Achernar
| catalogues and names | Achernar, a Eri, NSV 15353, HR 472, HD 10144, SAO 232481, FK5: 54 |
| constellation | Eridanus |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
| note (category: star names): | ACHERNAR. |
position, motion, parallax:
| position (J2000) | RA: 1h 37min 42,9sec | DEC: -57° 14' 12'' |
| position (J1900) | RA: 1h 33min 59,4sec | DEC: -57° 44' 41'' |
| proper motion (J2000) | RA: 0,095 arcsec/a | DEC: -0,035 arcsec/a |
| radial velocity | 16 km/s note: variable radial velocity |
|
| rotational velocity | 251 km/s (uncertain) (variable) | |
| trigonometric parallax | 0,026 arcsec | |
| note (category: radial and/or rotational velocities): | Period in RV and light (1.26d) seems best explained by rotation. Weak but significant variations in strength of MgII 4481. RV of H gamma and HeI 4471 consistent with period, amp. 30k/s. Variable light amp. 0.02V. |
magnitude
| visual magnitude | 0,46 (V on UBV Johnson system) |
spectral / color information
| spectral class | B3Vpe |
| B-V-magnitude | -0,16 |
| U-B-magnitude | -0,66 |
| R-I-magnitude | -0,11 |
| note (category: spectra): | Lyman alpha and Lyman beta observed from COPERNICUS. H alpha and H beta var. emission and possible high-velocity mass loss. Expanding circumstellar shell. |
variability information
| variable star identification | Var |
| note (category: variability): | EB or Ell, amp. 0.02V. H alpha var. emission and possible high-velocity mass loss. Expanding circumstellar shell. |
miscellaneous information
| note (category: group membership): | Member of Pleiades group. |
| note (category: stellar radii or diameters): | Diam. = 0.00185 - 0.00192". |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 1h 37min 42,852sec | DEC: -57° 14' 12,18'' | ±0,06 arcsec | source: 15 |
| proper motion (J2000) | RA: 0,0117 arcsec/a | DEC: -0,035 arcsec/a | source: 25 | |
| radial velocity | 16 km/s | source: 25 | ||
| trigonometric parallax | 0,026 | ±0,003 arcsec | source: 25 | |
| galactic coord. (B1950) | longitude: 290,84° | latitude: -58,79° | ||
| GCI unit vector (J2000) | X: 0,492723 | Y: 0,223805 | Z: -0,840914 | |
magnitude:
| visual | 0,46 (observed) | source: 25 |
| photovisual | 0,6 | source: 2 |
| photographic | 0,5 | source: 2 |
spectral information:
| spectral class | B5 | source: 96 | |
| Morgan-Keenan | B3Vnp(shell) | source: 25 | |
| B-magnitude | 0,3 ±0,05 | B-V-magnitude | -0,16 |
| U-magnitude | -0,36 ±0,05 | U-B-magnitude | -0,66 |
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 (J1950) | RA: 1h 35min 51,307sec | DEC: -57° 29' 24,93'' | ±0,008 arcsec |
| position (J2000) | RA: 1h 37min 42,925sec | DEC: -57° 14' 12,13'' | |
| proper motion J1950 (FK4) | RA: 0,0129 arcsec/a | DEC: -0,028 arcsec/a | ±0,001 arcsec/a in RA ±0,002 arcsec/a in DEC |
| proper motion J2000 (FK5) | RA: 0,0127 arcsec/a | DEC: -0,034 arcsec/a | |
| source of proper motion data | Determined by source catalog | ||
magnitude:
| visual | 0,6 (accuracy: 2 decimals) |
| source of visual magnitude data | Taken from the "Henry Draper Catalogue". |
spectral information:
| spectral class | B5 |
| source of spectral data | Taken from the Henry Draper Catalogue or no spectrum in source catalog. |
catalogues
| source catalogue | FK4, catalogue number: 54 |
| Durchmusterung | CP-57 334 |
| Boss General Catalogue | 1979 |
| Henry Draper Catalogue | 10144 |