July: scorpion and dragon: Scorpius and Draco are now at their highest in the south and north.
TWO SINISTER CELESTIAL beasts are especially well placed for observing on July evenings: Scorpius, the Scorpion, and Draco, the Dragon. The former is low in the south, the latter high in the north. Look for them there on our July evening sky map on the facing page.
Scorpius is much brighter, but Draco is important and interesting in some unusual ways.
Scorpius glitters with many 2nd- and 3rd-magnitude stars, and 1st-magnitude Antares marks its heart. Antares means "rival of Mars" or "anti-Ares," with Ares being the Greek name for Mars--a reference to this supergiant star's fiery orangered color.
On either side of Antares are its two "outrigger" stars, Sigma ([sigma]) and Tau ([tau]) Scorpii. Tucked just below the line from Antares to Sigma is the dim, fuzzy globular star cluster M4, detectable as a vague glow in binoculars and as a lovely starspeckle in a telescope.
To the upper right, marking the top of the head of Scorpius, is the fine telescopic double star Beta ([beta]) Scorpii.
The low tail of Scorpius is (literally and figuratively) striking, with its stinger including the bright side-by-side "Cat's Eyes," Lambda ([lambda]) and Upsilon ([upsilon]) Scorpii, named Shaula and Lesath. Upper left from the Cat's Eyes are the two big, bright open star clusters M6 and M7.
Now turn the all-sky chart so that its "Facing North" horizon label is right-side up. The ancient constellation Draco is now standing upright, with his nose pointing toward bright Vega and his back arching over the Little Dipper (Ursa Minor).
Alpha ([alpha]) Draconis, better known as Thuban, is far from being the brightest star in Draco. It got its "Alpha" name from its historical importance: it was the north star more than 4,000 years ago. Find it between the bowl of the Little Dipper and the bend in the Big Dipper's handle.
Draco's lozenge-shaped head is composed of 2nd-, 3rd-, 4th-, and 5th-magnitude stars. The Dragon's 2nd-magnitude nose, Gamma ([gamma]) Draconis (Eltanin), is moving our way through space and will become the brightest star in Earth's sky several million years from now.
Planets in July
Mercury emerges into view very low in the dawn around the end of July, to the lower right of brighter Jupiter and faint Mars. Bring binoculars.
Venus is low in the west in twilight.
Mars remains low in the east-northeast during dawn all month. On the morning of July 22nd it's next to much-brighter
Jupiter (0.8[degrees] apart). After that, find Mars to Jupiter's left or lower left.
Jupiter emerges into dawn visibility very low in the east-northeast by July 10th or 15th. Mars, much fainter, remains near it for the rest of the month.
Saturn glows in the southwest after dusk. It's roughly a fist-width at arm's length upper left of Spica.
|Printer friendly Cite/link Email Feedback|
|Date:||Jan 1, 2013|
|Previous Article:||June: exploring the June Depths: work upward through the scorpion, the scales, the snake, and the strongman.|
|Next Article:||August: Vega's deep companions: brilliant Vega now burns near the zenith, with interesting deep-sky sights close by.|