Alathfar
| catalogues and names |
| The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) |
| SKY2000 - Master Star Catalog |
| Smithsonian Astrophysical Observatory Star Catalog |
catalogues and names
| catalogues and names | Alathfar, m Lyr, 2 Lyr, HR 6903, HD 169702, SAO 66943, BD +39 3410, FK5: 3463 |
| other names | Al Athfar |
| constellation | Lyra |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | Alathfar; Al Athfar. |
position, motion, parallax:
| position (J2000) | RA: 18h 24min 13.8sec | DEC: +39° 30' 26'' | ||
| position (B1900) | RA: 18h 20min 56.1sec | DEC: +39° 27' 9'' | ||
| proper motion (J2000) | RA: -0.023 arcsec/a | DEC: -0.002 arcsec/a | ||
| radial velocity | -24 km/s note: spectroscopic binaries |
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| rotational velocity | 165 km/s (uncertain) (variable) | |||
| trigonometric parallax | 0.004 arcsec | |||
| galactic coordinates | longitude: 67.33° | latitude: 21.8° | ||
magnitude
| visual magnitude | 5.12 (V on UBV Johnson system) |
spectral / color information
| spectral class | A3IVn |
| B-V-magnitude | 0.03 |
| U-B-magnitude | 0.08 |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 18h 24min 13.779sec | DEC: +39° 30' 26.24'' | ±0.22 arcsec | source: 15 |
| proper motion (J2000) | RA: -0.002 arcsec/a | DEC: -0.002 arcsec/a | source: 25 | |
| radial velocity | -24 km/s | source: 25 | ||
| trigonometric parallax | 0.004 arcsec | - | source: 25 | |
| galactic coord. (B1950) | longitude: 67.33° | latitude: 21.8° | ||
magnitude:
| visual | 5.12 (observed) | source: 25 |
| photovisual | 5 | source: 2 |
spectral information:
| spectral class | A2 | source: 96 | |
| Morgan-Keenan | A3IVn | source: 25 | |
| B-magnitude | 5.15 ±0.05 | B-V-magnitude | 0.03 |
| U-magnitude | 5.23 ±0.05 | U-B-magnitude | 0.08 |
sources:
| 2 | HD and HDE Catalogs |
| Cannon, A.J., and E.C. Pickering, Harvard Annals, Vols 91-99, 1918-24, Cambridge, Massachusetts: Harvard University; Cannon, A.J., Harvard Annals, Vol. 100, 1925-36, Cambridge, Massachusetts: Harvard University; and Cannon, A.J., and M. Walton Mayall, Harvard Annals, Vol. 112, 1949, Cambridge, Massachusetts: Harvard University | |
| 15 | FK5, FK5 Extension and FK5 Supplement |
| Fricke, W., H. Schwan and T. Lederle, "Fifth Fundamental Catalogue (FK5), Part I. The Basic Fundamental Stars," Veroff. Astronomisches Recheninstitut, No. 32, Heidelberg, Germany, 1988, and Fricke, W., H. Schwan, and T.E. Corbin, "Fifth Fundamental Catalogue (FK5), Part II. The FK5 Extension," Veröff. Astronomisches Recheninstitut, No. 33, Heidelberg, Germany, 1991 | |
| 25 | Bright Star Catalogue, 5th edition |
| Hoffleit, D. and Warren, W.H. Jr., The Bright Star Catalogue, 5th Revised Edition, Version 2, 1994 | |
| 96 | SAO or HD/HDE Catalog |
| Reference from Value 1 or Reference from Value 2 | |
data from Smithsonian Astrophysical Observatory Star Catalog (SAO Staff 1966; USNO, ADC 1990)
position and proper motion:
| position (B1950) | RA: 18h 22min 34.868sec | DEC: +39° 28' 43.85'' | ±0.012 arcsec |
| position (J2000) | RA: 18h 24min 13.806sec | DEC: +39° 30' 25.73'' | |
| proper motion B1950 (FK4) | RA: -0.0019 arcsec/a | DEC: -0.007 arcsec/a | ±0.002 arcsec/a in RA ±0.002 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: -0.0015 arcsec/a | DEC: -0.007 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 5 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from Harvard or San Luis photometry. |
spectral information:
| spectral class | A2 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
| source catalogue | GC, catalogue number: 25137 |
| Durchmusterung | BD+39 3410 |
| Boss General Catalogue | 25137 |
| Henry Draper Catalogue | 169702 |