hydrae), Hydra takımyıldızında yer alan bir yıldızdır. Alphard, Hydra takımyıldızının en parlak yıldızıdır. Adını Arapçada yalnız anlamına gelen el-Ferd (الفرد) kelimesinden almaktadır.

Alfa Hydrae
Gözlem verisi Dönem J2000 Ekinoks J2000
Alphard'ın (α) Hydra takımyıldızındaki konumu.
Takımyıldız	Hydra
Sağ açıklık ( $α$ )	09^sa 27^d 35.2433^s
Dik açıklık ( $δ$ )	−08° 39′ 30.969″
Görünür büyüklük (V)	+2.00
Sınıflandırma
Tayfsal sınıf	K3 II-III
U−B renk ölçeği	+1.73
B−V renk ölçeği	+1.44
Astrometri
Dikey hız ( $v_{r}$ )	−4.3 km/s
Özdevinim ( $μ$ )	RA: −14.49 mys/y Dec.: 33.25 mys/y
Iraklık açısı ( $π$ )	18.40 ± 0.78 mys
Uzaklık	177 ± 8 Iy (54 ± 2 pc)
Mutlak büyüklük (V)	−1.69 ± 0.09
Özellikler
Kütle ( $m$ )	3.03 ± 0.36 `M`_☉
Yarıçap ( $r$ )	50.5 ± 4.0 `R`_☉
Aydınlatma gücü	780 ± 78 L_⊙
Sıcaklık	4,120 K
Metallik [Fe/H]	−0.06
Dönüş süresi	2,991 days
Dönüş hızı ( $v_{\mathrm {e} }\cdot \sin i$ )	1.1 km/s
Yaş	(4.2 ± 1.6) × 10⁸
Katalog belirtmeleri
Alphard, Alfard, Alphart, Kalbelaphard, Cor Hydrae, 30 Hydrae, HR 3748, −08° 2680, HD 81797, SAO 136871, FK5 354, HIP 46390.

Kaynakça

^ ^a ^b ^c ^d ^e Perryman, M. A. C.; Lindegren, L.; Kovalevsky, J.; Hoeg, E.; Bastian, U.; Bernacca, P. L.; Crézé, M.; Donati, F.; Grenon, M. (1997), "The Hipparcos Catalogue", Astronomy & Astrophysics, cilt 323, ss. L49-L52, Bibcode:1997A&A...323L..49P
^ ^a ^b ^c Piau, L.; Kervella, P.; Dib, S.; Hauschildt, P. (Şubat 2011), "Surface convection and red-giant radius measurements", Astronomy and Astrophysics, cilt 526, s. A100, arXiv:1010.3649 $2, Bibcode:2011A&A...526A.100P, doi:10.1051/0004-6361/201014442
^ ^a ^b Pfleiderer, J.; Mayer, U. (Ekim 1971). "Near-ultraviolet surface photometry of the southern Milky Way". Astronomical Journal. Cilt 76. ss. 691-700. Bibcode:1971AJ.....76..691P. doi:10.1086/111186.
^ Evans, D. S. (Haziran 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". Batten, Alan Henry; Heard, John Frederick (Ed.). Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto: International Astronomical Union. Bibcode:1967IAUS...30...57E.
^ ^a ^b ^c ^d da Silva, L. (Kasım 2006). "Basic physical parameters of a selected sample of evolved stars". Astronomy and Astrophysics. 458 (2). ss. 609-623. arXiv:astro-ph/0608160 $2. Bibcode:2006A&A...458..609D. doi:10.1051/0004-6361:20065105.
^ ^a ^b Cenarro, A. J. (Ocak 2007). "Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters". Monthly Notices of the Royal Astronomical Society. 374 (2). ss. 664-690. arXiv:astro-ph/0611618 $2. Bibcode:2007MNRAS.374..664C. doi:10.1111/j.1365-2966.2006.11196.x.
^ ^a ^b Setiawan, J.; Pasquini, L.; da Silva, L.; Hatzes, A. P.; von der Lühe, O.; Girardi, L.; de Medeiros, J. R.; Guenther, E. (Temmuz 2004), "Precise radial velocity measurements of G and K giants. Multiple systems and variability trend along the Red Giant Branch", Astronomy and Astrophysics, cilt 421, ss. 241-254, Bibcode:2004A&A...421..241S, doi:10.1051/0004-6361:20041042-1
^ "Alphard". SIMBAD. Centre de Données astronomiques de Strasbourg. 16 Haziran 2019 tarihinde kaynağından . Erişim tarihi: 15 Nisan 2016.

[hipparcos-1] Perryman, M. A. C.; Lindegren, L.; Kovalevsky, J.; Hoeg, E.; Bastian, U.; Bernacca, P. L.; Crézé, M.; Donati, F.; Grenon, M. (1997), "The Hipparcos Catalogue", Astronomy & Astrophysics, cilt 323, ss. L49-L52, Bibcode:1997A&A...323L..49P

[aaa526_A100-2] Piau, L.; Kervella, P.; Dib, S.; Hauschildt, P. (Şubat 2011), "Surface convection and red-giant radius measurements", Astronomy and Astrophysics, cilt 526, s. A100, arXiv:1010.3649 $2, Bibcode:2011A&A...526A.100P, doi:10.1051/0004-6361/201014442

[aj76-3] Pfleiderer, J.; Mayer, U. (Ekim 1971). "Near-ultraviolet surface photometry of the southern Milky Way". Astronomical Journal. Cilt 76. ss. 691-700. Bibcode:1971AJ.....76..691P. doi:10.1086/111186.

[rgcrv-4] Evans, D. S. (Haziran 20–24, 1966). "The Revision of the General Catalogue of Radial Velocities". Batten, Alan Henry; Heard, John Frederick (Ed.). Determination of Radial Velocities and their Applications, Proceedings from IAU Symposium no. 30. University of Toronto: International Astronomical Union. Bibcode:1967IAUS...30...57E.

[aaa458-5] Silva, L. (Kasım 2006). "Basic physical parameters of a selected sample of evolved stars". Astronomy and Astrophysics. 458 (2). ss. 609-623. arXiv:astro-ph/0608160 $2. Bibcode:2006A&A...458..609D. doi:10.1051/0004-6361:20065105.

[mnras374-6] Cenarro, A. J. (Ocak 2007). "Medium-resolution Isaac Newton Telescope library of empirical spectra - II. The stellar atmospheric parameters". Monthly Notices of the Royal Astronomical Society. 374 (2). ss. 664-690. arXiv:astro-ph/0611618 $2. Bibcode:2007MNRAS.374..664C. doi:10.1111/j.1365-2966.2006.11196.x.

[aaa421_241-7] Setiawan, J.; Pasquini, L.; da Silva, L.; Hatzes, A. P.; von der Lühe, O.; Girardi, L.; de Medeiros, J. R.; Guenther, E. (Temmuz 2004), "Precise radial velocity measurements of G and K giants. Multiple systems and variability trend along the Red Giant Branch", Astronomy and Astrophysics, cilt 421, ss. 241-254, Bibcode:2004A&A...421..241S, doi:10.1051/0004-6361:20041042-1

[SIMBAD-8] "Alphard". SIMBAD. Centre de Données astronomiques de Strasbourg. 16 Haziran 2019 tarihinde kaynağından . Erişim tarihi: 15 Nisan 2016.