Looking Up column: Antares, the red star of summer
Antares is what Betelgeuse is to winter nights. Antares, prominent on summer nights (Northern Hemisphere, that is; Down Under, winter has just begun), is likewise bright and red.
Like Betelgeuse, Antares is a “supergiant” star, far larger than our sun and so big the orbits of Mercury, Venus, Earth and Mars would fit inside it. Good thing its 604 light-years away - the time it takes for its light to reach our eyes - and not eight minutes like our own beloved star.
This column is meant to inspire you to “look up” at the stars, but for stars not far from the horizon, it’s more “look straight.” From where I live in northeast Pennsylvania (latitude 41.5 degrees), Antares only reaches 22 degrees above the southern horizon. That’s about a quarter of the way up the sky.
It’s the brightest star in the easily traced constellation Scorpius the Scorpion and is imagined as the fiery “heart” of this celestial arachnid.
Astronomers have traced the many varieties of stars as stages in their development, from rising from a gaseous, dusty nebula to its ultimate demise. As a supergiant, Antares is considered close to its end. When it has used up its hydrogen fuel, it will collapse and explode as a supernova (sometime in the next 10,000 years).
Antares is accompanied by a much fainter star in a slow orbit around it known as Antares B. Difficult to discern because of their apparent nearness to each other and Antares’ overwhelming glare, some have described the companion as green in hue, a contrast effect with red Antares. It is really blue-white.
Antares varies slightly in brightness, from 0.6 magnitude to +1.6. Its companion is +5.5. If it was well away from Antares, you could see Antares B on a dark night with unaided eyes.
On a dark night, sweep the area right around Antares with binoculars. You can find two fine globular star clusters, M4 and M80, close by.
The Scorpion figure is easy to imagine. The “head and pincers” are the stars to the upper right of Antares. Trace the stars to the lower-left ending in the “tail.” Two stars, similarly bright, shine close together at the very “tip” which are nicknamed “The Cat Eyes.”
They are also known as Shaula (on the left) and Lesuth.
You probably thought they were named Snowball and Mittens.
Scorpius is one of 13 constellations along the ecliptic, the apparent path the sun traces as the Earth circles the sun. The moon and major planets all closely follow the ecliptic.
First-quarter moon is on Sunday, June 28.
Jupiter rises around 11 p.m., followed by Saturn about 20 minutes later. Look southeast. Mars rises around 1 a.m.
Keep looking up at the sky!
Peter Becker is managing editor at The News Eagle in Hawley, Pennsylvania. Notes are welcome at firstname.lastname@example.org. Please mention in what newspaper or website you read this column.