A Smudge of a Super-giant
Like Antares, our own sun is destined to burn red
As the sun sets around 7:30 this week, a brilliant point of light pierces the darkening skies low in the west. Jupiter is the brightest light visible, and although it climbs no higher, there’s little mistaking its steady yellow-orange glow. Antares, the heart of Scorpio, shines directly below, halfway to the horizon, but is a ruddy smudge by comparison.
From 600 light years away the red giant Antares may look like a smudge, but it is 18 times larger and 19,000 times brighter than our sun.
Once, long ago, Antares was much like our own sun, what astronomers call a main sequence star. Seven billion years from now, our sun will become a red giant. As main sequence star stars age, they deplete their hydrogen fuel. The star then turns to cooler-burning helium, causing it to expand more than 100 times in size and to glow redder, hence their name.
In time, red giants, also called super-giants, meet one of two ends: the smaller ones lose their outer shell of gas and collapse upon themselves, becoming white dwarfs; the larger stars, like Antares, will instead self-destruct in massive supernova, spreading stellar debris and, as scientists now posit, the composite materials for new stars, planets and even life.
Back in our own solar system, the waning crescent moon pairs with Venus before dawn Saturday morning. The two appear around 5:00am in the east and climb 15 degrees above the horizon before daybreak, around 6:45 this week. From Venus, look to the horizon for a first glimpse of Saturn reappearing ahead of the sun. The next morning, the last sliver of moon before new phase hugs the horizon, halfway between Venus and Saturn.
Illustration: © Copyright 1925 M.C. Escher/Cordon Art-Baarn-Holland; Graphics: © Copyright 2007 Pacific Publishers. Reprinted by permission from the Tidelog graphic almanac. Bound copies of the annual Tidelog for Chesapeake Bay are $14.95 ppd. from Pacific Publishers, Box 480, Bolinas, CA 94924. Phone 415-868-2909. Weather affects tides. This information is believed to be reliable but no guarantee of accuracy is made by Bay Weekly or Pacific Publishers. The actual layout of Tidelog differs from that used in Bay Weekly. Tidelog graphics are repositioned to reflect Bay Weekly’s distribution cycle.Tides are based on National Oceanic and Atmospheric Administration and are positioned to coincide with high and low tides of Tidelog.