a2Crucis
| catalogues and names |
| The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) |
| SKY2000 - Master Star Catalog |
| The Washington Visual Double Star Catalog, 1996.0 |
catalogues and names
| catalogues and names | a2Cru, HR 4731, HD 108249, WDS 12266-6306B |
| constellation | Crux |
data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)
position, motion, parallax:
| position (J2000) | RA: 12h 26min 36,5sec | DEC: -63° 5' 58'' | ||
| position (2001,18) | RA: 12h 26min 41sec | DEC: -63° 6' 22'' | ||
| position (B1900) | RA: 12h 21min 2,5sec | DEC: -62° 32' 43'' | ||
| proper motion (J2000) | RA: -0,034 arcsec/a | DEC: -0,007 arcsec/a | ||
| radial velocity | -1 km/s | |||
| rotational velocity | 197 km/s (uncertain) (variable) | |||
| dynamical parallax | 0,008 arcsec | |||
| galactic coordinates | longitude: 300,13° | latitude: -0,36° | ||
magnitude
| visual magnitude | 1,73 (V on UBV Johnson system) |
spectral / color information
| spectral class | B1V |
| B-V-magnitude | -0,26 |
| U-B-magnitude | -0,95 |
double/multiple star system information
| number of components of multiple star system | 3 |
| separation | 4,4 arcsec |
| mag difference (of double or brightest multiple) | 0,4 |
| component ID | AB |
| note | Worley (1978) update of the IDS |
| note (category: double and multiple data): | Binary with HR 4730, CPM with 4729. |
| note (category: spectroscopic binaries): | Formerly considered SB, 56d, probably single companion to HR 4730. |
miscellaneous information
| note (category: group membership): | Member of the local association (Pleiades group); Sco-Cen assoc.; HII region. See HR 4730. |
| note (category: miscellaneous): | Possibly X-ray source 2U1223-62. |
data from SKY2000 - Master Star Catalog (Myers+ 1997)
position, motion, parallax:
| position (J2000) | RA: 12h 26min 36,401sec | DEC: -63° 5' 58,07'' | ±0,06 arcsec | source: 15 |
| position (2001,18) | RA: 12h 26min 40sec | DEC: -63° 6' 22'' | JD: 2451975,79 | |
| proper motion (J2000) | RA: -0,0052 arcsec/a | DEC: -0,012 arcsec/a | source: 15 | |
| radial velocity | -1 km/s | source: 25 | ||
| galactic coord. (B1950) | longitude: 300,13° | latitude: -0,36° | ||
magnitude:
| visual | 1,73 (observed) | source: 25 |
| photovisual | 2,1 | source: 2 |
| photographic | 1,9 | source: 2 |
spectral information:
| Morgan-Keenan | B1V | source: 25 | |
| B-magnitude | 1,47 ±0,05 | B-V-magnitude | -0,26 |
| U-magnitude | 0,52 ±0,05 | U-B-magnitude | -0,95 |
double/multiple star system information:
| separation between brightest and second brightest component | 4 arcsec |
| magnitude difference between brightest and second brightest component | 0,5 |
| position angle | 112 ° |
| component | magnitude | spectral class | catalogue(s)/name(s) |
| A | 1,33 | B1 | Acrux, a1Crucis, HR 4730, HD 108248, SAO 251904 |
| B | 1,73 | - | a2Crucis, HR 4731, HD 108249, |
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 | |
| 19 | WDS Catalog |
| Worley, C.E., and G.G. Douglass, Washington Catalog of Visual Double Stars 1996.0, United States Naval Observatory, 1996 | |
| 25 | Bright Star Catalogue, 5th edition |
| Hoffleit, D. and Warren, W.H. Jr., The Bright Star Catalogue, 5th Revised Edition, Version 2, 1994 | |
data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)
position and proper motion:
| position (J2000) | RA: 12h 26,6min | DEC: -63° 6' |
| proper motion (J2000) | RA: -0,036 arcsec/a | DEC: -0,012 arcsec/a |
double/multiple star system information:
| component | year | number of measures | position angle | angular separation | magnitude of 1st component | magnitude of 2nd component | spectral class(es) | discoverer code |
| AB | 1826 | 73 | 121° | 5,6'' | 1,3 | 1,8 | B1V | DUN 252 |
| 1994 | 112° | 4'' | ||||||
| AC | 1826 | 13 | 202° | 90,1'' | 1,3 | 4,86 | B4IV | DUN 252 |
| 1976 | 204° | 89,8'' | ||||||
| BC | 1859 | 1 | 205° | 90'' | 2,3 | 6 | - | DUN 252 |
discoverer information:
| discoverer code | discoverer | reference |
| DUN 252 | Dunlop, J. | - |
notes:
| note | Alpha (1) Cru. Spectroscopic binary. Common proper motion with HR 4729 and 4731, so that there are at least five components in the system. |