Double Star Database

These are some of the most impressive double and multiple stars visible from the Northern Hemisphere. They should all be separable with a 60mm refractor at 100x on a perfect night.

Column Explanations:

Name: The Greek letter or Flamsteed number designation of the star, followed by the three-letter constellation abbreviation.

RA and DEC: The star's Right Ascension in hours and minutes, and its Declination in degrees and minutes.

Sep: The separation of the star's components, given in seconds of arc. The larger the separation, the easier it is to see two stars rather than one. Small telescopes in the 60mm range will just be able to split Castor and the two pairs in Epsilon Lyrae on nights when the atmosphere is steady.

Mags: The magnitudes of the stars involved.

Notes: Colors if remarkable, or additional components.

Name              RA      DEC   Sep        Mags         Notes

Gamma And       02 03.9  42 20  9.8     2.3 , 4.8       orange,blue

Eta Cas         00 49.1  57 49  12.2    3.4 , 7.5       

Alpha CVn       12 56.0  38 19  19.4    2.9 , 5.5       Cor Caroli

Alpha Gem       07 34.6  31 53  2.5     1.9 , 2.9       Castor. m9.5 star 72" away

Zeta UMa        13 23.9  54 56  14.4    2.3 , 4.0       Mizar.  Alcor is 11' away

Beta Cyg        19 30.7  27 58  34.4    3.1 , 5.1       Albireo.  orange,blue

Nu Dra          17 32.2  55 11  61.9    4.9 , 4.9       

95 Her          18 01.5  21 36  6.3     5.0 , 5.1       

100 Her         18 07.8  26 06  14.2    5.9 , 6.0       

Epsilon Lyr     18 44.3  39 40  207.7   4.7 , 5.1       Each star double, seps. 
2.3" and 2.6"

Gamma Ari       01 53.5  19 18  7.8     4.8 , 4.8       

Beta Mon        06 28.8 -07 02  7.3     4.7 , 5.2       Third star, m6.1, 100" away

Gamma Leo       10 20.0  19 51  4.3     2.2 , 3.5       orange

Alpha Her       17 14.6  14 23  4.7     3v , 5.4        Red,green.  Primary variable

Gamma Del       20 46.7  16 07  9.6     4.5 , 5.5       white,yellow

Sigma Ori       05 38.7 -02 37          4,7,7.5,10      Quadruple.  3 stars in 60mm.

61 Cyg          21 06.4  38 41  20      5.3 , 5.9       orange