Friday, May 28, 2010

The Ellensburg sky for the week of 5/29/10

Saturday: Jupiter is two fists held upright and at arm’s length above the east-southeast horizon at 4:30 a.m. It will be easy to find since it is the brightest object in that portion of the sky. Uranus typically is not so easy to find. But for the next few mornings, Uranus will be about a pinky width to the left of Jupiter and be easy to spot with binoculars. It will look like a pale blue star compared to Jupiter.

Sunday: There are so many bright planets visible in the early evening sky, they deserve a tribute song. Since the movie “Grease” is being re-released this summer, how about this song sung to the tune of “Sandra Dee”: “Look at me, I’m evening sky. Lousy with planets moving by. Won’t go to bed ‘til my planet needs are fed. I can’t, I’m evening sky.” Those planet needs can be fed at 10 p.m. when Venus is one fist above the west-northwest horizon, Mars is three and a half fists above the west-southwest horizon and Saturn is four fists above the southwest horizon.

Monday: “Hey baby! What’s your sign?”
“Ophiuchus, of course”
The Sun is in the same part of the sky as the stars of Ophiuchus from about November 29 to December 17. This is what astrologers mean when they say the Sun is “in” a constellation. Thus, if you were born between these dates, you should be an Ophiuchus. The fact that the horoscopes never list Ophiuchus is a major flaw of astrology. Astrology says that some of our characteristics are based on the location of the Sun at our birth. How can astrologers leave out three weeks from their system? That is like a scientist saying she can explain the results of her experiment every month of the year except early December. Ophiuchus was a mythical healer who was a forerunner to Hippocrates. According to myth, he could raise people from the dead. Maybe that is why he is ignored by astrology. Raising people from the dead is much less impressive than giving highly personal advice such as “Today is a good day to be careful in love.”
Rasalhague (pronounced Ras’-al-hay’-gwee), the brightest star in Ophiuchus, is four fists above the east-southeast horizon at 11 p.m. Its name comes from the Arabic words for “head of the serpent charmer” or Ras Alhauge. The rest of Ophiuchus spreads out down and to the right of Rasalhague.

Tuesday: The month of June is named after Juno, the queen of the Roman gods and the mythological protector of the Roman state. In ancient Rome, the month began when the crescent moon was first seen in the evening sky from Capitoline Hill in Rome. If we still started months this way, June wouldn’t begin until about two weeks from now.

Wednesday: Although Venus is brighter, Arcturus is probably the first star you’ll see tonight. It is nearly six fists above the southeast horizon at 9:15 p.m.

Thursday: Nearly 400 years ago, Galileo viewed the Pleiades star cluster through his telescope and saw that the seven or so stars in the region visible to the naked eye became a couple dozen. Now we know there are about 100 stars in this open star cluster. There are two main types of star clusters. Open star clusters are groups of a few dozen to a few thousand stars that formed from the same cloud of gas and dust within our galaxy. Stars in open star clusters are young as far as stars go. The stars in the Pleiades are about 100 million years old, much younger than our five billion year old Sun. Globular clusters are groups of up to a few million stars that orbit the core of spiral galaxies such as our own Milky Way. June’s “Hot Topic” for astronomy is star clusters. Go to http://astronomy2009.nasa.gov/topics_jun.htm for more information.

Friday: One of the most well known star clusters is the globular cluster in Hercules, an object that is fairly easy to find with binoculars. First find Vega, the bright bluish star five fists above the east horizon at 11 p.m. Two fists above Vega is a keystone shape. Aim your binoculars at the upper left hand star of the keystone. The globular cluster is one third of the way to the rightmost star of the keystone. It looks like a fuzzy patch on the obtuse angle of a small obtuse triangle. If you don’t know what an obtuse angle is, you should not have told your teacher, “I’ll never need to know this stuff”. Go to http://astronomy2009.nasa.gov/observe_jun.htm for more information about the Hercules globular cluster.

The positional information in this column about stars and planets is typically accurate for the entire week.

Tuesday, May 18, 2010

The Ellensburg sky for the week of 5/22/10

Saturday: Saturn is one fist held upright and at arm’s length above the Moon at 10 p.m.

Sunday: Ophiuchus (pronounced O-fee-u’-kus) the serpent holder rises just before sunset this evening. By 11, p.m., the leading star, Yed Prior or “the preceding star of the hand” is three fists held upright and at arm’s length above the southeast horizon.

Monday: Spica, the brightest star in the constellation Virgo, is about one fist above the Moon at 10 p.m.

Tuesday: The constellation Aquila the eagle is starting its migration across the summer evening sky this month. Aquila, marked by its bright star Altair, rises above the east horizon at about 11 p.m. Not all animal migrations are fully understood by scientists. We might be inclined to attribute bird migrations to instinct. This answer certainly did not satisfy the theologian C. S. Lewis. In his short work “Men Without Chests”, he wrote “to say that migratory birds find their way by instinct is only to say that we do not know how migratory birds find their way”. In science (and theology), Lewis is telling us to look for real causes and not simply labels such as instinct. The cause for Aquila’s migration is the Earth orbiting the Sun. As the Earth moves around the Sun, certain constellations move into the evening sky as others get lost in the glare of the setting Sun.

Wednesday: Mercury is at greatest western elongation this morning. This means Mercury is farthest from the Sun in the morning sky for this orbit. Typically, that means it is a good time to view Mercury. But, Mercury still remains low in the morning sky for this western elongation. It is less than a half a fist above the east-northeast horizon at 5 a.m.

Thursday: Tonight’s full moon is in the constellation Scorpius the scorpion. Since this is the time for “May flowers”, the May full moon is called the Full Flower Moon. At 11 p.m., the bright star Antares is about a finger width to the right of the Moon.

Friday: Cygnus the swan flies tonight. Deneb, the brightest star in the constellation, whose name means “tail” in Arabic, is two fists above the northeast horizon at 10 p.m. Cygnus’ wings make a vertical line one half a fist to the right of Deneb. Its head, marked by the star Albireo, is two fists to the right of Deneb. While Deneb is at the tail of Cygnus, it is at the head of the line of bright stars. It is 160,000 times more luminous than the Sun making it one of the brightest stars in the galaxy. It does not dominate our night sky because it is 2,600 light years away, one of the farthest naked eye stars. If Deneb were 25 light years away, it would shine as bright as a crescent moon. Compare that to Vega, which is 25 light years away. Vega is three and a half fists above the east-northeast horizon at this time.

The positional information in this column about stars and planets is typically accurate for the entire week.

Thursday, May 13, 2010

The Ellensburg sky for the week of 5/15/10

Saturday: Venus is a half a fist held upright and at arm’s length to the upper left of the Moon at 9 p.m. While the planet was named for the Roman goddess of love and beauty, it is not a loving place. The surface of the planet is 460 degrees Celsius (860 degrees Fahrenheit), hot enough to melt lead. The barometric pressure on the surface is over 90 times greater than on Earth’s surface. Most missions to Venus have failed either before sending back data or after only a few minutes of sending back data. Not a very neighborly attitude from our nearest planetary neighbor. The next planned Venus explorer is the Japanese mission called Akatsuki, still in development. For an effective introduction to Venus and many other significant solar system objects including the eight planets, Pluto and the Sun, go to http://sse.jpl.nasa.gov/planets/.

Sunday: Spica, the brightest star in the constellation Virgo, is known as the Horn Mansion one of 28 mansions, or constellations, in the Chinese sky. Spica is about three fists above the south horizon at 11 p.m.

Monday: Late spring and early summer is a good time to look for star clusters. Last week, you learned about M3, the third object cataloged by French astronomer Charles Messier over 200 years ago. One of the best clusters is the globular cluster in the constellation Hercules, also called M13. (Hummm. Guess what number that object is in Messier’s catalog.) Globular clusters are compact groupings of a few hundred thousand stars in a spherical shape 100 light years across. (For comparison, a 100 light year diameter sphere near out Sun would contain a few hundred stars.) The globular cluster in Hercules is six fists above due east at 11 p.m. First find Vega, the bright bluish star about four fists above the east-northeast horizon. Two fists to the upper right of Vega is a keystone shape. Aim your binoculars at the two stars that form the uppermost point of the keystone. The globular cluster is one third of the way south of the uppermost star on the way to the rightmost star of the keystone. It looks like a fuzzy patch on the obtuse angle of a small obtuse triangle. If you don’t know what an obtuse angle is, you should not have told your teacher, “I’ll never need to know this stuff”.

Tuesday: When it is sitting low in the western sky, many people mistake the star Capella for a planet. It is bright. It has a slight yellow color. But, Capella is compelling on its own. It is the fourth brightest star we can see in Ellensburg. It is the most northerly bright star. It is a binary star consisting of two yellow giant stars that orbit each other every 100 days. At 10 p.m., Capella is two fists above the northwest horizon. If you miss it tonight, don’t worry. Capella is the brightest circumpolar star meaning it is the brightest star that never goes below the horizon from our point of view in Ellensburg.

Wednesday: Mars, looking like a bright orange star, is about a half a fist above the Moon at 10 p.m. They are four fists above the west-southwest horizon.

Thursday: The first quarter Moon is in the constellation Leo the lion, about a half a fist below the bright star Regulus.

Friday: Jupiter is two fists above the east-southeast horizon at 5 a.m.

The positional information in this column about stars and planets is typically accurate for the entire week.

Wednesday, May 5, 2010

The Ellensburg sky for the week of 5/9/10

Saturday: Say good bye to the nice doggy. “Good bye doggy. We’ll see you in a few weeks in the morning.” Sirius, the Dog Star, is less than a half a fist held upright and at arm’s length above the southeast horizon at 9 p.m. As the Earth revolves around the Sun, different groups of stars are in line behind the Sun. Soon Sirius and the rest of the constellation Canis Major will be lost in the glare of the Sun. As the Earth continues its revolution, those constellations behind the Sun move into the early morning sky.

Sunday: Jupiter is a half a fist to the lower right of the moon. They are about a fist above the east horizon at 5 a.m. That’s right. You have to get up early to see the morning sky objects in the mid to late spring and summer.

Monday: Give me an “M”. Give me a “3”. What does that spell? “M3.” “Big deal,” you say. It was a big deal to French comet hunter Charles Messier (pronounced messy a). M3 was the 3rd comet look-alike that Messier catalogued in the late 1700s. M3 is a globular cluster, a cluster of over 100,000 stars that is 32,000 light years away. It is too dim to be seen with the naked eye but is fairly easy find with binoculars. First find Arcturus five and a half fists above the southeast horizon at 10 p.m. (See Wednesday’s entry to learn how to find Arcturus.) Move your binoculars up a little so two stars of nearly identical brightness are in your field of view. When the top star is in the lower left part of your field of view, there should be a fuzzy patch near the center of your field of view. This is M3.

Tuesday: Mars is four and a half fists above the west-southwest horizon at 10 p.m.

Wednesday: This is a good time of the year to find the Big Dipper. It is nearly straight overhead at 10 p.m. The cup is to the west and the handle is to the east. You can always use the Big Dipper to find some other bright stars. First, follow the curve, or arc, of the Big Dipper down three fists into the southern sky. This is the bright star, Arcturus, the second brightest nighttime star we can see in Ellensburg. Next, continue on a straight line, or spike, another three fists down toward the south horizon to the star Spica. Spica is the tenth brightest nighttime star we can see in Ellensburg. You now know how to use the Big Dipper handle to “arc” to Arcturus and “spike” to Spica.

Thursday: Tonight’s Moon is new. Don’t bother looking for it. The new moon is the phase where the Moon is directly between the Earth and the Sun. Hence the side of the Moon facing Earth is not receiving any sunlight and cannot be seen. The term “new” comes from the moon seeming to be reborn with light every lunar cycle.

Friday: Saturn is four and a half fists above the south horizon at 10 p.m.

The positional information in this column about stars and planets is typically accurate for the entire week.