Thuban

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 (suspected variables)

catalogues and names Thuban, a Dra, NSV 06546, 11 Dra, HR 5291, HD 123299, SAO 16273, FK5: 521
other names Adib, Dragon's Tail
constellation Draco

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

note (category: star names): THUBAN; Adib; Dragon's Tail. Former Pole Star, about 2700 B.C.

position, motion, parallax:

position (J2000) RA: 14h 4min 23,3sec DEC: +64° 22' 33''
position (J1900) RA: 14h 1min 40,8sec DEC: +64° 51' 14''
proper motion (J2000) RA: -0,055 arcsec/a DEC: 0,018 arcsec/a
radial velocity -13 km/s
note: spectroscopic binaries
note: orbital data avaible
rotational velocity 18 km/s (uncertain) (variable)
trigonometric parallax 0,018 arcsec

magnitude

visual magnitude 3,65
(V on UBV Johnson system)

spectral / color information

spectral class A0III
B-V-magnitude -0,05
U-B-magnitude -0,08
R-I-magnitude -0,07
note (category: spectra): High Si and Cr abundance.

variability information

variable star identification 6546
note (category: variability): Alpha CV?, 3.64 - 3.67V.

double/multiple star system information

note (category: spectroscopic binaries): 51.420d, K 46.9k/s, V0 -13.0k/s, asini 30.7.

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

position, motion, parallax:

position (J2000) RA: 14h 4min 23,341sec DEC: +64° 22' 33,05'' ±0,06 arcsec source: 15
proper motion (J2000) RA: -0,0084 arcsec/a DEC: 0,018 arcsec/a source: 25
radial velocity -13 km/s source: 25
trigonometric parallax 0,018 ±0,002 arcsec source: 25
galactic coord. (B1950) longitude: 110,52° latitude: 50,96°
GCI unit vector (J2000) X: -0,370317 Y: -0,223365 Z: 0,90165

magnitude:

visual 3,65 (observed) source: 25
photovisual 3,6 source: 2

spectral information:

spectral class A0 source: 96
Morgan-Keenan A0III source: 25
B-magnitude 3,6 ±0,05 B-V-magnitude -0,05
U-magnitude 3,52 ±0,05 U-B-magnitude -0,08

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
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: 14h 3min 1,963sec DEC: +64° 36' 51,57'' ±0,004 arcsec
position (J2000) RA: 14h 4min 23,349sec DEC: +64° 22' 33,02''
proper motion J1950 (FK4) RA: -0,009 arcsec/a DEC: 0,015 arcsec/a ±0,001 arcsec/a in RA
±0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: -0,0083 arcsec/a DEC: 0,018 arcsec/a
source of proper motion data Determined by source catalog

magnitude:

visual 3,6 (accuracy: 2 decimals)
source of visual magnitude data Taken from the "Henry Draper Catalogue".

spectral information:

spectral class A0p
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.

catalogues

source catalogue FK4, catalogue number: 521
Durchmusterung BD+65 978
Boss General Catalogue 19019
Henry Draper Catalogue 123299

data from Combined General Catalogue of Variable Stars (suspected variables) (Kholopov+ 1998)

position:

position (J1950) RA: 14h 3min 2sec DEC: +64° 36' 52''

variability informations:

variability type ACV: rotating variable star
magnitute at max. brightness 3,64
magnitute at min. brightness 3,67
photometric system visual, photovisual or Johnson's V

spectral information

spectral class AP

references

to a study 290477D (designation: ZI 1048)

miscanellous

There are notes in the published catalog (Kukarkin et al.(1982)).

variability type description

variability type description
ACV
 Alpha2 Canum Venaticorum variables. These are main-sequence stars with spectral types B8p-A7p and displaying strong magnetic fields.
Spectra show abnormally strong lines of Si, Sr, Cr, and rare earths whose intensities vary with rotation. They exhibit magnetic field and brightness changes (periods of 0.5-160 days or more). The amplitudes of the brightness changes are usually withine 0.01-0.1 mag in V.

ACVO
Rapidly oscillating Alpha2 CVn variables. These are nonradially pulsating, rotating magnetic variables of Ap spectral type (DO Eri). Pulsation periods are in the range of 6-12 mmag (0.004-0.01 days), while amplitudes of light variation caused by the pulsation are about 0.01 mag in V. The pulsational variations are superposed on those caused by rotation.