Skip to main content

The Sky This Month - March 2012

Posted in
Written by Gary Boyle on
Post Date: 
Fri, 2012/03/02

When Beacons Meet

I am sure you have noticed the brighter than usual objects popping out in the western sky moments after sunset. These are the two brightest planets of our solar system. Over the next couple of weeks, follow Venus (brighter of the two) as it climbs the ecliptic to pair up with Jupiter on March 13th. Even on this special night, they will be separated by three degrees or six full moons placed side by side. A couple of nights prior on the 11th, the two will set parallel to the horizon and appear as a set of spooky eyes. Teamed up with the bright winter stars, the setting should be spectacular, so be sure and circle the calendar to photograph this celestial portrait. The next opportunity to catch these bright beacons will be early on the morning of July 3rd when they are located between the Pleiades and Hyades in the east.

There is no special significance to this close pairing. Over the course of any given year, the orbiting planets eventually meet up by line of sight, in a particular area of the sky and pose for these picturesque portraits. Said groupings can take the shape of a triangular, rectangle or even a perfect straight line. At times, the thin crescent Moon will nice placed and add character to our digital moment. Astrologers will use these close associations and the lining up of planets to forecast or predict what not. Keep in mind these grouping have no bearing on our everyday lives.

Now that you have put your camera away it is time to hunt down a few objects with the telescope. We first start off in Canis Minor (one of Orion’s hunting dogs) and its brightest sun named Procyon. Marking the left most point of the winter triangle (along with the stars Betelgeuse and Sirius), alpha Canis Minoris lies a mere 11.25 light years from us. It is one of the ten brightest stars in the sky and slightly fainter than Rigel in the constellation Orion. The only difference is Rigel’s distance of 1,600 light years from us.

Procyon has a companion designated Procyon B. The earth sized white dwarf is positioned as close to its parent star as Uranus is to our Sun thus making visual observation almost impossible. Procyon has almost consumed its internal fuel and will eventually expand to red giant status millions of years from now. Before leaving Procyon, try to locate a couple of challenging irregular galaxies. UGC 3912 lies about 1.3 degrees south west of the Procyon. Or you can try UGC 3946. It is locate 1.5 degrees south of Procyon and a bit fainter. These types of galaxies have no structure or central core which really makes it difficult to track down.

Draw an imaginary line from Procyon to Betelgeuse. Move about two-thirds the way west and then a bit south till you come across three pairs of stars in the constellation Monoceros. You have now found beautiful Rosette Nebula. Catalogued as Caldwell 49, the Rosette Nebula measures 1.3 degrees wide which yields 130 light years in width and lies 5,200 light years away. Astronomers have found that some of these stars are O and B class which are the hottest stars on the HR diagram. By comparison, our Sun is a G2 star.

Further on down in Monoceros and a bit east, look for NGC 2346 - the Butterfly Nebula. This planetary nebula is estimated to be around 2,000 light years away and could extend half a light year or 31,500 astronomical units wide. To scale, Neptune is only 31 astronomical units from the Sun. It seems that long ago, this was a binary star system and when one star became a red giant, it eventually consumed the other and it is now orbiting inside the giant’s atmosphere. The proximity of the two is causing a ring of material to be ejected out both sides with amazing results.

As we continue south reaching the Canis Majoris border, we come to a target mostly reserved for astrophotographers. The Seagull Nebula is a combination of an emission nebula, reflection nebulae and open star clusters. Wing tip to wing tip measures two and a half degrees or the area of five full moons in width. IC2177 is located 7.5 northeast of the bright star Sirius and estimated to be 3,650 light years from us.

Comet Garradd is now well placed high in the north and is visible all night long. As March opens, the comet will continue on its northern trek through Ursa Minor then Ursa Major. On the 1st it will still glow at magnitude 7.1. Go to heavens-above.com for a nightly chart to help locate our interplanetary visitor.

As mentioned at the top of the article, Venus and Jupiter are taking centre stage in the west. Keep following as Venus inches closer to Jupiter by making a quick sketch or taking a photo. Brilliant Venus reaches greatest eastern elongation of 46 degrees on the 27th. The red planet Mars will be at opposition on March the 3rd. It will now be out all night for our enjoyment. At opposition it will shine at magnitude -1.2 and is the most distant opposition in the past 30 years. For observers and planetary imagers, it can only get better from here.

Even the Lord of the Rings peeks above the east horizon at a decent 10 p.m. local time. It stands to the east of Spica and a little lower. Its majestic rings are finally tilting to a decent angle for all to enjoy.  

The full Worm Moon occurs on the 8th at 4:39 est and the new moon listed at 10:37 edst. And yes the clocks go ahead this month. Be sure to move them ahead one hour on the morning of the 11th where needed. We now loose and hour of night fall to observe but March is also the change of seasons. The Spring Equinox occurs on the 20th at 1:15 edst.

Until next month, clear skies everyone.

Gary Boyle