Looking Up: Bright red Antares is a summer delight
One of the jewels of the summer night shines like a fiery red ruby, glowing in the steam of a teapot and keeping alive a great scorpion. This is Antares, one of the brightest stars of the night.
This year (2017), the amazing ringed planet Saturn shines over to the left (eastward)! Saturn reflects the light of the Sun, and appears yellow-white. It shines a bit brighter than red Antares, but they make a nice pair this season.
Antares, also known as Alpha Scorpii is approximately 0 magnitude, listed as the 15th brightest in the entire night sky. Appropriately known as the “Heart of the Scorpion,” it is the brightest star in the constellation Scorpius. You may see it due south just after 10 p.m., during July and in the southwest an hour or so later, with the added advantage of twilight being over.
If you live in mid-northern latitudes, such as we have in Wayne County, Pa. at around 42 degrees north of the equator, you should look fairly low, no more than a quarter of the way up in the sky.
Antares is a red supergiant star with a diameter approximately 800 times that of our Sun. If the Sun were replaced with Antares, its outer surface would lie between the orbits of Mars and Jupiter and the cinders of Earth would be deep inside. The star is 600 light years away. The starlight you see tonight left Antares in about 1400 A.D.
A companion star orbits Antares, which appears greenish. Not quite the Christmas Star (Christmas in July?), the colors of this double star can lead to festive thoughts. Unfortunately you need a fairly large backyard telescope and a night of very steady air, to see the companion. Known as Antares-B, the companion is magnitude +5.5 and thus bright enough to be seen with unaided eyes, if the star were not normally lost in the glare of brilliant Antares. Users of small telescopes, however, can see Antares-B when the Moon passes in front of Antares. For a brief moment, it is possible to see only the companion on the very edge of the Moon.
The Greeks named Antares, for “Rival of Mars” due to its reddish hue.
The Lunar Module that took Astronauts Alan Shepard and Joseph Engle to the Moon aboard Apollo 14, in February 1971, was named Antares.
The region of sky just east of Antares (to your left) contains the hub of the Milky Way Galaxy. Here, you are looking right towards the middle of our grand spiral cosmic home. The Milky Way Band is widest and brightest in this area. The constellation Sagittarius the Archer lies in front of the Milky Way’s hub, and the constellation’s brighter stars easily resemble a tea pot. The billowing Milky Way Band rises from this tea pot, which you can picture as steam. You need to be at a rural location to witness this, and the further south you live, the higher it appears in the sky.
If you have a small telescope (or even a large one!!), be sure to point it at Saturn. With medium magnification, about 60x, you will easily see Saturn as a small ball, encircled with a bright wide ring system. The ring appears as an ellipse due to foreshortening. Look for what appears to be a dim star close by. This is very likely Titan, Saturn’s biggest moon. Watch night to night and you will see Titan orbiting the planet.
Full Moon is on July 8.
Keep looking up!
—Peter Becker is Managing Editor at The News Eagle in Hawley, PA. Notes are welcome at email@example.com. Please mention in what newspaper or web site you read this column.