Nunki


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 Nunki, s Sgr, 34 Sgr, HR 7121, HD 175191, SAO 187448, FK5: 706, WDS 18553-2618
other names Sadira
constellation Sagittarius

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

note (category: star names): NUNKI; Sadira.

object is infrared source (NASA merged infrared catalogue, Schmitz et al., 1978)

position, motion, parallax:

position (J2000) RA: 18h 55min 15,9sec DEC: -26 17' 48''
position (J1900) RA: 18h 49min 3,9sec DEC: -26 25' 15''
proper motion (J2000) RA: 0,013 arcsec/a DEC: -0,054 arcsec/a
radial velocity -11 km/s
note: variable radial velocity
rotational velocity 201 km/s (uncertain) (variable)

magnitude

visual magnitude 2,02
(V on UBV Johnson system)

spectral / color information

spectral class B2.5V
B-V-magnitude -0,22
U-B-magnitude -0,75
R-I-magnitude -0,21
note (category: spectra): Lyman alpha and Lyman beta observed from COPERNICUS.
note (category: colors): Color excess E(B-V) = +0.02.

double/multiple star system information

separation 309 arcsec
mag difference (of double or brightest multiple) 7,4
note Worley (1978) update of the IDS
note (category: double and multiple data): Interferometer measures indicate multiple star.

miscellaneous information

note (category: group membership): Sco-Cen assoc.

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

position, motion, parallax:

position (J2000) RA: 18h 55min 15,924sec DEC: -26 17' 48,23'' 0,06 arcsec source: 15
proper motion (J2000) RA: 0,001 arcsec/a DEC: -0,054 arcsec/a source: 25
radial velocity -11 km/s source: 25
galactic coord. (B1950) longitude: 9,56 latitude: -12,43
GCI unit vector (J2000) X: 0,214096 Y: -0,870572 Z: -0,44302

magnitude:

visual 2,02 (observed) source: 25
photovisual 2,1 source: 2
photographic 2 source: 2

spectral information:

spectral class B3 source: 96
Morgan-Keenan B2.5V source: 25
B-magnitude 1,8 0,05 B-V-magnitude -0,22
U-magnitude 1,05 0,05 U-B-magnitude -0,75

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 309 arcsec
magnitude difference between brightest and second brightest component 7,5
position angle 244

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: 18h 52min 9,927sec DEC: -26 21' 38,29'' 0,005 arcsec
position (J2000) RA: 18h 55min 15,918sec DEC: -26 17' 48,21''
proper motion J1950 (FK4) RA: 0,001 arcsec/a DEC: -0,054 arcsec/a 0,001 arcsec/a in RA
0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: 0,0009 arcsec/a DEC: -0,054 arcsec/a
source of proper motion data Determined by source catalog

magnitude:

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

spectral information:

spectral class B3
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.

catalogues

source catalogue FK4, catalogue number: 706
Durchmusterung CD-2613595
Boss General Catalogue 25941
Henry Draper Catalogue 175191

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

position and proper motion:

position (J2000) RA: 18h 55,3min DEC: -26 18'
proper motion (J2000) RA: 0,013 arcsec/a DEC: -0,054 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
- 1837 1 244 309'' 2,02 9,5 B2.5V SMY 4

discoverer information:

discoverer code discoverer reference
SMY 4 Smythe, W.H. -

notes:

note Sigma Sgr. B is CD-26@13591.