Chances to easily hunt down stunning Milky Way treasures come sky-watchers’ way this week, thanks to our trusty moon pointing the way.
Cosmic teapot. After nightfall on Wednesday, September 3, look toward the southern sky for a waxing gibbous moon. To its lower left is the constellation Sagittarius and its teapot-shaped pattern of stars—complete with handle, lid, and spout.
You’ll find the teapot slightly tilted, with its celestial steam rising into the sky. It’s amazing to think that when we look toward this gauzy region of the sky, we are gazing upon the central hub of our Milky Way, which is more than 26,000 light-years away. Of course, the moonlight will filter out the Milky Way’s glow this week, but binoculars and telescopes should help cut through the lunar glare.
For backyard astronomers, main attractions in Sagittarius include the numerous colorful gas clouds, or giant star factories, scattered within one of the spiral arms of the Milky Way. These nebulae are home to hundreds of newborn stars still wrapped in hot, gaseous blankets. And on Wednesday night, you can rely on the moon to guide you to some of the best known ones:
Lagoon Nebula. Among the most beautiful of these gems is the Lagoon Nebula. On a very dark, clear night far from city lights, its faint fuzzy glow can be glimpsed with the naked eye. Located about 6,500 light-years from Earth, the red- and orange-hued Lagoon has a cluster of young stars buried at its center.
Tonight it appears less than 5 degrees below the moon, a distance equal to about the width of your fist held at an arm’s length.
Trifid Nebula. Lying just above the Lagoon Nebula, about one degree higher, is the Trifid Nebula, made famous in the original Star Trek TV series, where its picture was often used as a backdrop.
Smaller and much dimmer, this 9,000-light-year-distant nebula has two distinct sections that glow red and blue in photographs. Through a telescope eyepiece, the two 30-light-year-wide gaseous areas appear as small hazy spots, slightly smaller than the full moon.
Finally, another major showpiece in Sagittarius is the M23 open star cluster. You’ll find this stellar gem less than 2 degrees to the right of the moon. Binoculars will help tease out Messier 23 from the moon’s glare. Not as impressive as some other Milky Way treats, this 2,100-light-year-distant group of 150 stars makes for a pretty sight, especially when seen through a small telescope. The entire cluster spans about 30 arc-minutes across the sky, equal to the diameter of the full moon—so it can fill the entire field of view in the eyepiece.
Venus and Regulus. Early bird sky-watchers up at the crack of dawn on Friday, September 5, will see the Goddess of Love snuggle up to the heart of the King of Beasts.
The planet Venus and the star Regulus, the brightest one in the constellation Leo, the Lion, will appear stunningly close, less than one degree apart, which is equal to the width of two full moons set side by side in the sky.
The trick to soaking in this cosmic treat will be to find a location that has a clear view, right down to the eastern horizon. Also because Regulus, some 77 light-years away, shines one hundred times fainter than Venus, a pair of binoculars will really help bring this conjunction into focus.
The Moon and Neptune. Late night on Sunday, September 7, look toward the southeast sky for the waxing gibbous moon parked near Neptune.
The blue ice giant will be about 6 degrees to the lower left of the moon, in the faint zodiacal constellation of Aquarius.
You will need binoculars or a small telescope to pick up the planet’s tiny blue disk, shining near magnitude 8 among the mythical water bearer’s faint stars.