What’s Up This Month – March 2009
The nights grow warmer this month as the stars of spring finally wheel into view. Along with the seasonal beauties like M35, M44, and the galaxy fields of Leo and Virgo, this month treats us to a spectacular view of Saturn and Venus. And Comet Lulin is still bright enough to see in binoculars, while in a telescope it looks like a fuzzy “apple on a stick” as it swings past the sun and begins its journey into interstellar space.
Celestial Events This Month
Spring Begins! At 7:44 a.m. EDT on March 20, the sun crosses the celestial equator moving northwards. This marks the beginning of spring in the northern hemisphere (and autumn in the southern hemisphere). On an unrelated note, daylight savings time begins in most of North America at 2 a.m. on March 8.
Ceres. The largest asteroid, Ceres, makes it’s closest approach to Earth for the next 2,155 years! At magnitude 6.9, Ceres is visible in binoculars and telescope as a star-like point, just above the “back” of Leo. On March 2, Ceres lies just north of the 4th magnitude double star 54 Leonis.
With a diameter of 950 km, Ceres is the largest asteroid, far larger than the next largest asteroid, Pallas, and is massive enough to maintain a round shape. The Hubble telescope has imaged Ceres and revealed some surface features.
How to find the asteroid Ceres this month (from Sky and Telescope)
Comet Lulin. The brightest comet in 15 months is moving rapidly across the sky, glowing green and sporting two short tails. On March 5-6, Comet Lulin will lie just 2 degrees from M44, the famous “Beehive” cluster. And on March 17-18, the comet will pass the star Wasat (“the waist, or middle”), also called delta Geminorum, in Gemini. More about Comet Lulin here.
Planets
Saturn. The ringed planet lies at opposition this month, directly opposite the Sun and closest to Earth. While it presents an easily-visible disk in a small telescope, the rings themselves are just 3 degrees from edge-on. So they look less like rings and more like tiny spikes sticking out of either side of the planet. Saturn well above the horizon by 9 p.m., and high in the sky by midnight local time.
Venus. The brightest planet in our sky moves closer to the Sun and reaches inferior conjunction on March 27, when it lies just 8 degrees north of the Sun. Early this month, Venus is a tall, thin crescent in the southwest sky. It’s face is just 10 percent lit, yet it stands nearly 60 arc-seconds tall, easily visible in a small telescope. For a few days at the end of the month, the planet will be visible in the evening and morning sky. In April, Venus takes its place as the “morning star” for the next many months.
Jupiter, Mars, and Mercury. These three planets are locked in a celestial minuet in the east-southeast sky just before sunrise.
Sights To See
Wasat. Mentioned above, the “waist star” in Gemini is a fine binary star, with a yellow-white primary and a fine red-dwarf companion star. At 5.5 arc-seconds separation, you need close to 100x to resolve this pair.
Star clusters in Puppis. Well positioned for observers in both hemispheres, the lovely open clusters M46, M47, and NGC2423 make fine targets on a cool March night. You can see all three clusters together with 7×50 binoculars, in a finder, or in a wide-field telescope at low power. An individual examination of each cluster in a telescope reveals a glowing swarm of hundreds of stars. M46 also holds a planetary nebula, NGC 2438, which you can see at 100x or more with the help of a UHC or deep-sky filter. M46 lies at RA 7h 41.8m, Dec -14d 49s.
M46, M47, and NGC2423 (center of map)
This month, a haiku to conjure thoughts of a warm place…
“Beyond swaying palms
A field of shimmering stars–
Eternity waits!”
