Pherkad


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 Pherkad, g UMi, gam UMi, 13 UMi, HR 5735, HD 137422, SAO 8220, FK5: 569
other names Pherkad Major
constellation Ursa Minor

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

note (category: star names): Pherkad; Pherkad Major. See HR 5563 and 5714.

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

position, motion, parallax:

position (J2000) RA: 15h 20min 43,7sec DEC: +71 50' 2''
position (J1900) RA: 15h 20min 52,9sec DEC: +72 11' 23''
proper motion (J2000) RA: -0,019 arcsec/a DEC: 0,02 arcsec/a
radial velocity -4 km/s
note: variable radial velocity
rotational velocity 171 km/s (uncertain) (variable)
trigonometric parallax 0,003 arcsec
note (category: radial and/or rotational velocities): 0.108449d, but not SB. Variable elements.

magnitude

visual magnitude 3,05
(V on UBV Johnson system)

spectral / color information

spectral class A3II-III
B-V-magnitude 0,05
U-B-magnitude 0,12
R-I-magnitude 0,06
note (category: spectra): Shell star, but shell possibly variable.

variability information

variable star identification Gam UMi
note (category: variability): Delta Sct? Amp. 0.03V. Hydrogen and CaII variable.

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

position, motion, parallax:

position (J2000) RA: 15h 20min 43,713sec DEC: +71 50' 2,49'' 0,06 arcsec source: 15
proper motion (J2000) RA: -0,004 arcsec/a DEC: 0,02 arcsec/a source: 25
radial velocity -4 km/s source: 25
trigonometric parallax 0,003 - source: 25
galactic coord. (B1950) longitude: 108,46 latitude: 40,84
GCI unit vector (J2000) X: -0,199642 Y: -0,239466 Z: 0,950157

magnitude:

visual 3,05 (observed) source: 25
photovisual 3,1 source: 2

spectral information:

spectral class A2 source: 96
Morgan-Keenan A3II-III source: 25
B-magnitude 3,1 0,05 B-V-magnitude 0,05
U-magnitude 3,22 0,05 U-B-magnitude 0,12

variability information:

source of data: 30
variability type 10
var. amplitude 0,05
var. period 0,14
var. epoch 2439950
3. April 1968, 12:00:00 UT
next max light 2451622,08
18. March 2000, 13:55:12 UT

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
30 GCVS, 4th edition
Kholopov, P.N., et al., General Catalogue of Variable Stars, fourth edition, Moscow: Nauka Publishing House, 1985-88
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: 15h 20min 47,347sec DEC: +72 0' 42,97'' 0,004 arcsec
position (J2000) RA: 15h 20min 43,726sec DEC: +71 50' 2,53''
proper motion J1950 (FK4) RA: -0,0051 arcsec/a DEC: 0,019 arcsec/a 0,001 arcsec/a in RA
0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: -0,0038 arcsec/a DEC: 0,021 arcsec/a
source of proper motion data Determined by source catalog

magnitude:

visual 3,1 (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: 569
Durchmusterung BD+72 679
Boss General Catalogue 20692
Henry Draper Catalogue 137422

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

position:

position (J1950) RA: 15h 20min 47,3sec DEC: +72 0' 43''

variability informations:

variability type DSCTC pulsating variable star
magnitute at max. brightness 3,04
magnitute amplitude 0,05
photometric system visual, photovisual or Johnson's V
epoch for maximum light [JD] 2439950,367
3. April 1968, 20:48:29 UT
period [d] 0,143009
next maximum light [JD] 2451622,046535
18. March 2000, 13:07:01 UT

spectral information

spectral class A3II-III

references

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

miscanellous

ID in the GCVS catalogue 84/9003
constellation Ursa Minor
notes on existence The star is equivalent to '0849005 eps'.
There are notes in published catalog.

variability type description

variability type description
DSCTC Variables of the Delta Scuti type. These are pulsating variables of spectral types A0-F5 III-V displaying light amplitudes from 0.003 to 0.9 mag in V (usually several hundredths of a magnitude) and periods from 0.01 to 0.2 days. The shapes of the light curves, periods, and amplitudes usually vary greatly. Radial as well as nonradial pulsations are observed. The variability of some
members of this type appears sporadically and sometimes completely ceases, this being a consequence of strong amplitude modulation with the lower value of the amplitude not exceeding 0.001 mag in some cases. The maximum of the surface layer expansion does not lag behind the maximum light for more than 0.1 periods. DSCT stars are representatives of the galactic disk (flat component) and are phenomenologically close to the SX Phe variables.

DSCTC
Low amplitude group of Delta Sct variables (light amplitude <0.1 mag in V). The majority of this type's representatives are stars of luminosity class V; objects of this subtype generally are representative of the Delta Sct variables in open clusters.