Epsilon Lyrae: The Double Double

This interesting multiple star system is easy to find.

Use the Summer Triangle to find the bright star Vega and the constellation Lyra. (Here are detailed instructions to find the Summer Triangle.)

Let's inspect the constellation Lyra more closely.

As a reminder, M57, the Ring Nebula, is on one of the lines in the diamond. That's not our present target.

Epsilon Lyrae is the star on the short end of the "hat" line passing through Vega.

Point your telescope at this star.

Before you move to the eyepiece, look closely with your naked eye, and confirm that you see a single star.

Start by observing at very low magnification - your 6x or 8x magnifying finder, or a pair of binoculars.

At low magnification, this star splits, and you will see a double star with two close-spaced components.

Next, try a series of eyepieces, gradually increasing the magnification.

Here, at 40x, we see the two components of this multiple star cleanly separated.

As you raise the magnification, something interesting happens. At about 100x (more or less, depending on your optics and the sky conditions), each of the two components will split into their own doubles, and you will realize that Epsilon Lyrae is actually a 4-star system. Two pairs of double stars, each orbiting its companion, also orbit each other.

Once you have this view in the eyepiece, switch between your 3 current views: naked eye (one star), magnifying finder (2 stars), and eyepiece (4 stars).