Epsilon Lyra, the Double Double   HOME INDEX BACK NEXT
 

Pair of double stars in Lyra

(Roll over the image to see the two stars of each pair.)

Without using any optics, some people with excellent eyesight can just barely detect that Epsilon Lyra is a double star. Through any binoculars or telescope, the two stars, Epsilon 1 and Epsilon 2, are obvious. However, it takes fairly high magnification and steady seeing to observe that each of these stars is itself a close double.

Many dimmer stars can be seen in background image, but the bright Epsilon 1 (on the right) and Epsilon 2 (left) are greatly overexposed. In the rollover image, which uses insets based on much shorter exposures, the two stars in each pair can be seen clearly.

The orbital periods are estimated to be about 1200 years for Epsilon 1 and about 600 years for Epsilon 2. The distances between the stars of each pair are about 160 and 140 astronomical units, respectively. (For comparison, the orbital period of Neptune is 165 years, and it is about 29 astronomical units from the Sun.)

Magnitudes 5.0, 6.1, 5.3, 5.4
Separations 2.2", 208", 2.4"
Distance (light yrs) 162
Right Ascension 18:44.9
Declination +39 41

Image details:  The background image is based on 10 exposures, 17 images, each 4 seconds at ISO 200, taken with a Canon T6i camera through a Meade 14” LX850 telescope at f/8.  The two insets in the rollover image are based on 100 exposures of 1/20 second.

October 2017