December 29
The Hare at Year's End
Sun Position
The Sun is in Capricorn, near 23.0 degrees south declination. Northern Hemisphere days are now measurably, if barely, longer than the solstice minimum; southern days are shortening equally slowly.
Sky Highlight
Lepus reaches its best elevation for December evening viewing this week, the hare is fully visible below Orion for all northern observers with a southern horizon, and from the Southern Hemisphere the whole figure rides comfortably in the north. Arneb and Nihal form its two brightest stars in a compact quadrilateral.
Deep Sky Object
M79, the globular cluster in Lepus, is accessible in binoculars as a faint fuzzy star and reveals a bright concentrated core in a 150mm telescope; at 41,000 light-years, it is one of the more distant Messier globulars, and its suspected origin as a captured extragalactic cluster adds context to its outlying position in the sky.
Featured Star
Arneb (α Lep) is an F0Ib yellow-white supergiant about 1,300 light-years away, returning at the end of December to mark the head of the hare crouching beneath Orion's feet. It is a massive evolved star well past the main sequence, and its warm spectral type gives it a faintly golden tint against the cold blue-whites of the surrounding winter stars.
Around This Date
- December 30, 1924Edwin Hubble presented his findings on the distance to the Andromeda Nebula to the American Astronomical Society, demonstrating that it lay far beyond the boundaries of the Milky Way and was a separate galaxy, a result that transformed cosmology overnight.
- December 27, 1571Johannes Kepler was born; his laws would eventually give Isaac Newton the empirical framework from which to derive the law of universal gravitation.
The hare sits still under the hunter every December without flinching. Arneb has been crouching in that same position for as long as the constellation has had a name.