Springtime stars

This week, let’s dip into the email bag and see what we find.

Dear Tom,

You are a big nerd. I went out­side with one of those star maps you sell at Perkins Obser­va­tory to try to find the Big Dip­per. I could see the stars okay, but I couldn’t see those lit­tle lines. What gives?

Jimmy Smith, age 10

Dear Jimmy,

Because of light pol­lu­tion, you can’t see those lit­tle lines from inside the city. You have to observe under dark, rural skies to see them.

Ha! Old Tom is just kid­ding. But seri­ously, I’m not a nerd. I’m an astronerd — and proud of it.

Even when you can see the lines, stargaz­ing can be dif­fi­cult. Some of the stars will be invis­i­ble because of out­side light­ing. What you need is a handy-dandy, sure-fire, four-step, spring­time pro­gram to find your first con­stel­la­tions. Here goes:

Step 1 — Point to Polaris: Around 10 p.m., go out­side and look north and hold your star map with the word “North” at the bot­tom. High in the sky will be the famil­iar stars of the Big Dip­per, which this time of year looks upside down before mid­night. Around the Dip­per, you may see some fainter stars that form the head and body of Ursa Major, the Big Bear, of which the Dip­per is the bright­est part. Hint: The han­dle of the Dip­per is the long tail of a very strange-looking bear.

Now find the far left stars of the Dip­per. They are called the “pointer stars” because they point down toward the hori­zon to a rel­a­tively faint star called Polaris. The North Star, as it is more com­monly known, always main­tains its northerly posi­tion because the entire sky appar­ently rotates around it. Fol­low the faint arc of stars to the right to locate the rest of the Lit­tle Dip­per, known to astronerds like me as Ursa Minor, the Lit­tle Bear. Con­grat­u­la­tions! You’ve found your sec­ond constellation.

Step 2 — Arc to Arc­turus: Now shift you eyes back to the Big Dip­per and turn the map until “East” is at the bot­tom. Find its han­dle, and fol­low the arc of stars toward the east until you come to a very bright star called Arc­turus. You are now look­ing low on the east­ern horizon.

Look to the left of Arc­turus to find the rest of the bright stars in the kite-shaped con­stel­la­tion Bootes, the Herds­man. Bootes is appar­ently lying down on the job, since he extends along the east­ern horizon.

Step 3 — Speed on to Spica: Con­tinue the arc to the south­east, tilt­ing the map accord­ingly, until you come to a slightly fainter star called Spica, the bright­est star in the con­stel­la­tion Virgo, the Maiden. Don’t con­fuse Spica with the bright planet Sat­urn, which is to its left. Since Spica is so close to the hori­zon, you prob­a­bly won’t be able to see the other, much fainter stars in Virgo.

Step 4 — Reach for Reg­u­lus: Go back to the Big Dip­per and flip the star map over so that “South” is on the bot­tom. Use the pointer stars to direct your vision south, over the top of the sky, until you come to a group of stars that look like a back­wards ques­tion mark. The bright star at the bot­tom of the ques­tion mark is Reg­u­lus, the Lit­tle King, the bright­est star in Leo, the Lion. You should be able to trace out the out­line of Leo, since its stars are rel­a­tively bright. You won’t find that bright “star” at the bot­tom of Leo on your star map because it isn’t a star at all. It’s the planet Mars.

Take heart, Jimmy. Per­ma­nent astro-nerdhood is just a trip out­side away!

Plan­ets

Yes, they are still there, but if you want to see the Great Jupiter/Venus Con­junc­tion of 2012, you’d bet­ter get out­side pronto.

Bright Jupiter is low in the west­ern sky dur­ing deep evening twi­light. Even brighter Venus is above it. Above them both is a pretty, naked-eye star clus­ter called the Pleiades, or Seven Sis­ters. Venus will pass right through the Pleiades dur­ing the evening of April 3. Get out your binoc­u­lars that night.

By 10 p.m., ruddy Mars is high in the SSE in Leo. Sat­urn is just peek­ing over the south­east­ern hori­zon. Look for it to the left of the bright star Spica in the con­stel­la­tion Virgo — a nice view!

Tom Burns is direc­tor of Ohio Wes­leyan University’s Perkins Obser­va­tory in Delaware and he’s glad to hear from you. Email him at tlburns@owu.edu.

Posted by Tom Burns on Mar 26 2012. You can follow any responses to this entry through the RSS Feed. Comments can be made below.