Night Sky: The beginning of Galaxy Season, and more highlights for March
March is a special time of year for astronomers. The constellation Virgo begins to rise right after dusk, and along with it there are a multitude of galaxies that can be seen with binoculars or small telescopes. Two of my favorites are M81 and M82.
M81 (on the left) and M82 are both about 12 million light-years away from us, but they are only about 130,000 light-years from each other. M81 has a visual magnitude of +6.9 and M82’s magnitude is +8.4.
Both galaxies were discovered by Johann Bode in 1774. Five years later, Pierre Merchain found the same pair and reported them to Charles Messier. Messier noted the observations and added both galaxies to his catalog of objects that are not to be mistaken for comets.
M81 is a large spiral galaxy noted for its spiral arms that contain millions of young blue stars. Blue stars are very hot, very large, and rather short-lived. Blue stars form the hottest class of stars with temperatures exceeding 30,000° c. They are at least three times the size of the sun and only last about 10 million years. If that seems like a fairly long life, remember that the sun has been around for 4.6 billion years!
M82 on the other hand, is irregularly shaped and does not appear to have large areas of blue stars like its neighbor. But M82 is a “starburst galaxy.” A starburst galaxy is a galaxy where there is very intense star formation. M82 is thought to be about 39 thousand light-years in diameter. Our own Milky Way is a much larger 53 thousand light-years across, but astrophysicists believe M82 creates about the same number of stars each year as the Milky Way.
What you can look for in March’s Night Skies
Uranus is the only planet in the evening night skies. With a visual magnitude of +5.8, it is very difficult to see without a telescope or good pair of binoculars. Look for Uranus about 30° above the western horizon right after dusk.
The early morning skies offer views of Venus and Mars. Venus rises at 4:00 a.m., followed by Mars at 4:22 a.m. Venus will be about 20° above the eastern horizon by 6:00 a.m. Mars will be about 5° lower than Venus.
The evenings of March offer good opportunities to identify some major stars. Most prominent is Sirius, the brightest star in our night skies. It will begin on March 1 about 37° above the southern horizon. Other bright stars in the southern skies include Rigel, (a blue giant), Betelgeuse, (a red giant), and Procyon, (a yellow-white star).
The brightest star in the Northern Hemisphere, Arcturus, rises in the NE at 8:38 p.m.
There are no major meteor showers in March.
Moon Phases:
New Moon is March 2
1st Quarter is March 10
Full Moon is March 18
Last Quarter is March 25
