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This Week’s Sky at a Glance, October 14 – October 21

The planet Uranus is at opposition this Thursday, rising at sunset and sitting high in the sky by late evening. I usually try to observe Uranus and Neptune at least once a year in binoculars or a telescope, often as part of an effort to see all eight planets (Earth is fairly easy) in one night or calendar day. Uranus can be seen with just your eyes around opposition but it requires a dark, transparent sky, good eyesight and knowledge of exactly where to look. Both of these planets are near dim naked-eye stars, making them easier to hunt down. A detailed star map including their locations is essential, such as the one published annually [pdf] on the Sky and Telescope website.

Uranus is about one degree above Omicron Piscium and is brighter than any star that close, using binoculars, and over the next two months it will move west of that star. Neptune can be found less than one degree below Lambda Aquarii over that time span, much dimmer than Uranus but still brighter than any star within that distance below Lambda. With binoculars, the two planets will resemble stars with, perhaps, a slight blue-green hue and less twinkling. A telescope at moderate to high magnification will expand the planets into discs, which I usually see as pale green for Uranus and pale blue for Neptune. Stars, being at vast distances from us, do not look larger under higher magnification, and using this technique was how these planets were distinguished from stars in 1781 and 1846, respectively.

Uranus and Neptune are nearly twins, with Uranus four times wider than Earth and Neptune just a bit smaller but more massive. They are referred to as ice giants. Although their atmospheres are composed primarily of hydrogen and helium, they also contain frozen water, ammonia and methane. In addition, their interiors are predominantly rock and ices. Methane absorbs wavelengths of light in the red part of the visible light spectrum, passing the shorter-wavelength green and blue light. Methane in the planets’ upper atmosphere is responsible for the colours we see through a telescope.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 7:35 am and sunset will occur at 6:34 pm, giving 10 hours, 59 minutes of daylight (7:39 am and 6:40 pm in Saint John). Next Saturday the Sun will rise at 7:44 am and set at 6:22 pm, giving 10 hours, 38 minutes of daylight (7:48 am and 6:28 pm in Saint John).

The Moon is new on Thursday, making this a great week for autumn deep-sky observing. Saturn continues to awe observers with views of its rings in early evening. Mercury and Jupiter are too low in the west for observing after sunset. Mars is about five degrees above Venus this weekend in the morning sky. Next weekend, look for meteors springing from Orion’s club early in the morning. This minor meteor shower is one of two arising from Halley’s Comet.

International Observe the Moon Night is on Saturday, October 28. Members and guests of RASC NB will have telescopes and binoculars set up at the Irving Nature Park in Saint John for this event on Friday, October 27 from 6:30 pm to 9 pm, with a back-up date of Saturday.

Questions? Contact Curt Nason at nasonc@nbnet.nb.ca.

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This Week’s Sky at a Glance, October 7 – October 14

Small constellations tend to get overlooked unless, like Delphinus the Dolphin, they have fairly bright stars or an eye-catching pattern. Aries the Ram and cleverly named Triangulum aren’t quite as pretty as Delphinus but they do get noticed. Okay, Triangulum isn’t pretty but it is acute, situated below Andromeda in mid-evening. Below it is brighter Aries, which resembles a somewhat squashed triangle.

In mythology, the god Hermes sent a flying, golden ram to rescue a prince who was being sacrificed to end a famine. The prince showed his gratitude by slaughtering the ram and giving its fleece to a man in exchange for his daughter’s hand in marriage. The Golden Fleece later became the quest of Jason and the Argonauts. Over 2000 years ago the Sun was in Aries on the first day of spring, and the vernal equinox is still called the First Point of Aries despite having moved into the constellation Pisces long ago. That movement is due to the precession of the equinox, a wobble of the Earth’s polar axis that completes a circuit every 25,800 years.

Triangulum is not associated with an exciting tale from mythology but at times it had been regarded as a tribute to both the Nile Delta and the island of Sicily. I use the tip of the triangle as a reference for locating the Triangulum Galaxy, also called M33. It is almost halfway and a tad to the right of a line from the tip to orange Mirach in Andromeda. Smaller and slightly more distant than the nearby Andromeda Galaxy (M31), this face-on spiral galaxy is dim but attainable with binoculars in a reasonably dark sky.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 7:25 am and sunset will occur at 6:47 pm, giving 11 hours, 22 minutes of daylight (7:30 am and 6:52 pm in Saint John). Next Saturday the Sun will rise at 7:35 am and set at 6:34 pm, giving 10 hours, 59 minutes of daylight (7:39 am and 6:40 pm in Saint John).

The Moon is at third quarter on Thursday, rising around 11:30 the previous evening and setting a little before 3 pm. Jupiter is just a few weeks from being in conjunction with the Sun so Saturn rules the early evening sky. Following their recent rendezvous, Venus and Mars proceed in opposite directions in the morning sky. Mercury is in superior conjunction with the Sun on Sunday, and moves into the evening western sky late in the month. The minor Draconid meteor shower is at its modest peak from Saturday evening to Sunday morning. You might see a few slow-moving meteors per hour coming out of the north, but it has surprised with intense activity a few times in the past century.

The Saint John Astronomy Club meets at the Rockwood Park Interpretation Centre on October 7 at 7 pm. The William Brydone Jack Astronomy Club meets at the Forestry-Earth Sciences building at UNB Fredericton on Tuesday at 7 pm. All are welcome.

Questions? Contact Curt Nason at nasonc@nbnet.nb.ca.

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This Week’s Sky at a Glance, September 30 – October 7

Two stellar crowns are included among the 88 official constellations. Both are above our horizon around 8 pm but one requires an unobstructed and near-pristine sky to the south. Both crowns arise from mythological tales of the popular demigod Dionysus (Bacchus in Roman mythology), the god of wine.

Corona Borealis, the Northern Crown, is a pretty semicircle of stars situated high in the west, one third of the way from Arcturus to Vega. In mythology, Ariadne was the daughter of King Minos of Crete. She helped Theseus slay the bull-headed Minotaur and escape from the Labyrinth, and then accompanied him and his crew on a voyage home to Athens where they were to wed. Along the way they stopped at the island home of Dionysus, who was a great and wily host. After a night of revelry Theseus was forced into leaving without Ariadne, and Dionysus presented her with a beautiful crown if she would be his bride. The crown was placed in the sky to commemorate their wedding.

The Sagittarius teapot asterism is low in the south before 8 pm this time of year, and Corona Australis, the Southern Crown, rides the horizon below. This semicircle of stars is sometimes called the lemon wedge asterism, to go with the teapot and the teaspoon above the teapot’s handle. Dionysus was the result of an affair between Zeus and a mortal woman. The gods had to be careful in such affairs as mortals could not withstand the full passionate heat of their embrace. Vengeful Hera, the wife of Zeus, tricked the now-pregnant woman into requesting Zeus hold her as he would a goddess, and as expected she did not survive. The unborn child was sewn into the thigh of Zeus and raised by his aunt after birth. Later, Dionysus honoured his mother by placing a wreath in the sky. Such a start in life would drive anyone to drink.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 7:16 am and sunset will occur at 7:00 pm, giving 11 hours, 44 minutes of daylight (7:21 am and 7:06 pm in Saint John). Next Saturday the Sun will rise at 7:25 am and set at 6:47 pm, giving 11 hours, 22 minutes of daylight (7:30 am and 6:52 pm in Saint John).

The full Harvest Moon occurs on Thursday, it being the full Moon near the autumnal equinox. Jupiter is pretty much out of the sky now, setting 20 minutes after sunset. Saturn is in the southwest after twilight, setting around 10:20 midweek. In the morning sky Venus has a close conjunction with Mars late in the week, appearing at its upper left on Thursday and lower left on Friday. Mercury is well on its way toward superior conjunction with the Sun on October 8.

RASC NB members in Saint John will be celebrating Fall Astronomy Day with public observing at the Rockwood Park Bark Park (First Arch) on Friday, September 29, with a cloud date of September 30. The Saint John Astronomy Club meets at the Rockwood Park Interpretation Centre on October 7 at 7 pm.

Questions? Contact Curt Nason at nasonc@nbnet.nb.ca.

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This Week’s Sky at a Glance, September 23 – September 30

Autumn has arrived, and dedicated stargazers are happy to have the longer observing time afforded by earlier sunsets. The summer constellations appear reluctant to move on, however; emerging from twilight in nearly the same place each night because the earlier darkness masks that they rise four minutes sooner each day. But move on they do, and by mid-evening the two groups of autumn constellations lord over us.

Perseus sits below W-shaped Cassiopeia in the northeast these evenings. Cepheus, the king of ancient Ethiopia, is a house-shaped constellation fenced within his wife Cassiopeia, Cygnus and the North Star. The feet of Princess Andromeda are below the W of Cassiopeia, and her head is at the tail end of Pegasus the winged horse. The asterism called the Great Square of Pegasus rises as a large diamond, a harbinger of the baseball post season. Rounding out the mythological tale is Cetus, playing the role of a ferocious sea monster that is stoned, in a manner of speaking, by Perseus in his rescue of Andromeda. Cetus is actually a whale, and segues to the second group – the water constellations.

To the left of the Sagittarius Teapot we see the large chevron of Capricornus the sea goat, representing the goat-boy flautist Pan who didn’t completely morph into a fish when he tried to escape monstrous Typhon. Above and left is the source of all this water – Aquarius, the water bearing servant of the Olympians. Below him is the southern fish, Piscis Austrinus, and further east we have Aphrodite and Eros as Pisces the fishes. Cetus swims below them, and well above Capricornus we see Delphinus the dolphin trying to leap back into summer.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 7:07 am and sunset will occur at 7:14 pm, giving 12 hours, 7 minutes of daylight (7:12 am and 7:19 pm in Saint John). Next Saturday the Sun will rise at 7:16 am and set at 7:00 pm, giving 11 hours, 44 minutes of daylight (7:21 am and 7:06 pm in Saint John).

The Moon is at first quarter on Wednesday, making the week a great time for lunar observing. Jupiter now sets less than an hour after sunset, but Saturn hangs around until 11 pm and hangs out with the Moon on Tuesday. Venus makes a move on Mars in the morning sky, while Mercury slowly drops sunward.

RASC NB members will offer views of the night sky and the Sun at the Kouchibouguac National Park Fall Festival on September 22 and 23. RASC NB members in Saint John will be celebrating Fall Astronomy Day with public observing at the Rockwood Park Bark Park (First Arch) on Friday, September 29, with a cloud date of September 30.

Questions? Contact Curt Nason at nasonc@nbnet.nb.ca.

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This Week’s Sky at a Glance, September 16 – September 23

From late summer into autumn, the Greek tale of Perseus and Andromeda plays out on the eastern stage of the night sky each evening. Princess Andromeda, the daughter of Cepheus and Cassiopeia, is chained to the rocky coast of Ethiopia as a sacrifice to a vicious sea monster, portrayed by the constellation Cetus the Whale. Our hero Perseus, on his way home aboard Pegasus after beheading Medusa, rescues the princess and wins her unchained hand in matrimony.

The constellation Andromeda consists of two lines of stars stretching toward Perseus from a common point. That point is the bright star Alpheratz, which is officially Andromeda’s head but it also forms one corner of the Great Square of Pegasus. The bottom line of stars is more prominent, containing the orange star Mirach and ending with Almach, which resolves as a pretty double star in a small scope.

The highlight of the constellation is M31, the Andromeda Galaxy, the nearest spiral galaxy to our own Milky Way. A telescope is not required to see this. It looks great in binoculars, and in a rural area on a cloudless night you can see it with the naked eye as a smudge of light. Place Mirach at the bottom of your binocular view and perhaps raise it a bit to see a slightly dimmer star in the upper line of Andromeda. Continue up about the same distance to another star and find the fuzzy expanse of the Andromeda Galaxy nearby. A small telescope will show two other galaxies, M32 and M110, in the same field of view. M31 is 2.5 million light years distant and heading our way. We will have a spectacularly starry sky in a few billion years.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 6:58 am and sunset will occur at 7:28 pm, giving 12 hours, 30 minutes of daylight (7:04 am and 7:32 pm in Saint John). Next Saturday the Sun will rise at 7:07 am and set at 7:14 pm, giving 12 hours, 7 minutes of daylight (7:12 am and 7:19 pm in Saint John). The Sun crosses the equator at 5:02 pm on Friday, September 22 to begin the autumn season in the northern hemisphere.

The Moon is new on Wednesday, making midweek a great time for seeking out those faint fuzzy objects with a telescope or binoculars. Jupiter sets around 8:30 this week, followed by Saturn a few hours later. It will be worthwhile to step outside around 6 am on Monday for a scenic view of Venus, Regulus, the crescent Moon, Mars and Mercury in a line about ten degrees long. Mercury appears very near to Mars this Saturday as it heads sunward, and Venus drops near Regulus on Wednesday.

The RASC NB star party at Fundy National Park takes place September 15 and 16 at the South Chignecto campground, and their telescopes will be set up on September 22 and 23 for the Fall Festival at Kouchibouguac National Park.

Questions? Contact Curt Nason at nasonc@nbnet.nb.ca.

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This Week’s Sky at a Glance, September 9 – September 16

The constellation Capricornus is a large chevron shape that is due south around 10 pm this week. A pair of stars marks each upper corner, and both stars of the western pair are colourful wide double stars in binoculars. The sea goat arises from a tale of the Olympian gods being surprised by Typhon, the most ferocious of the rival Titans. Knowing Typhon was not fond of water, the gods changed into fish and escaped to the sea. The god Pan, who was half-goat and half-man, panicked and dove in before the transformation was complete and wound up with a goat’s head and the tail of a fish.

There are four common targets for backyard telescope users near Capricornus, but only the globular cluster M30 off the east side of the chevron is officially within its borders. It is also the easiest of the targets for binoculars. The globular cluster M75 lies west of the chevron in Sagittarius, while globular cluster M72 and the four-star (literally four stars, it is not an observing highlight) asterism M73 are above in Aquarius. Nearby is the more challenging, but worth the effort, Saturn Nebula, the gaseous remnant of a dead star that somewhat resembles the ringed planet.

A few millennia ago the Sun was in Capricornus at the winter solstice, when at midday it is overhead at its most southerly point at latitude -23.5 degrees. This is the southern border of the tropics, and it is still called the Tropic of Capricorn despite the Sun being in Sagittarius at this time. Earth’s 25,800 year polar wobble, called the precession of the equinox, is responsible for this shift.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 6:50 am and sunset will occur at 7:41 pm, giving 12 hours, 51 minutes of daylight (6:55 am and 7:46 pm in Saint John). Next Saturday the Sun will rise at 6:58 am and set at 7:28 pm, giving 12 hours, 30 minutes of daylight (7:04 am and 7:32 pm in Saint John).

The Moon is at third quarter on Wednesday, rising a little before midnight Tuesday and setting at 3 pm. Around 10 am Tuesday, telescope users at high magnification might be able to see the Moon occult Aldebaran in daylight. Jupiter was in astronomical conjunction with Spica on September 5, having the same right ascension as Virgo’s brightest star. From our viewpoint, they will appear to be in conjunction on September 16 as Jupiter sits a few degrees above Spica, having the same azimuth. Saturn remains in good viewing position in the south after sunset, with its rings proudly on display for telescope users. Venus dominates the eastern morning sky despite being near its dimmest. Mercury is at greatest elongation on Tuesday, and it can be seen with binoculars near Regulus on Sunday and near Mars next Saturday.

The Saint John Astronomy Club and RASC NB share a meeting at the Rockwood Park Interpretation Centre on Saturday, September 9 at 1 pm. The William Brydone Jack Astronomy Club meets at the UNB Forestry / Earth Sciences Building in Fredericton at 7 pm on Tuesday. All are welcome. The RASC NB star party at Fundy National Park takes place September 15 and 16 at the South Chignecto campground.

Questions? Contact Curt Nason at nasonc@nbnet.nb.ca.

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This Week’s Sky at a Glance, September 2 – September 9

Another solar system event highlights this weekend, a relatively close encounter with the fourth largest near-Earth asteroid (NEA), 3122 Florence. This 4.4 kilometre diameter rock passed within seven million kilometres of Earth on the morning of September 1. It is fading slowly but will remain within reach of small telescopes over the long weekend. I have seen two NEAs in the past 15 years and consider them to be among my observing highlights, both for the challenge and the uniqueness.

Image Credit: NASA/JPL-Caltech

The trick to observing one is ambush it. Get a detailed star map of its path through the sky and pick out an easily identifiable star or group of stars that it will be passing during your observing time. Set your scope on that area ahead of time – then keep watch for a moving star entering the field of view. A smaller NEA making a closer passage can be affected by Earth’s gravity and have its orbit changed slightly, so a wide-field eyepiece helps (higher focal length eyepiece). However, Florence is large and still quite distant (no need to wear a helmet), making orbital perturbations unlikely. It moves among the starry background by about two-thirds the width of the Moon every hour, visible motion at higher magnification when it is near a star. The best time to try for it is around 9 pm Saturday when it passes between the belly and the nose of Delphinus the Dolphin. A map on the Sky & Telescope website [in PDF format] can be found here: http://wwwcdn.skyandtelescope.com/wp-content/uploads/3122-Florence-Chart-B-1.pdf

Delphinus is one of the prettiest constellations and can be seen high in the southeast around 9 pm. It is composed of a small diamond-shaped asterism with a couple of stars tailing off to the right, and it doesn’t take a lot of imagination to picture a dolphin leaping out of the sea. Although its stars are not bright, its compact shape is eye-catching. Below it are the watery constellations of Capricornus, Aquarius, Piscis Austrinus and Pisces. In mythology, Poseidon had designs on the sea nymph Amphitrite but she was afraid and hid from him. The dolphin ratted her out and was rewarded with a place of honour in the sky. The diamond part of the constellation has also been called Job’s Coffin but the origin of this has been lost to time.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 6:41 am and sunset will occur at 7:55 pm, giving 13 hours, 14 minutes of daylight (6:47 am and 7:59 pm in Saint John). Next Saturday the Sun will rise at 6:50 am and set at 7:41 pm, giving 12 hours, 51 minutes of daylight (6:55 am and 7:46 pm in Saint John).

The Moon is full on Wednesday, the Mi’kmaq Moose Calling Moon. Jupiter lies low in the west after sunset as it approaches a conjunction with Spica. Saturn remains in good viewing position in the south after sunset, with its rings proudly on display for telescope users. Venus rises after 4 am now and dominates the eastern morning sky despite being near its dimmest. Mercury, Mars and Regulus can be seen with difficulty within the same binocular field this week, rising about 75 minutes before the Sun.

The Saint John Astronomy Club and RASC NB share a meeting at the Rockwood Park Interpretation Centre on Saturday, September 9 at 1 pm. All are welcome.

Questions? Contact Curt Nason at nasonc@nbnet.nb.ca.

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Build Your Own Eclipse Projector

The Canadian Space Agency has published a web page on how to build your own eclipse projector using simple household materials. If you can’t attend a public eclipse viewing event, and haven’t had the chance to purchase eclipse viewing glasses, this is an effective way to see the moon take a bite out the sun.

English Instructions: http://asc-csa.gc.ca/eng/multimedia/activities/eclipse-projector.asp

Instructions en Français: http://asc-csa.gc.ca/fra/multimedia/activites/projecteur-eclipse.asp

Image Credit: Canadian Space Agency