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Dudley Observatory
Supporting research and education in astronomy, astrophysics, and the history of astronomy |
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Skywatch December 2005 Skywatch Line for Thursday,
December 1, through Sunday, December 4, 2005 This is the Skywatch Line
for Monday, December 5, 2005 The Sun sets at 4:22 PM, with
night falling at 6:03. Dawn breaks at 5:30 AM, ending with sunrise at 7:12. This is the Dudley Observatory Skywatch Line for Tuesday December 6th, 2005, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum. Sunrise today was at 7:16 AM, and it set tonight at 4:22 PM. It will rise tomorrow at 7:17 AM, and will set tomorrow at 4:22 PM. The Moon today is in a Waxing Crescent phase. It rose today at 11:52 this morning, and will set at 10:10 tonight. It will rise tomorrow a little after Noon, and will set at 11:25 tomorrow night. Venus is low in the west, visible even before darkness falls. It will appear as a very bright starlike object. Venus is the third brightest object in the Solar System, and is bright enough to see during the day. It will reach its greatest brightness for the year over the next few days. The planet Mars, looking like an orange-yellowish star, is visible in the east as soon as darkness falls. It is considerable dimmer than it was during the beginning of November, but is still easily visible. Next to Mars is the winter group of stars known as the Pleiades, or the Seven Sisters. Just past overhead at 8 PM, appearing as a dim smudge of light, is the Andromeda Galaxy. It is our closest neighbor galaxy, at a distance of 2.5 million light years away. The winter constellation of Orion is rising in the east by 8 PM, and is visible all night long. Saturn is up in the east by 10 PM. Public Programs at the Suits-Bueche Planetarium at the Schenectady Museum, are on Saturdays and Sundays at 1, 2, and 3 P. M. The 1:00 program is “The Friendly Stars”, a program for young people. At 2 P. M. is “Tis the Season”, and at 3 P. M. is a live narration of the Winter Sky. “Tis the Season” also plays Tuesday through Fridays at 2 PM.
Skywatch Line for December 7, 2005
Today the Sun sets at 4:21 PM. The waxing crescent moon, in the constellation of Aquarius, sets at 11:15 PM.
Tonight Venus, at almost minus five magnitude, sets at 7:15 PM in the constellation of Sagittarius. Mars remains relatively bright at almost minus two magnitude in the constellation of Aries. A month past opposition, Mars has shrunk to less than sixteen arc seconds. Mars transits, that is, it crosses the meridian, just after 9:00 PM and should still be an interesting object in amateur telescopes.
Saturn, at brighter than zero magnitude, rises at 8:29 PM in the constellation Cancer. Jupiter does not rise until just after 4:00 AM Thursday morning in the constellation of Libra, followed by Mercury, also in Libra, at 5:25 AM.
By 9:00 PM tonight the constellations of summer are setting in the west and the Autumn constellations of Perseus, Andromeda and Cassiopeia are well placed near the meridian. The winter constellations of Taurus, Auriga, Orion and Gemini have already risen.
Most of us associate the Milky Way, the cloudlike band of light, with the summer sky. But the winter Milky Way extends almost across the entire winter sky and is particularly rich through Auriga and between Gemini and Orion. Perhaps we are not as observant of the winter sky because the cold keeps us in doors. Maybe the exceptional number of bright stars in the winter sky dazzle our eyes and catch our attention.
In fact, the winter Milky Way is not nearly as bright as the summer Milky Way. When we are looking toward the winter Milky Way we are facing toward the outer edge of our galaxy, rather than toward its center. But, like the brighter Milky Way of summer, the winter Milky Way displays a seemingly infinite number of stars to the observer with a simple pair of binoculars. Now is an excellent time of year to follow the Milky Way from Cygnus, near the horizon in the northwest, all the way past Orion in the east. Skywatch Line for Friday, December 9 through Sunday, December 11 Skywatch Line for Monday, December 12, 2005 Dudley Observatory Skywatch Line for Tuesday December 13th, 2005, written by Steven Russo, Planetarium Manager of the Suits-Bueche Planetarium at the Schenectady Museum. Sunrise today was at 7:22 AM, and it set tonight at 4:23 PM. It will rise tomorrow at 7:22 AM, and will set tomorrow at 4:23 PM. The Moon today is in a Waxing Gibbous phase, with the Full Moon on the 15th. It rose today at 2:34 this afternoon, and will set at 6:38 tomorrow morning. Venus is still low in the west, visible even before darkness falls. It will appear as a very bright starlike object. Venus is the third brightest object in the Solar System, and is bright enough to see during the day. It has just reached its greatest brightness for the year. The planet Mars, looking like an orange-yellowish star, is visible in the east as soon as darkness falls. It has dimmed considerably since the beginning of November, but is still very easily visible. Look high up in the east after darkness, next to not too far from the star cluster known as the Seven Sisters. By 10 PM, the planet Saturn is up in the east. This is still one of the best objects to see in a small telescope, as just 30 power will reveal its ring system. Public Programs at the Suits-Bueche Planetarium at the Schenectady Museum, are on Saturdays and Sundays at 1, 2, and 3 P. M. The 1:00 program is “The Friendly Stars”, a program for young people. At 2 P. M. is “Tis the Season”, and at 3 P. M. is a live narration of the Winter Sky. “Tis the Season” also plays Tuesday through Fridays at 2 PM. Skywatch Line Dec 14, 2005 By Bernard Forman
Today, sunrise is at 7:17 AM and sunset at 4:22 PM. The waxing gibbous moon, in the constellation Taurus, the Bull, rises at 3:15 PM and sets tomorrow morning at 7:37 AM. Full moon occurs tomorrow.
As we are now, yet again, in the holiday shopping season, a yearly warning is in order regarding the sale of telescopes to the unsuspecting parent of the budding amateur astronomer. Derisively referred to as department store telescopes, such items can be found all over malls and in large retail stores. Primarily, though not exclusively, refractors, the sure sign that the scope is to be avoided is the touting of ridiculously high magnification, usually in excess of five hundred power! Often, the box containing the telescope will have several beautiful color photographs depicting nebulae and galaxies which look nothing like what can actually be seen with the scope. Such telescopes may be adequate for viewing the moon, but not much else. Even if the optics are adequate, oftentimes the mount is wobbly and impossible to properly aim at celestial objects. Generally speaking, it would be hard to go wrong by never buying a telescope at the local mall or big box retail store.
Before buying any expensive equipment, the budding amateur should first become familiar with, at least, the major constellations and be able to find the naked eye planets. The local public library should be consulted for appropriate books before spending any money at all.
With these basics understood, the next step is the purchase of a planisphere to display the sky as it changes over time. The planisphere can be adjusted to display the nighttime sky at any hours of any day during the year. Planispheres can be found at major bookstores or the gift shop of the local planetarium. Don’t forget to cover a small flashlight with red cellophane or nail polish to look at the planisphere at night without disturbing your eyes’ dark adaptation.
Finally, the first optical instrument for the budding amateur is surely a pair of decent quality binoculars. Often, a spare pair is already available. Binoculars are essential pieces of astronomical equipment. They afford wide field views and are thus easy to aim. Many objects, such as large open clusters, are best viewed with binoculars. The Milky Way is resolved into countless stars by simple binoculars. Here, too, binoculars touting high powers, anything more than a magnification of ten, should be avoided as a first pair. But a pair of seven or ten magnification binoculars, with fifty millimeter objective lenses, will open up a whole new world for anyone who turns them skyward.
Skywatch Line for Friday,
December 16, through Sunday, December 18, 2005, by This is the Skywatch Line
for Monday, December 19 The Sun sets at 4:24
tonight, with night falling at 6:06. Dawn breaks at 5:40 tomorrow morning, and
ends with sunrise at 7:22. Dudley Observatory Skywatch Line for Tuesday December 20th, 2005 Sunrise today was at 7:27 AM, and it set tonight at 4:25 PM. It will rise tomorrow at 7:28 AM, and will set tomorrow at 4:25 PM. Tomorrow, is one of the shortest days of the year, as it is also the Winter Solstice. Officially Winter begins at 1:35 PM. The Moon today is in a Waning Gibbous phase, with the Last Quarter Moon on the 23rd. It will rise tonight at 9:09 and will set at 11:20 tomorrow morning. Venus is still low in the west, visible even before darkness falls. It will appear as a very bright starlike object. Venus is the third brightest object in the Solar System, and is bright enough to see during the day. It has just reached its greatest brightness for the year. The planet Mars, looking like an orange-yellowish star, is visible in the east as soon as darkness falls. It has dimmed considerably since the beginning of November, but is still very easily visible. Look high up in the east after darkness, next to not too far from the star cluster known as the Seven Sisters. By 10 PM, the planet Saturn is up in the east. This is still one of the best objects to see in a small telescope, as just 30 power will reveal its ring system. Public Programs at the Suits-Bueche Planetarium at the Schenectady Museum, are on Saturdays and Sundays at 1, 2, and 3 P. M. The 1:00 program is “The Friendly Stars”, a program for young people. At 2 P. M. is “Tis the Season”, and at 3 P. M. is a live narration of the Winter Sky. “Tis the Season” also plays Tuesday through Fridays at 2 PM.
Skywatch Line for December 21, 2005
The Sun sets today at 4:25 PM. The waning gibbous moon rises at 10:16 PM and sets tomorrow morning at 11:33 AM. Today is the first day of Winter.
Venus, at almost minus five magnitude, sets in the southwest at 6:52 PM. Through a telescope at moderate power, Venus is a beautiful crescent, growing larger and thinner throughout the month of December.
Mars, not quite as bright as minus one magnitude in the constellation Aries, the Ram, transits at 8:17 PM and is less than fourteen arc seconds in diameter.
Saturn, slightly brighter than zero magnitude, rises at 7:31 PM in the constellation of Cancer, the Crab. Saturn is less than three and one half degrees from M 44, the Beehive Cluster.
Finally, Jupiter rises at 3:20 AM in the constellation Libra. With the exception of the moon and Venus, Jupiter, at almost minus two magnitude, is the brightest object in the nighttime sky.
With the great winter constellation Orion passing the meridian before midnight, and with the nights being so cold, we are definitely into the winter observing season. While the single greatest showpiece of the winter sky is probably the Great Orion Nebula, M 42, there are other sights worth seeking out.
Most of us associate globular clusters with the nighttime summer sky, when we are peering toward the center of our galaxy. However, interestingly, there exists a globular cluster in the winter sky, below Orion in the constellation of Lepus, the Hare. M 79, an eighth magnitude object, was discovered by a friend and colleague of Charles Messier, Pierre Mechain, in 1780. Visible in binoculars as a small, nebulous object, a moderately large telescope is required to resolve any of its stars. M 79 never gets very high up, so the best time to look for it is when it passes the meridian, around 11:15 PM. Lepus, being so low, is a relatively obscure constellation, with its brightest star being dimmer than second magnitude. A simple star chart will enable anyone to locate it, below Orion’s feet. A line from Alpha to Beta Leporis going an equal distance south will bring you to M 79.
Skywatch Line Dec. 28, 2005
The Sun sets today at 4:29 PM. The waning crescent moon has already set, at 1:54 PM and, accordingly, will not interfere with nighttime skywatching. Now that the winter solstice has arrived, the days are finally getting longer.
Starting in the west at sunset, Venus is readily visible at minus four and a half magnitude. Venus sets in the west south west almost two hours after the Sun. Following Venus along the ecliptic, we first come to Neptune in Capricornus and Uranus in Aquarius, but both will require a telescope for identification.
Next is Mars in the constellation Aries, which continues to grow dimmer and smaller. Mars transits at 7:54 PM. Saturn, in the constellation Cancer, the Crab, rises at 7:01 PM. Brighter than zero magnitude, Saturn is now less than three degrees from M 44, the Beehive Cluster. Saturn transits at 2:14 AM on Thursday morning.
Finally, Jupiter rises before dawn on Thursday at 2:59 AM in the constellation Libra. At almost minus two magnitude, the king of the planets is already brighter than Mars or Saturn, even though Jupiter doesn’t reach opposition until next May.
If globular clusters are, primarily, Summer objects, open clusters, which are found near the plane of the Milky Way, are found in abundance in both the Summer and Winter sky. Unlike globular cluster, open clusters are made up primarily of young, often hot and bluish, stars, which are readily seen in small telescopes, binoculars, or even the naked eye. There are several prominent open clusters visible during the Winter, many listed in Messier’s famous catalogue.
Two such objects are M 46 and M 47 in the constellation of Puppis, the Stern, which is part of the former constellation Argo Navis, the ship of the Argonauts. Puppis can be found to the east and southeast, i.e. left and lower left, of the constellation Canis Major. Since it lies in the Milky Way, Puppis contains rich star fields best viewed with binoculars or a rich field telescope.
M 46, at around sixth magnitude, is the dimmer of the two clusters, but contains more stars, approximately one hundred in all. M 46 lies approximately 5400 light years away. On its northern edge can be seen a tenth magnitude planetary nebula, which is a foreground object about 3000 light years distant.
M 47, at magnitude 4.4, is brighter, slightly smaller, and contains approximately 30 stars. It lies approximately 1600 light years away.
M 46 and M 47 lie less than one and a half degrees apart and are easily found in binoculars by scanning approximately twelve degrees, or slightly more than the width of a fist held at arms length, to the left of Sirius.
Skywatch line for Thursday, Dec. 29, 2005 Skywatch Line for Friday, December 30, through Sunday, January 1 by Alan French The International Space Station, or ISS, will pass directly over the Capital District early on New Year's Eve. We see the ISS because it is still up in the sunlight while we are down in the Earth's shadow, and it looks like a bright star moving across the sky. Its appearance Saturday night will be quite interesting – just after passing overhead it will move into the Earth's shadow and fade from view. The ISS will first appear at 6:10:45 PM on Saturday night, rising above the horizon toward the west-southwest. It will be highest at 6:13:39 when it will be 83 degrees above the north northwestern horizon. (If you missed it as it moved up from the horizon, simply look for a moving star high overhead just after 6:13.) At 6:13:45 – less than 10 seconds after its highest point – the ISS will begin moving into our Earth's shadow and will gradually fade from view. The Moon is new on Friday, December 30, at 10:42 PM. (This is the second New Moon of December.) By Sunday night, a pretty crescent Moon will be gracing the southwestern sky just after sunset. If you look just before sunset on Sunday night, you'll have a good chance to spot Venus near the Moon in the daytime sky. Look for a thin, pale crescent Moon toward the southwest at 4:25 on Sunday afternoon. This will be just before the Sun has set. The Moon will be 24 degrees above the horizon (keep in mind that a fist held at arm's length spans 10 degrees across the knuckles). Venus will be 22 degrees to the right of the Moon, and 15 degrees above the horizon. Can you spot Venus before the Sun has completely set? If not, Venus should become increasingly obvious as the sky darkens. Between 5:15 and 5:30, the pair should be a very pretty sight low in the southeast, but you will need a good, unobstructed view toward the southeast to catch Venus. By 5:30 our sister planet will be only five degrees above the horizon. |
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