Tag Archives: Astronomy

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, December 28th and 29th written by Joe Slomka.

The Sun sets at 4:28 PM; night falls at 6:11. Dawn breaks at 5:43 AM and ends with the Sun rising at 7:25.

The twilight sky contains the planets Uranus, in Pisces, and Neptune, in Aquarius. They become visible as twilight gives way to night. Mercury blazes at magnitude minus 0.5 about eight degrees above the southwestern horizon. Binoculars may help find Mercury amid the sky glow. Mercury sets at 5:57.

Night finds the asteroid 4Vesta, in Cetus, joining Uranus and Neptune. While Uranus is bright enough for binoculars, all three require detailed finder charts for location. These charts are available from astronomical magazines, websites and apps. Uranus is best observed at 6:24 PM, and sets at 12:53 AM. Neptune sets at 9:32 PM. Vesta sets at 11:42 PM.

The eighteen-day-old waning Moon rises at 8:11 PM on Monday, near Leo’s front paw and appears about 85 percent illuminated. Tuesday, the slimmer crescent, rises at 9:11 PM near Leo’s forward rear leg.

Jupiter rises at 10:21 PM between Leo’s tail and Virgo’s head. It begins a pre-dawn planetary parade. Telescopic observers can see Jupiter’s Great Red Spot, a giant storm, at 5:36 AM Tuesday and 1:28 AM Wednesday. They can also witness the Jovian moon Ganymede’s shadow beginning to cross the planet’s face at 12:09 AM Tuesday and exit at 3:26 AM. The moon Io reappears from behind Jupiter at 1:11 AMalso Tuesday.

The term ecliptic is heard many times on the Skywatch Line.
The Dawn sky dramatically demonstrates it. Go out about 5:45 AM and look southeast. On both days, a waning Moon is high in Leo. Look to the lower right, and find Jupiter, Mars, Venus and Saturn. One can draw a straight line through these heavenly bodies. This line is the ecliptic – the path of the Sun, Moon and planets across the sky. Mars lies in in Virgo, near the bright star Spica. Venus is in Libra and newly risen Saturn is in Ophiuchus.

Comet Catalina follows its own path. It is about four degrees below the bright star Arcturus in Bootes. Recent reports have the comet shining at about magnitude 6.3, visible through binoculars under good conditions.

Since Saturn is a feature of our Dawn sky. Let us consider his importance. This time of the year was dedicated to Saturn, the Roman God of Harvests. A series of feasts were held during the week of the Winter Solstice – the Saturnalia. Saturn was depicted as a jolly old man. People decorated evergreen trees. Candles were lit everywhere. Houses were decorated with wreaths and Holly. Decorated cookies were baked. People wore red peaked hats, similar to the “Santa hats” of today. Banquets were held both in honor of the harvest and wishing for a prosperous new year. Gifts were exchanged: dolls for the children, candles and fruits for the adults. Benefits were held for he poor. Saturnalia was an official government holiday. The holiday was so popular that Christians moved the feast of Christ’s birth to compete and adopted many of the symbols and traditions of this pagan feast.

The Dudley Observatory and Albany Amateur Astronomers wish their followers Happy Holidays.

This is the Dudley Observatory Skywatch Line for Wednesday, December 23rd and Thursday, December 24th written by Louis Suarato

The 97% illuminated, waxing gibbous Moon rises around 3:00 Wednesday afternoon. It was on December 23, 1968, that American astronauts Frank Borman, James A. Lovell, Jr., and William Anders, became the first men to orbit the Moon. The Apollo 8 mission was not only the first manned flight to the Moon and back, but it served to survey potential landing sites for the first lunar landing. At nightfall, you’ll see that the Moon resides in Taurus, about three degrees from the constellation’sbrightest star, Aldebaran. Aldebaran is sometimes mistakenly considered part of the Hyades Star Cluster, but at the distance of 65 light-years, Aldebaran is much closer than the stars of the Hyades, which are about 150 light-years away. Similar to using Orion’s belt to find Sirius, the brightest star in our sky, you can follow the Belt in the other direction, and the first bright reddish-orange star you’ll see is Aldebaran. The Pioneer 10 spacecraft is headed in Aldebaran’s general direction and should be in its vicinity in about 2 million years.

Jupiter appears above the horizon around 11 p.m. at the top of the constellation Virgo. Comet C/2013 US10 Catalina rises between Arcturus and Mars around 1:30 a.m., and at approximately 4:30 a.m., the comet will be about 30 degrees above the east-southeastern horizon. The bright star to the lower right of Mars, is Spica, the constellation Virgo’s brightest. Venus rises 11 minutes after 4 a.m., followed by Saturn an hour and 40 minutes later. 

December’s Full Moon occurs at 6:11 a.m. Christmas Day. This month’s Full Moon is known as the Full Cold Moon and the Long Night Moon. The Long Night Moon is derived from the Full Moon closest to the winter solstice, when, because of the axial tilt of the Earth, the Full Moon crosses the sky higher than any full Moon of the year. The Moon will be at its highest around midnight, and being closer to perigee than average, will add brightness to objects below. The Full Moon will be visible from Thursday at 3:54 p.m. until Friday at 6:55 a.m., a full 15 hours.

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, December 21st and 22nd written by Joe Slomka.

The Sun sets at 4:24 PM; night falls at 6:06. Dawn breaks at 5:40 AM and ends with sunrise at 7:23.

The eleven-day-old Moon blazes in the Southeast. Today it in Aries, but tomorrow it migrates to Taurus. Our satellite remains up most of the night, setting at 3:57 AM on Tuesday, and 5:05 AM on Wednesday.

Nightfall reveals Uranus in Pisces. The sixth magnitude planet is best observed at 6:56 PM. Neptune still inhabits Aquarius and is highest at 9:58 PM. Asteroid 4Vesta, at seventh magnitude, lies about three-and-a-half degrees above the star Iota Scuti. All three require finder charts from astronomy magazines, websites and apps. Neptune sets first at 9:58 PM; Vesta sets at 11:55 PMand Uranus sets at 1:20 AM.

Jupiter is already up at Midnight, rising at 11:11 PM. The Red Planet hovers between Leo and Virgo. Tuesday, Telescopic observers can witness Io reappearing from behind the planet at 11:19 PM, and Ganymede finishing its transit of the planet 11:31. Jupiter sets at 3:57 AM.

Mars is the next to rise at 1:26 AM, thirty degrees below Jupiter. It is gradually growing brighter and larger in our instruments. Under high powers, Mars looks 92 percent illuminated. First magnitude Mars lies about 6 degrees from the bright star Antares.

Comet Catalina rises on 1:49 AM, but east of Mars. Recent reports say the comet is at sixth magnitude, which permits binocular observing, if conditions are favorable.

Venus rises at 4:04 AM about 27 degrees below Mars. Venus is easy to identify, it’s the brightest object in the sky. While it is visible to the naked eye, binoculars or telescope reveals that Venus is three-quarters illuminated.

The last planet to rise is Saturn at 5:44 AM, 19 degrees below Mars. However, Saturn is moderately low, requiring a clear, unobstructed horizon.

If you see meteors streaming from the area of the Little Dipper, you are seeing the Ursid meteor shower. The shower lasts only for a day and produces about 10 meteors per hour, under ideal conditions. Unlike other meteor showers, no one has discovered the source of the shower. The peak takes place at 9 PM on Tuesday.

Monday’s main event happens shortly before Midnight. At 11:48, the Winter Solstice takes place. The Sun appears at its lowest point in the sky. This event marks the first day of winter. From then on, the noonday Sun is a bit higher in the sky. The Sun also rises earlier until June 21, the first day of summer. You can measure the progress of the Sun for yourself. Simply note where the Sun rises or sets. Every few days, note that the Sun rises or sets a bit closer to the North. This simple experiment replicates the first calendars that ancient cultures devised.

This is Dudley Observatory’s Skywatch Line for Friday, December 18, through Sunday, December 20, written by Alan French.

Reaching first quarter early Friday, a waxing gibbous Moon will dominate the early evening sky this weekend. The Moon will be due south and highest – ideally placed for observing with a telescope or binoculars – at 6:11 pm Friday, 7:03 pm Saturday, and 7:56 pm Sunday.

There is a bright and interesting pass of the International Space Station (ISS) over the Capital District on Saturday night. When halfway across the sky and well above the northern horizon, the station will move into our Earth’s shadow and fade from view. (Times will be given in hours, minutes, and seconds.)

Look for the ISS coming up from the northwestern horizon at 6:08:36 pm. Its path will take it up toward the North Star, Polaris, and just after it passes above Polaris it will move into the Earth’s shadow and disappear. This happens at 6:11:27 pm.

There is another pass of the ISS across the northern sky on Sunday night. This pass will be lower and will not move into the Earth’s shadow until it is approaching the eastern horizon.

Look for the space station at 5:15:38 pm when it will be moving up from the northwestern horizon. It will be highest at 5:18:39 when it will be thirty-two degrees above the north northeastern horizon, and will move into the Earth’s shadow and fade from view at 5:21 when just 14 degrees above the eastern horizon.

Its path will take it above the Big Dipper, which is low in the north and may be obscured by trees in many locations. In the northeastern sky the ISS will pass through the constellation Auriga, passing very closed to its brightest star, Capella. Soon after moving through Auriga it will fade from view.

When the prominent pattern of the Big Dipper, part of the constellation Ursa Major, the Great Bear, is low in the north, Cassiopeia, the Queen, rides high in the north. The Queen is easily spotted by her familiar “W’ of bright stars, although it will be tipped almost completely over and look like an “M.”

The area around Cassiopeia is rich in faint stars, many of which are revealed through binoculars.

This the Dudley Observatory Skywatch Line for Wednesday, December 16th and Thursday, December 17th written by Louis Suarato

With Comet C/2013 US10 Catalina gracing the pre-dawn skies, it seems appropriate to mention two prominent comet hunters born on December 16th. Born in poverty in 1857, Edward Emerson Barnard, more popularly known as E.E. Barnard, received little in the way of a formal education, but was drawn to photography, and became a photographer’s assistant at age nine. Barnard later developed an interest in Astronomy, and in 1881 discovered his first comet. By the end of 1882, Barnard discovered two more comets. Barnard combined his skills as a photographer with his interest in Astronomy to make the first photographic discovery of a comet while working at the Lick Observatory. The discovery was Comet 206P/Barnard-Boattini, observed on the night of October 13, 1892.

Giovanni Battista Donati was an Italian astronomer born on December 16, 1826. Donati was the first to observe the spectrum of a comet and discovered that a comet not only reflected sunlight, but its tail was formed by luminous gases. On June 2, 1858, he discovered what was to be known as Donati’s Comet, formally known as C/1858 L1. At its brightest magnitude of -1, Comet Donati was one of the most visible comets of the 19th century, and displayed a curved tail extending 60 degrees across the sky. Comet Donati was the first comet to be photographed. George P. Bond photographed Donati’s Comet at the Harvard College Observatory on September 28, 1858. Due to Comet Donati’s long elliptical orbit, it will not be seen passing Earth until after the year 4000.

Thursday morning, look for Comet C/2013 US10 Catalina about 20 degrees to the east of Mars and Spica, and 16 degrees above Venus. The bright star above and left of Comet Catalina is Arcturus. The comet will pass very close to Arcturus on New Year’s Day. Comet Catalina is currently at 6th magnitude and can be seen emitting a dust tail and a faint ion tail.

Thursday marks the 50 anniversary of when David Levy began searching for comets. Levy began his telescopic comet search, called CN3, on December 17, 1965. Levy’s achievements include 8 visual comet discoveries, and 13 photographic comet discoveries shared with Gene and Carolyn Shoemaker. The 22 comet discoveries ties Levy for the third most comets discovered by an individual.

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, December 14th and 15th written by Joe Slomka.

The Sun sets at 4:22 PM; night falls at 6:04. Dawn breaks at 5:36 AM and ends with sunrise at 7:18.

The three-day-old Moon rose this morning and, by Civil Dusk, is moderately high in the southern sky. It appears as a thin crescent in Capricornus on Monday, and fatter crescent on Tuesday. The Moon sets by 9 PM on both nights.

Neptune occupies the constellation Aquarius; it sets at 10:22 PM. Uranus swims with the fishes of Pisces; it is best observed at 7:24 PM and sets 1:48 AM. Both planets, while giants, appear small in our telescopes; detailed finder charts from astronomy magazines, websites, or apps are necessary.

By 10 PM, constellation Perseus is almost due South. It depicts a man with one short, and one long leg. The brightest star in the short leg is Algol – The Demon Star. Algol is an eclipsing binary – two bodies that orbit each other. About every three days, something gets between Algol’s primary star and us. The eclipsing body dims Algol from second to third magnitude. The eclipse occurs at 11: 58 PM Monday night.

Nightfall finds asteroid 4Vesta two degrees from the nose of the Sea Monster Cetus. It is moderately bright at magnitude 7.7. Finder charts are necessary to locate this small object. Vesta sets after Midnight.

Jupiter rises before Midnight and is located near the rear leg of Leo, the Lion. Jupiter is so large that even binoculars show some features and its four Galilean moons.

Mars appears in Virgo, about 26 degrees below Jupiter. Mars is easy to spot due to its distinct rust color. Venus, also in Leo, rises about 3:49 AM. Through a telescope, Venus is about three-quarters illuminated and blazes at minus 4th magnitude.

Comet Catalina rose at 2:42 AM, and by Daybreak, is moderately high in the eastern sky. Mars serves as a guide to the comet, since it is about 16 degrees West of Catalina.

Saturn returns to our sky. It rises about 6:08 AM, providing a challenge for the observer. It is very close to the Sun’s glare. If you don’t see it now, wait a few weeks and try again.

The annual Geminid meteor shower happens on the night of the 14th and 15th. The shower lasts only one day, but is spread over two nights. The shower is predicted to peak at about 1 PM Eastern Time on Tuesday. With the Moon out of the way, the skies are clear for meteor watchers.

By 10 PM, Gemini is high in the southeastern sky, along with Orion and Canis Major. Sky watchers should notice enhanced meteor activity. Meteors seem to stream from the twin stars Castor and Pollux. Under ideal conditions and a dark sky, one can see 120 meteors per hour.

Most meteor showers are the result of comet litter. But, the Geminids are the result of a three-mile long asteroid, Phaeton – the only known asteroid generated meteor shower. Last year, we witnessed the disintegration of Comet ISON as it looped around the Sun. UCLA astronomers discovered that Phaeton suffers similarly from the Sun. Its close proximity to solar heat bakes Phaeton’s rocks, which crumble and shed, just like a comet’s ices.

This is Dudley Observatory’s Skywatch Line for Friday, December 11, through Sunday, December 13, written by Alan French.

With the Moon reaching new early Friday, the weekend will be dark and moonless. A young crescent Moon, however, will make a brief return to Sunday evening’s sky as darkness falls.

On Sunday at 5:00 pm look for the slender Moon just over 15 degrees above the southwestern horizon. As the Sun moves farther below the horizon the southwestern sky will darken and the Moon will move lower, but the Moon will not set until 6:54 pm.

If you were standing on the Moon a bright, nearly full Earth would be a lovely sight in your skies. Sunlight reflected from Earth shines on the entire visible face of the Moon, brightening the large area experiencing night there. This allows you to see the entire Moon – a bright crescent with the rest of the lunar surface aglow with Earthshine. It is a lovely sight, and with the right foreground could be the subject of a great photograph. Vary your exposures to get one with just the right balance between the crescent and the rest of the Moon. Too long an exposure and the crescent will be overly bright and details will vanish. Too short an exposure and the Earthshine will not show well. (Don’t forget a tripod to keep the camera steady during the relatively long exposures.)

The absence of the Moon is good news for sky watchers – this weekend starts the peak of the annual Geminid meteor shower. The shower will be at its peak on the night of Sunday, December 13 and morning of Monday, December 14, and night of December 14 and morning of Tuesday, December 15. The Geminids rivals the Perseids of August as the best and most reliable meteor shower of the year.

The weather is certainly more agreeable for the August Perseids, but there are no biting insects to provide a distraction in December. Just be sure to dress extra warmly so you won’t get chilled. Since you won’t be active you’ll need more layers than you need when outside for normal winter activities.

If you trace the path of the shower’s meteors backwards, they will all intersect in the constellation Gemini at what is called the “radiant.” As darkness falls, the radiant will be low and few meteors will be seen. If you do see one then it will likely be a long one. As the radiant rises higher, more meteors will be visible, and by about 10 pm the show should be in full swing.

The best views will be from dark skies away from city lights. A reclining lawn chair is ideal for meteor watching. Look high in the sky but facing toward the radiant, which is not far from the star Castor, in Gemini. It is high toward the east at 11 pm and was low in the north northeast early in the evening.

This is the Dudley Observatory Skywatch Line for Wednesday, December 9th and Thursday, December 10th written by Louis Suarato

The 3% illuminated, waning crescent Moon sets at 3:15 Wednesday afternoon, and will reappear as a 1% illuminated, razor thin crescent Moon at 5:54 Thursday morning. Saturn rises 15 minutes later, but both will be a challenge to see. The New Moon occurs at 5:29 a.m. Friday.

The Big Dipper asterism in the constellation Ursa Major is parallel to, and low on the northern horizon after Wednesday’s sunset. Throughout the night, the Dipper will climb up the sky, as if scooping up a sea of stars. By midnight, the Big Dipper will be tipped straight up on its handle, perpendicular to the northeastern horizon. As the Big Dipper is rising in the sky, the brightest star in the sky, Sirius moves from east to south. To the east of Sirius, a line of no fewer than 20 open clusters escort Canis Major’s brightest star. The open clusters range from NGC 2301 and 2232 in Monoceros, the constellation to the upper left of Sirius, to M93 and NGC 2527 in the constellation Puppis, to the lower left of Sirius. Another open star cluster, M41, is four degrees below Sirius. M41 was discovered by Giovanni Batista Hodierna before 1654. M41 contains approximately 100 stars and is the size of the full Moon. This open star cluster is estimated to be about 190 million years old and is 2,300 light-years away. According to Robert Burnham, Jr., “M41 is a beautiful object in low power instruments…There is a bright reddish star near the center; many of other stars seem to be arranged in curving rows or groups..”.

You’ll have to stay up late, and into the early morning hours, to see the naked eye visible planets. Jupiter is first, as it clears the eastern horizon around midnight. Jupiter’s moon, Europa, begins its transit at 15 minutes past midnight, followed by its shadow 19 minutes later. The Great Red Spot transits 2 minutes after Europa’s shadow. Mars appears at 2 a.m. in the constellation Virgo, followed by Venus an hour and 40 minutes later. Comet C/2013 US10 Catalina is now to Venus’ upper left, less than a degree from Virgo’s star, Syrma.