Skywatch Line for Friday, January 25 through Sunday, January 27, 2019

This is Dudley Observatory’s Skywatch Line for Friday, January 25 through Sunday, January 27, written by Sam Salem.

On Friday, the Sun rises at 7:17am and sets at 4:59pm; the waning gibbous Moon rises at 10:38pm and sets at 10:16am. The Moon reaches last quarter phase at 4:10pm on Sunday, however, it doesn’t rise until after 1am on Monday.

Mars, at magnitude 0.8, hovers in the south-southwest in the evening. The sole evening planet is still a conspicuous sight amid the faint stars of constellation Pisces. Mars sets around 11pm. Venus and Jupiter rise a few minutes after 4am. Venus has been steadily losing altitude while Jupiter has been gaining. The two planets pass in the dawn as the magnitude –4.4 Venus slowly slips by the magnitude –1.8 Jupiter. If you have an unobstructed east-southeast horizon, try to find Saturn using binoculars. It’s just now slowly emerging from its January 2nd. solar conjunction. Saturn shines at magnitude 0.5, and rises roughly one hour before the Sun.

Winter constellations are climbing higher in the early evening as the end of January nears. Evenings over the weekend are moon-free, allowing for some winter deep-sky hunting. One of the season’s most recognizable shapes is the distinct W of Cassiopeia, now high overhead. Cassiopeia is home to two Messier clusters, M52 and M103, as well as several rich NGC clusters. You can spend a rewarding hour or two with a small telescope exploring the stellar swarms located just between the stars Delta (δ) and Epsilon (ε) Cassiopeiae. Begin your hunt with M103, which is found just one degree northeast of 2.6-magnitude star Delta. M103 glows at magnitude 7.4. You can easily see it with binoculars. M103 is a tight knot of stars that features a few standout members brighter than magnitude 8. From M103, it’s a short hop northeast to NGC663, the region’s other bright open cluster. NGC 663, also known as Caldwell 10, is a young open cluster of about 400 stars in the Cassiopeia constellation. It spans about a quarter of a degree across the sky. It can reportedly be detected with the unaided eye. It looks conspicuous in binoculars as the brightest members of the cluster can be viewed.

M 52 is another bright open cluster located in constellation Cassiopeia. Messier 52 can easily be seen with binoculars. In 10×50 binoculars, it appears as a hazy, nebulous patch of light. 4-inch telescopes reveal a dense, compressed star cluster populated by many faint stars, with a shape resembling that of the letter V. More stars are visible in 6-inch and larger instruments. The cluster occupies an area just less than half of the size of the full Moon. M 52 is very easy to find as it lies near Cassiopeia‘s prominent W asterism. The cluster can be located by extending the line from the stars Schedar (Alpha Cassiopeiae) to Caph (Beta Cassiopeiae) to the northwest, about the same distance as that between the two stars. Messier 52 lies near another prominent deep sky object, the Bubble Nebula (NGC 7635). The nebula can be seen about 35 arc-minutes southwest of the cluster.

Skywatch Line for Wednesday, January 23rd, and Thursday, January 24th, 2019

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

The 89% illuminated, waning gibbous Moon rises at 8:04 Wednesday night below the constellation Leo. Thursday night, the Moon will make its trip across the sky in Virgo. The constellation Leo has been identified as a lion by many ancient civilizations, including the Mesopotamians, Perians, Turks, Syrians, Hebrews, and Indians. This easily distinguishable constellation can be found by following the pointer stars of the Big Dipper in the opposite direction of Polaris, the North Star. The cycle of stars forming the lion’s mane are Algenubi, Kasalas, and Adhafera. The end of the Lion is marked by the star Denebola, which means “lion’s tail”.  

Mars remains the only easily visible planet in the nighttime sky. Look for Mars in Pisces before it sets at 11:06 p.m.. The pre-dawn sky continues to be dominated by the planets Venus and Jupiter, which are 3 degrees apart. Look over the southeastern sky after 5 a.m. for these bright, closely paired planets.  Venus and Jupiter will move apart as Venus travels closer toward the Sun. Saturn joins Venus and Jupiter, as it makes its reappearance in the morning sky. If you have a clear southeastern horizon, you may be able to see Saturn after 6:07 a.m. and before it’s lost in the glow of sunrise.

On January 24, 1986, the spacecraft Voyager II made its closest approach to the planet Uranus. Traveling as close as 50,600 miles above the planet, Voyager II transmitted thousands of images back to Earth. Among its discoveries, Voyager II sent images of 10 previously unknown moons, and 2 never before seen rings. Launched by NASA on August 20, 1977, Voyager II is currently travelling toward interstellar space, having traveled 9.5 billion miles.

Skywatch Line for Monday and Tuesday, January 21st and 22nd, 2019

This is the Skywatch Line for Monday and Tuesday, January 21st and 22nd.

The Sun sets at 4:54 PM; night falls at 6:33. Dawn begins at 5:40 AM and ends with the Sun rising at 7:19.

Mars is the only naked-eye visible planet in the evening. The Red Planet shines with zero magnitude in Pisces, appears about 89% illuminated, is 6.5 arc-seconds in size, and about 51º high in the South. Mars sets at 11:07 PM. Uranus shares Pisces with Mars, but is about 14º to Mars’ upper left. Uranus shines with 6th magnitude and is seen with 3.5 arc-seconds in size. Uranus is best observed at 5:38 PM and sets at 12:20 AM.

Neptune, about 30º below Mars in Aquarius, glimmers with 8th magnitude and is a tiny 2.2 arc-seconds in our telescopes. Neptune sets at 8:33 PM.

Nightfall sees the post-eclipse Moon rising in Cancer at 5:39 PM. The nearly full Moon blazes with minus 12th magnitude and is about 8º high in the East. It is best observed at 1:08 AM, Tuesday and sets during daytime. Tuesday’s Moon rises in Leo at 6:55 PM, appearing about 94% lit and 20º high. It is best observed at 2:08 AM, Wednesday and also sets during daytime.

Despite the blazing Monday Moon, Comet Wirtanen is still visible. It currently occupies the Great Bear’s head and is reported to be about 6th magnitude, visible to naked-eye viewers in dark rural skies.

Finder charts for Uranus, Neptune and Comet Wirtanen are available from online astronomical sites.

Bright planets blaze in the pre-dawn sky. Venus, rising in Ophiuchus at 4:03 AM, appears abut 58% lit, 21 arc-seconds in size and at magnitude minus 4. About 2.4º below Venus, lies Jupiter, also in Ophiuchus. It shimmers with minus 1st magnitude, rises at 4:14 AM and a large 33 arc-seconds in size.  Note their positions; last week they were further apart, and will, later this month, appear very close to each other. Jupiter also lies about 8º from the red giant star Antares.

Finally, Saturn, in Sagittarius, rises at 6:15 AM, about 28º below the Venus-Jupiter pair but 5º above the horizon. Saturn shines with zero magnitude. Again, note its position. Saturn, too, in on the move and approaches a sinking Venus.

With Venus so prominent in the pre-dawn sky, let us examine her in detail. Venus is the second planet from the Sun. It is almost an Earth twin, about the same size and slightly less mass. Early telescopic observers noted its complete cloud cover. They speculated that Venus was a lush, tropical planet. As science obtained better instruments, rude shocks came. Venus did not rotate in 24 hours like Earth; its day lasts 243 earth-days. Russian and US probes landed on Venus; pictures showed a rock filled wasteland. Those same probes recorded a toxic atmosphere with true acid rain. Since Venus is closer to the Sun, it gets twice the solar radiation. Temperatures approach the melting point of lead and atmospheric pressure is 90 times that of Earth. Its slow rotation and lack of axis tilt means no seasons or weather. Most planetary scientists now think that Venus is a case of uncontrolled global warming. Any oceans boiled off, leaving an atmosphere of 96 percent carbon dioxide. Without oceans, there was no water to capture the carbon dioxide into limestone rocks, as on Earth.

Skywatch Line for Friday, January 18 through Sunday, January 20, 2019

This is Dudley Observatory’s Skywatch Line for Friday, January 18 through Sunday, January 20, written by Sam Salem.

On Friday, the Sun rises at 7:22am and sets at 4:50pm; the waxing gibbous Moon rises at 2:22pm and sets at 4:36am.

Mars, at magnitude 0.7, continues to have the evening sky all to itself as the lone planet, outshining the stars nearby. Its distinctive color makes Mars easy to spot, slightly west of due south at dusk. Venus, at magnitude –4.5, rises around 4am. In a telescope with enough magnification, all one generally sees is a snow-white disk exhibiting a moonlike phase. Not far behind Venus is Jupiter, which clears the southeast horizon a little more than half an hour later. Jupiter shines at magnitude –1.8 and attains an altitude of 15 degrees in bright morning twilight. Jupiter offers lots of detail in a telescope, but only when it climbs higher. It will be several more weeks before we can productively turn our telescopes on Jupiter once again.

This weekend has the year’s first full Moon, first lunar eclipse, and first supermoon. Full Moon occurs Sunday night at 12:16am. Lunar eclipse occurs when Moon is full. Yet, a lunar eclipse doesn’t happen at every full Moon. The reason is that Moon swings anywhere from five degrees north or south of the Earth’s shadow. Lunar Eclipse occurs when the Moon is directly opposite the Sun in Earth’s sky. Examine the Moon during eclipse as it appears larger than normal. Perigee, when the Moon is closest to the Earth, occurs only about 14 hours after maximum eclipse. A full Moon that comes within 90% of its closest approach to Earth is defined as a supermoon.

The total eclipse of the Moon lasts for somewhat more than one hour, and is preceded and followed by a partial umbral eclipse, each time persisting for over an hour. The whole umbral eclipse from start to finish has a duration of nearly 3-1/3 hours. The total eclipse and can be viewed from North and South America, Greenland, Iceland, Europe, northern and western Africa plus the Arctic region of the globe. A penumbral lunar eclipse takes place before and after the umbral lunar eclipse. A penumbral lunar eclipse is so faint that many people won’t even notice it while it is happening. The lunar disk often exhibits a coppery color during a total lunar eclipse. Although the Moon is completely immersed in the Earth’s dark shadow, the Earth’s atmosphere refracts sunlight and the longer wavelengths of light, red and orange, pass onward to fall on the Moon’s face.

Binoculars make eclipse colors more vivid and give 3D views of the eclipsed Moon suspended among the stars. A telescope will reveal subtle colors in Earth’s shadow as well as “mini-eclipses” of craters and other lunar features as the gradually advancing shadow covers them one after another. Also notice that the shadow is curved. That was the clue ancient observers used to deduce that Earth must be spherical.

The lunar eclipse runs from 9:36pm on Sunday night to 2:48am. The penumbral eclipse begins at 9:36pm. The partial eclipse begins at 10:33pm, when the Moon enters umbra. The full eclipse begins at 11:41pm. The Moon is deepest in umbral shadow, mid-eclipse, at 12:12am. Full eclipse ends at 12:43am, when the Moon starts to leave umbra. Partial eclipse ends at 1:50pm, when Moon exits umbra. Penumbral eclipse ends at 2:48am, when Moon exits penumbra.
For more information on the Supermoon Lunar Eclipse visit the link below.
https://www.skyandtelescope.com/observing/your-guide-to-januarys-supermoon-total-lunar-eclipse/
The Dudley Observatory is organizing a Lunar Eclipse party on Sunday night at miSci. The party includes Planetarium shows, Lunar Eclipse viewing (weather permitting), viewing through their antique 19th century Comet Seeker telescope (rain or shine), live streaming of the eclipse indoor, food coffee and hot chocolate, and a variety of other activities. The Party runs from 9pm to 2am.
For more information and pre-registration, visit the link below. http://dudleyobservatory.org/lunar-eclipse-2019/

Skywatch Line for Wednesday, January 16th, and Thursday, January 17th, 2019

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

The 77% illuminated, waxing gibbous Moon rises at 12:59 p.m. Wednesday. The evening sky will reveal the Moon is in the constellation Taurus. Use binoculars to find the Pleiades and Hyades star clusters close to the Moon Wednesday and Thursday nights. The Pleiades will be above, and left of the Moon Wednesday night, and above, and right of the Moon on Thursday. The Hyades star cluster will be to the right of the Moon Wednesday, and to its left on Thursday. The bright star closest to the Moon on both nights is Aldebaran, Taurus’ brightest. The only naked-eye visible planet in the night sky is Mars. Look about 40 degrees above the southwest horizon at 7 p.m.. The red planet sets at 10:31 Wednesday night. The pre-dawn sky features Venus and Jupiter 4 degrees apart above the southeastern horizon.

In addition to the Hyades and Pleiades star clusters, other binocular targets for these wintry nights include the Beehive Cluster (M44), the Great Orion Nebula (M42), and the Andromeda Galaxy (M31). The Beehive Cluster rises in the east-southeast after 7 pm. This open star cluster is one of the nearest to Earth, and contains more stars than any of its kind that close to our planet. The Beehive Cluster is 577.3 light-years away, containing stars estimated to be 625 million years old. The Great Orion Nebula is a star making cloud of gas and interstellar dust. A telescopic view of this nebula will reveal four stars at its center, known as the Trapezium. These young, bright stars illuminate the nebula. Look halfway down the “sword” of stars hanging from Orion’s belt for M42. At a distance of 2.5 million light-years, the Andromeda Galaxy is our Milky Way’s closest neighboring galaxy. Estimated to contain one trillion stars, the Andromeda Galaxy has more than twice the Milky Way’s estimated 200 to 400 billion stars. Find M31 by using Cassiopeia’s deeper “V” which points to this galaxy abut 15 degrees away.

The Albany Area Amateur Astronomers invite you to join them for their monthly meeting to be held at miSci beginning at 7:30 p.m., Thursday, January 17th. The guest speaker will be Dr. Evan Halstead, cosmologist and professor of Physics at Skidmore College. Dr. Halstead’s topic will be “The Expanding Universe”.

Skywatch Line for Monday and Tuesday, January 14th and 15th, 2019

This is the Skywatch Line for Monday and Tuesday, January 14th and 15th.

The Sun sets at 4:45 PM; night falls at 6:26. Dawn breaks at 5:43 AM and ends with the Sun rising at 7:23.

The First Quarter Moon dominates the sky. Monday’s Moon begins the evening in Pisces, but migrates into Cetus by nightfall. It blazes with minus 10th magnitude on both nights. The Moon sets at 1:14 AM on Tuesday and at 2:18 AM on Wednesday.

Mars, in Pisces, is the only easily seen planet. It appears about 88% lit, shines with zero magnitude and lies about 5º high in the South. It is best observed at 4:53 PM and sets at 11:10 PM.

Neptune occupies Aquarius, about 25º below and to Mars’ left. Neptune glows with 8th magnitude and appears a tiny 2.2 arc-seconds, 36º high; it sets at 9 PM. Uranus, in Pisces, is brighter with 5th magnitude and a larger 3.6 arc-seconds in our telescopes. However, it lies only 5º from the brilliant Moon, which hinders observation. Uranus is best observed at 6:06 PM and sets at 12:48 AM.

Comet P46/Wirtanen is still available for viewing. The comet is pulling away, so its image in telescopes is constantly shrinking and becoming dimmer. Wirtanen is quite close to the star Omega Ursae Majoris, which forms the nose of the Great Bear. Recent reports are the comet appears as a 6.6 magnitude haze. Up all night, it is best observed at 6:06 AM.

Finder charts for Neptune, Uranus and Wirtanen are available from various astronomy media.

Dawn brings new bright planets. Venus, in Ophiuchus, rises at 3:54 AM, flashing with minus 4th magnitude and about 16º high at Civil Dawn. Venus’ 22 arc-seconds in size appears as a 55% crescent. Jupiter shares Ophiuchus with Venus, but lies about 7º below. It glimmers with minus 1st magnitude and appears about 32 arc-seconds in size at an altitude of 9º above the eastern horizon.

Saturn returns to our skies by rising in Sagittarius at 6:39 AM. It glows at zero magnitude, appears about 15 arc-seconds in size, but is about 2º high in the East. It requires an unobstructed horizon to be seen.

By nightfall, Orion is already high in the southeastern sky. The bright white star Rigel marks the mighty hunter’s knee. A dim line of stars begins at Rigel and flows westward and downward until it disappears below the horizon. This is the river Eridanus. To see the full extent of this heavenly waterway, one must travel to Florida. There, Eridanus ends with the bright star Achernar, which literally means, “star at the river’s end.” The identity of this stream is a bit of a mystery. Ancient authors differ as to whether it refers to the Euphrates or the Nile. Both rivers were revered from time immemorial. Both were the sources of water and bountiful harvests. It is no coincidence that all civilizations and cities were founded along the banks of great rivers. The ancients thought of the Earth as an island surrounded by an immense body of water. The creation story in the Book of Genesis alludes to this view, as do Babylonian creation myths. The sky also bears out this vision. For the past several months we have been observing water related constellations. Delphinus (the Dolphin), and Capricornus (the Sea Goat), began the procession, followed by Aquarius, Cetus and Pisces. Eridanus spills its heavenly waters to sustain this celestial aquarium.

The Albany Area Amateur Astronomers hold their monthly meeting on Thursday, January 17th, at 7:30PM at miSci. Dr Evan Halstead will talk about “The Expanding Universe”. He earned bachelor degrees in physics and electrical engineering and a PhD in Physics all at the University of Buffalo. He is a cosmologist and professor of Physics at Skidmore College who has studied gravitational collapse, black holes, and Big Bang inflationary fields.

All club events are free and open to the public.

Skywatch Line for Friday, January 11 through Sunday, January 13, 2019

This is Dudley Observatory’s Skywatch Line for Friday, January 11 through Sunday, January 13, written by Sam Salem.

On Friday, the Sun rises at 7:25am and sets at 4:42pm; the waxing crescent Moon rises at 10:36am and sets at 10:08pm. On Saturday evening, the crescent Moon slowly drifts south of Mars. At their closest, around 9:27pm, they’ll be separated by a little more than five degrees. Mars’ steady eastward drift has kept it near the meridian in the early evening for months.

The morning sky is home to Venus and Jupiter. Venus, at magnitude –4.5, rises a little before 4am. Jupiter, at magnitude –1.8, rises at the southeast horizon around 4:45am. Jupiter is obviously fainter than Venus, and yet it’s still more luminous than the brightest stars.

Evenings over this weekend are partly lit by the waxing crescent Moon that doesn’t set until nearly midnight on Saturday. The early winter sky is rich with bright deep-sky treasures. The Pleiades, or Seven Sisters, in constellation Taurus, is one of the few deep-sky objects that are splendid in binoculars. Also known as Messier 45 (M45), the Pleiades cluster looks like a miniature, short-handled version of the Big Dipper. The main “dipper” stars range in brightness from 2.8-magnitude Alcyone, to 4.2-magnitude Merope. In addition to the group’s main components, one feature that always attracts attention is the distinctive curving row of 7th- and 8th-magnitude stars leading into Alcyone from just below the tiny dipper’s stubby handle. All this is set against an attractive scatter of faint stellar glints throughout the field. It’s a wonderful sight in any pair of binoculars. If you’re observing M45 under a very clear, dark sky, try to catch sight of the nebulosity near Merope. This weekend, you’ll have to wait for the Moon to set before making your attempt. In binoculars the glow resembles a faint, broad comet tail extending south from the star. A small, low-power scope also shows this feature well, though telescopes generally don’t have sufficiently wide fields of view to contain the entire Pleiades cluster. This is one celestial object binoculars really do show best.

On January 11 1787, the German Astronomer, William Herschel, discovered the first two moons of Uranus, Titania and Oberon, six years after he had discovered the planet. Titania is the largest of the moons of Uranus and the eighth largest moon in the Solar System. Its orbit lies inside Uranus’ magnetosphere. Oberon is the outermost major moon of the planet Uranus. It is the second largest moon of Uranus and the ninth most massive moon in the Solar System. Oberon’s orbit lies partially outside Uranus’ magnetosphere. Although the first two Uranian moons were discovered in 1787, they were not named until 1852. The responsibility for naming them was taken by Herschel’s son, John. Instead of assigning names from Greek mythology, John named the moons after magical spirits from William Shakespeare’s A Midsummer Night’s Dream. Titania is named after the queen of the fairies and Oberon is named after the mythical king of the fairies from A Midsummer Night’s Dream.

Skywatch Line for Wednesday 9th, and Thursday, January 10th, 2019

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

The 8% illuminated, waxing crescent Moon sets at 7:16 p.m. Wednesday. Last week, China made history by accomplishing the first soft landing on the far side of the Moon. China’s Chang’e-4 probe, consisting of a lander and rover, landed in the Von Karman crater. The lunar rover, Yutu 2, began its trek out of the crater on January 3rd. High above to the Moon’s left, you’ll find Mars in the constellation Pisces. The morning planets, Venus and Jupiter, rise about an hour apart in Scorpius. Venus rises first at 3:47 a.m., followed by Jupiter at 4:49. Look over the southeast horizon before dawn for these two bright planets. A telescopic view of Venus will reveal it is 53% illuminated.

Comet 4P/Wirtanen has dimmed from 3.4 magnitude to 5.5 magnitude as it moves away from the Earth and Sun. It is still bright enough to see through binoculars. As Ursa Major rises along the eastern side of Polaris, the top two stars of the Big Dipper’s bucket point to the comet. Beyond these two stars in the Big Dipper, are Alhaud IV and Muscida. Look 2 degrees to the east of Muscida for Comet 46P/Wirtaen.

Fifty years ago Thursday, NASA successfully landed Surveyor 7 on the Moon. This unmanned spacecraft was the last in a series of exploratory missions to find a suitable landing site for Apollo 11. On January 10, 1968, Surveyor 7 landed on the rim of the crater Tycho. From that vantage point, Surveyor 7 transmitted 21,091 photos back to Earth. Unlike the previous Surveyor missions, which had already determined the feasibility of a manned landing, Surveyor 7 was the only spacecraft to land in the lunar highlands.

Skywatch Line for Monday and Tuesday, January 7th and 8th, 2019

This is the Skywatch Line for Monday and Tuesday, January 7th and 8th.

The Sun sets at 4:37 PM; night falls at 6:19. Dawn begins at 5:44 AM and ends with the Sun rising at 7:25.

The only easily visible evening planet is Mars. Mars, in Pisces, is now brightest and largest for this year. This month it dims from 0.5 to 0.9 magnitude; it also thins from 7 to 6 arc-seconds in size. Mars appears about 87% illuminated and about 49º high at Civil Dusk. It sets at 11:13 PM.

Mars is sandwiched between two dimmer planets, each about 20º away. Neptune, in Aquarius, is a dim 8th magnitude and a tiny 2.2 arc-seconds in size. About 37º high at Dusk, it sets at 9:26 PM. Brighter Uranus shares Pisces with Mars, but at opposite sides of the constellation. Uranus is about 6th magnitude and a bit larger and 57º high when it is best observed at 6:33 PM; it sets at 1:16 AM.

The 2-day-old Moon, in Capricornus, appears about 3% lit and 9º high on Monday, setting at 6:14 PM. Tuesday it is brighter, about 7% lit and 16º high; it sets at 7:11 PM.

The Moon’s absence makes observing Comet Wirtanen easier. The comet is found in the faint constellation Lynx, midway between Auriga’s bright star Capella and the bowl stars of the Big Dipper, Megrez & Dubhe. It is up all night, shining with 5th magnitude.

Finder charts for Neptune, Uranus and comet Wirtanen are available from astronomical media.

The pre-dawn sky shows the brightest planet. Venus, in Libra, was at its greatest elongation from the Sun on Sunday. Rising at 3:45 AM, at Dawn, it is about 51% lit, blazes with minus 4th magnitude, 24 arc-seconds in size and stands 17º above the eastern horizon. Jupiter, in Ophiuchus, follows at 4:56 AM, shines with minus 1st magnitude and appears a large 32 arc-seconds in size. However, its 7º altitude makes observing the giant planet difficult. Note their 12º separation; later this month, they have a conjunction.

Mercury, in Sagittarius, is now ending its morning apparition; it rises at 6:40 AM. Mercury appears about 94% lit, glows with minus zero magnitude and appears about 5 arc-seconds in size. However, its low 2º altitude requires an unobstructed horizon for the observer to see this elusive planet.

Sunday, January 6th, was the Christian feast of the Epiphany, otherwise known as “Three Kings Day.” But, who were these “kings?” Most likely they were Magi from the eastern empire of Babylon. Babylonians were famous for their astronomical skill. By 2000 BC, they identified all five visible planets, the major constellations, the zodiac and the Saros cycle of eclipses. These priest-astrologers were very powerful and respected throughout the known world.

These dedicated sky watchers would certainly have noticed any new object or event in the night sky. While some think that a comet or supernova may have been the “Christmas Star.” The prevailing opinion is that it may have been an astrological event: the most likely being a triple conjunction between Saturn and Jupiter during the year 7 BC. During the course of the year, Jupiter appears to: chase Saturn, catch up with it, pass it, turn around and catch up with and pass Saturn again, and finally catch up with Saturn one more time before sailing eastward past it. This startling series of events took place in Pisces, a significant constellation. While we now know the planets to be worlds like our own Earth, to the ancients stars and planets were messengers from the gods. When two planets, associated with the most powerful gods, keep meeting, the Magi knew something significant was about to happen. These scholars were also familiar with their neighbors. A search of Jewish documents provided the inspiration to set off for that distant land and a possible meeting with a new god-king.

Skywatch Line for Friday, January 4 through Sunday, January 6, 2019

This is Dudley Observatory’s Skywatch Line for Friday, January 4 through Sunday, January 6, written by Sam Salem.

On Friday, the Sun rises at 7:27am and sets at 4:35pm; the waning crescent Moon rises at 6:06am and sets at 3:38pm. The new Moon occurs on Saturday at 8:28pm. 2019’s first new Moon will pass between the Earth and Sun to stage a partial eclipse of the Sun. It happens on the night of January 5 for time zones in the Americas, thus we won’t see it. The partial eclipse will be visible from China, Korea, Japan, Russia, North Pacific Ocean and Alaska’s Aleutian Islands.

Mars, at magnitude 0.5, stands out readily from the faint stars populating the early evening sky. Mars, in constellation Pisces, sets around 11:15pm. In a telescope, Mars is gibbous and quite small, about 7½ arc-seconds from pole to pole. The rest of the solar system action takes place at dawn. Venus, at magnitude –4.6 in constellation Virgo, clears the southeast horizon at about 3:40am. In a telescope, Venus is almost half sunlit. Venus is at greatest elongation from the Sun on Sunday. Elongation is the angle observed from the Earth between the direction to the Sun and the direction to the planet. From this point on Venus will appear to gradually drift sunward. The brilliant planet will remain standing out in the morning sky through to summer. Venus is an inferior planet that orbits the Sun inside of Earth’s orbit. Venus swings out to its greatest elongation as a “morning star” this Sunday going 47 degrees west of the Sun on the sky dome.

Jupiter, at magnitude –1.8, rises at around 5:10am, lower left of brighter Venus. By the time twilight brightens the sky, Jupiter has climbed to an altitude of nearly 14 degrees. Look closer to Jupiter’s lower right for orange Antares. Mercury, at magnitude –0.4, is at the tail end of its current apparition. Mercury is getting lower in the dawn rising at about 6:30am. It sits lower left of brighter Jupiter, which in turn is lower left of even brighter Venus. Mercury and Jupiter move farther apart every day. To see Mercury you’ll need an unobstructed horizon to the east-southeast.

Dog Star, Sirius, reaches its highest point in the sky around midnight every New Year’s Eve. It rises 4 minutes earlier each passing night. Find Sirius below constellation Orion, very low in the southeast. Sirius is easy to see because it’s so bright and because the three prominent Belt stars in the constellation Orion always point to it. Sirius flashes different colors as it rises near the horizon. The prismatic effects of Earth’s atmosphere cause this optical illusion. Look for Sirius and the faint star cluster near it. It’s the lovely star cluster M41. This cluster lies about four degrees, south of Sirius. M41 is sometimes also called the Little Beehive, after the other famous Beehive star cluster (M44), also an open cluster, in the constellation Cancer. In clear, dark skies, M41 is visible to the naked eye. It has an apparent magnitude of 4.5 and lies at an approximate distance of 2,300 light years from Earth. M41 can be seen in the same binocular field with Sirius and Nu-2 Canis Majoris, an evolved orange giant with a visual magnitude of 3.95. The cluster forms a triangle with the two stars. The cluster is relatively loose and can be resolved in a small telescope. It is best observed at low magnifications. Small telescopes resolve about 50 stars, while 6-inch and 8-inch telescopes show many more fainter members. The best time of year to observe M41 is in the months of December, January, and February. M41 occupies an area of 38 arc-minutes in apparent diameter, roughly the size of the full Moon.