Autumn is a season where the nights are getting longer and in a few months, Orion and the Winter Milky Way will take center stage. While the autumn night sky appears devoid of any brighter stars, it’s still home to many fine double stars. Here are a few of my favorites:
α1, α2 (alpha) Capricorni (α1, magnitudes 4.2 and 9.2, separation 45.4 arcseconds; α2, mags 3.6 and 9.3, sep 154.6”) The magnitude 4.2 (α1) and 3.6 (α2) stars form a naked eye pair separated by 376”. A 4 inch telescope will capture their 9th magnitude companions. Though an optical double it is still worth a look.
γ (gamma) Delphini (mags 4.5 and 5.5, sep 9.6”) One of the finest double stars for small telescopes. The pair’s subtle yellow and blue colors are sometimes a challenge.
ζ (zeta) Aquarii (mags 4.3 and 4.5, sep 2.2”) A beautiful twin binary that is slowly widening from a minimum separation of 1.7”. A tough one so use at least 100X for a comfortable split.
σ (sigma) Cassiopeiae (mags 5.0 and 7.1, sep 3.0”) A tough “split” for small scopes, because of the two-magnitude difference of the component stars.
η (eta) Cassiopeiae (mags 3.4 and 7.5, sep 13.0”) What makes this slow-moving binary pair noteworthy is its stunning color scheme – yellow and. The colors really stand out in a 8 inch or larger telescope.
α (alpha) Ursae Minoris (mags 2.0 and 9.0, sep 18.4”) Polaris, the North Star. This is a classic light test for the common 60mm refractor. The 9th magnitude companion is hard to spot in the glare of the bright primary star. Fantastic in a large telescope; shows yellow and blue colors.
γ (gamma) Arietis (mags 4.8 and 4.8, sep 7.8”) A grand “twin” pair, both white. Their telescopic appearance are like the headlights of a oncoming automobile, are really cool looking!
Clear and Dark Skies, Dave Holland
