September 9

The Fish's Mouth at Dusk

Sun Position

The Sun is in Virgo at about +3° declination, within two weeks of the autumnal equinox. Day length is very close to 12 hours at all latitudes; twilight is noticeably shorter than midsummer.

Sky Highlight

Fomalhaut is rising in the southeast in the early evening hours, presenting its best window for Northern Hemisphere viewing during September and October. From southern latitudes it rises high and is one of the most prominent stars of the spring sky.

Deep Sky Object

M30 (NGC 7099), globular Cluster, Capricornus. About 28,000 light-years away, M30 has a post-core-collapse structure with a very concentrated center that makes it look different from typical globulars. Best placed high in the south for Northern Hemisphere observers; accessible from southern latitudes.

Featured Star

Fomalhaut (α PsA) is a main-sequence star of spectral class A3Va just 25 light-years away, ringed by one of the best-studied debris disks in the sky, a narrow ring whose slight offset from center has been interpreted as evidence of planetary gravitational influence. It is the southernmost first-magnitude star and was one of four ancient Persian royal stars.

Around This Date

September 9, 2006The Hinode (Solar-B) spacecraft launched from Japan, carrying a solar optical telescope and X-ray imager that would produce the highest-resolution images of the solar surface and corona yet achieved.
September 12, 1959The Soviet Luna 2 spacecraft impacted the Moon, becoming the first human-made object to reach the surface of another world.

Fomalhaut hangs low and solitary in the south, the fish's mouth, ancient marker, with a ring of debris telling a story about something we have not yet fully seen.