Suhail al Muhlif

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 Suhail al Muhlif, g2Vel, gam 2 Vel, HR 3207, HD 68273, SAO 219504, FK5: 309, WDS 08095-4720A
other names Al Suhail al Muhlif, Spectral Gem of Southern
constellation Vela

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

note (category: star names): Suhail al Muhlif; Al Suhail al Muhlif; "Spectral Gem of Southern Skies".

position, motion, parallax:

position (J2000) RA: 8h 9min 32sec DEC: -47 20' 12''
position (J1900) RA: 8h 6min 27sec DEC: -47 2' 30''
proper motion (J2000) RA: -0,004 arcsec/a DEC: 0,006 arcsec/a
radial velocity 35 km/s
note: spectroscopic binaries, double lined spectra
note: orbital data avaible
trigonometric parallax 0,017 arcsec


visual magnitude 1,78
(V on UBV Johnson system)

spectral / color information

spectral class WC8+O9I
B-V-magnitude -0,22
U-B-magnitude -0,99
R-I-magnitude -0,13
note (category: spectra): Magnesium and iron depleted by factor of 100 relative to the sun. UV spectrum dominated by supergiant companions. The Wolf-Rayet component appears to be the most massive known. Radio emission indicates a circumstellar gas cloud extending beyond the orbit of the binary. Also classified WC8+O7.5e.

variability information

variable star identification Gam2 Vel
note (category: variability): 1.6 - 1.8V, 154 sec. Sp. var. in about 200 sec. Variability too great to be explained by the 78.5d SB companion. Possibly a third close companion: a collapsed star of less than 2 solar masses.

double/multiple star system information

number of components of multiple star system 5
separation 41,2 arcsec
mag difference (of double or brightest multiple) 2,3
component ID AB
note Worley (1978) update of the IDS
note (category: double and multiple data): See HR 3206. Mag. and colors blended with other companions. C = CoD -46d3848, 7.65V, B6V at 63", physical. D, 9.07V, Am at 94", SB, over 7d?, optical.
note (category: spectroscopic binaries): Comp. A of visual double, 78.5d, K 43.1k/s, V0 -18.0k/s, asini 45.8. Alternate orbit 78.5002d, K 70k/s, V0 +12k/s, msin3i 32, asini 67. Possible mass transfer from WR to O-type component.

miscellaneous information

note (category: group membership): Gamma Velorum group which includes HR 3206, probably also HD 68157 at 20' and HR 3213 at 36' from A; HII region.
note (category: stellar radii or diameters): Diam. = 0.00043 - 0.00044".
note (category: miscellaneous): Low degree of polarization indicates symmetric shell. The brightest O-type star and one of only four WR stars bright enough to have been observed spectroscopically in UV by COPERNICUS. With 3165, appears capable of producing most of the observed ionization of Gum Neb. The brightest and presumably the nearest Wolf-Rayet binary. Radio emission interpreted as coming from circumstellar gas cloud extending farther than the orbital radius of the binary.

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

position, motion, parallax:

position (J2000) RA: 8h 9min 31,965sec DEC: -47 20' 11,91'' 0,06 arcsec source: 15
proper motion (J2000) RA: -0,0004 arcsec/a DEC: 0,006 arcsec/a source: 25
radial velocity 35 km/s source: 25
trigonometric parallax 0,017 0,002 arcsec source: 25
galactic coord. (B1950) longitude: 262,81 latitude: -7,69
GCI unit vector (J2000) X: -0,362956 Y: 0,572299 Z: -0,735348


visual 1,81 (observed) source: 30
photovisual 1,9 source: 2

spectral information:

spectral class O0 source: 96
Morgan-Keenan WC8+O9I source: 25
B-magnitude 1,56 0,05 B-V-magnitude -0,22
U-magnitude 0,57 0,05 U-B-magnitude -0,99

variability information:

source of data: 30
variability type 201
var. amplitude 0,06

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 41,3 arcsec
magnitude difference between brightest and second brightest component 2,49
position angle 220

component magnitude spectral class catalogue(s)/name(s)
A 1,81 O0 Suhail al Muhlif, g2Velorum, HR 3207, HD 68273, SAO 219504
B 4,27 B3 g1Velorum, HR 3206, HD 68243, SAO 219501


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
30 GCVS, 4th edition
Kholopov, P.N., et al., General Catalogue of Variable Stars, fourth edition, Moscow: Nauka Publishing House, 1985-88
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: 8h 7min 59,465sec DEC: -47 11' 18,31'' 0,009 arcsec
position (J2000) RA: 8h 9min 31,99sec DEC: -47 20' 12,04''
proper motion J1950 (FK4) RA: -0,0006 arcsec/a DEC: 0,004 arcsec/a 0,002 arcsec/a in RA
0,002 arcsec/a in DEC
proper motion J2000 (FK5) RA: -0,0001 arcsec/a DEC: 0,005 arcsec/a
source of proper motion data Determined by source catalog


visual 1,9 (accuracy: 2 decimals)
source of visual magnitude data Taken from the "Henry Draper Catalogue".

spectral information:

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


source catalogue FK4, catalogue number: 309
Durchmusterung CD-46 3847
Boss General Catalogue 11105
Henry Draper Catalogue 68273

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

position and proper motion:

position (J2000) RA: 8h 9,5min DEC: -47 20'
proper motion (J2000) RA: -0,004 arcsec/a DEC: 0,006 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 22 220 41,3'' 1,78 4,27 WC8+O7.5e DUN 65
AC 1835 10 151 62,3'' 2,2 8,5 - DUN 65
AD 1846 4 141 93,5'' 2,2 9,4 - DUN 65
BC 1835 4 112 61'' 6 8 - DUN 65
BD 1902 2 116 '' - - - DUN 65
CD 1826 6 125 33'' 9 11 - DUN 65
DE 1928 3 146 1,6'' 9,4 12,8 - I 1175

discoverer information:

discoverer code discoverer reference
DUN 65 Dunlop, J. -
I 1175 Innes, R.T.A. -


note Gamma (2) Vel. B is CD-46@3846, Gamma (1) Vel. Both components are spectroscopic binaries, and B is variable. A is probably the nearest Wolf-Rayet system. Spectrum: WC8+O7.5e. Spectrum of B B1IV. DE: DE is I 1175 (= RST 4878) at 08 09.5 -47 25.

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


position (J1950) RA: 8h 7min 59,5sec DEC: -47 11' 18''

variability informations:

variability type WR eruptive variable star
magnitute at max. brightness 1,81
magnitute at min. brightness 1,87
photometric system visual, photovisual or Johnson's V

spectral information

spectral class WC8+O9I


to a study Vol. I GCVS (see Kholopov et al. 1985-1988)
to a chart/photograph no chart is avaible, but the star is contained in the 'Cordoba Durchmusterung'


ID in the GCVS catalogue 85/90032
constellation Vela
notes on existence The star is equivalent to '0859011 lam'.
There are notes in published catalog.

variability type description

variability type description
WR Eruptive Wolf-Rayet variables. Stars with broad emission features of He I and He II as well as C II-C IV, O II-O IV, and N III-N V. They display irregular light changes with amplitudes up to 0.1 mag in V, which are probably caused by physical processes, in particular, by nonstable mass outflow from their atmospheres.