e Ursae Minoris

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 (Vol. I-III)

catalogues and names e UMi, eps UMi, 22 UMi, HR 6322, HD 153751, SAO 2770, FK5: 912, WDS 16460+8202
constellation Ursa Minor

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

position, motion, parallax:

position (J2000) RA: 16h 45min 58,1sec DEC: +82 2' 14''
position (J1900) RA: 16h 56min 12,2sec DEC: +82 12' 8''
proper motion (J2000) RA: 0,017 arcsec/a DEC: 0,006 arcsec/a
radial velocity -11 km/s
note: spectroscopic binaries, single lined spectra
note: orbital data avaible
rotational velocity 23 km/s (uncertain) (variable)
trigonometric parallax 0,01 arcsec


visual magnitude 4,23
(V on UBV Johnson system)

spectral / color information

spectral class G5III
B-V-magnitude 0,89
U-B-magnitude 0,55
R-I-magnitude 0,47

variability information

variable star identification Eps UMi
note (category: variability): EA 4.22 - 4.28V, 39.4809d.

double/multiple star system information

separation 76,9 arcsec
mag difference (of double or brightest multiple) 8,3
note (category: spectroscopic binaries): 39.4809d, K 31.8k/s, V0 -10.6k/s, asini 17.3.

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

position, motion, parallax:

position (J2000) RA: 16h 45min 58,142sec DEC: +82 2' 14,22'' 0,06 arcsec source: 15
proper motion (J2000) RA: 0,0082 arcsec/a DEC: 0,005 arcsec/a source: 25
radial velocity -11 km/s source: 25
trigonometric parallax 0,01 0,001 arcsec source: 25
galactic coord. (B1950) longitude: 115 latitude: 31,05
GCI unit vector (J2000) X: -0,043974 Y: -0,131364 Z: 0,990358


visual 4,23 (observed) source: 25
photovisual 4,4 source: 2

spectral information:

spectral class G5 source: 96
Morgan-Keenan G5III source: 25
B-magnitude 5,12 0,05 B-V-magnitude 0,89
U-magnitude 5,67 0,05 U-B-magnitude 0,55

variability information:

source of data: 30
variability type 10
var. amplitude 0,04
var. period 39,48
var. epoch 2433078
10. June 1949, 12:00:00 UT
next max light 2451633,6
30. March 2000, 02:24:00 UT

double/multiple star system information:

source of data: 19
separation between brightest and second brightest component 76,9 arcsec
magnitude difference between brightest and second brightest component 7
position angle 3


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
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: 16h 51min 0,905sec DEC: +82 7' 21,54'' 0,003 arcsec
position (J2000) RA: 16h 45min 58,124sec DEC: +82 2' 14,32''
proper motion J1950 (FK4) RA: 0,0052 arcsec/a DEC: 0,003 arcsec/a 0,001 arcsec/a in RA
0,001 arcsec/a in DEC
proper motion J2000 (FK5) RA: 0,008 arcsec/a DEC: 0,006 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 G5
source of spectral data Taken from the Henry Draper Catalogue or no spectrum in source catalog.


source catalogue FK4, catalogue number: 912
Durchmusterung BD+82 498
Boss General Catalogue 22749
Henry Draper Catalogue 153751

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

position and proper motion:

position (J2000) RA: 16h 46min DEC: +82 2'
proper motion (J2000) RA: 0,017 arcsec/a DEC: 0,006 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
- 1879 4 6 77,6'' 4,23 11,2 G5III HDO 143
1959 3 76,9''

discoverer information:

discoverer code discoverer reference
HDO 143 - -


note Epsilon UMi. A is an Algol-type system.

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


position (J1950) RA: 16h 51min 0,9sec DEC: +82 7' 22''

variability informations:

variability type EA/D/RS close binary eclipsing system
eruptive variable star
magnitute at max. brightness 4,19
magnitute at min. brightness 4,23
photometric system visual, photovisual or Johnson's V
epoch for maximum light [JD] 2433077,75
10. June 1949, 06:00:00 UT
period [d] 39,4809
next maximum light [JD] 2451633,773
30. March 2000, 06:33:07 UT
duration of the eclipse 04 % of period
the duration of the light constancy phase at minimum light is equal to zero

spectral information

spectral class G5III


to a study Vol. I GCVS (see Kholopov et al. 1985-1988)
to a chart/photograph no chart is avaible, but the star is contained in the 'Bonner Durchmusterung'


ID in the GCVS catalogue 84/9005
constellation Ursa Minor
notes on existence The star is equivalent to '0850001 R'.
There are notes in published catalog.

variability type description

variability type description
EA Eclipsing binary systems. These are binary systems with orbital planes so close to the observer's line of sight (the inclination i of the orbital plane to the plane orthogonal to the line of sight is close to 90 deg) that the components periodically eclipse each other.
Consequently, the observer finds changes of the apparent combined brightness of the system with the period coincident with that of the components' orbital motion.

Algol (Beta Persei)-type eclipsing systems. Binaries with spherical or slightly ellipsoidal components. It is possible to specify, for their light curves, the moments of the beginning and end of the eclipses. Between eclipses the light remains almost constant or varies insignificantly because of reflection effects, slight ellipsoidality of components, or physical variations. Secondary minima may be absent. An extremely wide range of periods is observed, from 0.2 to >= 10000 days. Light amplitudes are also quite different and may reach several magnitudes.

Beta Lyrae-type eclipsing systems. These are eclipsing systems having ellipsoidal components and light curves for which it is impossible to specify the exact times of onset and end of eclipses because of a continuous change of a system's apparent combined brightness between eclipses; secondary minimum is observed in all cases, its depth usually being considerably smaller than that of the primary minimum; periods are mainly longer than 1 day. The components
generally belong to early spectral types (B-A). Light amplitudes are usually <2 mag in V.

W Ursae Majoris-type eclipsing variables. These are eclipsers with periods shorter than 1 days, consisting of ellipsoidal components almost in contact and having light curves for which it is impossible to specify the exact times of onset and end of eclipses. The depths of the primary and secondary minima are almost equal or differ insignificantly. Light amplitudes are usually <0.8 mag in V. The components generally belong to spectral types F-G and later.
D Detached systems, with components not filling their inner Roche lobes.
RS Eruptive variables of the RS Canum Venaticorum type. This type is ascribed to close binary systems with spectra showing Ca II H and K in emission, their components having enhanced chromospheric activity that causes quasi-periodic light variability. The period of variation is close to the orbital one, and the variability amplitude is usually as great as 0.2 mag in V (UX Ari). They are X-ray sources and rotating variables. RS CVn itself is also an eclipsing system.