Acrux


The object was found in the following catalogues:
  1. The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version)

  2. SKY2000 - Master Star Catalog

  3. Smithsonian Astrophysical Observatory Star Catalog

  4. The Washington Visual Double Star Catalog, 1996.0


catalogues and names Acrux, a1Cru, HR 4730, HD 108248, SAO 251904, FK5: 462, WDS 12266-6306A
constellation Crux

data from The Bright Star Catalogue, 5th Revised Ed. (Preliminary Version) (Hoffleit+, 1991)

note (category: star names): ACRUX.

position, motion, parallax:

position (J2000) RA: 12h 26min 35,9sec DEC: -63 5' 57''
position (J1900) RA: 12h 21min 2sec DEC: -62 32' 41''
proper motion (J2000) RA: -0,036 arcsec/a DEC: -0,012 arcsec/a
radial velocity -11 km/s
note: spectroscopic binaries
note: orbital data avaible
rotational velocity 117 km/s (uncertain) (variable)
dynamical parallax 0,008 arcsec

magnitude

visual magnitude 1,33
(V on UBV Johnson system)

spectral / color information

spectral class B0.5IV
B-V-magnitude -0,24
U-B-magnitude -1,03

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): AB 1.35 B0.5IV, 1.75 B3n or B0.5Vn, q = 0.916". Mag. and colors for blend of HR 4730-31, 0.76V, -0.25(B-V), -1.00(U-B), -0.24(R-I). Masses 14 and 10 solar for hyperbolic orbit with periastron distance 61 AU.
note (category: spectroscopic binaries): Primary of visual double, 75.769d, K 32.8k/s, V0 +7.5, asini 30.0.

miscellaneous information

note (category: group membership): HII region. Although there is disagreement in the RV of HR 4730, 4731, they are both members of the Sco-Cen assoc.
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 35,871sec DEC: -63 5' 56,58'' 0,06 arcsec source: 15
proper motion (J2000) RA: -0,0052 arcsec/a DEC: -0,012 arcsec/a source: 15
radial velocity -11 km/s source: 25
galactic coord. (B1950) longitude: 300,13 latitude: -0,36
GCI unit vector (J2000) X: -0,449406 Y: -0,052391 Z: -0,89179

magnitude:

visual 1,33 (observed) source: 25
photovisual 1,6 source: 2
photographic 1,4 source: 2

spectral information:

spectral class B1 source: 96
Morgan-Keenan B0.5IV source: 25
B-magnitude 1,09 0,05 B-V-magnitude -0,24
U-magnitude 0,06 0,05 U-B-magnitude -1,03

double/multiple star system information:

source of data: 19
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
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: 12h 23min 48,064sec DEC: -62 49' 19,43'' 0,01 arcsec
position (J2000) RA: 12h 26min 35,948sec DEC: -63 5' 56,5''
proper motion J1950 (FK4) RA: -0,0036 arcsec/a DEC: -0,017 arcsec/a 0,002 arcsec/a in RA
0,002 arcsec/a in DEC
proper motion J2000 (FK5) RA: -0,0044 arcsec/a DEC: -0,012 arcsec/a
source of proper motion data Determined by source catalog

magnitude:

visual 1,6 (accuracy: 2 decimals)
source of visual magnitude data Taken from the "Henry Draper Catalogue".

spectral information:

spectral class B1
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.

catalogues

source catalogue FK4, catalogue number: 462
Durchmusterung CP-62 2745A
Boss General Catalogue 16952
Henry Draper Catalogue 108248
The "SAO Catalog" entry refers to two consecutive HD numbers, the lower of which is given.

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.