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

The bright stars Arcturus and Vega, fourth and fifth brightest of the night sky, are seen high above in twilight. I use them to locate the constellation Hercules, which is one third of the way from Vega to Arcturus. Another constellation, the nominal crowning glory of the northern sky, is one third of the way from Arcturus to Vega. Corona Borealis, the Northern Crown, does not stand out among its neighbours or contain any popular telescopic treasures like Hercules does, but its semicircle of stars is pretty to look at. If you have a really clear view of the southern horizon you might catch the Southern Crown, Corona Australis, hugging the horizon below Sagittarius around 2 am this week or midnight in late July.

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. Along the way they stopped at the island home of Dionysus, the god of wine. After a night of revelry the crew was made to leave 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 constellation also represents a bear’s den in a local aboriginal legend of the bear and seven hunters, which includes stars in the Big Dipper and Boötes.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 5:28 am and sunset will occur at 9:14 pm, giving 15 hours, 46 minutes of daylight (5:36 am and 9:15 pm in Saint John). Next Saturday the Sun will rise at 5:31 am and set at 9:14 pm, giving 15 hours, 43 minutes of daylight (5:39 am and 9:15 pm in Saint John). The nights are getting longer!

The Moon is full at 1:53 am on Thursday, the Mi’kmaq Trees Fully Leaved Moon. It is near Jupiter this Saturday, Saturn on Wednesday and Mars next Saturday. Venus sets around 11:30 pm this week, and a telescope will show it slightly more than half-lit by sunlight. Look for Mercury with binoculars 15 degrees to the lower right of Venus, starting a half hour after sunset when it is about 9 degrees above the horizon. Jupiter is situated for great observing in the evening and a telescope could show its Red Spot eyeing us around 10 pm on Monday. The shadow of its largest moon, Ganymede, might also be seen at that time, starting its transit across the Jovian cloud top. Saturn is at opposition on Wednesday, rising below the Moon around sunset. Mars rises well before midnight this week and perhaps it will look more yellow than bright orange. The dust storm that sprang up a couple of weeks ago has gone global. We hope the storm will dissipate before the end of July, when Mars will be at its closest in 15 years.

The last RASC NB meeting until September takes place on June 23 at 1 pm in Moncton High School. All are welcome.

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

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

Seasons are the result of Earth’s rotational axis being tilted about 23.5 degrees off the vertical with respect to its orbit. The first day of astronomical summer occurs this Thursday. The “astronomical” qualification is used because meteorologists have taken to confusing people with meteorological seasons based on temperatures. Meteorological summer in the northern hemisphere includes June, July and August because they have the highest average temperatures for the year. Anyone who has lost crops this month due to frost will not be in total agreement with that.

On the summer solstice, the Sun rises and sets at its most northerly points on the horizon. For those of us at 45 degrees latitude, at midday (1:21 pm in Moncton) the Sun is 90 – 45 + 23.5 = 68.5 degrees above the southern horizon, at its highest for the year. If we lived at latitude 23.5 degrees the Sun would be directly overhead at midday on the solstice. Several millennia ago the Sun was “in” the constellation Cancer on the solstice, hence that latitude is marked on maps as the Tropic of Cancer. The dim constellation does resemble a crab somewhat, but there is speculation that the Sun’s forth and back movement along the horizon at that time of year was reminiscent of a crab’s sidewise walk.

Prior to being in Cancer at the start of summer, the Sun was in Leo. Lions tended to gather by the Nile in the dry season around the solstice. Now the summer solstice point on the ecliptic, the Sun’s path through the constellations, lies in Taurus, just within its boundary with Gemini. The roaming solstice is due to Earth’s axis wobbling like a top, making one revolution every 25,800 years in what we call the precession of the equinox. Enjoy your summer, whenever it starts.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 5:27 am and sunset will occur at 9:12 pm, giving 15 hours, 45 minutes of daylight (5:35 am and 9:14 pm in Saint John). Next Saturday the Sun will rise at 5:28 am and set at 9:14 pm, giving 15 hours, 46 minutes of daylight (5:36 am and 9:15 pm in Saint John). Summer solstice occurs at 7:07 am on Thursday.

The Moon is at first quarter on Wednesday, giving great views in a telescope throughout the week. If you can spot it in the east this Saturday morning, look for Venus within a binocular field above it. If you are successful with that, try for Venus without the binoculars. After twilight on Tuesday look for M44, the Beehive Cluster, just below Venus. Jupiter is situated for great observing in the evening and it will get extra attention on June 23 with the Moon nearby. A binocular view of Jupiter will show its line-up of moons and the double star Zubenelgenubi to its lower left. Saturn rises around 9:30 pm and a late evening view of it in binoculars will include the globular cluster M22 to its lower left. A dust storm has kicked up on Mars – hopefully, it will dissipate soon and not obscure features of the Red Planet like one did in 2001.

The first RASC NB star party of the year takes place at Kouchibouguac National Park on June 15-16. The last RASC NB meeting until September takes place on June 23 at 1 pm in Moncton High School. All are welcome.

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

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

Globular clusters are among the oldest and largest objects associated with our galaxy, being about 12 billion years old and containing tens to hundreds of thousands of stars packed into a compact sphere. There are more than 150 globulars orbiting in the halo of the Milky Way galaxy, and many more are known to be orbiting larger galaxies like M31 in Andromeda. Many can be seen in binoculars as a fuzzy patch of light, perhaps resembling those little white patches you see below bird feeders. A good sized telescope is able to resolve some of their stars. The larger globulars seen from a dark location have been described as granules of sugar against black velvet.

Summer is the season for observing globular clusters. M4 is just to the right of Antares in the constellation Scorpius and it is one of the closest to us at 7000 light years. M13 in the Keystone of Hercules is relatively close at 22,000 light years. One that would outshine M13 if it were higher in our sky is M22, just left of the lid of the Teapot in Sagittarius. Another easy target is M3, located halfway between Arcturus and Cor Caroli, the brightest star in the small constellation Canes Venatici below the handle of the Big Dipper. Two other standouts are M92 in Hercules and M5 in Serpens. From a dark sky, many dimmer globulars can be picked out in the region of Sagittarius and Ophiuchus.

The concentration of globular clusters in this region of sky is not by accident, and it played a role in another lesson of humility for humanity. Harvard’s Harlow Shapley studied globular clusters a century ago and noticed that most were located around Sagittarius. If they were evenly distributed around the core of our galaxy, as believed, then the centre of the galaxy must lie in that direction. Just as Copernicus and Galileo demoted Earth from the centre of the solar system, Shapley showed that the Sun was not at the centre of the Milky Way.

This Week in the Solar System

Saturday’s sunrise in Moncton is at 5:28 am and sunset will occur at 9:09 pm, giving 15 hours, 41 minutes of daylight (5:36 am and 9:10 pm in Saint John). Next Saturday the Sun will rise at 5:27 am and set at 9:12 pm, giving 15 hours, 45 minutes of daylight (5:33 am and 9:14 pm in Saint John).

The Moon is new on Wednesday and, if you can spot it around 10 am on June 16, look for Venus within a binocular field above it. If you are successful with that, try for Venus without the binoculars. Jupiter is at its best for observing around 11 pm, and with a telescope you might see its Red Spot around 10 pm on Wednesday and midnight on Friday. Saturn rises around 10 pm above the lid of the Sagittarius Teapot. Mars continues to brighten in the morning sky; it will be the main attraction for observers this summer.

The William Brydone Jack Astronomy Club meets in the UNB Forestry / Earth Sciences building in Fredericton on Tuesday at 7 pm. All are welcome. The first RASC NB star party of the year takes place at Kouchibouguac National Park on June 15-16.

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

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

When Charley Pride sang “Snakes Crawl at Night” he wasn’t talking about the constellations, but he might as well have been. When twilight gives way to darkness there are two snakes stretching nearly halfway across the sky. The first is Hydra the female water snake, which is also the largest constellation. It is so long it takes eight hours to rise completely. At 11 pm these evenings it stretches along the horizon with its head in the west and its tail to the south. In this position the snake takes only three hours to nestle underground

Almost as long but more U-shaped is Serpens, the only constellation that is in two parts, separated by Ophiuchus the Serpent Bearer. The western half is called Serpens Caput, the head of the snake, and the eastern half is the tail, Serpens Cauda. Ophiuchus represents Asclepius, a son of the Greek god Apollo, who learned the healing arts by watching a snake bring another back to life. The Rod of Asclepius, a snake entwined around a staff, is the symbol of medicine and health.

If your like things in threes you can look at serpentine Draco as a snake instead of a dragon. Its tail begins above the bowl of the Big Dipper, with the body curling around the Little Dipper before arcing back toward the foot of Hercules. If that doesn’t suit you then you can go Down Under to see Hydrus the male water snake slithering around the south celestial pole.

This Week in the Solar System
Saturday’s sunrise in Moncton is at 5:30 am and sunset will occur at 9:04 pm, giving 15 hours, 34 minutes of daylight (5:38 am and 9:06 pm in Saint John). Next Saturday the Sun will rise at 5:28 am and set at 9:09 pm, giving 15 hours, 41 minutes of daylight (5:36 am and 9:11 pm in Saint John).

The Moon is near Mars on Sunday and is at third quarter on Wednesday. Venus and Jupiter dominate the western and southeastern sky, respectively, during the evening. If you can landmark where they are in bright twilight, try to see them before sunset without optical aid the next clear evening. Saturn is slowly moving westward over the lid of the Sagittarius Teapot asterism, and by the end of the month it will be rising before sunset. Mars continues to brighten in the morning sky; it will be the main attraction for observers this summer. Mercury is in superior conjunction on Tuesday, passing behind the Sun.

The Saint John Astronomy Club meets in the Rockwood Park Interpretation Centre on June 2 at 7 pm. All are welcome.

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

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