Albireo

**Albireo B**
	Data pengamatan; Epoch J2000.0 (ICRS) Equinox J2000.0 (ICRS)
Rasi bintang	Cygnus
Asensio rekta	19j 30m 45.3954d
Deklinasi	+27° 57′ 54.995″
Magnitudo semu (V)	5.09
	Karakteristik
Klasifikasi bintang	B8Ve
U-B Indeks warna	-0.30
B-V Indeks warna	-0.06
	Astrometri
Kecepatan radial (Rv)	-18 km/s
Gerak diri:
RA (μα cos δ)	-1.95 m.b/thn
Dec. (μδ)	-0.98&nbspm.b/thn
Paralaks (π)	8.67 ± 0.65 m.b
Jarak	380 ± 30 tc ; (115 ± 9 pc)
	Details
Massa	3.7 ± 0.8 M☉
Radius	2.7 R☉
Gravitasi permukaan (log g)	4.00 ± 0.15
Luminositas (bolometriks)	230 ± 90 L☉
Temperatur	13200 ± 600 K
Rotasi	<0.6 days
Umur	4×107 to 2×108 thn
	Position (relative to Albireo A)
Epoch of observation	2006
Jarak anguler	35.3″
Position angle	54°
	Referensi Database
SIMBAD	data
	Nama lain
	β Cygni B, β2 Cygni, 6 Cygni B, STF 4043B, ADS 12540 B, BD+27 3411, CCDM J19307+2758B, HD 183914, HIP 95951, HR 7418, SAO 87302, WDS 19307+2758B

**Albireo A**
	; Albireo's position, lower right corner. ; The cross-like figure is the Northern Cross. ; The blue line shows the boundaries of the constellation the Swan.
	Data pengamatan; Epoch J2000.0 (ICRS) Equinox J2000.0 (ICRS)
Rasi bintang	Cygnus
	Karakteristik
	Astrometri
Gerak diri:
Paralaks (π)	8.46 ± 0.58 m.b
Jarak	390 ± 30 tc ; (118 ± 8 pc)
	Details
	Orbit
Periode (P)	213.859 yr
Sumbu semi-mayor (a)	0.536″
Eksentrisitas (e)	0.256
Inklinasi (i)	154.9°
Bujur node menaik (Ω)	170.4°
Periastron epos (T)	B1997.995
Argumen periastron (ω); (secondary)	39.4°
	Referensi Database
SIMBAD	data
	Nama lain
	β Cygni A, β1 Cygni, 6 Cygni A, MCA 55 Aac, ADS 12540 A, BD+27 3410, CCDM J19307+2758A, FK5 732, HD 183912/183913, HIP 95947, HR 7417, NSV 12105, SAO 87301, WDS 19307+2758Aa/Ac

Albireo (β Cyg / β Cygni / Beta Cyg / Beta Cygni) adalah bintang tercerah kelima di rasi Cygnus. Meskipun oleh Bayer diberikan nama beta, namun sesungguhnya ia adalah bintang yang lebih redup daripada Gamma Cygni, Delta Cygni, dan Epsilon Cygni. Albireo dipandang oleh mata telanjang sebagai satu bintang, namun oleh binokular, bintang ini terlihat sebagai bintang ganda, terdiri dari bintang kuning cemerlang dan bintang yang berwarna biru redup. Albireo merupakan bintang yang menarik di pandangan astronom amatir dengan menggunakan teleskop^[6]

Bintang ganda

Albireo berada pada jarak 380 tahun cahaya (120 parsec) dari Bumi. Bintang ganda ini terdiri dari Albireo A (berwarna kuning dengan magnitudo 3.1), dan Albireo B (biru kehijauan, bermagnitudo 5.1.)^[10]. Terpisah dengan jarak 35 arcsecond, kedua bintang ini menghasilkan warna kontras yang sangat menarik di langit. Diperkirakan periode orbitnya adalah 100,000 years.^[10]

Albireo A

Pada tahun 1976, komponen A ditemukan sebagai bintang ganda, menggunakan speckle interferometry dan teleskop 2.1 meter di Kitt Peak National Observatory.^[9]^[11].

Albireo B

Albireo B merupakan bintang yang berotasi cepat, dengan kecepatan rotasi ekuatorial kurang lebih 250 per detik.^[6] Temperaturnya diperkirakan sekitar 13,200 Kelvin.

Nama dan etimologi

Sejak Cygnus dijadikan rasi berbentuk angsa, dan Albireo diletakkan di atas kepala (rasi) angsa tersebut, Albireo kadang-kadang disebut sebagai "bintang di paruh (sang bebek)".^[17]

Astronom pada masa Arab kuno menyebut Albireo adalah minqār al-dajāja^h, yang berarti "paruh ayam"^[18] Nama tersebut merupakan mistranslasi. Mereka mengira bahwa Cygnus berasal dari nama ornis yang di-Arab-kan menjadi urnis.^[19] Ketika diterjemahkan dalam bahasa Latin, nama ini merujuk kepada sejenis tanam Erysimum officinale, dan kemudian dirujukanlah nama ini untuk tanaman tersebut, ireo. Kalimat ab ireo kemudian di-Arab-kan menjadi al-bireo.^[20]Nama lainnya untuk bintang ini adalah :

nama lain	asal bahasa	arti
輦道增七 / Niǎndàozēngqī	China	bintang ketujuh (lanjutan) pada rasi Jalan Terusan Kerajaan^[21]
Rostrum Gallinae	Latin	paruh ayam^[22]

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

nama rasi / asterisma	asal	arti	anggota lainnya
Northern Cross^[23]		salib di utara	α Cyg, δ Cyg, ε Cyg
Al Fawāris	Arab	pengendara	α Cyg, γ Cyg, ε Cyg, δ Cyg, ζ Cyg, κ Cyg, η Cyg

Referensi

^ ^a ^b ^c HIP 95947, record for component 1, Hipparcos catalogue; CDS ID I/239.
^ ^a ^b ^c HIP 95947, record for component 2, Hipparcos catalogue; CDS ID I/239.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j Binary Star Differential Photometry Using the Adaptive Optics System at Mount Wilson Observatory, Theo ten Brummelaar, Brian D. Mason, et al., Astronomical Journal 119, #5 (May 2000), pp. 2403–2414. DOI:10.1086/301338. Bibcode: 2000AJ....119.2403T. See tables 4, 5, 6, and 8. Luminosity from L_bol=10^{2(4.75−M_bol)/5}.
^ ^a ^b Entry, The Washington Double Star Catalog, identifier 19307+2758, discoverer identifier MCA 55. Accessed on line July 9, 2008.
^ ^a ^b CCDM J19307+2758A -- Double or multiple star, database entry, SIMBAD. Accessed on line July 9, 2008.
^ ^a ^b ^c ^d ^e Albireo, Stars, Jim Kaler. Accessed on line July 9, 2008.
^ Entry, HD 183912, Catalogue of Stellar Diameters (CADARS); CDS ID II/224.
^ ^a ^b Entry, WDS identifier 19307+2758, Sixth Catalog of Orbits of Visual Binary Stars, William I. Hartkopf & Brian D. Mason, U.S. Naval Observatory. Accessed on line July 9, 2008.
^ ^a ^b Speckle observations with PISCO in Merate: IV. Astrometric measurements of visual binaries in 2005, M. Scardia et al., Astronomische Nachrichten 329, #1 (2008), pp. 54–68. Bibcode: 2008AN....329...54S. DOI:10.1002/asna.200710834.
^ ^a ^b p. 46, The Monthly Sky Guide, Ian Ridpath, Wil Tirion, Cambridge University Press, 2006, ISBN 0-521-68435-8.
^ Speckle interferometric measurements of binary stars. VI, H. A. McAlister and E. M. Hendry, Astrophysical Journal Supplement Series 48 (March 1982), pp. 273–278. Bibcode: 1982ApJS...48..273M. DOI:10.1086/190778.
^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j HD 183914 -- Emission-line Star, database entry, SIMBAD. Accessed on line July 9, 2008.
^ UBV observations of visual double stars, T. E. Lutz, Publications of the Astronomical Society of the Pacific 83 (August 1971), pp. 488–490. Bibcode: 1971PASP...83..488L.
^ ^a ^b ^c ^d ^e Table 1, Physical Parameters of Southern B- and Be-Type Stars, R. S. Levenhagen and N. V. Leister, The Astronomical Journal 127, #2 (February 2004), pp. 1176–1180, DOI:10.1086/381063, Bibcode: 2004AJ....127.1176L.
^ Entry, HD 183914, Catalogue of Stellar Diameters (CADARS); CDS ID II/224.
^ ^a ^b ^c Entry, The Washington Double Star Catalog, identifier 19307+2758, discoverer identifier STFA 43. Accessed on line July 9, 2008.
^ p. 416, In Quest of the Universe, Theo Koupelis and Karl F. Kuhn, 5th ed., Sudbury, Massachusetts: Jones & Bartlett Publishers, 2007, ISBN 0-7637-4387-9.
^ p. 196, Star-names and Their Meanings, Richard Hinckley Allen, New York, G. E. Stechert, 1899.
^ p. 24, The names of the stars and constellations compiled from the Latin, Greek and Arabic, W. H. Higgins, Leicester: Samuel Clarke, 1882.
^ p. 194, Allen.
^ salah satu rasi bintang menurut bangsa Cina
^ http://articles.adsabs.harvard.edu//full/1895MNRAS..55..429K/0000431.000.html
^ Northern Cross, entry, The Internet Encyclopedia of Science, David Darling. Accessed on line July 24, 2008.

Pranala luar

Albireo as a Triple Star
Photo by Richard Yandrick; August 30, 2005
A picture of Albireo by Stefan Seip
NightSkyInfo.com - Albireo
Albireo at Alcyone Software's Star Data Pages

[viziera-1] HIP 95947, record for component 1, Hipparcos catalogue; CDS ID I/239.

[vizierb-2] HIP 95947, record for component 2, Hipparcos catalogue; CDS ID I/239.

[bsd-3] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j Binary Star Differential Photometry Using the Adaptive Optics System at Mount Wilson Observatory, Theo ten Brummelaar, Brian D. Mason, et al., Astronomical Journal 119, #5 (May 2000), pp. 2403–2414. DOI:10.1086/301338. Bibcode: 2000AJ....119.2403T. See tables 4, 5, 6, and 8. Luminosity from L_bol=10^{2(4.75−M_bol)/5}.

[wds-4] Entry, The Washington Double Star Catalog, identifier 19307+2758, discoverer identifier MCA 55. Accessed on line July 9, 2008.

[simbada-5] CCDM J19307+2758A -- Double or multiple star, database entry, SIMBAD. Accessed on line July 9, 2008.

[stars-6] Albireo, Stars, Jim Kaler. Accessed on line July 9, 2008.

[7] Entry, HD 183912, Catalogue of Stellar Diameters (CADARS); CDS ID II/224.

[wdsa-8] Entry, WDS identifier 19307+2758, Sixth Catalog of Orbits of Visual Binary Stars, William I. Hartkopf & Brian D. Mason, U.S. Naval Observatory. Accessed on line July 9, 2008.

[pisco-9] Speckle observations with PISCO in Merate: IV. Astrometric measurements of visual binaries in 2005, M. Scardia et al., Astronomische Nachrichten 329, #1 (2008), pp. 54–68. Bibcode: 2008AN....329...54S. DOI:10.1002/asna.200710834.

[msg-10] . 46, The Monthly Sky Guide, Ian Ridpath, Wil Tirion, Cambridge University Press, 2006, ISBN 0-521-68435-8.

[11] Speckle interferometric measurements of binary stars. VI, H. A. McAlister and E. M. Hendry, Astrophysical Journal Supplement Series 48 (March 1982), pp. 273–278. Bibcode: 1982ApJS...48..273M. DOI:10.1086/190778.

[simbadb-12] ^ ^a ^b ^c ^d ^e ^f ^g ^h ⁱ ^j HD 183914 -- Emission-line Star, database entry, SIMBAD. Accessed on line July 9, 2008.

[13] UBV observations of visual double stars, T. E. Lutz, Publications of the Astronomical Society of the Pacific 83 (August 1971), pp. 488–490. Bibcode: 1971PASP...83..488L.

[physparms-14] Table 1, Physical Parameters of Southern B- and Be-Type Stars, R. S. Levenhagen and N. V. Leister, The Astronomical Journal 127, #2 (February 2004), pp. 1176–1180, DOI:10.1086/381063, Bibcode: 2004AJ....127.1176L.

[15] Entry, HD 183914, Catalogue of Stellar Diameters (CADARS); CDS ID II/224.

[wdsb-16] Entry, The Washington Double Star Catalog, identifier 19307+2758, discoverer identifier STFA 43. Accessed on line July 9, 2008.

[17] . 416, In Quest of the Universe, Theo Koupelis and Karl F. Kuhn, 5th ed., Sudbury, Massachusetts: Jones & Bartlett Publishers, 2007, ISBN 0-7637-4387-9.

[18] . 196, Star-names and Their Meanings, Richard Hinckley Allen, New York, G. E. Stechert, 1899.

[19] . 24, The names of the stars and constellations compiled from the Latin, Greek and Arabic, W. H. Higgins, Leicester: Samuel Clarke, 1882.

[20] . 194, Allen.

[sb0-21] salah satu rasi bintang menurut bangsa Cina

[22] ttp://articles.adsabs.harvard.edu//full/1895MNRAS..55..429K/0000431.000.html

[23] Northern Cross, entry, The Internet Encyclopedia of Science, David Darling. Accessed on line July 24, 2008.

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Albireo's position, lower right corner. The cross-like figure is the Northern Cross. The blue line shows the boundaries of the constellation the Swan.
Data pengamatan Epoch J2000.0 (ICRS) Equinox J2000.0 (ICRS)
Rasi bintang	Cygnus
Asensio rekta	19^j 30^m	19^j 30^m
	43.281^s	43.302^s
Deklinasi	+27° 57′^[1]	+27° 57′^[2]
	34.85″	34.61″
Magnitudo semu (V)	3.18^[3]	5.82^[3]
Karakteristik
Klasifikasi bintang	K3III^[4]	B0V^[4]
V-R Indeks warna	0.92^[3]	0.09^[3]
Astrometri
Gerak diri:
RA (μ_α cos δ)	−7.09^[1] m.b/thn	5.04^[2] m.b/thn
Dec. (μ_δ)	−5.63^[1]&nbspm.b/thn	6.48^[2]&nbspm.b/thn
Paralaks (π)	8.46 ± 0.58^[5] m.b
Jarak	390 ± 30 tc (118 ± 8 pc)
Magnitudo mutlak (M_V)	−2.18^[3]	0.46^[3]
Details
Massa	5^[6] M_☉	3.2^[6] M_☉
Radius	16^[7] R_☉
Luminositas (bolometriks)	1200±200^[3] L_☉	950±250^[3] L_☉
Temperatur	4080±10^[3] K	30000±100^[3] K
Orbit^[8]
Periode (P)	213.859 yr
Sumbu semi-mayor (a)	0.536″
Eksentrisitas (e)	0.256
Inklinasi (i)	154.9°
Bujur node menaik (Ω)	170.4°
Periastron epos (T)	B1997.995
Argumen periastron (ω) (secondary)	39.4°
Referensi Database
SIMBAD	data
Nama lain
β Cygni A, β¹ Cygni, 6 Cygni A, MCA 55 Aac, ADS 12540 A, BD+27 3410, CCDM J19307+2758A, FK5 732, HD 183912/183913, HIP 95947, HR 7417, NSV 12105, SAO 87301, WDS 19307+2758Aa/Ac^[8]^[9]^[5]

Data pengamatan Epoch J2000.0 (ICRS) Equinox J2000.0 (ICRS)
Rasi bintang	Cygnus
Asensio rekta	19^j 30^m 45.3954^d^[12]
Deklinasi	+27° 57′ 54.995″^[12]
Magnitudo semu (V)	5.09^[12]
Karakteristik
Klasifikasi bintang	B8Ve^[12]
U-B Indeks warna	-0.30^[13]
B-V Indeks warna	-0.06^[12]
Astrometri
Kecepatan radial (R_v)	-18^[12] km/s
Gerak diri:
RA (μ_α cos δ)	-1.95^[12] m.b/thn
Dec. (μ_δ)	-0.98^[12]&nbspm.b/thn
Paralaks (π)	8.67 ± 0.65^[12] m.b
Jarak	380 ± 30 tc (115 ± 9 pc)
Details
Massa	3.7 ± 0.8^[14] M_☉
Radius	2.7^[15] R_☉
Gravitasi permukaan (log g)	4.00 ± 0.15^[14]
Luminositas (bolometriks)	230 ± 90^[14] L_☉
Temperatur	13200 ± 600^[14] K
Rotasi	<0.6 days^[6]
Umur	4×10⁷ to 2×10⁸ ^[14]thn
Position (relative to Albireo A)
Epoch of observation	2006
Jarak anguler	35.3″ ^[16]
Position angle	54°^[16]
Referensi Database
SIMBAD	data
Nama lain
β Cygni B, β² Cygni, 6 Cygni B, STF 4043B, ADS 12540 B, BD+27 3411, CCDM J19307+2758B, HD 183914, HIP 95951, HR 7418, SAO 87302, WDS 19307+2758B^[16]^[12]