Megrez


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

  5. Combined General Catalogue of Variable Stars (suspected variables)


catalogues and names Megrez, d UMa, NSV 05513, 69 UMa, HR 4660, HD 106591, SAO 28315, FK5: 456, WDS 12154+5702A
other names Kaffa in Becvar
constellation Ursa Major

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

note (category: star names): MEGREZ; Kaffa in Becvar.

position, motion, parallax:

position (J2000) RA: 12h 15min 25,6sec DEC: +57 1' 57''
position (J1900) RA: 12h 10min 28,7sec DEC: +57 35' 18''
proper motion (J2000) RA: 0,104 arcsec/a DEC: 0,009 arcsec/a
radial velocity -13 km/s
note: variable radial velocity
rotational velocity 177 km/s (uncertain) (variable)
trigonometric parallax 0,061 arcsec

magnitude

visual magnitude 3,31
(V on UBV Johnson system)

spectral / color information

spectral class A3V
B-V-magnitude 0,08
U-B-magnitude 0,07
R-I-magnitude 0

variability information

variable star identification 5513

double/multiple star system information

number of components of multiple star system 3
separation 189,6 arcsec
mag difference (of double or brightest multiple) 6,6
component ID AB
note Worley (1978) update of the IDS

miscellaneous information

note (category: group membership): "Dipper Stars"; Ursa cluster; Sirius group; UMa stream.

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

position, motion, parallax:

position (J2000) RA: 12h 15min 25,56sec DEC: +57 1' 57,42'' 0,06 arcsec source: 15
proper motion (J2000) RA: 0,0127 arcsec/a DEC: 0,009 arcsec/a source: 25
radial velocity -13 km/s source: 25
trigonometric parallax 0,061 0,006 arcsec source: 25
galactic coord. (B1950) longitude: 132,56 latitude: 59,42
GCI unit vector (J2000) X: -0,542929 Y: -0,036599 Z: 0,83898

magnitude:

visual 3,31 (observed) source: 25
photovisual 3,4 source: 2
photographic 3,3 source: 16

spectral information:

spectral class A2 source: 96
Morgan-Keenan A3V source: 25
B-magnitude 3,39 0,05 B-V-magnitude 0,08
U-magnitude 3,46 0,05 U-B-magnitude 0,07

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 188,5 arcsec
magnitude difference between brightest and second brightest component 6,7
position angle 73

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
16 PPM North and PPM South Catalogs and PPM Supplement
Roser, S., and U. Bastian, "Catalogue of Positions and Proper Motions," A&AS, Vol. 74, p. 449, 1988, and Bastian, U., et al., "Catalogue of Positions and Proper Motions - South," 1993
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: 12h 12min 57,584sec DEC: +57 18' 36,95'' 0,004 arcsec
position (J2000) RA: 12h 15min 25,57sec DEC: +57 1' 57,35''
proper motion J1950 (FK4) RA: 0,0126 arcsec/a DEC: 0,004 arcsec/a 0,001 arcsec/a in RA
0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: 0,0128 arcsec/a DEC: 0,009 arcsec/a
source of proper motion data Determined by source catalog

magnitude:

visual 3,4 (accuracy: 2 decimals)
source of visual magnitude data Taken from the "Henry Draper Catalogue".

spectral information:

spectral class A2
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.

catalogues

source catalogue FK4, catalogue number: 456
Durchmusterung BD+57 1363
Boss General Catalogue 16736
Henry Draper Catalogue 106591

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

position and proper motion:

position (J2000) RA: 12h 15,4min DEC: +57 2'
proper motion (J2000) RA: 0,104 arcsec/a DEC: 0,009 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 1878 5 73 192,4'' 3,31 10 A3V BLL 29
1923 - 188,5''
AC 1879 2 124 188,6'' 3,4 11,6 - BUP 140
1907 125 186,4''

discoverer information:

discoverer code discoverer reference
BLL 29 Ball, R.S. -
BUP 140 - -

notes:

note Delta UMa.

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

position:

position (J1950) RA: 12h 12min 57,6sec DEC: +57 18' 37''

variability informations:

magnitute at max. brightness 3,27
magnitute at min. brightness 3,34
photometric system visual, photovisual or Johnson's V

spectral information

spectral class A3

references

to a study 290477D (designation: ZI 919)

miscanellous

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