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

catalogues and names Polaris, a UMi, alf UMi, 1 UMi, HR 424, HD 8890, SAO 308, FK5: 907, WDS 02309+8915A
other names Alruccabah, Cynosura, Phoenice, Lodestar, Pole Star, Tramontana, Angel Stern, Navigatoria, Star of Arcady, Yilduz, Mismar
constellation Ursa Minor

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

note (category: star names): POLARIS; Alruccabah; Cynosura; Phoenice; Lodestar; Pole Star; Tramontana; Angel Stern; Navigatoria; Star of Arcady; Yilduz; Mismar.

position, motion, parallax:

position (J2000) RA: 2h 31min 48,7sec DEC: +89 15' 51''
position (J1900) RA: 1h 22min 33,7sec DEC: +88 46' 26''
proper motion (J2000) RA: 0,038 arcsec/a DEC: -0,015 arcsec/a
radial velocity -17 km/s
note: spectroscopic binaries
note: orbital data avaible
rotational velocity 17 km/s (uncertain) (variable)
trigonometric parallax 0,007 arcsec
note (category: dynamical parallaxes): 0.006".


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

spectral / color information

spectral class F7:Ib-II
B-V-magnitude 0,6
U-B-magnitude 0,38
R-I-magnitude 0,31
note (category: spectra): Also classified F7Ib-F8Ib.

variability information

variable star identification Alp UMi
note (category: variability): CDelta 1.92 - 2.07V, 3.969778d. Period increases 53 sec./century. Probably unreddened.

double/multiple star system information

number of components of multiple star system 5
separation 18,4 arcsec
mag difference (of double or brightest multiple) 6,8
component ID AB
note (category: double and multiple data): A* 2.0 var. F8Ib, 30.46y, a = 0.038". AB physical; B, 8.20V, +0.49(B-V), +0.16(U-B), F3V, 0.0 color excess, vsini =<60k/s; C, 13v at 43"; D, 14v at 83".
note (category: spectroscopic binaries): ADS 1477A, K 4.1k/s, V0 -16.4k/s, asini 482. Period 6-8y? Unresolved by speckle interferometry. RV varies in 2 periods, 3.968d pulsation, 27.6y revolution of unseen blue companion.

miscellaneous information

note (category: group membership): Red star Pleiades group.

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

position, motion, parallax:

position (J2000) RA: 2h 31min 48,704sec DEC: +89 15' 50,72'' 0,06 arcsec source: 15
proper motion (J2000) RA: 0,1988 arcsec/a DEC: -0,015 arcsec/a source: 25
radial velocity -17 km/s source: 25
trigonometric parallax 0,007 0,001 arcsec source: 25
galactic coord. (B1950) longitude: 123,28 latitude: 26,46
GCI unit vector (J2000) X: 0,010127 Y: 0,007899 Z: 0,999918


visual 1,9 (observed) source: 31
photovisual 2,1 source: 2

spectral information:

spectral class F8 source: 96
Morgan-Keenan F7:Ib-II source: 25
B-magnitude 2,62 0,05 B-V-magnitude 0,6
U-magnitude 3 0,05 U-B-magnitude 0,38

variability information:

source of data: 30
variability type 115
var. amplitude 0,27
var. period 3,97
var. epoch 2431496
9. February 1945, 12:00:00 UT
next max light 2451623,9
20. March 2000, 09:36:00 UT

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 18,4 arcsec
magnitude difference between brightest and second brightest component 7
position angle 216

component magnitude spectral class catalogue(s)/name(s)
A 1,9 F8 Polaris, a Ursae Minoris, 1 UMi, HR 424, HD 8890, SAO 308
B 8,2 F1


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
31 CRM' (non-GCVS variable data)
Warren, W.H. Jr., Northern Hemisphere Catalog of Red Magnitudes, 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: 1h 48min 48,786sec DEC: +89 1' 43,74'' 0,003 arcsec
position (J2000) RA: 2h 31min 48,711sec DEC: +89 15' 50,64''
proper motion J1950 (FK4) RA: 0,1811 arcsec/a DEC: -0,004 arcsec/a 0,001 arcsec/a in RA
0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: 0,2012 arcsec/a DEC: -0,016 arcsec/a
source of proper motion data Determined by source catalog


visual 2,1 (accuracy: 2 decimals)
source of visual magnitude data Arithmetic mean of maximum and minimum magnitudes of a variable star

spectral information:

spectral class F8v
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.

remarks for duplicity and variability

Variable star in visual magnitude in source catalog


source catalogue FK4, catalogue number: 907
Durchmusterung BD+88 8
Boss General Catalogue 2243
Henry Draper Catalogue 8890

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


position (J1950) RA: 1h 48min 48,8sec DEC: +89 1' 44''

variability informations:

variability type DCEPS pulsating variable star
magnitute at max. brightness 1,86
magnitute at min. brightness 2,13
photometric system visual, photovisual or Johnson's V
epoch for maximum light [JD] 2431495,813
9. February 1945, 07:30:43 UT
period [d] 3,9696
next maximum light [JD] 2451625,6546
22. March 2000, 03:42:37 UT
rising time 50 % of period

spectral information

spectral class F7Ib-F8Ib


to a study Vol. III GCVS
to a chart/photograph no chart is avaible, but the star is contained in the 'Bonner Durchmusterung'


ID in the GCVS catalogue 84/9001
constellation Ursa Minor
notes on existence The star is equivalent to '0849003 gam'.
There are notes in published catalog.

variability type description

variability type description
DCEPS These are Delta Cep variables having light amplitudes <0.5 mag in V (<0.7 mag in B) and almost symmetrical light curves (M-m approx. 0.4 - 0.5 periods); as a rule, their periods do not exceed 7 days. They are probably first-overtone pulsators and/or are in the first transition across the instability strip after leaving the main sequence (SU Cas).