Tuesday, August 30, 2016

The Ellensburg WA sky for the week of 9/3/16


Saturday: The Ellensburg Rodeo is a “Top-25” rodeo. What does it take to be a “Top-25” star? There are many ways to rank stars. The most obvious way for a casual observer to rank stars is by apparent brightness. The apparent brightness is the brightness of a star as seen from Earth, regardless of its distance from the Earth. Shaula (pronounced Show’-la) is the 25th brightest star in the nighttime sky as seen from Earth. It represents the stinger of Scorpius the scorpion. In fact, Shaula means stinger in Arabic. Shaula has a visual brightness rating of 1.62. Sirius, the brightest star has a visual brightness rating of -1.46. (Smaller numbers mean brighter objects.) The dimmest objects that can be seen with the naked eye have a visual brightness rating of about 6. There are approximately 6,000 stars with a lower numbered visual brightness rating than 6 meaning there are 6,000 stars visible to the naked eye. Shaula is a blue sub-giant star that radiates 35,000 times more energy than the Sun. It is 700 light years away making it one of the most distant bright stars. Shaula is a challenge to find because it never gets more than a half a fist above the horizon. Look for it tonight about a half a fist held upright and at arm’s length above the south horizon, a little bit west of due south, at 8:30.

Sunday: School starts this week so it is time for a little geometry review. A square is a regular quadrilateral, which means it has four equal sides, four equal angles, and it uses the restroom on a set schedule. Go outside at 10 p.m. tonight with notebook in hand to sketch one. The Great Square of Pegasus is balancing on its corner two and a half fists above due east. The top corner of the square is two fists above the bottom corner. The other two corners are to the left and right of the line segment connecting the top and bottom corners.

Monday: Labor Day was the brainchild of labor unions and is dedicated to American workers. The first Labor Day was celebrated in 1882. The Greek mythical hero Hercules probably wished there was a Labor Day to commemorate his work. As punishment for killing his family while he was temporarily insane, he had to perform twelve nearly impossible tasks such as killing monsters or stealing things from deities. Hmmm. Maybe we shouldn’t commemorate his labors. But we can enjoy his constellation. The keystone asterism representing the body of Hercules is six fists above the west horizon at 10 p.m. For more information about the Labors of Hercules, go to http://goo.gl/ozVF5.

Tuesday: Geometry review, part 2. Go outside at 10 p.m. tonight with notebook in hand. (Good teaching involves a little repetition.) You’ll have an easy time seeing your notebook because the moon is just a little past full. A triangle is a polygon with three corners and three line segments as sides. A good example is the Summer Triangle made up of the bright stars Vega, Deneb and Altair. Vega, the brightest star in the triangle, is a little bit southwest of straight overhead. Deneb is a little bit east of straight overhead and Altair is five fists above the south horizon.

Wednesday: Look for Venus and Jupiter very low in the western sky right after sunset. By 8 p.m., Venus is less than a half a fist above the west horizon.

Thursday: “I’m a little teapot, short and stout. The galactic center, I pour it out.” (I’m a Little Teapot, astronomy version, 2014.) Despite its great size and importance, the center of our Milky Way galaxy and its giant black hole remains hidden to the naked eye behind thick clouds of gas and dust. By plotting the orbits of stars near the middle of the galaxy, astronomers have determined that the black hole’s mass is equal to about 4.5 million Suns. While you can’t see the actual galactic center, you can gaze in the direction of the center by looking just to the right of the teapot asterism in the constellation Sagittarius. This point is about one fist above the south-southwest horizon at 9 p.m.

Friday: The most effective learning requires frequent review, especially when first introduced to a topic. So let’s review triangles. Mars, Saturn, and Antares form a small triangle one fist above the southwest horizon and just to the left of the Moon at 9 p.m. Mars, the brightest object is on the far left. Saturn is one fist to the right of Mars and Antares is less than a fist below Saturn.

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to http://nightsky.jpl.nasa.gov/planner.cfm.

Thursday, August 18, 2016

The Ellensburg WA sky for the week of 8/20/16


Saturday: Jupiter, Venus, and Mercury crowd very low, making a small triangle above due west a half hour after sunset. Jupiter is at the upper left of the triangle, a half a fist held upright and at arm’s length above due west. The bright Venus is less than a fist to the right of Jupiter. Mercury is lost in the glare below Jupiter.

Sunday: Arcturus is two fists above due west at 10:30 p.m. This star, whose name means bear watcher, is the brightest in the sky’s northern hemisphere. It follows Ursa Major, the Great Bear, around the North Star. Arcturus is the closest giant star to Earth. It is one of the few stars whose diameter can be measured directly rather than being inferred from its density and mass, which, themselves are derived from other parameters.

Monday: Had the script been written a little differently for a well-known Robin Williams movie, we might have heard Mr. Williams shout, “Goooood Morning Orion the hunter”. Orion is typically thought of as a winter constellation. But, it makes its first appearance in the summer sky. The lowest corner of Orion’s body, represented by the star Saiph (pronounced “safe”), rises at 3:30 a.m., well before the Sun. By 5:30 a.m., Orion’s belt is nearly three fists above the southeast horizon.

Tuesday: Have you ever gone to a family reunion, looked around and asked, “How in the world are we related to each other?” Astronomers look around the Solar System and wonder if there is life anywhere else that we are related to. The Mars Science Laboratory landed on Mars in 2012 to investigate whether it ever had conditions favorable for life. The Cassini Mission continues to study the plume of complex organic chemicals streaming from Saturn’s moon Enceladus. NASA and the European Space Agency are planning missions to study Europa, the Jovian moon with an ice-covered ocean. And many astronomers consider the methane haze in the atmosphere in Saturn’s moon Titan similar to that of the early Earth. To learn more about the search for life in the Solar System and beyond, go to https://astrobiology.nasa.gov/. While you won’t see anyone waving back, you can see Saturn, Mars, and the bright star Antares in a short line segment in the sky. Saturn is two fists above and Mars, which is about twice as bright as the ringed planet, is one and a half fists above the south-southwest horizon. Antares is right below Mars.

Wednesday: Deneb is nearly straight overhead at 11:30 p.m. When you look at Deneb, you are seeing light that left Deneb about 1,800 years ago.

Thursday: In 1987, the rock group Def Leppard sang “Pour some sugar on me, in the name of love. Pour some sugar on me, come on fire me up”. In 2012, some European astronomers “found some sugar near stars, they were very young. Found some sugar near stars, out where planets formed.” Astronomers observed molecules of glycolaldehyde, a simple form of sugar, in the disk of gas and dust orbiting young binary stars. This is the first time astronomers have found this simple sugar so close to a star indicating that organic molecules can be found in planet-forming regions of stars. For more information, go to http://goo.gl/tfwy1.

Friday: All stars rotate. Our Sun takes a little less than an Earth month to make one rotation. Astronomers have started to study the relationship between mass, stellar rotation, and planetary formation by aiming NASA’s Kepler space telescope toward the Pleiades open star cluster. All 1,000 stars in this group is nearly the same age, 125 million years old. Since all of the stars are the same age and formed from the same set of materials, astronomers have the ideal “laboratory” to isolate the role star mass plays on star rotation and evolution. Read more about the findings at http://goo.gl/osijIY. See the Pleiades for yourself, one fist above the east-northeast horizon at 11:30 p.m.

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to http://nightsky.jpl.nasa.gov/planner.cfm.

Wednesday, August 10, 2016

The Ellensburg WA sky for the week of 8/13/16

--> Saturday: Sometimes you find a quarter on the ground. Maybe you find a dollar in the lining of your jacket. But how often do you find a galaxy in a well-known part of the sky? The Hubble Space Telescope discovered a face-on spiral galaxy in the Coma Cluster of galaxies about 320 million light years away. This galaxy, called NGC 4911, contains regions of gas and dust as well as glowing newborn star clusters. The Coma Star cluster is in the constellation Coma Berenices, found two and a half fists held upright and at arm’s length above the west-northwest horizon at 10 p.m. For more information about this recently discovered galaxy, plus a zoomable image, go to http://goo.gl/5OXUX.

Sunday: Saturn, Mars, and Antares make an equilateral triangle about a fist and a half above the south-southwest horizon at 9 p.m. Mars, the brightest of the three objects, is on the right hand side and Saturn is on the top.

Monday: Let’s all sing the galactic black hole monster song: “D is for dusty, that’s good enough for me. D is for dusty that’s good enough for me. D is for dusty that’s good enough for me. Oh dusty, dusty, dusty starts with D.” Astronomers know that spiral galaxies such as our own have super massive black holes in the center, black holes that are billions of times the mass of the Sun. They thought they got to be this massive by mergers where two galaxies collide and the gas, dust and black holes at the center of each colliding galaxy form a larger central black hole. But many distant galaxies show no signs of galactic mergers. Astronomers think the black holes at the center of these galaxies grew simply by snacking on the gas and dust that comes from supernova explosions and normal star formation. Just like the Cookie Monster gains weight by snacking on individual cookies rather than eating a cookie factory. Cookie crumbs, I mean dust, block your view of the center of our galaxy.  It is about one fist above due south at 10 p.m., between the constellations Sagittarius and Scorpius. For more information, go to http://goo.gl/L9ppJf.

Tuesday: Hit the road Mercury. And don’t you come back no more, no more. For a few weeks, Mercury has been hitting the road and moving away from the Sun in the sky. Today, Mercury is as far away from the Sun as it will get on the evening half of this cycle. This is known as its greatest eastern elongation. Yet, this distance does not translate into good viewing because Mercury will be very low in the sky…. Wait a minute. Look back at the April 16, 2016 entry of this column. I wrote the exact same thing. Am I just lazy, taking advantage of the secret organizations paying me a million doll hairs to write this column? Yes, I am. But, the statement is true once again and will be true in a few months. As the closest planet to the Sun, Mercury moves back and forth from the morning to the evening sky several times a year. In addition, it never gets very far from the Sun in the sky so it is almost always difficult to view.
Tonight, Mercury is less than a half a fist above due west at 8:30 p.m., between the much brighter Jupiter to its left and Venus to its right. Over the next few weeks, Mercury will move toward the Sun in the sky. After it passes in front of the Sun, it will appear in the morning sky by the end of September.

Wednesday: Need a caffeine pick-me-up? Make it a double. Need an astronomy pick-me-up? Make it a double double. Find Vega, in the constellation Lyra the lyre, nearly straight overhead at 10:00 tonight. Less than half a fist to the east (or left if you are facing south) of the bright bluish star Vega is the “star” Epsilon Lyra. If you look at Epsilon Lyra through binoculars, it looks like two stars. If you look at Epsilon Lyra through a large enough telescope, you will notice that each star in the pair is itself a pair of stars.  Each star in the double is double. Hence, Epsilon Lyra is known as the double double. The stars in each pair orbit a point approximately in the center of each respective pair. The pairs themselves orbit a point between the two pairs.

Thursday: The August full moon was called the full sturgeon moon by Midwest and northeastern Native American tribes because the sturgeon in lakes in this part of the country were easiest to catch during this full moon time.

Friday: Hercules stands six fists above the southwest horizon at 10:00 this evening. Four moderately bright stars form a lopsided square that represents his body, while his head points southward.

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to http://nightsky.jpl.nasa.gov/planner.cfm.

Tuesday, August 2, 2016

The Ellensburg WA sky for the week of 8/6/16


Saturday: The Perseid meteor shower hits its peak late for the next few nights with Thursday and Friday being the peak of the peak. The meteors appear to come from a point just below the W of the constellation Cassiopeia. This point is about two and a half fists held upright and at arm’s length above the northeast horizon at 11 p.m. By dawn, this point is about seven fists above the northeast horizon. If you fall asleep or forget to set your alarm, you will be able to observe this shower from about 11 p.m. to dawn for the next few nights in about the same location in the sky. The Perseid shower is one of the longest lasting showers. With dark skies owing to the moon being below the horizon during peak viewing times, you may see over 100 meteors per hour in the late night and early morning hours all week. For tips about optimizing your viewing this year, go to http://goo.gl/Ylk9jA. As your Mother might say, dress warm and sit in a comfortable chair for maximum enjoyment. These meteors are sand to pea-sized bits of rock that fell off of Comet Swift-Tuttle. They are traveling about 40 miles per second as they collide with the Earth and burn up in the atmosphere.

Sunday: At 8:45 tonight, Jupiter, Mercury, and Venus make a two fist wide line, low on the horizon, angling down toward the west horizon. Venus, the brightest of the three, is on the bottom right of the line and Jupiter is on the upper left.

Monday: Sometimes you get to your car and realize that you are missing your keys or your sunglasses. The asteroid, dwarf planet, and fifth Beatle (not really) Ceres is missing craters. Astronomers thought there would be many large, old craters marking the surface of Ceres. Instead, close-up images from NASA’s Dawn mission shows that Ceres is covered with numerous small, young craters. Possible explanations include the relatively soft icy surface smoothing out over time or that eruptions from ice volcanoes, called cryovolcanoes, buried the older craters. Read more about this “whodunit” at http://goo.gl/uoU9kc. Ceres is visible in small telescopes or even 10x50 binoculars, three and a half fists above due southeast at 4 a.m. First find Menkar, the second brightest star in Cetus the sea monster. It is a reddish star a little east of due southeast and a little more than three fists above the horizon. Then move your binoculars to the upper right until a star about half as bright as Menkar is in the lower left portion of your field of view. Ceres will be a point of light in the upper right portion of your field of view, looking like part of an arc of stars.

Tuesday: Altair, at one corner of the Summer Triangle, is four fists above the southeast horizon at 11 p.m. Altair is one of the closest bright stars, so close that fictional astronauts visited a planet orbiting Altair in the 1956 movie “Forbidden Planet”.

Wednesday: Saturn, Mars, and Antares make an equilateral triangle about two fists above the south horizon at 9 p.m. Mars, the brightest of the three objects, is on the right hand side and Saturn is on the top.

Thursday: Many big city dwellers never see the milky white, nearly continuous band of stars known as the Milky Way. As cities grow and add more lights, it has become harder to see the bulk of the Milky Way galaxy, our home in the universe. But, there are two easy ways to see the Milky Way. The first way is to look in the mirror. You are part of the Milky Way. The second way is to look from due north through the point straight overhead (called the zenith) to due south from 10:30 p.m. to 1 a.m. for the next two weeks. This is the time of year when the Milky Way is highest in the sky and away from the city lights on the horizon.

Friday: Friday night is date night and there is no better date than going to the Wild Horse Renewable Energy Center to view the Perseid meteor shower. The event starts with kids activities at 8 p.m. and a twilight turbine tour at 8:30 p.m. The viewing starts at 10 p.m. The CWU Astronomy Club and other people will be there with telescopes. This will be a great opportunity to see meteors, distant celestial objects, and the Milky Way. For more information, go to https://goo.gl/tlPPSD.

The positional information in this column about stars and planets is typically accurate for the entire week. For up to date information about the night sky, go to http://nightsky.jpl.nasa.gov/planner.cfm.