by Geoff Chester, USNO Public Affairs | 21 November 2023 Jupiter, imaged 2023 November 15, 02:09 UT at the U.S. Naval Observatory with the 66-cm (26-inch) f/15 "Great Equatorial" refractor on the occasion of the 150th anniversary of its "First Light" in November, 1873 The Moon brightens the evening sky this week, waxing to her full phase as she climbs northward along the ecliptic, ending the week high among the rising stars of winter. Full Moon will occur on the 27th at 4:16 am Eastern Standard Time. November’s Full Moon is widely known in North America as the Beaver Moon. The name originates in Native American lore, which was passed on to early European fur trappers. This is the time of year when beavers become particularly active, repairing their dams and dens for their winter hibernation. Since they are mostly nocturnal, the light of November’s Full Moon aids them in their busy tasks. Other names for this occasion are the Frost Moon and the Mourning Moon. Look for Luna just to the east of bright Jupiter on the evening of the 24th. On the night of the 26th you will find the Moon just over a degree southeast of the Pleiades star cluster. As Luna waxes, her light increasingly obscures the dim stars that make up many of the autumnal constellations. However, the last of summer’s bright stars can still be seen in the western sky in the form of the Summer Triangle. Altair, Vega, and Deneb, respectively, begin to set after 10:00 pm local time, while to the east the brilliant stars of the Great Winter Circle climb into the night. Even when the Moon is full, her bright glow can’t extinguish the colorful luminaries that grace the overnight hours. Nine of the 25 brightest stars in the sky are located within the confines of the Circle, which is centered on the distinctive shape of Orion, the Hunter. One of the most prominent of these stars is Capella, a dazzling yellow-tinted luminary in the constellation of Auriga, the Charioteer. The sixth-brightest star in the sky, its name means “little goat”, and it is nearly overhead at midnight in late November. In Greek mythology, it represented Amalthea, the goat that suckled the infant Zeus. The rambunctious toddler accidentally broke off one of the goat’s horns, which was then transformed into the Cornucopia, or “Horn of Plenty”. Today we observe Thanksgiving Day close to the time when Capella passes overhead at midnight. Capella is the northernmost star in the Great Winter Circle, and, as with many prominent stars across the sky, a multiple star system. It was the first binary star to be identified spectroscopically by astronomers at the Lick Observatory in 1899, and in 1914 a faint companion star was found to be moving with the brighter pair. This faint star, in turn, was found to be a binary star inn 1936, so the Capella system consists of at least four stars. If you look at Capella with a pair of binoculars, scan just to the southwest of the star for a small triangle of third-magnitude stars popularly known as “The Kids”. Two of these stars are long-period eclipsing binary stars. The northernmost, Almaaz, undergoes an eclipse by a large, dark companion every 27 years. The eclipses last about two years and cause the stars’ combined brightness to drop by nearly a full magnitude. Saturn is now best seen in the early evening hours. The ringed planet appears in deep twilight near the meridian, and sets shortly after 11:00 pm. The best time to get him centered in the telescope is during the early part of the evening, but it is well worth the effort. The planet’s rings are gradually becoming less tilted toward our line of sight, and by the time 2025 rolls around they will disappear as Earth crosses Saturn’s ring plane. Jupiter can be seen in fading evening twilight climbing into the eastern sky. The giant planet reaches his highest point in the sky at around 10:00 pm, which should give you plenty of time to enjoy his company. Old Jove is far and away my favorite telescopic planet, presenting a generously sized apparent disc that teems with fine detail. The dark equatorial cloud belts are visible in just about any telescope, and modest instruments of six inches or more will show finer details. If you happen to be looking when the planet’s famous Great Red Spot is rotating across the disc, keep in mind that this feature on Jupiter is over twice the size of the Earth! Venus remains a feature in the pre-dawn sky, and she will remain so through the end of the year. If you are out on a crisp clear morning when the Sun rises, try to spot Venus near a familiar landmark like a tree branch. Once the Sun is up, try to keep the dazzling planet in view as daylight sweeps over the land. You may be able to follow her well into the daylight hours.