We've had some exciting news from the Kepler space telescope - the Kepler science team had just announced the discovery of 715 new planetary systems around other stars! More details will be posted soon.
Friday, February 28, 2014
Thursday, February 20, 2014
The Stars of February
Returning this evening from a board meeting of the Gunnison Valley Observatory, I couldn't help but notice that it's the first truly clear night in quite a while. I was quickly reminded of how clear and dark winter nights in Gunnison can be - perfect for stargazing (if you don't mind the cold).
The current star (excuse the pun) of the night sky is the constellation of Orion, the hunter. At 9 PM Orion is seen very high in the sky when facing south. You can identify Orion by the three stars in a line that form Orion's belt. Above and slightly left of the belt is the bright star Betelgeuse ("beetlejuice") that represents Orion's right shoulder (the word betelgeuse is Greek for "armpit of the giant"). Below and slightly right of Orion's belt is the bright blue star Rigel, which represents Orion's knee. Look carefully from a dark location and you might find Orion's sword, hanging from his belt, his right arm raised above his head, and even the curved arc of stars forming the shield in his left hand. Orion is one of my favorite constellations because it's one of the few constellations that actually looks a bit like what it's supposed to represent.
Another reason I like Orion is that it's a very useful constellation for locating other stars and constellations in the sky. Following the line of Orion's belt down and to the left brings you to the brightest star in the northern hemisphere sky, Sirius. Follow the belt up and to the right and you'll encounter the sideways "v" of Taurus, the bull. Look for the red eye of the bull, the star Aldebaran. Continue in the same direction and you'll find the little cluster of stars called the Pleiades. Some people describe the Pleiades as a tiny dipper, but if you own a Subaru, you'll recognize this as the pattern that adorns the Subaru symbol - Subaru is the Japanese name for the Pleiades.
Not to willing to let Orion steal the show, turn around and face north and you'll find the iconic Big Dipper standing on its tail and dominating the northern sky. Jupiter also continues to be a prominent member of the night sky, outshining everything else from its position above Orion's head.
The current star (excuse the pun) of the night sky is the constellation of Orion, the hunter. At 9 PM Orion is seen very high in the sky when facing south. You can identify Orion by the three stars in a line that form Orion's belt. Above and slightly left of the belt is the bright star Betelgeuse ("beetlejuice") that represents Orion's right shoulder (the word betelgeuse is Greek for "armpit of the giant"). Below and slightly right of Orion's belt is the bright blue star Rigel, which represents Orion's knee. Look carefully from a dark location and you might find Orion's sword, hanging from his belt, his right arm raised above his head, and even the curved arc of stars forming the shield in his left hand. Orion is one of my favorite constellations because it's one of the few constellations that actually looks a bit like what it's supposed to represent.
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| Identifying Orion and using Orion's belt to find the star Sirius |
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| Star chart showing the constellations as they appear around 9PM in February. |
Not to willing to let Orion steal the show, turn around and face north and you'll find the iconic Big Dipper standing on its tail and dominating the northern sky. Jupiter also continues to be a prominent member of the night sky, outshining everything else from its position above Orion's head.
Friday, February 14, 2014
Happy Valentines Day!
Also known as "Singles Awareness Day" or "The day before all the chocolate goes on sale". Today also corresponds with a full moon so it's guaranteed to be an eventful day. Most astronomers agree that strange things happen within two weeks of a full moon...
The full moon occurs when the Moon and Sun are on opposite sides of the Earth, so the Moon rises as the Sun sets and the Moon sets when the Sun rises. This means that the Moon is up all night, and because the side facing Earth is fully illuminated by the Sun, it's also very bright - put those together and the full moon the most noticeable of moon phases. In contrast, the crescent moon phase occurs when the Moon is almost between the Earth and the Sun, so when the Moon is in the crescent phase, we only see a sliver of the illuminated side and the Moon is very near the Sun in the sky. This means that a crescent moon is both dim and primarily in the sky during the day, making it far less noticeable than the full moon.
The reason why the full moon is often attributed with strange behavior and occurrences probably has more to do with how bright the night is when there's a full moon than any other sort of "lunar influences". It's easy to stay out all night when there's a full moon to guide your way!
So enjoy the full moon Friday Valentine's day - tomorrow you can sleep in and then go buy discounted chocolate!
Please let me know if there are (astronomical) topics you'd like me to write about!
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| The phases of the Moon depend on the relative positions of the Earth, Moon and Sun. At different orientations we see different amounts of the illuminated side of the Moon |
So enjoy the full moon Friday Valentine's day - tomorrow you can sleep in and then go buy discounted chocolate!
Please let me know if there are (astronomical) topics you'd like me to write about!
Thursday, February 6, 2014
Speaking of the weather...
Seeing as how it's snowing again and looks like it's going to be too cloudy to observe for quite some time, I though this might be a good time to talk about weather - space weather, that is.
What is space weather? For the most part it's the Sun throwing stuff at us, and by stuff, I mean charged particles. The Sun is a giant ball of hydrogen and helium gas (to get a sense of the size, imagine shrinking the Earth down to the size of a peppercorn - on that scale the Sun is the size of a basketball) that has a surface temperature of nearly 10,000 degrees Fahrenheit. The gas is so hot that most of the atoms have lost their negatively charged electrons, leaving positively charged ions. At the surface of the Sun these ions are constantly flying off into space creating the solar wind. This isn't a wind like we experience on Earth, but rather a continual flow of these charged particles.
The Earth is surrounded by a magnetic field, and that field acts like a shield against the solar wind. The charged particles can't pass through the field, and are forced to flow around the field. But near the north and south magnetic poles there are "holes" in the magnetic field (see figure), and at these locations the particles leak inside the field where they become trapped in two belts surrounding Earth, call the Van Allen belts (the blue "ears" on either side of Earth in the figure). When two many particles are trapped in the belts, they start to overflow, and the particles stream into the atmosphere around the north and south poles.
The most common yellow-green color results from oxygen atoms being struck by medium energy particles, while red auroras are caused by high energy particles colliding with nitrogen.
What is space weather? For the most part it's the Sun throwing stuff at us, and by stuff, I mean charged particles. The Sun is a giant ball of hydrogen and helium gas (to get a sense of the size, imagine shrinking the Earth down to the size of a peppercorn - on that scale the Sun is the size of a basketball) that has a surface temperature of nearly 10,000 degrees Fahrenheit. The gas is so hot that most of the atoms have lost their negatively charged electrons, leaving positively charged ions. At the surface of the Sun these ions are constantly flying off into space creating the solar wind. This isn't a wind like we experience on Earth, but rather a continual flow of these charged particles.
The Earth is surrounded by a magnetic field, and that field acts like a shield against the solar wind. The charged particles can't pass through the field, and are forced to flow around the field. But near the north and south magnetic poles there are "holes" in the magnetic field (see figure), and at these locations the particles leak inside the field where they become trapped in two belts surrounding Earth, call the Van Allen belts (the blue "ears" on either side of Earth in the figure). When two many particles are trapped in the belts, they start to overflow, and the particles stream into the atmosphere around the north and south poles.
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| Solar wind flowing around Earth's magnetic field |
When this happens, we see the beautiful Aurora, or Northern and Southern lights. Charged particles colliding with gasses in the atmosphere cause those gasses to glow. The different colors of the aurora come from the different gasses in the atmosphere and the energy of the charged particles.
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| The Northern Lights (Image from theguardian.com) |
Like the weather we experience here on Earth, space weather sometimes experiences storms. The surface of the Sun is a very violent and chaotic place. Occasionally a bubble of gasses will "pop" off the surface of the sun and fly off into space (a bit like the bubbles in a pot of boiling liquid). This is called a solar flare, or if it's a really big bubble of gas, a coronal mass ejection. These things can be several times larger than Earth! When one of these bubbles of gas heads for Earth, we're in for a storm! We can expect to see very active auroras, sometimes extending down to lower latitudes. These storms put a lot of energy into the atmosphere and that energy can sometimes disrupt power transformers and shut down power in entire regions (this happened in Quebec in 1989). They're also a danger to satellites and astronauts. The good news is, it takes about three days for solar material to reach Earth and there are several satellites that continually watch the Sun and look for dangerous solar storms. When we see a storm coming, we can protect our satellites, power stations, and astronauts from damage. And then we can go outside and enjoy natures fabulous light show!
Saturday, February 1, 2014
What is that really bright star?
I'm going to go ahead and begin this first post with a shameless plug. Maybe you stumbled upon this blog because you are contemplating a vacation in Colorado this summer and happen to be interested in astronomy. (Or maybe you already live in Colorado and just like stargazing - that works too.) Look no further! The Gunnison Valley is not only Colorado at it's finest with all the best scenery, outdoor adventures, fishing, and more, we also happen to have some of the most incredible night skies in the country and our own public observatory with which to explore them! The Gunnison Valley Observatory is open to the public every Friday and Saturday night from mid-June to mid-September, and also hosts private parties from April through October. Ok, end of advertisement.
When people learn that I am an astronomer, it always leads to interesting conversations. I usually try to avoid the conversations that start with "do you believe in UFO's?" or "I have this theory...". But my I always get excited when the conversation turns to explaining what's up in the night sky, because, the fact is, I love teaching people about astronomy (probably a good thing as I do it for a living). Recently, as part of my college astronomy class, I met a group of students out on a dark corner of campus on a particularly chilly evening to point out constellations. One of my students pointed to an especially bright star in the east and asked,
"What is that?"
I responded that it was the planet Jupiter.
"No really, what is it?"
"Really, it's Jupiter."
"NO WAY, THAT IS SO COOL!"
Yes. Yes it is.
Currently Jupiter is the brightest star-like object up at night - you'll find it high in the east in the evening sky - it's pretty hard to miss. When the planets Venus, Jupiter or Saturn are in the sky at night, they each appear like very bright stars - Venus is the brightest of the three, followed by Jupiter and then Saturn. Mars and Mercury are also visible to the unaided eye, but are much less obvious - Mars looks like an average red star, while Mercury appears as an average white star very low on the horizon in either the evening or morning.
Other than Jupiter, Mercury is currently the only other planet visible in the evening, and it's a hard one to catch. This week, look for Mercury low in the evening twilight below the crescent moon. Mars rises around 11 PM below the bright blue star Spica and Saturn is high in the southern sky before dawn.
As I write this, we're enjoying the tail end of a pretty fantastic snowstorm in the Gunnison Valley, but it looks like some stargazing opportunities might present themselves this weekend or later next week.
When people learn that I am an astronomer, it always leads to interesting conversations. I usually try to avoid the conversations that start with "do you believe in UFO's?" or "I have this theory...". But my I always get excited when the conversation turns to explaining what's up in the night sky, because, the fact is, I love teaching people about astronomy (probably a good thing as I do it for a living). Recently, as part of my college astronomy class, I met a group of students out on a dark corner of campus on a particularly chilly evening to point out constellations. One of my students pointed to an especially bright star in the east and asked,
"What is that?"
I responded that it was the planet Jupiter.
"No really, what is it?"
"Really, it's Jupiter."
"NO WAY, THAT IS SO COOL!"
Yes. Yes it is.
Currently Jupiter is the brightest star-like object up at night - you'll find it high in the east in the evening sky - it's pretty hard to miss. When the planets Venus, Jupiter or Saturn are in the sky at night, they each appear like very bright stars - Venus is the brightest of the three, followed by Jupiter and then Saturn. Mars and Mercury are also visible to the unaided eye, but are much less obvious - Mars looks like an average red star, while Mercury appears as an average white star very low on the horizon in either the evening or morning.
Other than Jupiter, Mercury is currently the only other planet visible in the evening, and it's a hard one to catch. This week, look for Mercury low in the evening twilight below the crescent moon. Mars rises around 11 PM below the bright blue star Spica and Saturn is high in the southern sky before dawn.
As I write this, we're enjoying the tail end of a pretty fantastic snowstorm in the Gunnison Valley, but it looks like some stargazing opportunities might present themselves this weekend or later next week.
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