Monday, August 19, 2013
Saturday: Geometry review: part 3. School starts this week so it is time to continue our little geometry review from last week. Did you forget last week’s lesson? Well, go to the litter box, dig out last Saturday’s paper and review it. Then go outside at 9 p.m. with notebook in hand. Ready? A square is a quadrilateral with four sides of equal length and four right angle corners. A good example in the sky is the Great Square, an asterism (group of stars) consisting of three stars from the constellation Pegasus and one star from the constellation Andromeda. At 9 p.m., the bottom of the Great Square is two fists held upright and at arm’s length above due east.
Sunday: There is a lot to see at the Kittitas County Fair. But there is not a lot to see in the sky when you are at the fair because the fair lights, which are fairly bright, obscure most celestial objects. The bluish star Vega is one of the few objects bright enough to be seen. As you are finishing your rides at 10 p.m., look for Vega nearly straight overhead.
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. Humm. 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: Friday: “I’m a little teapot, short and stout. The galactic center, I pour it out.” (I’m a Little Teapot, astronomy version, 2013.) 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.
Wednesday: The calendar says summer is nearing an end. School starting today says summer is nearing an end. The summer triangle in the sky begs to differ, as it is still high in the sky. Vega, the brightest star in the triangle, is a little bit west of straight overhead at sunset. Deneb is a little bit east of straight overhead and Altair is five fists above the south horizon.
Thursday: Start thinking about saying good-bye to the evening planets. At 8 p.m., Venus is about a fist above the west-southwest horizon and Saturn is one and a half fists above the southwest horizon.
Friday: Start saying “Good Morning” to Mars and Jupiter. (Or “God Morgen” if you thing the planets speak Norwegian.) They have been out for a while but now they are high in the sky at 6 a.m. Jupiter is four and a half fists above the east-southeast horizon and Mars is three fists above the east horizon.
The positional information in this column about stars and planets is typically accurate for the entire week. This column is also available online at http://theellensburgsky.blogspot.com/.
Saturday: School starts next week so it is time for a little geometry review. A square is a four-sided figure with four equal sides and four right angles. 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 fists held upright and at arm’s length 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.
Sunday: Geometry review, part 2. Go outside at 10 p.m. tonight with notebook in hand. (Good teaching involves a little repetition.) 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 west of straight overhead. Deneb is a little bit east of straight overhead and Altair is five fists held upright and at arm’s length above the south horizon.
Monday: You think the Ellensburg wind is bad. Some of the Jovian planets have winds of over 1000 miles per hour. Jupiter and Saturn have belts of rapidly moving clouds that can be observed with back yard telescopes. To learn more about windy worlds, go to http://goo.gl/GLWAi.
Tuesday: The moon is midway between the Hyades star cluster and the Pleiades star cluster throughout the night. At midnight, they are just above the east-northeast horizon. By 5 a.m., they are high above due southeast.
Wednesday: 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 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 above the south horizon, a little bit west of due south, at 8:30.
Thursday: Venus is one fist above the west-southwest horizon and Saturn is one and a half fists above the southwest horizon at 9 p.m. Enjoy them while they last in the evening sky because they are getting closer to the Sun’s glare.
Friday: Deneb is about seven fists above the east horizon at 10 p.m. When you look at Deneb, you are seeing light that left Deneb about 1,800 years ago.
Wednesday, August 14, 2013
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 horizon at 9 p.m. For more information about this newly discovered galaxy, plus a zoomable image, go to http://goo.gl/5OXUX.
Sunday: You may have gone to the link about the galaxy and said, “That was discovered 3 years ago. What’s actually NEW in the sky?” Is less than a week ago new enough for you? A Japanese astronomer noticed a star on his August 14 image that was not on his August 13 image in the constellation Delphinus that was not there the day before. Of course, this star was there the day before. It just was not bright enough. For more information about this “new star” or nova, go to http://goo.gl/WSFB69. The nova can be easily seen using binoculars. At 10 p.m., find the constellation Delphinus five fists above due southeast. It is shaped like a dolphin. The nova is three fingers, or a typical binocular field of view, above the dolphin. It won’t stand out in binoculars but rest assured that one of those stars in the field of view is not on any star chart.
Monday: 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 11:00 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.
Tuesday: Tonight’s full moon is in the constellation Aquarius the water bearer.
Wednesday: Venus is about a half a fist above the west horizon and Saturn is about one and a half fists above the southwest horizon at 8:30 p.m.
Thursday: Mars is two fists and Jupiter is three and a half fists above the east horizon at 5:30 a.m.
Friday: 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 last summer 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 a trip 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 http://goo.gl/ewtfr.
The positional information in this column about stars and planets is typically accurate for the entire week.
Thursday, August 8, 2013
Saturday: The Perseid meteor shower hits its peak late for the next few nights. 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 three nights in about the same location in the sky. The Perseid shower is one of the longest lasting showers. With dark skies, you can see up to 100 meteors per hour in the late night and early morning hours all week. This is a good year for viewing because the moon will have set before the late night and early morning hours. 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. For more tips about meteor watching, go to http://goo.gl/6glPq.
Sunday: 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.
Monday: Saturn is a half a fist above the moon at 9 p.m. Venus is a half a fist above the west horizon at this time.
Tuesday: Arcturus is two and a half fists above due west at 11 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 and is one of the few stars whose diameter can be measured directly.
Wednesday: The Gemini twins are crowded for the next couple of weeks. The planets Jupiter and Mars are in line with the constellation. Jupiter will be spending the next few weeks between the brothers. (Isn’t that cozy.) Mars is just below the constellation and moving farther away by the day. At 5 a.m., Mars is one and a half fists above the east-northeast horizon and the very bright Jupiter is nearly two and a half fists above the east horizon. The “twin” stars of Pollux and Castor are about a fist to the left of the planets.
Thursday: Antares is a fist to the lower right of the moon at 10 p.m.
Friday: It’s time for a new moon haiku.
Hubble image shows
Neptune has a small new moon.
Now there are fourteen.
For more information about this discovery, go to http://goo.gl/HlmLwj.
The positional information in this column about stars and planets is typically accurate for the entire week.