December 3
The Horn Points Outward
Sun Position
The Sun is in Sagittarius, near 22.4 degrees south declination. Northern Hemisphere daylight is now under nine hours for many mid-latitude locations; southern days grow generous.
Sky Highlight
Perseus and Auriga are well placed high in the north and overhead for observers around 45°N by late evening, bringing the rich Auriga Messier clusters (M36, M37, M38) into easy binocular range. For southern observers, Perseus stays low but Auriga clears the northern horizon.
Deep Sky Object
M37, the richest of the three Auriga open clusters, lies about 4,500 light-years away and contains roughly 500 stars with a striking central concentration, a compact binocular object with a telescope revealing its crowded core.
Featured Star
Elnath (β Tau) is a B7III blue-white giant about 131 light-years away, shared between the constellations of Taurus and Auriga, marking both the tip of the bull's northern horn and a corner of the charioteer's hexagon. It points in the rough direction of the Perseus Arm of the Milky Way, out toward the galaxy's far reaches.
Around This Date
- December 3, 1973Pioneer 10 made its closest approach to Jupiter, passing within about 130,000 kilometers of the cloud tops and returning unprecedented data on the magnetic field, radiation belts, and atmosphere.
- December 9, 1978The Pioneer Venus Multiprobe mission released four atmospheric probes that entered the Venusian atmosphere, returning pressure, temperature, and composition measurements down to near the surface.
Elnath is a modest name for a star pointing toward the edge of everything we can map.