Sirius

Sirius
Cineál	déréalta agus réalta threorach
Cineál speictreach (réalta)	A1Vm/DA2; A1V+DA
Réaltbhuíon	an Madra Mór
Aois	J2000.0
Saintréithe fisiceacha agus réaltmhéadracha
Fad ón Domhan	8.6 ly
Ga	1.711 R☉
Dearbhmhéid	11.8
Méid dhealraitheach (V)	−1.46 (banda V)
Teocht éifeachtach	9,797 K
Saobhdhiallas	379.21 mas
Dualghluaisne (diallas)	−1,223.07 mas/y
Dualghluaisne (dronairde)	−546.01 mas/y
Luas rothlaithe réaltach	16.7 km/s
Luas gathach	−5.5 km/s
Imtharraingt dromchla	16,000 cm/s²
Dronairde (α)	6h 45m 8.9173s
Diallas (δ)	-16° -42′ -58.0171″
Miotalacht	0.5
Lonrachas	25.4 lonrachas na gréine
Cuid de	Winter Hexagon (en) agus Winter Triangle (en)
Le cuid	Sirius A; Compánach Sirius
Catalóga réalteolaíochta
	LHS 219k (Luyten Half-Second catalogue (en) ); NSV 17173 (New Catalogue of Suspected Variable Stars (en) ); RAFGL 1007 (The Revised AFGL (RAFGL) catalogue (en) ); TD1 8027 (TD1 Catalog of Stellar Ultraviolet Fluxes (en) ); UBV 6709 (UBV Photoelectric Photometry Catalogue (en) ); WDS J06451-1643A,BC (Washington Double Star Catalog (en) ); ADS 5423 A (Aitken Double Star Catalogue (en) ); CCDM J06451-1643A (Catalog of Components of Double and Multiple Stars (en) ); CEL 1368 (Celescope Catalogue of Ultraviolet Magnitudes (en) ); FK5 257 (FK5 (en) ); GCRV 4392 (General Catalogue of Stellar Radial Velocities (en) ); GJ 244 A (Gliese Catalogue of Nearby Stars (en) ); HD 48915A (catalóg Henry Draper); IDS 06408-1635 A (Index Catalogue of Visual Double Stars (en) ); JP11 1425 (JP11 (en) ); LFT 486 (Luyten Five-Tenths catalogue (en) ); LPM 243 (Luyten Proper-Motion catalogue (en) ); LTT 2638 (Luyten Two-Tenths catalogue (en) ); N30 1470 (Catalog of 5,268 Standard Stars Based on the Normal System N30 (en) ); NLTT 16953 (New Luyten Two-Tenths catalogue (en) ); PLX 1577 (General Catalogue of Trigonometric Stellar Parallaxes (en) ); PMC 90-93 186 (Tokyo Photoelectric Meridian Circle Catalog (en) ); PPM 217626 (PPM Star Catalogue (en) ); ROT 1088 (Catalogue of rotational velocities of the stars (en) ); UBV M 12413 (Photoelectric catalogue, magnitudes and colors of stars in the UBV and UCBV systems (en) ); uvby98 100048915 A (uvbyβ Photoelectric Photometric Catalogue (en) ); Zkh 91 (Zhakozhaj (en) ); BD-16 1591A (Durchmusterung (en) ); TYC 5949-2777-1 (catalóg Tycho-2); SBC7 288 (Seventh catalogue of the orbital elements of spectroscopic binary systems (en) ); PM 06430-1639A (Catalogs of proper-motion stars. I. Stars brighter than visual magnitude 15 and with annual proper motion of 1" or more (en) ); HGAM 556 (A catalogue of Hgamma measures (en) ); Ci 20 396 (Catalogue of proper motion stars (en) ); CSI-16 1591 1 (Microfiche edition of CSI (en) ); SBC9 416 (Eighth catalogue of the orbital elements of spectroscopic binary systems (en) ); WEB 6525 (Vitesses radiales. Catalogue WEB: Wilson Evans Batten. Radial velocities: The Wilson-Evans-Batten catalogue (en) )

Sirius nó Sotis nó Réalt an Mhadaidh: an réalt is gile ar an spéir, agus í suite i réaltbhuíon an Mhadaidh Mhóir. Tá Sirius cóngarach go maith dúinn - ocht solasbhliain go leith - agus siúd is go bhfuil sí níos gile agus níos mó ná an Ghrian, ní fathachréalta í ar aon nós. Gnáthréalt de chuid an phríomhsheichimh atá inti, go bunúsach. Mar sin féin, tá rún nó dúthomhas ag baint le Sirius: tá cuid mhaith foinsí stairiúla ó réalteolaithe na seanBhabalóine go dtí na Meánaoiseanna ar aon fhocal gur réalt dhearg a bhí i Sirius lena lá féin. Ní réalt dhearg atá i Sirius mar is aithin dúinn inniu í, ach réalt bhán. Fuarthas amach ins an naoú haois déag go bhfuil leathbhádóir ag Sirius - an abhacréalt bhán ar a dtugtar Sirius B inniu. Ós abhacréalt bhán atá inti, is seanréalt í a bhí ina fathachréalta dhearg roimhe seo, agus nuair a bhí, is follasach go raibh sí in ann léaró bán Sirius (nó Sirius A) a bháthadh lena loinnir dhearg. Ní féidir linn an t-athrú tobann ó réalt dhearg go réalt bhán a mhíniú mar sin féin, nó ní bhíonn na fathachréaltaí dearga ag caochló go habhacréaltaí bána taobh istigh de mhíle bliain - bíonn na hathruithe ins an spéir ag teacht i gcrann i bhfad níos moille ná sin.

Naisc sheachtracha

Yale Bright Star Catalog
an Madra Mór ar shuíomh Robin Gatter Curtha i gcartlann 2006-05-08 ar an Wayback Machine
Star Tales de chuid Ian Ridpath
an Madra Mór agus miotaseolaíocht an Domhain Curtha i gcartlann 2006-07-19 ar an Wayback Machine
an Madra Mór ar shuíomh Richard Dibon-Smith
Peoria Astronomical Society: an Madra Mór Curtha i gcartlann 2006-06-15 ar an Wayback Machine
The Deep Photographic Guide to the Constellations: an Madra Mór

↑ "General Catalogue of Stellar Spectral Classifications" (2013): 2023.
↑ "Catalogue of Stellar Photometry in Johnson's 11-color system" (as Béarla) (2002).
↑ Tabetha S. Boyajian (13 Meitheamh 2013). "Stellar diameters and temperatures. III. Main-sequence A, F, G, and K stars: additional high-precision measurements and empirical relations" (as Béarla) (1): 40. doi:10.1088/0004-637X/771/1/40.
↑ ^4.0 ^4.1 ^4.2 ^4.3 ^4.4 Floor van Leeuwen (2007). "Validation of the new Hipparcos reduction" (as Béarla) (2): 653–664. doi:10.1051/0004-6361:20078357.
↑ "Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum" (as Béarla) (Iúil 2011). doi:10.1051/0004-6361/201016386.
↑ "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system" (as Béarla) (Samhain 2006) (11): 759–771. doi:10.1134/S1063773706110065.
↑ Owen Gingerich (1968). ""On the composition of Sirius" revisited": 160–162.
↑ "The Abundance Patterns of Sirius and Vega" (as Béarla) (20 Feabhra 2001) (2): 953–965. doi:10.1086/319000.

[1fca2916895364f244bae19227333ede90ffaf87-1] "General Catalogue of Stellar Spectral Classifications" (2013): 2023.

[516c6376dc30b5f910553b4bdbe9df63faf19478-2] "Catalogue of Stellar Photometry in Johnson's 11-color system" (as Béarla) (2002).

[c5d07d86faa18e1dc0e29a5d72cb9f57cc9ffbac-3] Tabetha S. Boyajian (13 Meitheamh 2013). "Stellar diameters and temperatures. III. Main-sequence A, F, G, and K stars: additional high-precision measurements and empirical relations" (as Béarla) (1): 40. doi:10.1088/0004-637X/771/1/40.

[8e44f98b341f30b3364d0e4d57e8f5829bdd4a1d-4] 4.0 ^4.1 ^4.2 ^4.3 ^4.4 Floor van Leeuwen (2007). "Validation of the new Hipparcos reduction" (as Béarla) (2): 653–664. doi:10.1051/0004-6361:20078357.

[fd000b4cf2eaedd68ecd3cc0acd052d4e67a1032-5] "Accurate stellar rotational velocities using the Fourier transform of the cross correlation maximum" (as Béarla) (Iúil 2011). doi:10.1051/0004-6361/201016386.

[d97363a8d511dad40aadc5b607f05c88e1a7c85b-6] "Pulkovo Compilation of Radial Velocities for 35 495 Hipparcos stars in a common system" (as Béarla) (Samhain 2006) (11): 759–771. doi:10.1134/S1063773706110065.

[cb0bd75732b74543ba701cdd9c601db835071aca-7] Owen Gingerich (1968). ""On the composition of Sirius" revisited": 160–162.

[c8666c4bec00daf11eef45d864896da57dc7a611-8] "The Abundance Patterns of Sirius and Vega" (as Béarla) (20 Feabhra 2001) (2): 953–965. doi:10.1086/319000.

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