What's up in the sky 7/2/11
Today: Monday night, while you are looking at an explosion of fireworks, the NASA spacecraft Kepler may be looking at an “explosion” of exoplanets. So far, Kepler has found 16 planets whose presence has been confirmed by other means and evidence of 1,235 planet candidates. Something is called a planet candidate when the light from a star being observed by Kepler dims in a systematic way. Astronomers still need to compare the pattern of dimming with the potential pattern of star wobble caused by being tugged on by one or more planets before they can say for certain that they have actually found planets orbiting these stars. But if even half of these stars show the characteristic wobble, it will more than double the number of planets known to orbit other stars, also known as exoplanets. And this is only the beginning. The Kepler spacecraft is monitoring the brightness of over 156,000 stars in the constellations Cygnus the swan and Lyra the lyre. This region is midway between the bright stars Deneb and Vega. It is about the size of your hand held at arm’s length and is about six fists held upright and at arm’s length above due east at 11 p.m.
Sunday: Hot enough for you? Don’t blame the Earth-Sun distance. Surprisingly, the overall temperature of the Earth is slightly higher in July, when the Earth is farthest from the Sun, than in January, when it is closest. That’s because in July, the Northern Hemisphere is tilted towards the Sun. (This is the real cause of the seasons.) The Northern Hemisphere has more land than the Southern Hemisphere. Thus, in July, the large amount of Northern Hemisphere land heats up the entire Earth about two degrees Celsius warmer than in January. In January, the watery Southern Hemisphere is tilted toward the Sun. But, water does not heat up as fast as land so the Earth is a few degrees cooler. The Earth-Sun distance is 152.1 million kilometers tomorrow. This is called aphelion from the Greek prefix “apo” meaning “apart” and Helios, the Greek god of the Sun.
Monday: The little king gets mooned! Regulus, Latin for “little king”, is less than a fist from the upper right-hand portion of the Moon at 9:30 p.m.
Tuesday: When people find out that you read this column, they may ask you all sorts of tough astronomy questions such as “Where can I see the Milky Way?” That one is easy. Just look in the mirror. We are all part of the Milky Way. The center of the Milky Way galaxy is in the direction of the constellation Sagittarius, about one and a half fists above due south at 11:30 p.m.
Wednesday: The elusive Mercury is a half a fist above the west-northwest horizon at 9:45 p.m. It will be hard to see in the glow of the setting sun. But I know you can find it. I have much more faith in you than in that person standing next to you reading the celebrity magazine. “Best Beach body!” Puh-lease.
Thursday: In 1982, the Australian rock group Men at Work sang “Isolation, rows and rows of cars. Isolation, like Jupiter and Mars” in their song “Catch a Star”. Mars is certainly not isolated this week. It is about a half a fist to the upper left of the open star cluster called the Hyades cluster. They are one and a half fists above the east-northeast horizon at 4:30 a.m. Jupiter, on the other hand, is in a portion of the sky with no other bright stars. It is three fists above the east-southeast horizon at this time.
Friday: Saturn is two and a half fists above the southwest horizon at 10 p.m.
The positional information in this column about stars and planets is typically accurate for the entire week.
Thursday, June 30, 2011
Thursday, June 23, 2011
The Ellensburg sky for the week of 6/25/11
Saturday: Don’t wait until the 4th of July to go to those wimpy firecracker shows. Find the hypergiant star Rho Cassiopeiae. Astronomers think that Rho Cassiopeiae will likely go supernova (explode) in the near future. Of course, for stars, near future might mean today. It might mean 20,000 years from now. Rho Cassiopeiae is in the constellation Cassiopeia the queen. At 11:00 tonight, Cassiopeia looks like the letter “W” about three fists held upright and at arm’s length above the northeast horizon. Rho Cassiopeiae is about a finger’s width to the right of the rightmost star in the “W”. Once you find it you’ll be thinking, “Big deal, I can hardly see it.” Although it is barely visible to the naked eye, it is actually very bright. It is the 20th most luminous star in the sky, a whopping 550,000 times more luminous than the Sun.
Sunday: Jupiter is about a half a fist to the lower right of the Moon at 4:30 a.m. They are low in the eastern sky just ahead of the soon to be rising Sun.
Monday: What you can’t see can’t hurt you… if it does not hit the Earth. An asteroid estimated to be 25-55 feet across will come within 8,000 miles of hitting the Earth this morning at 6:30 a.m. Pacific Daylight Time. This asteroid is too dim to be seen by the naked eye anywhere in the world but will be visible to people with moderate sized telescopes in the far Southern Hemisphere. If an asteroid this size exploded close to the ground due to heating by the atmosphere, it would cause significant damage. Go to http://goo.gl/X19Zd for more information.
Tuesday: Mars is less than a half a fist to the lower left of the Moon at 4:30 a.m. You’ll have to look carefully to see Mars in the dawn sky.
Wednesday: The green ring forged for the Green Lantern by the Guardians of the Universe couldn’t save the movie from bad reviews. But the green rings found by NASA’s Spitzer Space Telescope are helping astronomers learn more about “O” type stars, the most massive stars known. Go to http://goo.gl/kBY6I for an example of a highly rated green ring.
Thursday: The constellation Cepheus the king (husband of Cassiopeia the queen) is about four fists above the northeast horizon at 11 pm. Cepheus is about one and a half fists above Cassiopeia. Cepheus looks like a house on its side with the roof peak pointing towards the west. Cassiopeia and Cepheus revolve around the North Star every night like a happy couple going through life together.
Friday: At the beginning of the June, I wrote about Mizar. Now that it is the beginning of July, I need to warn you not to confuse Mizar with its rhyming brother Izar in the constellation Bootes. Izar is also a binary star with about the same apparent brightness. And both were featured in different episodes of Star Trek. Izar was featured in the Star Trek episode “Whom Gods Destroy” from the original series. It is the base of Fleet Captain Garth, a former big shot in the federation and one of Kirk’s heroes before he went insane. Garth kidnaps Kirk and Spock before eventually being out smarted. Mizar doesn’t play as big a role in its episode. It is the star of the home world of one of the alien species in The Next Generation episode “Allegiance”. Izar is one fist above the bright star Arcturus and seven fists above the south horizon at 10 p.m. Mizar is seven fists above the northwest horizon at this time.
The positional information in this column about stars and planets is typically accurate for the entire week.
Sunday: Jupiter is about a half a fist to the lower right of the Moon at 4:30 a.m. They are low in the eastern sky just ahead of the soon to be rising Sun.
Monday: What you can’t see can’t hurt you… if it does not hit the Earth. An asteroid estimated to be 25-55 feet across will come within 8,000 miles of hitting the Earth this morning at 6:30 a.m. Pacific Daylight Time. This asteroid is too dim to be seen by the naked eye anywhere in the world but will be visible to people with moderate sized telescopes in the far Southern Hemisphere. If an asteroid this size exploded close to the ground due to heating by the atmosphere, it would cause significant damage. Go to http://goo.gl/X19Zd for more information.
Tuesday: Mars is less than a half a fist to the lower left of the Moon at 4:30 a.m. You’ll have to look carefully to see Mars in the dawn sky.
Wednesday: The green ring forged for the Green Lantern by the Guardians of the Universe couldn’t save the movie from bad reviews. But the green rings found by NASA’s Spitzer Space Telescope are helping astronomers learn more about “O” type stars, the most massive stars known. Go to http://goo.gl/kBY6I for an example of a highly rated green ring.
Thursday: The constellation Cepheus the king (husband of Cassiopeia the queen) is about four fists above the northeast horizon at 11 pm. Cepheus is about one and a half fists above Cassiopeia. Cepheus looks like a house on its side with the roof peak pointing towards the west. Cassiopeia and Cepheus revolve around the North Star every night like a happy couple going through life together.
Friday: At the beginning of the June, I wrote about Mizar. Now that it is the beginning of July, I need to warn you not to confuse Mizar with its rhyming brother Izar in the constellation Bootes. Izar is also a binary star with about the same apparent brightness. And both were featured in different episodes of Star Trek. Izar was featured in the Star Trek episode “Whom Gods Destroy” from the original series. It is the base of Fleet Captain Garth, a former big shot in the federation and one of Kirk’s heroes before he went insane. Garth kidnaps Kirk and Spock before eventually being out smarted. Mizar doesn’t play as big a role in its episode. It is the star of the home world of one of the alien species in The Next Generation episode “Allegiance”. Izar is one fist above the bright star Arcturus and seven fists above the south horizon at 10 p.m. Mizar is seven fists above the northwest horizon at this time.
The positional information in this column about stars and planets is typically accurate for the entire week.
Friday, June 17, 2011
The Ellensburg sky for the week of 6/18/11
Saturday: “Mom, I can’t sleep. It is too light out!” A poor excuse you say? Good astronomy skills, I say. The latest sunset of the year happens over the next two weeks. Surprisingly, the earliest sunrise and the latest sunset do not both happen on the longest day of the year, the day of the summer solstice. The earliest sunrise occurs just before the longest day and the latest sunset occurs just after the longest day. (The earliest sunrise happened last week.) This phenomenon relates to the angle of the Sun’s path near rising and setting. In Ellensburg, that angle is about 66 degrees near the first day of summer. Because of the Earth’s orbit, which causes the Sun’s apparent motion, the angles are not symmetric. The asymmetry in orbital angles leads to the asymmetry in rise and set times. By the way, the “can’t sleep because it is too light out” line may just be an excuse because the sunset times change by only a few seconds each day this time of year. The sun sets between 9:01 and 9:02 p.m. between June 21 and July 3 2011.
Sunday: Summer is nearly here. How do I know? Because my kids are home from school. Also, because the Summer Triangle is fairly high in the eastern sky at 10 p.m. Vega, the third brightest star visible from Ellensburg, is about five fists held upright and at arm’s length above the east horizon. Deneb, at the tail of Cygnus the swan is about three and a half fists above the northeast horizon. The third star in the triangle, Altair, in Aquila the eagle is two fists above the east horizon.
If you want to put somebody off, tell her or him to wait until Deneb sets. At Ellensburg’s latitude of 47 degrees, Deneb is a circumpolar star meaning it never goes below the horizon.
Monday: Saturn is three fists above the southwest horizon at 10 p.m.
Tuesday: Today is the first day of summer, the day that the Sun reaches its highest declination (the official name for sky latitude) of 23.5 degrees above the celestial equator. The celestial equator is the line that divides the northern sky from the southern sky. In Ellensburg, the Sun is about seven fists held upright and at arm’s length above the south horizon at 1:00 p.m. (noon standard time). Contrary to popular belief, the Sun is never straight overhead in Ellensburg or anywhere else in the 48 contiguous states. The northernmost portion of the world where the Sun can be directly overhead is 23.5 degrees north latitude. In ancient times, the Sun was in the constellation Cancer the crab on the first day of summer. Hence, 23.5 degrees north latitude has the nickname "Tropic of Cancer". Because the Earth wobbles like a spinning top, the Sun's apparent path through the sky changes slightly over time. Now, the Sun is in the constellation Taurus the bull on the first day of summer. However, citing the high cost of revising all of the science books, geographers are not changing the name of 23.5 degrees north latitude to "Tropic of Taurus". The first day of summer is often called the summer solstice. However, astronomers refer to the summer solstice as the point in the sky in which the Sun is at its highest point above the celestial equator. Thus, summer starts when the Sun is at the summer solstice point. This year, that happens at 10:17 a.m.
Wednesday: Jupiter is two fists above the east horizon and Mars is one fist above the east-northeast horizon at 4:30 a.m.
Thursday: This morning’s last quarter Moon is in the constellation Pisces the fish.
Friday: The early summer days are long so take some time to safely observe the Sun. The best way to do that is to go to http://sdo.gsfc.nasa.gov/ and watch the great images and videos that come from the Solar Dynamics Observer, or SDO for short. We are approaching a sunspot maximum scheduled to peak 2013. So what, you say? Sunspots and associated phenomena greatly influence the strength of solar flares. The strongest flares can affect satellites orbiting the Earth and even electronics on the Earth’s surface.
The positional information in this column about stars and planets is typically accurate for the entire week.
Sunday: Summer is nearly here. How do I know? Because my kids are home from school. Also, because the Summer Triangle is fairly high in the eastern sky at 10 p.m. Vega, the third brightest star visible from Ellensburg, is about five fists held upright and at arm’s length above the east horizon. Deneb, at the tail of Cygnus the swan is about three and a half fists above the northeast horizon. The third star in the triangle, Altair, in Aquila the eagle is two fists above the east horizon.
If you want to put somebody off, tell her or him to wait until Deneb sets. At Ellensburg’s latitude of 47 degrees, Deneb is a circumpolar star meaning it never goes below the horizon.
Monday: Saturn is three fists above the southwest horizon at 10 p.m.
Tuesday: Today is the first day of summer, the day that the Sun reaches its highest declination (the official name for sky latitude) of 23.5 degrees above the celestial equator. The celestial equator is the line that divides the northern sky from the southern sky. In Ellensburg, the Sun is about seven fists held upright and at arm’s length above the south horizon at 1:00 p.m. (noon standard time). Contrary to popular belief, the Sun is never straight overhead in Ellensburg or anywhere else in the 48 contiguous states. The northernmost portion of the world where the Sun can be directly overhead is 23.5 degrees north latitude. In ancient times, the Sun was in the constellation Cancer the crab on the first day of summer. Hence, 23.5 degrees north latitude has the nickname "Tropic of Cancer". Because the Earth wobbles like a spinning top, the Sun's apparent path through the sky changes slightly over time. Now, the Sun is in the constellation Taurus the bull on the first day of summer. However, citing the high cost of revising all of the science books, geographers are not changing the name of 23.5 degrees north latitude to "Tropic of Taurus". The first day of summer is often called the summer solstice. However, astronomers refer to the summer solstice as the point in the sky in which the Sun is at its highest point above the celestial equator. Thus, summer starts when the Sun is at the summer solstice point. This year, that happens at 10:17 a.m.
Wednesday: Jupiter is two fists above the east horizon and Mars is one fist above the east-northeast horizon at 4:30 a.m.
Thursday: This morning’s last quarter Moon is in the constellation Pisces the fish.
Friday: The early summer days are long so take some time to safely observe the Sun. The best way to do that is to go to http://sdo.gsfc.nasa.gov/ and watch the great images and videos that come from the Solar Dynamics Observer, or SDO for short. We are approaching a sunspot maximum scheduled to peak 2013. So what, you say? Sunspots and associated phenomena greatly influence the strength of solar flares. The strongest flares can affect satellites orbiting the Earth and even electronics on the Earth’s surface.
The positional information in this column about stars and planets is typically accurate for the entire week.
Thursday, June 9, 2011
The Ellensburg sky for the week of 6/11/11
Have you bought your favorite CWU graduate a graduation gift yet? Why not get her or him a star? I don’t mean from one of those organizations that offers to “register the name of YOUR star with the U.S. Patent Office”. No company owns the right to name stars after people. Besides, the stars those companies “name” are so dim you can’t find them. In this column, I’ll pick a constellation and representative star for each of the four colleges at CWU. Then, I’ll briefly tell the story of the constellation and relate that story to the aspect of public service CWU graduates from that college are uniquely qualified to engage in based on my version of sky interpretation. A couple can have “their” song so your favorite CWU graduate can have her or his star.
Saturday: Just as gyms and stadiums have been crowded with smart people for many evenings for the past few weeks, the eastern morning sky is crowded with bright planets for the next week. Tomorrow morning at 4:30 a.m., right as your CWU graduation party is winding down, you can see two, or possibly three, planets. Venus, the brightest planet, is just above the east--northeast horizon. Mars is a fist held diagonally and at arm’s length to the upper right of Venus. You may need binoculars to see it. Finally, Jupiter is one and a half fists above due east.
Sunday: College of Arts and Humanities: You are the people who interpret the world in unique ways. Then, you share those ways with others. According to Greek mythology, Orpheus charmed everyone he met when he played the lyre or harp. After his wife died tragically, he journeyed to the underworld to charm its inhabitants in an effort to win his wife back to the living world. Your service reminder: use your talent to bring joy to others. The constellation Lyra and its bright star Vega should remind you of the power of the arts. Vega is five fists held upright and at arm’s length above the southwest horizon at 11 p.m.
Monday: College of Business. You are the future movers and shakers. The future CEOs. The future big donors to Central. Auriga represented a king of Athens who happened to be mobility impaired. Instead of sitting around waiting for others to transport him, he took the initiative to invent the four-wheeled chariot. He solved a problem for a special need. Your service reminder: address the problems of those in the most need. To remind you of that, look to the constellation Auriga. Its bright star Capella is about one fist above the north horizon at 11 p.m.
Tuesday: What? Did your favorite graduate tell you that one of these star names is not good enough for them? If their favorite color is red, promise them a blood-red Moon… and a trip to Uzbekistan to see it. There will be a total lunar eclipse visible tomorrow in the Eastern Hemisphere. During a total lunar eclipse, white sunlight passes through the Earth’s atmosphere. The blue component of the white light is scattered and the remaining light that bends toward the Moon is reddish. Thus, the Moon looks red during a total lunar eclipse. Call it blood red for effect.
Wednesday: College of Education and Professional Studies. You are the teachers. The craftspeople. The facilitators of learning in a diverse world. Bootes, the herdsman, was such a person. Bootes’ job was to guide the northern constellations to the feeding place and the watering hole. He and his dogs were especially in charge of Ursa Major and Ursa Minor, the greater and lesser bears. Your service reminder: guide others to a better place in life. Look to the constellation Bootes and its bright star Arcturus to remind you of this. Arcturus is six fists above the southwest horizon at 11 p.m.
Thursday: College of the Sciences. You are the people who will systematically study how the world works. Agriculture is an important scientific application. Each year, farmers must use the findings of science to be successful. Who better to represent the College of the Sciences than Virgo, the goddess of the harvest? Virgo looms large in the sky holding an ear of wheat in her hand. Your service reminder: study the practical aspects of the scientific world. The ear of wheat, and your service reminder, is represented by the bright star Spica. Spica is two and a half fists above the southwest horizon at 11 p.m.
Friday: Saturn is three and a half fists above the south-southwest horizon at 10 p.m.
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/
The positional information in this column about stars and planets is typically accurate for the entire week.
Saturday: Just as gyms and stadiums have been crowded with smart people for many evenings for the past few weeks, the eastern morning sky is crowded with bright planets for the next week. Tomorrow morning at 4:30 a.m., right as your CWU graduation party is winding down, you can see two, or possibly three, planets. Venus, the brightest planet, is just above the east--northeast horizon. Mars is a fist held diagonally and at arm’s length to the upper right of Venus. You may need binoculars to see it. Finally, Jupiter is one and a half fists above due east.
Sunday: College of Arts and Humanities: You are the people who interpret the world in unique ways. Then, you share those ways with others. According to Greek mythology, Orpheus charmed everyone he met when he played the lyre or harp. After his wife died tragically, he journeyed to the underworld to charm its inhabitants in an effort to win his wife back to the living world. Your service reminder: use your talent to bring joy to others. The constellation Lyra and its bright star Vega should remind you of the power of the arts. Vega is five fists held upright and at arm’s length above the southwest horizon at 11 p.m.
Monday: College of Business. You are the future movers and shakers. The future CEOs. The future big donors to Central. Auriga represented a king of Athens who happened to be mobility impaired. Instead of sitting around waiting for others to transport him, he took the initiative to invent the four-wheeled chariot. He solved a problem for a special need. Your service reminder: address the problems of those in the most need. To remind you of that, look to the constellation Auriga. Its bright star Capella is about one fist above the north horizon at 11 p.m.
Tuesday: What? Did your favorite graduate tell you that one of these star names is not good enough for them? If their favorite color is red, promise them a blood-red Moon… and a trip to Uzbekistan to see it. There will be a total lunar eclipse visible tomorrow in the Eastern Hemisphere. During a total lunar eclipse, white sunlight passes through the Earth’s atmosphere. The blue component of the white light is scattered and the remaining light that bends toward the Moon is reddish. Thus, the Moon looks red during a total lunar eclipse. Call it blood red for effect.
Wednesday: College of Education and Professional Studies. You are the teachers. The craftspeople. The facilitators of learning in a diverse world. Bootes, the herdsman, was such a person. Bootes’ job was to guide the northern constellations to the feeding place and the watering hole. He and his dogs were especially in charge of Ursa Major and Ursa Minor, the greater and lesser bears. Your service reminder: guide others to a better place in life. Look to the constellation Bootes and its bright star Arcturus to remind you of this. Arcturus is six fists above the southwest horizon at 11 p.m.
Thursday: College of the Sciences. You are the people who will systematically study how the world works. Agriculture is an important scientific application. Each year, farmers must use the findings of science to be successful. Who better to represent the College of the Sciences than Virgo, the goddess of the harvest? Virgo looms large in the sky holding an ear of wheat in her hand. Your service reminder: study the practical aspects of the scientific world. The ear of wheat, and your service reminder, is represented by the bright star Spica. Spica is two and a half fists above the southwest horizon at 11 p.m.
Friday: Saturn is three and a half fists above the south-southwest horizon at 10 p.m.
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/
The positional information in this column about stars and planets is typically accurate for the entire week.
Thursday, June 2, 2011
The Ellensburg sky for the week of 6/4/11
Saturday: In 1979, the group Foreigner recorded the song “Head Games”. They could have been singing about the constellations Hercules and Ophiuchus when they said “head games, it’s just you and me baby, head games, I can’t take it anymore” because the heads of these two constellations have been right next to each other in the nighttime sky for all of human history. Each head is represented by a star bears an Arabic name that means "the head." In Hercules, it's Ras Algethi (head of the kneeler); in Ophiuchus, Ras Alhague (head of the serpent charmer). At 11 p.m., Ras Alhague, the brighter of the two, is a little more than four fists held upright and at arm’s length above the southeast horizon. Ras Algethi is about a half a fist to the upper right of Ras Alhague.
Sunday: Jupiter is one fist above the east horizon and Mars is a half fist above the east-northeast horizon at 4:30 a.m.
Monday: Venus, named after the Roman goddess of love, is spending time near the seven sisters for the next few mornings. Not that there is anything wrong with that. The seven sisters, also known as the open star cluster the Pleiades, is a group of about 100 young stars – 50 million years old – in the constellation Taurus. Yes, 50 million years is young for stars. The Sun is about five billion years old. The seven sisters are named after the daughters of Atlas and the nymph Pleione and are nymphs themselves, companions to Artemis. According to Greek mythology, several important gods such as Zeus and Poseidon had affairs with the seven sisters. Are your children reading this? Put them to bed so they can wake up at 4:30 a.m. At this time, Venus will be a few fingers above the east-northeast horizon and the Pleiades will be a few fingers to the upper left of the Pleiades. Over the next few days, Venus will move lower in the sky and move underneath the Pleiades.
Tuesday: 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 many more. 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. Globular clusters are groups of up to a few million stars that orbit the core of spiral galaxies such as our own Milky Way. 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”.
Wednesday: Tonight’s first quarter Moon is in the constellation Leo the lion.
Thursday: Saturn is one fist to the upper left of the Moon at 10 p.m.
Friday: Mizar is a well known binary star in the constellation Ursa Major. You can find it at the bend in the Big Dipper handle, nearly straight overhead at 10 p.m. tonight. Its name is Arabic for waistband. Mizar has an optical double called Alcor which is less than a pinky width away and can easily be seen with the naked eye. Optical doubles are stars that are close together in the sky but do not orbit a common center of mass as true binary stars. Not wanting to deceive sky gazers who call Mizar a binary star, two stars that DO orbit a common center of mass, Mizar actually is a binary. It was the first binary star system discovered by telescope. Mizar A and Mizar B are about 400 astronomical units apart from each other and about 80 light years from Earth. 400 astronomical units is about 10 times the distance between the Sun and Pluto.
The positional information in this column about stars and planets is typically accurate for the entire week.
Sunday: Jupiter is one fist above the east horizon and Mars is a half fist above the east-northeast horizon at 4:30 a.m.
Monday: Venus, named after the Roman goddess of love, is spending time near the seven sisters for the next few mornings. Not that there is anything wrong with that. The seven sisters, also known as the open star cluster the Pleiades, is a group of about 100 young stars – 50 million years old – in the constellation Taurus. Yes, 50 million years is young for stars. The Sun is about five billion years old. The seven sisters are named after the daughters of Atlas and the nymph Pleione and are nymphs themselves, companions to Artemis. According to Greek mythology, several important gods such as Zeus and Poseidon had affairs with the seven sisters. Are your children reading this? Put them to bed so they can wake up at 4:30 a.m. At this time, Venus will be a few fingers above the east-northeast horizon and the Pleiades will be a few fingers to the upper left of the Pleiades. Over the next few days, Venus will move lower in the sky and move underneath the Pleiades.
Tuesday: 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 many more. 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. Globular clusters are groups of up to a few million stars that orbit the core of spiral galaxies such as our own Milky Way. 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”.
Wednesday: Tonight’s first quarter Moon is in the constellation Leo the lion.
Thursday: Saturn is one fist to the upper left of the Moon at 10 p.m.
Friday: Mizar is a well known binary star in the constellation Ursa Major. You can find it at the bend in the Big Dipper handle, nearly straight overhead at 10 p.m. tonight. Its name is Arabic for waistband. Mizar has an optical double called Alcor which is less than a pinky width away and can easily be seen with the naked eye. Optical doubles are stars that are close together in the sky but do not orbit a common center of mass as true binary stars. Not wanting to deceive sky gazers who call Mizar a binary star, two stars that DO orbit a common center of mass, Mizar actually is a binary. It was the first binary star system discovered by telescope. Mizar A and Mizar B are about 400 astronomical units apart from each other and about 80 light years from Earth. 400 astronomical units is about 10 times the distance between the Sun and Pluto.
The positional information in this column about stars and planets is typically accurate for the entire week.
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