a Arae

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

  5. Combined General Catalogue of Variable Stars (Vol. I-III)

catalogues and names a Ara, alf Ara, HR 6510, HD 158427, SAO 228069, FK5: 651, WDS 17318-4953
constellation Ara

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

position, motion, parallax:

position (J2000) RA: 17h 31min 50,5sec DEC: -49 52' 34''
position (J1900) RA: 17h 24min 6,6sec DEC: -49 47' 48''
proper motion (J2000) RA: -0,031 arcsec/a DEC: -0,07 arcsec/a
radial velocity 0 km/s
note: spectroscopic binaries
rotational velocity 298 km/s (uncertain) (variable)
trigonometric parallax 0,007 arcsec


visual magnitude 2,95
(V on UBV Johnson system)

spectral / color information

spectral class B2Vne
B-V-magnitude -0,17
U-B-magnitude -0,69
R-I-magnitude -0,24
note (category: spectra): Shell star with variable H alpha emission.

variability information

variable star identification 8999
note (category: variability): 2.76 - 2.90V.

double/multiple star system information

separation 55,6 arcsec
mag difference (of double or brightest multiple) 8
note Worley (1978) update of the IDS
note (category: double and multiple data): Companion K0IV, optical.

miscellaneous information

note (category: group membership): Cas-Tau group; member of the local association (Pleiades group); Sco-Cen assoc.; probable member of Sco-Cen cluster.

data from SKY2000 - Master Star Catalog (Myers+ 1997)

position, motion, parallax:

position (J2000) RA: 17h 31min 50,509sec DEC: -49 52' 34,29'' 0,06 arcsec source: 15
proper motion (J2000) RA: -0,0032 arcsec/a DEC: -0,07 arcsec/a source: 25
radial velocity 0 km/s source: 25
trigonometric parallax 0,007 0,001 arcsec source: 25
galactic coord. (B1950) longitude: 340,76 latitude: -8,83
GCI unit vector (J2000) X: -0,078979 Y: -0,639584 Z: -0,764654


visual 2,95 (observed) source: 25
photovisual 3 source: 2
photographic 2,8 source: 2

spectral information:

spectral class B3 source: 96
Morgan-Keenan B2Vne source: 25
B-magnitude 2,78 0,05 B-V-magnitude -0,17
U-magnitude 2,09 0,05 U-B-magnitude -0,69

variability information:

source of data: 28
variability type 275
var. amplitude 0,1

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 55,6 arcsec
magnitude difference between brightest and second brightest component 8,05
position angle 173


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: 17h 27min 58,353sec DEC: -49 50' 19,61'' 0,009 arcsec
position (J2000) RA: 17h 31min 50,558sec DEC: -49 52' 34,52''
proper motion J1950 (FK4) RA: -0,0025 arcsec/a DEC: -0,071 arcsec/a 0,002 arcsec/a in RA
0,002 arcsec/a in DEC
proper motion J2000 (FK5) RA: -0,0027 arcsec/a DEC: -0,073 arcsec/a
source of proper motion data Determined by source catalog


visual 3 (accuracy: 2 decimals)
source of visual magnitude data Taken from the "Henry Draper Catalogue".

spectral information:

spectral class B3p
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.


source catalogue FK4, catalogue number: 651
Durchmusterung CD-4911511
Boss General Catalogue 23708
Henry Draper Catalogue 158427

data from The Washington Visual Double Star Catalog, 1996.0 (Worley+, 1996)

position and proper motion:

position (J2000) RA: 17h 31,8min DEC: -49 53'
proper motion (J2000) RA: -0,031 arcsec/a DEC: -0,07 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
- 1913 1 173 55,6'' 2,94 10,99 B2Vne HJ 4955

discoverer information:

discoverer code discoverer reference
HJ 4955 Herschel, J. -


note Alpha Ara. A spectroscopic binary.

data from Combined General Catalogue of Variable Stars (Vol. I-III) (Kholopov+ 1998)


position (J1950) RA: 17h 27min 58,4sec DEC: -49 50' 20''

variability informations:

variability type BE
magnitute at max. brightness 2,79
magnitute at min. brightness 3,13
photometric system b in Stroemgren system


to a study J.Cuypers, L.A.Balona, F.Marang, AsAp Suppl 81, No.2, 151, 1989.
to a chart/photograph no chart is avaible, but the star is contained in the 'Cordoba Durchmusterung'


ID in the GCVS catalogue 6/9001
constellation Ara
notes on existence The star is equivalent to '71293'.

variability type description

variability type description
BE It becomes more and more clear that, although the majority of Be stars are photometrically variable, not all of them could be properly called GCAS variables. Quite a number of them show small-scale variations not necessarily related to shell events; in some cases the variations are quasi-periodic. By now we are not able to present an elaborated system of classification for Be variables, but we adopt a decision that in the cases when a Be variable cannot be readily described as a GCAS star we give simply BE for the type of variability.