August 10
Amber and Blue at the Swan's Head
Sun Position
The Sun is in late Leo at approximately +14° declination. The Northern Hemisphere's summer is palpably waning; the Southern Hemisphere is tilting back toward the Sun.
Sky Highlight
The Perseid shower peaks around August 11-13 and is at its height this week. August 10 typically offers rates of 50-80 meteors per hour from dark northern sites, with the radiant high in Perseus after midnight. Southern Hemisphere observers can see occasional Perseids near the northern horizon.
Deep Sky Object
M27, the Dumbbell Nebula in Vulpecula, is the largest and brightest planetary nebula in the sky and well placed on August evenings for Northern Hemisphere observers. Roughly 1,360 light-years away, its bilobed shape is visible even in binoculars under dark skies; it is the expanded outer atmosphere of a star that has since collapsed to a white dwarf.
Featured Star
Albireo, the beta Cygni system at the head of the Swan, is one of the most celebrated double stars in the sky: an orange K3II giant and a blue-white B8Ve star separated widely enough to split in any small telescope, sitting about 430 light-years away. The color contrast (warm amber against cold blue) makes it a reliable crowd-pleaser at any star party.
Around This Date
- August 12, 1877Asaph Hall discovered Deimos from the US Naval Observatory, the first time in two centuries that a new planetary moon had been found.
- August 20, 1977NASA's Voyager 2 spacecraft launched from Cape Canaveral, beginning the Grand Tour trajectory that would carry it past Jupiter, Saturn, Uranus, Neptune, and ultimately into interstellar space.
Albireo is the reason small telescopes exist, a star that turns a quiet eyepiece session into something that stops conversation cold.