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

catalogues and names Yildun, d UMi, 23 UMi, HR 6789, HD 166205, SAO 2937, FK5: 913
other names Vildiur, Gildun
constellation Ursa Minor

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

note (category: star names): Yildun; Vildiur; Gildun.

position, motion, parallax:

position (J2000) RA: 17h 32min 12,9sec DEC: +86 35' 11''
position (J1900) RA: 18h 4min 32,7sec DEC: +86 36' 48''
proper motion (J2000) RA: 0,009 arcsec/a DEC: 0,056 arcsec/a
radial velocity -8 km/s
note: suspected variable radial velocity
rotational velocity 174 km/s (uncertain) (variable)
trigonometric parallax 0,004 arcsec


visual magnitude 4,36
(V on UBV Johnson system)

spectral / color information

spectral class A1Vn
B-V-magnitude 0,02
U-B-magnitude 0,03
R-I-magnitude -0,01

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

position, motion, parallax:

position (J2000) RA: 17h 32min 12,872sec DEC: +86 35' 11,32'' 0,06 arcsec source: 15
proper motion (J2000) RA: 0,0097 arcsec/a DEC: 0,056 arcsec/a source: 25
radial velocity -8 km/s source: 25
trigonometric parallax 0,004 - source: 25
galactic coord. (B1950) longitude: 119,29 latitude: 28,24
GCI unit vector (J2000) X: -0,007201 Y: -0,059105 Z: 0,998226


visual 4,36 (observed) source: 25
photovisual 4,4 source: 2

spectral information:

spectral class A0 source: 96
Morgan-Keenan A1Vn source: 25
B-magnitude 4,38 0,05 B-V-magnitude 0,02
U-magnitude 4,41 0,05 U-B-magnitude 0,03


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
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 48min 18,338sec DEC: +86 36' 34,78'' 0,003 arcsec
position (J2000) RA: 17h 32min 12,983sec DEC: +86 35' 11,45''
proper motion J1950 (FK4) RA: 0,0107 arcsec/a DEC: 0,054 arcsec/a 0,001 arcsec/a in RA
0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: 0,0108 arcsec/a DEC: 0,057 arcsec/a
source of proper motion data Determined by source catalog


visual 4,4 (accuracy: 2 decimals)
source of visual magnitude data Taken from the "Henry Draper Catalogue".

spectral information:

spectral class A0
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.


source catalogue FK4, catalogue number: 913
Durchmusterung BD+86 269
Boss General Catalogue 24236
Henry Draper Catalogue 166205