91 Aquarii (Psi1 Aquarii): A Mulitple Star System

Zeta Aquarii, a binary star system in Aquarius, is about 92 light-years away. First identified by William Herschel in 1777, it appears as a single point to the naked eye. Both stars are similar F-type main-sequence stars, orbiting each other every 587 years, exhibiting complexity beneath their apparent simplicity. This post explores the star and illustrates what it looks like in the telescope. Also known as: STF 2909, SAO 146108, HIP 110960, GC 31398, HR 8558, Zet1 Aqr, 55 Aquarii, HD 213052, 55 Aqr

Struve 331: A Binary of White and Blue-Green in Perseus

Struve 331 (HD 18537) is an optical double star in the constellation Perseus, bet viewed in Autumn. The pair of stars feature a bright white primary and a secondary fainter star that’s blue. Backyard astronomers should be able to split the double easily with most scopes to find that the bright white contrasted against the blue star makes for a pretty enchanting pair.

This double is also known as STF 331 and SAO 23763.