This is a star party of the Black Hills Astronomical Society that is open to the public with no admission fee. Seating is limited so bringing a lawn chair is recommended. Event may be cancelled due to inclement weather. Cancellations are generally last minute in hopes the sky will clear. Check our Facebook page for a cancellation notice https://www.facebook.com/sdbhas 

It’s estimated that in our galaxy alone over 50% of stars are actually multiple-star systems, which puts our sun in the minority. There are many different kinds of binary star systems, but the ones we’ll be seeing tonight are either optical doubles, which look like stars that orbit each other but simply just lie along the same line of sight, and visual binaries, which are stars that do truly orbit each other.

A presentation will be shown in the outdoor classroom with sky observing to follow. Observation is by the observatory telescope and a variety of telescopes owned by club members placed in the open area next to the observatory.  For more information, visit our website https://sdbhas.org/etiquette/