Skywatch Line for Friday, December 18, through Sunday, December 20

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.

Skywatch Line for Wednesday, December 16th and Thursday, December 17th

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.

Skywatch Line for Monday and Tuesday, December 14th and 15th

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.

Skywatch Line for Friday, December 11, through Sunday, December 13

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.

Night Sky Adventures @ miSci Tuesday, December 15th, 6 pm “December Solstice”

The December solstice occurs on December 22 when the South Pole of the earth will be tilted toward the Sun. This is the first day of winter (winter solstice) in the Northern Hemisphere and the first day of summer (summer solstice) in the Southern Hemisphere.

The Adventure takes place at miSci, museum of innovation and science, 15 Nott Terrace Heights, Schenectady, New York 12308 518-382-7890
$ 3 per person, $ 5 per family, free for miSci members.

Lead by astronomy educators and volunteers from the Albany Area Amateur Astronomers group.

Amateur astronomers and families are invited to bring binoculars or telescopes. One or more telescopes will be provided by The Dudley.

Family friendly! Programs will be held rain, snow, or shine!

Dudley Observatory @ miSci
15 Nott Terrace Heights
Schenectady, NY 12308
(518) 382-7890 ext 259

Skywatch Line for Wednesday, December 9th and Thursday, December 10th

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.

Skywatch Line for Monday and Tuesday, December 7th and 8th

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, December seventh and eighth written by Joe Slomka.

The Sun sets at 4:21 PM; night falls at 6:03. Dawn breaks at 5:31 and ends with the Sun rising at 7:13.

The early evening sky holds no bright planets. Nightfall reveals Neptune, Uranus and the asteroid 4Vesta. Neptune still resides in Aquarius; it sets at 8:52 PM.  Pisces still contains Uranus, which is best observed at 7:52 PM. Both gas giants appear blue-green; they require detailed star charts from astronomy magazines, websites and apps. Asteroid 4Vesta hangs out about one-and-a-half degrees from the star Iota, in Cetus. Tiny Vesta also requires a detailed star chart and is best detected at 7:02 PM.

We have been following the continuing planetary parade for the past few months. Bright Jupiter rises first a bit before Midnight. By Astronomical Dawn, it is quite high in Leo, by the lion’s rear leg. On Tuesday morning, the Jovian moon Europa disappears into Jupiter’s shadow at 3:36 AM; at 4:17 AM also Tuesday, the moon Callisto’s shadow begins to march across the planet’s face.

Dawn finds Mars, in Virgo, about 23 degrees below Jupiter; Mars rose about 2 AM. Mars shines at 1.5 magnitude, much dimmer than Jupiter; but, its distinctive rust color gives it away. It appears between Virgo’s bright stars Porrima and Spica. A telescope shows Mars to be about 93 percent illuminated.

Blazing Venus rises, also in Virgo, at 3:34 AM near the star Kappa. It is easily identified about eighteen-and-a-half degrees below Mars. Under moderate powers, Venus appears about ninety percent illuminated.

Venus serves as a guide to Comet Catalina. Catalina shines at magnitude 4.8. It is about five degrees east of Venus.  Both may fit within a wide view telescope or binoculars. As previously mentioned, Catalina is slowly climbing higher daily.

The twenty-seven-day-old Moon shines about eight degrees below Venus. In Libra, it shines at magnitude minus 4.9, but is only 8.5 percent illuminated. Wednesday finds it lower in Libra and only minus 2.5 magnitude and four percent illuminated.

Every history student knows that December 7th marks the anniversary of the Japanese attack on Pearl Harbor. Few people are aware of the date’s astronomical significance. The Japanese high command chose that date because the eighteen-day-old Moon rose before midnight and shone at 87 percent, permitting attack planes to launch and fly to their targets. However, the Moon almost helped foil the surprise raid. The Condor, an American minesweeper, spotted a submarine periscope silhouetted against the moonlight. The Condor called the Ward, a destroyer, who attacked a second submarine and radioed the incident to headquarters. That report was not heeded. Had that information been acted upon, the American fleet would have had at least an hour and a half to prepare.

Skywatch Line for Friday, December 4, through Sunday, December 6

This is Dudley Observatory’s Skywatch Line for Friday, December 4, through Sunday, December 6, written by Alan French.

Reaching last quarter early Thursday, a waning crescent Moon will rise after midnight this weekend, leaving much of the night moonless and dark. The Moon rises at 1:20 am Saturday, 2:17 am Sunday, and 3:14 am Monday.

We’re in a time of transition, moving from the stars of summer toward the winter skies. You can get a preview of the stars of winter, low toward the east to east southeast, by 9:30 pm, and this will likely be offered under much more moderate temperatures.

First look for a very bright star low toward the south southeast, just seven degrees above the horizon. This is Sirius, the Dog Star. It is the brightest star in the night sky and lies only 8.7 light years away. Sirius makes its home in the constellation Canis Major, the Big Dog.

East of Sirius and higher in the sky is Procyon, the luminary of Canis Minor, the Little Dog. It is also bright largely because it is a nearby neighbor, lying 11.4 light years from us.

Moving farther left or northward along the horizon and looking higher still you should spot a pair of star of very similar brightness. The lowest is Pollux, and the upper is Castor, and they mark the heads of the Gemini twins. Pollux, lying at 33.8 light years distance, is closer than Castor at 50.9 light years.

Well above and perhaps a bit right of Castor and Pollux you’ll find bright Capella, which we wrote about last week. To its right and lower in the sky look for the bright reddish star Aldebaran. This is the brightest star in Taurus, the Bull, and marks his eye. If you have found the right star, you should see that it is the top of the lower half of a “V” of stars, lying on its side  and open top to the left. Aldebaran is almost 70 light years away.

Below Aldebaran you should easily spot the distinctive and bright star pattern of Orion, the Hunter, one of the most recognizable constellations in the night sky. The three stars of Orion’s belt are vertical in the sky, with the two stars marking his shoulder to their upper left. Brighter, reddish Betelgeuse marks the hunter’s right shoulder. Now look below and right of the belt to two stars mark Orion’s knees. The brightest, marking his left knee, is Rigel.

Compared to the other stars we’ve visited, Orion’s luminaries are distant neighbors and must be intrinsically bright stars. Rigel lies at a distance of 860 light years and Betelgeuse is 500 light years away. As we look at stars farther way from our Earth, our measurements of distance grow more uncertain.

Revisit our winter stars regularly. They rise four minutes earlier each night. That may not seem like much, but it amounts to two hours in a month, so our winter friends will rapidly move higher in the evening sky as the nights pass. In two months they will be due south at 9:30 pm.

Skywatch Line for Wednesday, December 2nd and Thursday, December 3rd

This is the Dudley Observatory Skywatch Line for Wednesday, December 2nd and Thursday, December 3rd written by Louis Suarato

On December 2, 1995, NASA launched the Solar and Heliospheric Observatory, better known as SOHO. The development of SOHO was brought about by an international collaboration between NASA and the European Space Agency, or ESA. SOHO was designed to provide data from the Sun’s deep core to outer corona and solar wind. In addition to providing spectacular images and videos of sunspots, filaments, prominences, and coronal mass ejections for the last 20 years, SOHO has revolutionized the ability to forecast space weather, providing up to a three day warning of Earth-directed disturbances, and playing a lead role in the early warning system for systems and instruments that may be affected by space weather.

Sunset occurs at 4:22 p.m. Wednesday, providing 9 hours and 16 minutes and 4 seconds of sunlight for the day. Although this weekend will have the earliest sunset of the year at 4:21 p.m., the shortest amount of daylight will occur on December 21st and 22nd at 9 hours and 2 minutes and 36 seconds.

By 6 p.m., the constellation Taurus, with its brightest star, Aldebaran, and Pleiades and Hyades star clusters, is already above the eastern Horizon. Taurus is followed by Orion, which can be viewed in full after 8 p.m., with its brightest stars Betelgeuse and Rigel, and great Orion nebula at the middle of its sword hanging from the Hunter’s belt.

Jupiter rises about 20 minutes after midnight in the constellation Virgo, just 3 degrees above the Last Quarter Moon, which occurs at 2:41 a.m. Thursday. The Moon sets at 12:14 Thursday afternoon. Friday, before dawn, the 30% illuminated, waning crescent Moon and Jupiter will be within 2 degrees. Binoculars or a small telescope should capture both the Moon and Jupiter in the same field of view. It also may be a good opportunity to view Jupiter during daylight hours, using the Moon to find the planet. Mars rises at a few minutes after 2 a.m., followed by Venus an hour and half later. Look about 8 degrees to the lower left of Venus for Comet C/2013 US10 Catalina. Recent reports indicated Comet Catalina is now displaying two tails. Estimates for the comet’s current magnitude range from 7.6 to 6.

Skywatch Line for Monday and Tuesday, November 30th and December 1st

This is the Dudley Observatory Skywatch Line for Monday and Tuesday, November 30th and December 1st written by Joe Slomka.

The Sun sets at 4:23 PM; night falls at 6:03. Dawn begins at 5:25 AM and ends with the Sun rising at 7:05.

There are no bright planets in early twilight sky. Nightfall reveals two outer planets and one asteroid. Neptune is the first to rise in Aquarius.  It appears as a tiny two-second blue dot with a brightness of magnitude 8. Uranus, in Pisces, is brighter at magnitude 5.8 also appears blue. Asteroid 4Vesta is situated about two degrees from the star Iota Ceti. All three require detailed finder charts from astronomy magazines, websites or apps. Neptune sets at 11:19 PM, Vesta at 1:01 AM and Uranus at 2:44 AM.

By 10 PM Monday, the twenty-day-old Moon, which rose at 9:27 PM, shines in Cancer. At magnitude minus 10.6, its brilliance blocks out the beautiful Beehive Star Cluster and its companion M 67. Both are best seen through binoculars, since telescopes magnify them too much. Tuesday the Moon migrates into Leo and parks itself near the bright star Regulus. The Moon remains up the rest of the night.

For a while, we have been watching the parade of bright planets in the dawn sky. Jupiter rises first after Midnight and, by Dawn, is perfectly placed for observation. Telescopic observers can see the Great Red Spot, a giant storm in Jupiter’s atmosphere, at 4:09 AM.

Mars rises next, in Virgo, about twenty degrees below Jupiter. It outshines the nearby star Porrima; Mars is 1.5 magnitude, while Porrima is a dimmer 3.5. Venus is the last planet to rise, also in Virgo and about fourteen degrees beneath Mars. Venus’ minus 4.2 magnitude outshines nearby Spica, which is only first magnitude. In binoculars or telescope, Venus exhibits a crescent illuminated at 67 percent.

The Dawn sky also hosts a visitor – Comet Catalina. Catalina is one of two Arizona telescopes commissioned by Congress to hunt for asteroids that may threaten Earth. As part of its duties, it also captures comets. This comet, officially named C/2013 US10, was discovered two years ago on Halloween. Now the comet is close enough for amateurs to see. It appears about one-and-a-half degrees from the star Kappa Virginis and about ten-and-half degrees below Venus. Tuesday finds it about eleven degrees above the eastern horizon and shines at magnitude 4.7, easily within binocular range. During the next few months, the comet will steadily climb higher and, by New Year’s, will be next to the bright star Arcturus. The comet passed behind the Sun and is on its way out of the Solar System, never to return.

Comets are leftovers from Solar System formation. They reside in the Kuiper Belt, beyond Pluto, and the further Oort Cloud. Comets are mostly ice, with some dirt mixed in. Most stay in those distant regions. However, a comet may receive a gravitational bump and head into the inner Solar System. There are three basic orbits. Some revisit every few years, for example Halley’s Comet; some come too close to the Sun and evaporate away, like 2013’s Comet Ison. A third type arrives and never returns; this is the fate of Comet Catalina.