March 31, 2017


The Night Sky:
March was a good month for galaxies

By GERRY LEBING



This is M51, the Whirlpool Galaxy. The larger galaxy is M51A and the smaller is M51B.  They are located about 23 million light years away and have a visual magnitude of 8.4. M51A contains more than 100 billion stars.




Messier 101, the Pinwheel Galaxy, is about 21 million light years away and has a visual magnitude of 7.7. It is estimated that M101 has a trillion stars!



Messier 63, the Sunflower Galaxy is 27 million light years away.  It has a visual magnitude of 9.3. M63 has more than 400 Billion stars.


What to Look for in April


If you are an early riser, you will be able to see Venus (magnitude -4) in the morning, close to the eastern horizon, throughout April.  On April 1, Venus will rise just before sunrise.   By the end of the month, it will be coming up at 4:21 AM. Venus will be at its brightest point of the year on April 30th!
Mercury and Mars will be visible on April 1 near the western horizon, just after sundown.  Mercury will fade into the sunset by the 9th but re-emerge as a morning star on the 29th.

On April 7, Jupiter will be at opposition with the Earth and Sun.  That means you can draw a line through the three, with Earth in the middle.  It also means Jupiter is the closest it gets to us this year!  So that makes the 7th a great opportunity for viewing and taking pictures. Jupiter is the very bright object that will be visible just above the eastern horizon at dusk.  Best viewing will be around midnight.



I took this picture of Jupiter on March 8.  The faint object to the upper right isn’t a smudge--it’s one of Jupiter’s moons.

The two very bright stars in the eastern evening skies this month are Arcturus, which is the 4th brightest star in the night sky, and Vega, which is the 5th.   Arcturus will rise in the East just after sundown.  It is the closest red giant star to the Earth (about 37 light-years) and is estimated to be 7 billion years old.  Vega will rise about 3 hours later.  It has a visual magnitude of +0.2 and is 25 light-years away.  Vega is a blue-white star that’s about twice the size of the Sun.  It is believed to be about 400 million years old.

If you have a telescope or good pair of binoculars, you can use these two stars to help find the globular cluster M13, the Hercules Cluster.  Mentally draw a line between the two and then look about 1/3 the distance from Vega to Arcturus.  With a little patience, you should be able to find the cluster.
 


M13, the Hercules Cluster, is about 22 thousand light years away.  It has a visual magnitude of 5.8.   M13 contains about 300 thousand stars.


The Lyrid Meteor Shower will take place between April 16 and 25.  It should peak on the night of April 22. The meteors will seem to originate from the star Vega.  Vega is the very bright star that rises in the NE at about 9:00 PM.  You can expect about 18 meteors per hour throughout the night.

Moon phases:
New moon: April 26
First Quarter: April 3
Full moon: April 11
Last Quarter: April 19


(Gerry Lebing is a retired computer scientist with the U.S. Geological Survey in Washington, D.C.  He has visited Hatteras Island since the mid-1970s. He and his wife, Karen, have owned property here for several years and moved to their home in Waves full-time in 2013.  Astronomy is a subject that Gerry says he has always been interested in and one that he pursues seriously -- he's built an small observatory next to his house. You can send him questions about the night sky through e-mail, [email protected]g.)


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