September 4
The Lonely Star of the South
Sun Position
The Sun is in Virgo at roughly +6° declination. In the Northern Hemisphere, daylight is about 13 hours near 40° latitude; in the Southern Hemisphere, spring evenings are growing noticeably milder.
Sky Highlight
Fomalhaut reaches its highest point in the sky for mid-northern-latitude observers this month, though it still transits only about 20° above the southern horizon at 40°N. From southern latitudes it passes nearly overhead. No major meteor shower peaks today.
Deep Sky Object
NGC 253, Sculptor Galaxy, Sculptor. About 11.4 million light-years away, this edge-on spiral is one of the brightest and most dust-laced galaxies in the sky. It is best placed for Southern Hemisphere observers, who see it high in the south; Northern Hemisphere viewers need a clear southern horizon.
Featured Star
Fomalhaut (α PsA) is a nearby main-sequence A-type star (spectral class A3Va) just 25 light-years away, making it one of our closer stellar neighbors. It is encircled by a narrow, offset debris disk, and the asymmetry of that disk has long been studied as evidence of gravitational sculpting by one or more planets.
Around This Date
- September 4, 1995Astronomers announced the confirmation of 51 Pegasi b, the first exoplanet detected around a sun-like star, discovered by Michel Mayor and Didier Queloz using the radial-velocity method, a result that earned them the 2019 Nobel Prize in Physics.
- September 8, 2004The Genesis spacecraft's sample-return capsule crash-landed in Utah after its parachute failed to deploy, though scientists later recovered solar-wind samples from the wreckage.
Twenty-five light-years is close enough that Fomalhaut's light left home roughly when your grandparents were young, a reminder that nearby stars mark real distances, not just pretty points.