Watching the Big Dipper

If you’ve been playing with your computer planetarium and looking at the stars at night, you should be starting to know some constellations and stars. Since it’s the weekend and you may be able to stay up a little later, this will be a good time to take a closer look at Ursa Major, the Great Sky Bear.

UrsaMajorAs soon as it gets good and dark (around 7:30 pm), head on outside and look for Ursa Major, the Big Dipper. (Check it out on your computer first to remind you what to look for) You should be facing North. Can you find the four stars that make up the bowl of the dipper? Can you see the three or four stars that make up the dipper’s handle? Make a sketch of the Big Dipper. You should include North marked on your sketch.  Draw in any objects you see in the foreground like houses, trees, etc. and leave lots of room for the sky.  Now add  the Big Dipper  and the time of your observation right next to it. Be very accurate, you’re going to need a good sketch to compare to later. Now look for your other constellations and stars or you can go back in or do what ever else you had planned for the evening.

In a about 3 hours head back on outside (this is why a weekend night is a good one to do this, if this week doesn’t work out you can try again next Friday). Where’s the Big Dipper now? Does it look any different? Why? Add it to your sketch and label the time. That takes care of req. 4c.

Good observing.

Mike

Stars Science Theater

http://www.mike-francis.com/sst.htm

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The Winter Circle

Lets look for some more constellations and stars.  When you go out tonight  try to find some of the Winter constellations.  Start by finding Orion.  It should be just about a little west of due South  at around 8:00 (turn around after you finished finding the North Star).  You should see the three stars in a row that mark Orion’s belt.  If you find the belt, the two stars that make up his shoulders should be just above  and the three stars that are his head will be a little above that.  Hanging from Orion’s belt is a sword, another three stars going down this time.  Below the sword there will be two more very bright stars that mark Orion’s legs.  The star that marks Orion’s shoulder on the East is Betelgeuse, the one on the West is Bellatrix.  The leg below Betelgeuse is Saiph, the leg below Bellatrix is Rigel. Take a close look at Betelgeuse.  If you’ve got them use binoculars.  What color is it?  Look at Rigel.  What color is it?orion

Look at Orion’s belt.  Use his belt as pointers and look to the West.  You should see what looks like a letter V.  That V reminded the folks who gave the constellations their names of the smiling face on a bull when he’s getting ready to charge.  The brighter star at the top of the V on the left is Aldebaran.  Now look a little further to the West (right) and see if you can find the little cluster of stars that make up the asterism called the Pleiades.  That marks the shoulder of the bull.

Back to Orion again.   We followed the three stars of Orion’s belt to the West to find Taurus.  Go the other way, about the same distance and you’ll see a very bright star.  That’s Sirius.  How does it compare in brightness to Jupiter high up above it?  Sirius is the Dog Star so it must be part of the Big Dog or as astronomers like to call it, Canis  Major.  If you look carefully you should be able to make out the dog’s nose, back, front and back legs and it’s droopy tail.

Where there’s a Big Dog there must be a Little Dog, so look higher in the sky until you find two fairly bright stars all by themselves.  The brighter of the two is Procyon.  Don’t be fooled by going too far and finding the Gemini brothers.  If you’re not sure which is which, the brothers should have stick figure bodies, the dog is just two stars.  Another way to find the Little Dog is to first find the Gemini and then go from Pollux’s head to his arm and on to Canis Minor.

The next constellation to try to find should be almost directly over your head.  There will be five fairly bright stars that make up a pentagon (five sided figure).  That’s Auriga the Shepard.  The very bright star at the top of the constellation is Capella the mother goat and if you look very closely you should see her three kids right beside her.

A little above Orion and just to the East there will be two stars that look almost alike.  Those are the Gemini brothers, Pollux and Castor.  Pollux is on the East, Castor is on the West.  See if you can find the stick figures that make up their bodies.

We’re up to 12 constellations now and 12 bright stars.  If you can find all of those in the night sky, you’ve learned more than enough to pass the test.  If you’re still having trouble, practice on Stellarium and I’ll explain how to find a few more constellations in a future blog.

Mike

Stars Science Theater

http://www.mike-francis.com/sst.htm

Mike Francis Stars Science Theater

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Circum Polar Constellations

Let’s hope we get a clear night.  Before 7:30 pm Mars should be visible in the West, if you don’t have trees in the way.  If you can’t see it, try to find a place to look at the sky that has a clear view of the horizon. You may also be able to see Mercury and Venus very low on the horizon if there aren’t trees in the way.  If you haven’t looked for it planets yet, get out there on our next clear night.

 

Circum Polar Constellations

As soon as it gets good and dark look for Ursa Major, the Big Dipper. You should be looking into the North. Look for the four stars that make up the bowl of the dipper? Can you see the three or four stars that make up the dipper’s handle?  The two stars at the front of the dipper are Dubhe (on your left) and Merak (on your right).

Now that you’ve found Ursa Major you can look for the other circum polar constellations.  To find Ursa Minor (the Little Dipper) use the pointer stars Dubhe and Merak, draw an imaginary line between them and continue it 5 times further towards the North. See a star there? That’s Polaris, the North Star. It’s right at the end of the Little Dipper’s handle or the little bear’s tail. Can you see the handle and the four stars that make up the bowl?

Keep your line going West about the same distance as the line from Ursa Major to Ursa Minor.  Find the big W?  That’s Cassiopia’s throne.  If you find Cassiopia the Queen, King Cephus must be close by. Imagine the Queen sitting on her throne looking at the nearby stars to the right and you’ll see the four stars for Cephus’s head and the hat that looks like a clown hat.

Want to try another?  Look right below Ursa Minor and see if you can find the head of Draco the dragon.  It should be right on the horizon, so trees may make it impossible to find where you are. Do you see the dragon’s body? Good luck.

If you can find all five constellations, you’re half way to the number of constellations you need to learn.Every night when you go out, you should try to re-find these constellations and stars, so it becomes second nature.

Mike

Stars Science Theater

http://www.Mike-Francis.com/sst.htm


Planetarium on your computer

One of the hardest parts of the Astronomy Merit Badge is identifying at least ten constellations (requirement 4), four of them in the zodiac, and eight conspicuous stars. Here is a list of most prominent constellations and stars, which are visible in the night sky now. This is the list you should try to learn to identify for the test.

Constellations:

  • Ursa Major
  • Ursa Minor
  • Cassiopia
  • Cephus
  • Draco
  • Orion
  • Taurus
  • Auriga
  • Gemini
  • Canus Major
  • Canus Minor
  • Cancer
  • Leo

Stars

  • Dubhe
  • Merak
  • Polaris
  • Sirius
  • Betelgeuse
  • Bellatrix
  • Rigel
  • Saiph
  • Aldeberan
  • Capella
  • Castor
  • Pollux
  • Procyon
  • Regulus
  • Arcturus
  • Spica

You don’t have to learn all of them (see the book), but if you know all of them it will make it easier to take the test. One way to learn them is by using a computer planetarium program. One of my favorite free programs is Stellarium. It’s available in Windows, Mac and Linux versions so download it (with your parents permission of course) and play around with it for a while, to get a hang of how it works.

Stellarium a desktop planetarium

If you’re using another program adjust what you do to the program you’re using.

First thing is to set your location. If you’re using Stellarium there will be a little tool bar on the lower left side of your screen and one of the tools is a little wrench. Click on it to open the set up box. Click on the location tab and you will find several options, but the ones we’re interested in are latitude and longitude.

Do you know yours? If you don’t you can go here to find it: http://www.zipinfo.com/search/zipcode.htm . To check latitude and longitude just enter your zip code. This will be your local post office as your observation point which is close enough for us. Enter your coordinates by using the little up and down arrows next to lat. and long. in Stellarium and click save, so you always start out looking at the sky the way it will in your back yard.

Now click on the Date & Time tab and check to make sure the current date and time are set. If they are incorrect, your computer may have the wrong date set so check your computer’s clock. If you want to play with the landscapes, go for it, but Guerens (the skyline you get when you first start the program) seems to be the best choice for keeping the screen fairly clean and still give us a reference for where the horizon is. Close the set up screen and now we can take a look at the sky.

If it is already night time you’re all set, if it’s day time you need to speed time up a little. Click the fast forward (>>) on the lower right of the screen two or three times. Don’t get carried away or time will really fly. When the sky gets dark hit the play (>) and time will slow down to real time. Now you should see a nice clear night sky and a few stars. If you have a scrolling mouse, try scrolling your view in and out. If you don’t have a scrolling mouse use the page up and page down keys. Too much ground, too few stars? Left click anywhere on the screen and drag your view up or down. You can also drag left and right to look to the East, West, North or South. Play around with this for a while until you get used to it.

If you can find Mars ( it will be low in the West at around 8:00 pm ), click on it and hit your space bar. What happens? Now try scrolling or using the page up and down keys. You can do this with any objects that could be seen with a telescope, I’ll give you some things to look for on another day.

Now to start learning the constellations and star names.  Try playing with the three controls on the left end of the control bar. By turning these on and off and learning the star patterns behind the graphics, you should be able to start learning the constellations.

If you are using another desktop planetarium and having trouble, you can email me with your questions as I have several other programs and I should be able to help out. When it’s clear at night go out right after sunset and see if you can apply what you’ve learned.

If you have any problems or questions, send them along.

Mike