Nair al Saif

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 Nair al Saif, i Ori, 44 Ori, HR 1899, HD 37043, SAO 132323, FK5: 209, WDS 05354-0555A
other names Hatysa in Becvar
constellation Orion

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

note (category: star names): Nair al Saif; Hatysa in Becvar.

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

position, motion, parallax:

position (J2000) RA: 5h 35min 26sec DEC: -5 54' 36''
position (J1900) RA: 5h 30min 32,4sec DEC: -5 58' 32''
proper motion (J2000) RA: 0 arcsec/a DEC: 0,001 arcsec/a
radial velocity 22 km/s
note: spectroscopic binaries, double lined spectra
note: orbital data avaible
rotational velocity 130 km/s (uncertain) (variable)
trigonometric parallax 0,025 arcsec
note (category: radial and/or rotational velocities): ADS 4193A, mass ejection vel. up to 1600k/s. ADS 4193B, +16k/s.
note (category: dynamical parallaxes): 0.005".


visual magnitude 2,77
(V on UBV Johnson system)

spectral / color information

spectral class O9III
B-V-magnitude -0,24
U-B-magnitude -1,08
R-I-magnitude -0,2
note (category: spectra): Enhanced ultraviolet emission. Helium weak. Interstellar Lyman alpha absorption observed by AEROBEE rocket. Iota Ori B is a helium weak star. Helium deficient by factor of 10 relative to standard stars. P and Ga enormously enhanced. uv 1240 absorption strong; weak 1548.
note (category: colors): Color excess E(B-V) = +0.07.

variability information

variable star identification 2334
note (category: variability): Component B is NSV 2334, 7.4V.

double/multiple star system information

number of components of multiple star system 3
separation 11,4 arcsec
mag difference (of double or brightest multiple) 4,5
component ID AB
note (category: double and multiple data): AB fixed. B is B7IV; vsini 50k/s.
note (category: spectroscopic binaries): ADS 4193A, 29.1351d, K 115.2k/s, V0 +26.6k/s, msin3i 15.7, asini 30.0.

miscellaneous information

note (category: group membership): Iota Ori cluster; Ori OB1c4; sword of Orion; HII region.

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

position, motion, parallax:

position (J2000) RA: 5h 35min 25,974sec DEC: -5 54' 35,61'' 0,06 arcsec source: 15
proper motion (J2000) RA: 0 arcsec/a DEC: 0,001 arcsec/a source: 25
radial velocity 22 km/s source: 25
trigonometric parallax 0,025 0,002 arcsec source: 25
galactic coord. (B1950) longitude: 209,53 latitude: -19,58
GCI unit vector (J2000) X: 0,10642 Y: 0,988976 Z: -0,102964


visual 2,77 (observed) source: 25
photovisual 2,9 source: 2

spectral information:

spectral class O0 source: 96
Morgan-Keenan O9III source: 25
B-magnitude 2,53 0,05 B-V-magnitude -0,24
U-magnitude 1,45 0,05 U-B-magnitude -1,08

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 11,4 arcsec
magnitude difference between brightest and second brightest component 4,1
position angle 141


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: 5h 32min 59,126sec DEC: -5 56' 28,26'' 0,006 arcsec
position (J2000) RA: 5h 35min 25,982sec DEC: -5 54' 35,6''
proper motion J1950 (FK4) RA: -0,0003 arcsec/a DEC: 0,001 arcsec/a 0,001 arcsec/a in RA
0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: 0,0001 arcsec/a DEC: 0,001 arcsec/a
source of proper motion data Determined by source catalog


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

spectral information:

spectral class Oe5
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.


source catalogue FK4, catalogue number: 209
Durchmusterung BD-06 1241
Boss General Catalogue 6937
Henry Draper Catalogue 37043

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

position and proper motion:

position (J2000) RA: 5h 35,4min DEC: -5 55'
proper motion (J2000) RA: 0 arcsec/a DEC: 0,001 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 1831 40 141 11,4'' 2,9 7 O9III STF 752
AC 1824 3 103 49,5'' 2,9 - - STF 752
BC 1901 1 92 '' - - - STF 752

discoverer information:

discoverer code discoverer reference
STF 752 Struve, F.G.W. -


note Iota Ori. A is a spectroscopic binary, P = 29.1d.