|Skywatch May 2013
(newest at top)
Skywatch Line scripts are written by members of the Albany Area Amateur Astronomers. They can be heard by calling 518-382-7584.
Friday, May 17th, marks the 137th day of the year. There are 228 days left in the year. The Sun rises at 5:31 and sets at 8:13.
The Moon is at first quarter on early Saturday morning at 12:36. Rising each day at about noontime in the east, it will be seen hovering over the southern horizon after sundown. Times of Moonset are 1:32 for Saturday morning, 2:00 for Sunday morning, and 2:29 for Monday morning. Viewing the Moon at this phase through even a small telescope will reveal the Straight Wall, several large craters including Aristoteles at the Moon’s north pole, Archimedes near the center of the Moon at the day/night terminator, and the easily visible Apennine Mountain range.
To the west-northwest 30 minutes after sundown can be seen Jupiter, Venus, and Mercury, all in a straight line and one week before they gather together in a tight cluster called a Trio, 3 to 5 degrees wide. Venus and Mercury are emerging ever higher each evening towards Jupiter, with Mercury the quicker of the two. Jupiter itself is getting ever lower in the sky each night. Jupiter will be 10 degrees to the upper left of brighter Venus and Venus itself will be 5 degrees to the upper left of dimmer Mercury.
Saturn will be found rising in the south-southeast after sundown. The sixth planet was at opposition just a few weeks ago so a telescope will show fine views of Saturn's globe and rings as well as several of its brighter moons.
Earlier this year solar physicists were divided into two camps debating whether the current Solar Cycle number 24 had just peaked and was on the downswing toward its next minimum, or whether it would peak again before beginning to sink back into minimum. Well it looks like the group from the second camp had won the debate. Solar activity has just surged tremendously from its months long lull. The Sun's disk is peppered with sunspots. And a large group of those sunspots, Active Region 1748, just emerging into view from the far side of the Sun, shot off four X-class flares in the space of 48 hours a few days ago. X-class flares are the most powerful and destructive of all flares, and a coronal mass ejection accompanied one flare. Sunspot AR1748 is slowly rotating into a direct line with the Earth and there are high hopes for another flare that would bring on major geomagnetic storms and a fine display of the northern lights. Stay tuned to this site for updates.
On Wednesday, the 26% illuminated, waxing Crescent Moon rises at approximately 10 am EDT and can be seen until setting at 12:30 am Thursday. As the sky darkens, the Moon can be seen high above the western horizon, to the upper left of Jupiter and, low on the horizon, Venus. The bright star about 10 degrees directly below the Moon is Canis Minor’s brightest star, and the eighth brightest star in the sky, Procyon. Procyon translates to “before the dog”, indicating a time when it once rose before the Dog Star, Sirius, thousands of years ago. At a distance of about 11.4 light years, Procyon is one of our closest stellar neighbors, the fifth nearest of the naked eye stars. Although it appears to be a single star to the naked eye, Procyon is a binary star. Procyon’s companion, Procyon B, is a white dwarf star, a stellar remnant in its final evolutionary stages. Saturn can be found above the southeastern horizon after sunset and will be visible throughout the night until the predawn hours Thursday. On Thursday night, the Moon will be 6.5 degrees south-southwest of the Beehive Cluster. The Beehive Cluster, or M44, is a wonderful target through binoculars. M44 is an open star cluster located in the constellation Cancer. Estimated to be approximately 600 light years from Earth, the Beehive Cluster is one of the closest open clusters to our Solar System. Sue French comments on M44 in her book, Celestial Sampler, “Visible in 14 x 70 binoculars are about 20 bright stars and 30 dimmer ones in a loose gathering nearly 1.5° across”. Cancer is also the home of another open star cluster, M67. Look for M67 about 9 degrees south of the Beehive Cluster and 1.8 degrees west of Cancer’s brightest star, Alpha Cancri. M67 is populated with over 500 stars, 100 of which are similar to our Sun. It is estimated the age for the stars within M67 range 3.2 billion to 5 billion years, about the same age as our Sun which formed 4.6 billion years ago. The age, temperature, chemistry, and close distance of the stars within M67 have led some astronomers to believe it may be the parent cluster of our Sun but recent simulations have provided data to disprove that theory.
The Sun sets at 8:09 PM; night falls at 10:08. Dawn breaks at 3:34 AM and ends with sunrise at 5:33.
As the Sun sets, the Moon joins Jupiter and Venus. The four-day-old Moon is moderately high in the western sky. Monday’s thin crescent Moon lies between Gemini’s legs; Tuesday finds a fatter Moon resting on Pollux’s knee. It sets before Midnight.
Jupiter still glows between the horns of Taurus, the Bull. Monday evening sees two of Jupiter’s 65 moons on either side of the giant planet; Tuesday finds three moons on one side and the other moon on the other side. Jupiter sets before 11 PM.
Venus appears about 14 degrees to Jupiter’s lower right. Although Venus is the second brightest object, it is so low that the sunset glare hides its full beauty. In a telescope, Venus is almost “full”. It sets about 9:10 PM.
Saturn rose at 6:30 PM, and, by nightfall, is moderately high in the eastern sky, hovering between Virgo and Libra. Even though it passed Opposition two weeks ago, it is still ideally situated for observation. Any size telescope displays its famed ring system, while eight of its 62 moons are visible, depending on telescope type and observing conditions. Saturn sets before sunrise.
Neptune rises in Aquarius at about 2:30 AM, followed by Uranus, in Pisces, at 3:50 AM. Observing guides are available from astronomy magazines, websites and apps.
About Midnight, the constellation Scorpius lies due South and high enough for it to rise above the tree line. Its brightest star, the Lucida, is Antares. The Greek name means "Rival of Ares," the Greek version of the Roman war god Mars. Antares is one of the brightest stars in the northern sky. It is one of only two bright supergiant stars; the other is Betelgeuse. Antares is truly a giant star. Its diameter is 600 million miles, beyond Jupiter's orbit, if it replaced the Sun. Antares lies about 600 light years away; only Betelgeuse is closer. This star is nearing the end of its life. It is slightly variable, and will, one day, blow itself up as a supernova. In 1970, Antares was the first star, proven to emit radio waves.
Friday, May 10th, marks the 130th day of the year. There are 235 days left in the year. The Sun rises at 5:39 and sets at 8:06.
The Moon is a very slender crescent one to four days past new and can be found setting in the west-northwest soon after sundown. Times of moonset are 8:55 for Friday evening, 9:47 for Saturday evening, and 10:35 for Sunday evening.
Most of the planetary action this weekend and over the next few weeks occurs during the early evening hours with Mercury, Venus and Jupiter coming into play, and all within the confines of Taurus the Bull over the west-northwestern horizon. Watch how the three planets shift their positions over the next two weeks and close in for a spectacular conjunction by Memorial Day weekend. And you can use the brighter planets Venus and Jupiter as a guide to find the very slender young Moon over the next few nights.
The elusive planet Mercury will not yet be seen, for it is in superior conjunction on Saturday, stationed precisely behind the Sun for that day. But by next week, Mercury will have emerged far enough away from the Sun to be seen as an evening planet above the horizon after sundown.
Venus is also emerging away from the Sun, moving out of the bright evening twilight and found between the Hyades and the Pleiades star clusters of Taurus about 30 minutes after sunset. Venus sets at 9:00, giving ample time to find the dazzling planet. With the help of Venus, you can find the very slender, one day-old Moon just below Venus on Friday evening.
The planet Jupiter, higher over the horizon than Venus and setting at 10:30, is now making it final appearances in the evening sky. Unlike the emergence of Venus, Jupiter will sink ever lower each night and disappear into the bright evening twilight by the end of this month. Use Jupiter on Saturday and Sunday evenings 30 minutes after sundown to find the Moon. On Saturday evening, the two-day old Moon will be just below Jupiter but above Venus. By Sunday evening the three-day old Moon will be to the left of Jupiter.
By the start of the Memorial Day weekend, Mercury, Venus and Jupiter will all be found in a field of view ranging from 3 to 5 degrees across and remain so for the week after.
Only Saturn is left out of this planetary grouping in the west. Saturn rises in the east at 7:00, well before the Sun sets, and having passed opposition with the Earth more than a week ago. Saturn will be at its highest at midnight over the southern horizon.
As for the stars, by 10:00, look up to see the seven stars that make up the Big Dipper, an asterism of stars that is part of the constellation Ursa Major, the Great Bear, yet familiar in its own right as it is called - a dipper, which is a ladle used for serving liquid foods. But the dipper has also been described as a plow, a net, a wagon, a cleaver, and even Native Americans chasing a bear.
Almost all of the naked eye stars of the Big Dipper are of the same magnitude, roughly +2.0. An interesting fact about most of the stars that make up the Dipper is that they make up a very large open cluster of stars physically related to each other, sharing a common origin, and moving through space together in the same general direction towards the constellation Sagittarius. This group of stars is called the Ursa Major Moving Group and most of the stars lie about 80 light years away. Since these blue-white stars also have roughly the same metallicity along with the same age - 500 million years old - in all likelihood they were probably formed from the same stellar nebulae that spawned these stars. This cluster of stars started out as a smaller open cluster but over time gradually dispersed into the larger one it is now at roughly 30 by 18 light years in dimension. It is actually one of our closest cluster of stars.
The stars of the Big Dipper make up the core of the cluster. There are also other stars that probably belong to this cluster but are found scattered about in various other constellations, including Orion, Taurus, Sagittarius, and Lyra. Our own Sun and the star Sirius were once believed to be part of this group, but the Sun is too different in chemical composition and also too old at 5 billion years of age to belong to this cluster and Sirius is way too young at 200 million years old.
While most planetary views are reserved for the end of May when Venus, Jupiter and Mercury will form a conjunction within a 5 degree circle, Saturn provides the best current opportunity to view a planet. Saturn rises at approximately 7 p.m. EDT, and will be 15 degrees over the southeastern horizon as the sky darkens. Look for Saturn about 20 degrees east, or two fists of an extended arm, from Virgo’s brightest star, Spica. Saturn will remain observable until setting in the early morning hours. A telescopic view of Saturn on Wednesday night will reveal Saturn’s largest moon, Titan on one side of the ringed planet, while Dione, Enceladus and Rhea extend outward on the other side. Enceladus has been in the news lately after the NASA spacecraft, Cassini, returned images of about 100 jets or geysers spraying outward 100 of miles into space from the Saturnian moon. These images allowed scientists to determine the geysers are composed of water vapor, icy particles and organic compounds. It is theorized that Enceladus contains a subsurface ocean which is heated from the tidal forces created by Saturn, and rock and ice forces below force the water through cracks in the surface of the moon’s south pole. While Saturn is rising, Jupiter will be declining in the west, setting at 10:30 p.m. Look 30 degrees above Saturn for the bright star Arcturus, the brightest star in the constellation Bootes and the fourth brightest star in the sky. Another way to locate Arcturus is to follow the arc from the Big Dipper’s handle to the bright star. Arcturus is an orange giant star 26 times the diameter of our Sun and approximately 37 light years from Earth. The New Moon occurs at 8:28 p.m. EDT on Thursday. Take advantage of the moonless night to observe two deep sky objects located in Bootes near Arcturus. NGC 5248 is a compact spiral galaxy ten degrees south of Arcturus and one and one half degrees west. A dim, but large globular cluster in Bootes is NGC 5466. NGC 5466 can be found nine degrees north of Arcturus and one and one half degrees west. The Albany Area Amateur Astronomers invite you to join them for a Star Party on Friday, May 10th at their eastern dark sky site in Grafton Lakes State Park located in Grafton, NY. If Friday’s Star Party is cancelled due to clouds, it will be rescheduled for Saturday night. Directions can be found on the Dudley Observatory website. http://www.dudleyobservatory.org/AAAA/Directions.html
Note: 8 PM May 10 - Octagon Barn Star Party, rain or shine
"Star Tracks: music to gaze with" Talk by Philip Erner
The Sun sets at 8:02 PM; night falls at 9:56. Dawn breaks at 3:47 AM and ends with sunrise at 5:41.
After a long drought, the evening sky is beginning to be populated with bright planets. Jupiter is moderately low in the northwestern sky, and visible shortly after sunset. Jupiter is about 21 degrees above the horizon. Binoculars show three of the moons that Galileo discovered on Monday; Tuesday shows four. Jupiter sets at 10:41 PM.
Saturn, another gas giant planet, is also moderately low, but in the eastern sky. It rose about 7 PM, and sets about sunrise. Saturn passed opposition last week, so it is at its best for observation. Binoculars show a tiny planet with its famous rings. Telescopes reveal not only the rings, but also several of its sixty-six moons, depending on telescope size and sky conditions.
Venus appears 21 degrees below Jupiter, just after sunset, and begins its appearance in evening skies. At -3.9 magnitude, it is far brighter then Jupiter, but very low amid the sunset glare. Binoculars may assist in finding Venus. The planet increases visibility in coming months.
Comet PANSTARRS is still observable in our skies. At eighth magnitude, it is visible only in telescopes. Between Cassiopeia and Cepheus, it is four degrees from the peak of the house-shaped constellation, the star Errai (gamma in Cepheus). The comet is up all night.
Neptune rises at about 3 AM in Aquarius. Astronomy magazines, websites and apps provide finding information.
The 27 day-old Moon rises during Dawn on Tuesday. The thin sliver lies next to the rising planet Uranus, seven degrees away. Both are quite low on the eastern horizon. Wednesday finds a thinner Moon even lower.
Like its fellow outer planets: Jupiter, Saturn and Uranus,
Neptune is a gas giant, which means that it is a large ball of mostly Hydrogen. It is seventeen times heavier and thirty times further than Earth. Neptune takes almost 164 years to circle the Sun. It sports a faint ring system, visible only to space telescopes. Like Jupiter it has a "Great Dark Spot," similar to Jupiter's gigantic hurricane. But it is also different. It is warmer at its equator and poles than its middle, and also has a chaotic weather system that permits storms to switch latitudes.
Friday, May 3rd, marks the 123rd day of the year. There are 242 days left in the year. The Sun rises at 5:48 and sets at 7:58.
The Moon is one to four days past last quarter. Moonrise occurs in the east after midnight. Times of Moonrise are 2:51 for Saturday morning, 3:20 for Sunday morning, and 3:49 for Monday morning.
Venus is now peeping up above the western horizon very soon after sundown. In a few more weeks it will begin to keep us company during the early evenings throughout the spring and summer. Jupiter, still locked in the horns of Taurus the Bull, is above the western horizon after sundown and sets soon afterwards. Jupiter, Venus, and Mercury will all join together for a spectacular conjunction toward the end of the month. Saturn rises in the east at sundown and will be visible all night long. And on the surface of Our Mister Sun there are several crackling sunspots capable of emitting powerful flares that could produce geomagnetic storms and aurorae over the next few days.
Friday, May 3rd marks the 10th anniversary of the collapse of the Old Man of the Mountain, one of New Hampshire’s rocky profiles that looked like the face of an old man as seen from its side. Of course the Old Man was simply a cliff ledge carved by the glaciers thousands of years ago and is just one of many examples of what is known as pareidolia – the ability of the human brain to interpret vague, inanimate images into a more familiar one - like seeing elephants in the clouds. But pareidolia has long been common in the world of astronomy and space exploration. The canals of Mars is a very good example of space pareidolia. And of course we have all seen the man or the rabbit in the Moon - created by connecting the darker areas, or the maria, of the Moon.
Space pareidolia goes beyond the Moon. Looking at photographs of Mercury taken by the Messenger spacecraft will show a set of three closely grouped craters resembling Mickey Mouse and elsewhere on the same planet another group of three that resemble Sesame Street's Cookie Monster.
No-one will forget the Face of Mars photographed by the Viking spacecraft in the 1970s and taken by many to be evidence of an ancient extraterrestrial civilization. Time, of course, proved that the face is simply a flat, geological formation which, when hit just right by the light of the Sun, shows remarkable human face-like features. On the humorous side of Mars, there is the Smiley or Happy Face Crater photographed many times by a number of spacecraft orbiting Mars. Of course the eyes are simply two clusters of mountains near the top of the Galle crater while the mouth is a curved chain of mountains near the bottom of the crater. And last year, Curiosity spotted the "Mars Flower," which is simply a rock that was carved into the shape of a flower by wind erosion over time.
Onto the asteroid Vesta, we can see a Snowman created by three large craters linked together at their rims. And into the realms of Deep Space, we can see the so called Hand of God, taken by the Chandra X-ray Observatory, and which is simply nebulae or clouds of gas stunningly shaped by stellar winds into an arm, wrist, and outstretched fingers reaching up for an object.
Space pareidolia is everywhere and people will read into them however they like - whether as evidence of our creation, signs of intelligent alien life, or simple reminders of the paradise we are so familiar with here on Earth.
On Wednesday, Venus is six degrees above the western horizon at sunset and sets approximately 45 minutes later. Jupiter will be higher above the western horizon and will set at 11:00 p.m. EDT. Jupiter’s moon, Ganymede, is eclipsed by the planet’s shadow at 8:38 p.m. EDT and reappears 11:18 p.m. EDT. Ganymede is not only Jupiter’s largest moon, it is the largest moon in the solar system. With a diameter of 3,273 miles, Ganymede is 8% larger than the planet Mercury and 2% larger that the solar systems’ second largest moon, Saturn’s Titan. Ganymede was discovered by Galileo on January 7, 1610. Galileo believed the moons were stars near Jupiter. Ganymede completes a revolution every seven days, three hours. Like our Moon, Ganymede is tidally locked, which means one side always faces Jupiter. Ganymede has three main layers. At its core is a sphere of metallic iron which generates its magnetic field. Surrounding the core is its mantle, a layer of rock below 497 miles of ice. Data from the Hubble Space Telescope in 1996 was used to determine that Ganymede has a thin oxygen atmosphere. Some scientists theorize that microbiotic life may exist in oceans below Ganymede’s ice layer. Our Moon reaches its Last Quarter phase on Thursday at 7:15 a.m. EDT. You’ll have an opportunity to view a daylight Moon until it sets around 12:30 p.m. EDT. Saturn is just past opposition and provides a bigger and brighter telescopic view for most of the night. Saturn will appear rising above the east-southeastern horizon below the constellation Virgo as the sky darkens and will set around 6 a.m. the following morning. Virgo is the second largest constellation after Hydra. Virgo’s brightest star, Spica, a blue-white eclipsing binary star, is the tenth brightest in our sky. At magnitude 1.0, Spica stands out due to the lack of bright stars nearby. Virgo contains many deep sky objects including the Virgo Galaxy Cluster which contains 11 Messier objects. That is more than any other constellation with the exception of Sagittarius, which contains fifteen. According to Robert Burnham, the Virgo Galaxy Cluster section of the sky “is one of the most remarkable areas of the heavens”. Burnham recommends exploring this region with telescopes of six inch apertures or larger. Explore the western side of Virgo, to the upper right of Spica, for the 1,000+ galaxies in this cluster. The Albany Area Amateur Astronomers invite you to join them for Star Parties at the Landis Arboretum in Esperance, NY on Friday, May 3rd and Saturday, May 4th. Star Parties may be cancelled if skies are mostly cloudy.
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