Category: Astronomy For Kids

Now that we’ve hunted down Orion and been bull ridin’ with Taurus, it’s time for us to discover a pair of celestial brothers – the Gemini twins. Gemini is one of the members of the zodiac which means the imaginary path the Sun, Moon and planets follow across the sky passes through the stars of this constellation. But what happens when you don’t have these solar systems objects to point the way to the pair? Then look over the top of Orion’s left shoulder and you’ll see two bright stars that live about a thumb’s length apart from each other – Castor and Pollux. For many of us, Gemini will be almost directly overhead at sky dark.

The slightly fainter star to the northwest is named Castor, and his almost identical brother star angled away to the southeast is Pollux. If you live where skies are dark, give your eyes plenty of time to adjust and you will begin to see the fainter stars that make up the stick figures of their bodies. Their “feet” will always point towards Orion. Once you understand the positions of the stars, it isn’t hard to see how ancient civilizations connected these two stars as twins! The ancient Romans saw the brothers Romulus and Remus, the two heroes that founded Rome. The Greek astronomers saw the twins Castor and Pollux, sons of the god Zeus. Oddly enough, both cultures believed the brothers were raised by the half-man, half-bull centaur called Chiron. Perhaps because of the nearby constellation of Taurus? It was Chiron who sent them to help Jason and the Argonauts in their quest to find the golden fleece. Legend has it that the twins rescued Jason’s ship from a killer storm and thus earned their place in the sky. Other stories say the twins were born of different fathers, making one mortal and one immortal. Pollux, who would live forever, was an excellent boxer. Castor, who would age normally, was an excellent horseman. When both were called upon to fight in the Trojan war, Castor was killed. Pollux love for his brother was so strong that he could not bear to be parted from him, so he begged Zeus to place them both in the sky as stars. The Arabs also saw this pair of stars as twins, while the Chinese referred to them as Yin and Yang!

But there’s a lot more “twins” here than can just be seen with your eyes alone. Two million year old Castor is also a very special type of “twin” star called a visual binary. This means it has another star that can be seen with a telescope very close to it. The two stars aren’t physically connected to each other, but its twin star is also a twin star! Pollux is also very special, too. Why? Because on on June 16, 2006 it was announced that there is planet just about twice the size of Jupiter orbiting it! The planet’s name is Polydeuces – another derivation of the word twin. In real life, this pair of stars couldn’t be more different than each other if they tried. Castor is a hot, blue/white A-type star – a multiple system located almost 50 light years away from Earth. Pollux is a cooler, singular star – a 35 light year distant orange giant that’s not only more massive than our Sun, but probably younger, too.

If you have binoculars or a telescope, be sure to take a look right around Castor’s big toe on a dark night. Here you will see colorful and bright galactic star cluster known as Messier Object 35. A large telescope will also reveal another nearby star cluster, NGC 2158, too. Another “twin”! There is also a planetary nebula called the “Eskimo” (NGC 2392) near the “arm” of the twin on the left. There are many other clusters and nebulae which are part of the constellation of Gemini, but most are too faint to seen without a large telescope.

Have fun with all your new knowledge of Gemini – the twins!

Gemini Map courtesy of the University Corporation for Atmospheric Research (UCAR), Mythological Figures courtesy of Stellarium, Constellation photography courtesy of Till Credner, M35 and NGC 2158 courtesy of N.A.Sharp/NOAO/AURA/NSF. Thank you so much!

Now that we’ve discovered the easy constellation of Orion “The Hunter”, it’s time to take a look at what else is around! Instead of chasing down game with a bow and magic sword, this time we’ll be cowboys and rope the heavenly steer – Taurus – and take him for a ride! There won’t be any rodeo clowns to keep us safe. Just you and me and a starry night. Your mission? Locate Orion again. Now connect the three stars that make up his “belt” from left to right and keep drawing the line until you reach the next bright star. What we’re looking for is hiding just above Orion’s right shoulder…

Throughout history, almost every culture has seen this grouping of stars as a Bull. It is believed that there are cave paintings that depict Taurus and its many myths include it being everything from a giant white bull set out to capture a princess to one of the labors of Hercules. Maybe it was even one of the animals that Orion was hunting! Right now, one of the best times to find Taurus is about an hour after the Sun sets. If you live in the northern hemisphere, Taurus will be high to the south/southwest. For those near the equator, you’ll see this constellation well overhead and slightly to the west. For those who view from the southern hemisphere, Taurus will appear low to the northwest. But, no matter where you live, if your skies are bright from light pollution, you will have difficulty seeing the many faint stars that belong to the constellation of Taurus. So how do you find it? It’s easy! Look for the bright orange alpha star – Aldebaran. Now you’re looking the “Bull” right in the eye…

Giant star Aldebaran is one of the brightest of all the stars in the night sky and is about 65 light years away from Earth. At about 44 times the size of our Sun, it’s no wonder we can see it easily! If you were to look at Aldebaran with a telescope, you’d discover it is not alone – there are five other faint stars nearby, making it a multiple star system. As your eyes begin to adjust to the dark, you’ll slowly notice that Alpha Tauri is part of a V-shaped pattern of stars called an “asterism”. This marks the head of the bull and you’ve roped your first deep sky object with just your eyes!

This group of stars called the “Hyades” and ancient stories say these stars are the five daughters of Atlas. When their brother Hyas died, Atlas placed the girls in the sky to mourn. Although you cannot see all of them with just your eyes alone, there are many more stars which belong to this group… up to 400! Here on the ground, Aldebaran looks like it might be part of this open star cluster, but the true members are about 150 light years away, about two and half times further than our bright orange friend. If you look at the Hyades with binoculars, you’ll discover that many of the stars form angular pairs, like a giant domino game in the sky! But there is more than one set of “sisters” to find here…

Perhaps by now you’ve noticed a “fuzzy spot” to the northwest of Aldebaran? Now that you’ve roped the Bull and are ready to ride, let’s take a trip 440 light years away to visit with the “Pleiades”. Mankind has also seen and recognized this group of stars for about as long as… well… as long as mankind has been looking at the stars! The Oriental culture refers to them as “Suburu” and the Russians call them “Baba Yaga” – the witch with the fiery broom. They are mentioned in the Bible and the Greeks knew them as the “Seven Sisters”. In India, they are the “Stars of Fire” and native American Indians saw them as seven sisters hiding from the bears. Some cultures refer to the Pleiades as the “Little Eyes” and others associated them with fish caught in a net. Even the ancient Druids got in on the act, because they celebrated All Hallow’s Eve on the date this blue group of stars reached their highest point in the sky at midnight! If you take a look at them with binoculars or a telescope, you might notice a faint whisper of light around these stars that’s called nebulosity. They are passing through a region of dust in outer space and lighting up the cloud. Not bad for a group of stars that’s over 100 million years old!

Now the whistle has blown and it’s time to jump down off the Bull and run to safety, for Taurus is also home to one of the scariest things that can happen in space… A supernova! Now, in our times, we need a telescope to see what is left of an exploding star – but 900 years ago it was so bright that it could be seen during the day! Now all that’s left is a neutron star – a pulsar that sends off radio signals just like a heartbeat… and the “smoking” leftovers of the star’s mass shooting out into space at a speed of 1,500 kilometers per second. But don’t worry… the “Crab Nebula” is about 6,500 light-years from our solar system.

If you don’t find Taurus right away, don’t worry… But keep watching in the days ahead as the Moon gets closer and closer each night. Why? Because you’re in for a very special treat. Be sure to take a look at the constellation of Taurus on the night of February 21, 2010. For many of you, the Moon will cover up (occult) some of the stars of the Pleiades! For others, the Moon may just slide right by the edge… But no matter where you live, the Moon and the Seven Sisters will keep each other company all night long.

Image Credits: Taurus Chart courtesy of University Corporation for Atmospheric Research (UCAR), Taurus Mythological courtesy of Starry Nights Software, Aldebaran and Hyades illustration courtesy of Wikipedia, the Pleiades and Crab Nebula courtesy of the Hubble Space Telescope and occultation chart courtesy of Your Sky.

If you’ve been peeking out the windows at night, or maybe looked up while walking the dog before bedtime or taking out the trash after dinner, perhaps you’ve seen three fairly bright stars in a row. Depending on how early or late you look, you may see them lined up side-by-side above the horizon, or they may be one on top the other when they are setting to the west. If you’ve noticed them, you wouldn’t be the first… Humankind has been telling stories about this set of stars for centuries!

The three stars are the most notable feature in the ancient constellation of Orion and it’s best to look for them just after the Sun sets and the skies get dark. If you live in the northern half of the world, you’ll find them to the south. If you llive near the equator, they will be overhead. If you live in the southern hemisphere, you’ll spy the trio north. But no matter where you live, the Star Hunter is visible to everyone! Once you see it, hold your left hand out at arm’s length and spread your fingers wide – covering the three stars with your palm. If you look just above your little finger, you will see an orange looking star. It’s name is Betelgeuse and it’s the brightest of all the stars in the constellation. Just below your thumb you’ll see another bright star. This blue/white giant is named Rigel and it’s the second brightest star. Now, take your hand away and look at the pattern. Do you see a connect-the-dots hourglass shape? Congratulations! If your skies are dark enough, you’ll see a patch of stars to the north that represents the head of the hunter. To the west you may see a curved line of stars that represents his bow or shield. But the most special place of all is just below those three stars…

The ancient Greeks gave us a lot of great stories – many of them very different from each other. One might say that Orion was a great hunter who was banished to the sky for bragging on how many animals he could kill and the two bright stars which follow him represent his hunting dogs. Another says Orion fell in love with a goddess and was killed by an arrow when the goddess’ brother was tricked into shooting him. Still another says he was killed by a sting from Scorpio, the Scorpion. No matter which tale you may care to listen to, the fact remains that cultures all over the world have recognized this constellation for centuries on end and all see Orion as a human figure. But why would they notice this constellation more than any other? Maybe it’s the magic that’s just below those three stars!

If you live where the skies are dark, you’ll see another line of stars just below the trio. In myth, this represents Orion’s “sword”, but it’s a magic one. Take a close look and you’ll see a ghostly glow just about in the center of the sword. If you don’t spot it with your eyes alone, try using a pair of binoculars. It will look like a glowing cloud for a very good reason. It’s a cloud where stars are being born! This glowing gas cloud is called the Great Orion Nebula and the light you see now left on its journey to your eyes around 500 A.D. That’s about the time that King Arthur was around! Inside are hundreds of stars being born and their energy lights up the gas, just like a neon tube. While you won’t see the pretty colors with your eyes the way the camera does, you can still enjoy the magic and share what you’ve learned with your friends. All you need to do is just find three stars in a row…

Image Credits: Orion Chart courtesy of University Corporation for Atmospheric Research (UCAR), Orion Sky Shot courtesy of Mouser Williams, Stellarium represenation of Orion and Orion Nebula courtesy of the Hubble Space Telescope.