Stars over Sisters

Aries the Ram is a late-fall/early-winter constellation, and from our latitude it appears nearly overhead in the early evenings during December.

It ranks 39th in size among all constellations and is bordered by Pisces to the west, Taurus to the east, Cetus to the south, and Perseus and Triangulum to the north.

More than 2,000 years ago the vernal equinox - the intersection of the ecliptic and the celestial equator as the sun moves northward - was located in Aries. Though sometimes still referred to as the First Point of Aries, this node point now resides in Pisces, due to the westward precession of the earth's axis of rotation.

Aries is comprised of only four stars that are easily seen by the unaided eye, of which Hamal is the brightest. One of these stars, however, is a very fine double star. Mesarthim was discovered accidentally by English philosopher and scientist Robert Hooke in 1664, while he was following a comet. The two stellar components are separated by eight seconds of arc, easily visible in almost any backyard telescope.

While there are few deep-sky objects in Aries, galaxy NGC 772 is worthy of mention. Twice the size of our Milky Way galaxy, this object is surrounded by several satellite galaxies. It is located at a distance of approximately 130 million light-years.

The Aries constellation has a story to it. Phrixos was the son of King Athamas and his first wife, Nephele. But the king's second wife, Ino, was jealous of the child and wished him killed. To accomplish this, she caused a famine in the land, then falsified a message from the Oracle of Delphi that said Phrixos must be sacrificed to end the famine. Just as Athamas was about to slay his son, a golden ram (Aries) came to the rescue, sent by Nephele. Afterward, Phrixos sacrificed the ram to the gods. The Golden Fleece later appeared in the "Jason and Argonauts" legend.

The winter solstice occurs at 9:11 a.m. PST on December 21. This marks the southern-most point on the sun's annual journey across the sky and results in the shortest day for residents in the northern hemisphere. The term solstice originates from the Latin phrase "sun stands still." That's due to the fact that the sun's arc through the sky appears to stabilize with the sun seeming to rise and set in the same two places on the same two days.

One of the most prolific meteor showers of the year peaks on the morning of December 13. As many as 75 to 100 meteors can be seen radiating from the constellation of Gemini. Unfortunately, a waxing gibbous moon will wash out all but the brightest streaks of light this time around. The meteors are caused by debris associated with asteroid 3200 Phaethon.

Brilliant Venus continues to hang low in the southwestern sky during December. By month's end the planet will only be 11 percent illuminated and will set less than two hours after the sun. Jupiter is in Gemini and its brilliance will dominate the evening sky.

Mars and Saturn are currently morning objects. The Red Planet will gradually brighten throughout the month as the faster-orbiting Earth starts to close ground. The solar system's ringed jewel will rise in the east at 3:30 a.m. by month's end.

After December 2 the moon's face will become more illuminated until the full Cold Moon occurs on December 17. Thereafter, the moon will gradually dim during the remainder of the month.

Look for comet ISON in the northeast just before dawn any time after about December 6. Hopefully it will have survived its close encounter with the sun on November 28 and will put on a spectacular celestial display.