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The Sky This Month

Canis Major

The star Sirius is by far the brightest and closest visible star in the Canadian winter sky. Sirius belongs one of Orion’s hunting dogs, it is only 8.6 light years away and at magnitude -1.47 is a great daytime telescopic object. Along with the stars Betelgeuse and Procyon, Sirius forms the Winter Triangle. AKA, the Dog Star, Sirius is a binary with a magnitude 8.44 white dwarf companion nicknamed the Pup. The white dwarf orbits Sirius once every 50 years in an elliptical orbit that ranges in distance from eight to 31 astronomical units. The much fainter Sirius B is located very close to brilliant Sirius making it extremely difficult to spot. As you can see by the chart, the companion is almost at its farthest from its primary. I remember catching a glimpse of it back in 1979.

Located a few degrees to the south of Sirius is a lovely open cluster cataloged as M41. It is located 2,316 light years away and estimated to be 12.5 light years across. This cluster makes a striking view in wide-angle binoculars and with wide-angle photography when you include Sirius. Nine degrees to the northeast of Sirius is Thor’s Helmet (NGC 2359). At a distance of 12,000 light years, this 30 light year wide structure is comprised of a bubble and filaments. At the middle is the Wolf-Rayet star WR 7 that has an estimated brightness 280,000 times brighter than the Sun. It has a surface temperature of 112,000 K and is about to explode into a supernova.

Exoplanets seem to be everywhere and there is a naked eye star located southwest from Sirius. Named Nu2 Canis Majoris or V2, this star is located 64 light years away. At fourth magnitude, V2 should be an easy target to see. The exoplanet seems to be in the habitable zone where oceans (if any) would stay liquid. The planet orbits 1.9 AU from the parent star.

The planet Mercury is now at magnitude zero and low in the western sky after sunset. It sets about an hour after sunset so you will only have a few evening to search for Mercury as it is sinking fast. Moving up the ecliptic, we can still see the orangey hue of Mars. Now at magnitude 1.3, the crescent moon will be almost seven degrees to the left of the red planet on March 11. For the first ten evenings of the March, look for the faint zodiacal lights in the west that follows the ecliptic towards the Pleiades. Photography will be your best bet to capture this slanted triangular glow of interstellar dust. After March 10, moonlight will interfere.

The other three naked eye planets are found in the morning sky. Jupiter rises at 2:30 a.m. local time with the ringed planet Saturn a full two hours later and brilliant Venus, a half an hour after Saturn. This year the vernal equinox occurs on March 20, which happens to be a full Worm Moon and this is why Easter is so late this year. The holiday occurs on the Sunday after the full moon after spring. Therefore, we have to wait for the next full moon on April 19 (Good Friday) with Easter Sunday on April 21. 

This month’s new moon occurs on March 6 and Daylight Saving Time (DST) begins at 2 a.m. on March 10.

Until next month, clear skies everyone.

Gary Boyle

Author: Gary BoyleeNews date: Friday, March 1, 2019Category: Northern SkiesTweet::  Pages

The Sky This Month - February 2019

Gemini Twins

Castor and Pollux are bright stars belonging to the constellation Gemini and are part of the dozen bright stars that light up the winter sky. They represent the heads of the twin which were actually half brothers as stated in mythology. Located 34 light years away, Pollux is a magnitude 1.14 orange coloured star with a spectral class K0. Although Pollux has a diameter of 9 or 10 times that of our Sun, surface temperatures are 4,770 K and cooler than our Sun‘s 5,778 K. Pollux is in the process of fusing helium in carbon and oxygen in its core. It seems to have an outer corona comparable to our Sun. The exoplanet Pollux b resides 1.6 astronomical units from the parent star and takes 1.6 years to complete a circular orbit. 

To the upper right of Pollux we find Castor. This white coloured spectral class A1 star shines at magnitude 1.58 and is located 52 light years from us. With a surface temperate about twice that of Pollux, Castor is a collection of three pairs of stars in a very unique dance. A telescope will show Castor’s close companion with both components Castor A & B are themselves doubles and possess a mysterious third double companion. Although components A & B orbit each other in 445 years, component C orbits A & B every 14,000 years.

One of the best examples of an open cluster is M35. Found near Castor’s foot, this group of 200 stars glows at magnitude 5.2 and is a fantastic object in binoculars. When viewed with a telescope, the tiny cluster NGC 2158 is now revealed. M35 is located 2,800 light years away while smaller NGC 2158 is four times farther from us. Gemini is also home to the Eskimo Nebula also called the Clownface Nebula. With the catalogue number NGC 2392

 or Caldwell 39, this bi-polar planetary nebula is estimated to reside 2,870 light years from Earth. In small telescopes the Eskimo appears as a fuzzy bright greenish object but larger instruments will reveal more detail. About 10,000 years ago a Sun like star eventually ran out of fuel and grew to become a red giant. Over time the weak gravity allowed the release of its outer layers into space thus forming this celestial portrait.

Comet  C/2018 Y1 (Iwamoto) was discovered by a Japanese astronomer in late 2018 is now racing through space at 66 km/sec. It passes close to the star Regulus in the constellation Leo on February 11 and this night along with the 12th will be the best nights to see and photograph it. Brightness estimates range from magnitude 7 to 7.8 at its best and safely passes the Earth at 45 million kilometres. Moonset on February 11 is before midnight local time and an hour later the next night.

The brilliant duo of planets Venus and Jupiter continues as Venus continues sinking to the south-eastern horizon on its way to rounding the sun in its orbit. Venus passes the planet Saturn on the morning of the 18th. Jupiter on the other hand is steadily climbing higher and rises just before 4 a.m. on February 1 and after 2 a.m. on February 28. Mars is still visible low in the western sky after dark moving from Aries to Taurus and is much fainter than its summer time show. It passes one degree north of the planet Uranus on February 13.

For a two week period starting on February 21, look for the zodiacal light in the eastern sky before the sky lightens. From a dark location away from any and all light sources, you might see a slanted column of light close to Leo and along the ecliptic. This is the reflection of the leftover  cosmic dust from our solar system. This light is seen close to the seasons of spring and autumn.

New moon is on February 4 and the full Snow moon is on the 19th.

 

Until next month, clear skies everyone.

Gary Boyle

 

Twitter: @astroeducator

Author: Gary BoyleeNews date: Friday, February 1, 2019Category: Northern SkiesTweet::  Pages

The Sky This Month - January 2019

The Total Lunar Eclipse

The year 2018 ended with two great celestial events. We had the Geminid meteor shower that peaked on the night of December 13/14 as well as the great appearance of Comet 46/P Wirtanen. The comet was closest to the earth on December 16 and was near the Pleiades star cluster. Wirtanen is now moving towards Ursa Major and fading rapidly.

On the night of January 20/21 there will be a total lunar eclipse and Canada is well placed to see the entire show. In contrast to a solar eclipse when special filters are required for safety reasons, a lunar eclipse is completely safe to see and photograph. Prior to the lunar eclipse, the Sun, Moon and Earth will produce a partial solar eclipse on January 6 over North East Asia and the North Pacific.

As the full Moon sinks deeper into our planet’s shadow, it first darkens and then takes on an orangey colour. This is a result of sunlight refracting or passing through Earth’s atmosphere. This eclipse is also referred as the “Super Blood Moon”. The term “Super Moon” was derived by an astrologer in the 1970’s and refers to the combination of the full or new Moon along with its closest approach to the Earth in its elliptical orbit around us.

If you were on the moon during mid totality, you would see the same orange colour ring around the Earth. From this vantage point you would witness every sunset occurring on the left side of the Earth and every sunrise on the right side at the same time.  Although the Earth witnesses total and partial eclipses a couple of times a year, it will be a few year before the entire country will see the eclipse from beginning to end. The following times are local:

                                                      EST                  CST                   MST                 PST

Partial eclipse begins at:            10:34 p.m.            9:34 p.m.          8:34 p.m.          7:34 p.m.

Total eclipse begins at:               11:41 p.m.         10:41 p.m.           9:41 p.m.          8:41 p.m.      

Mid eclipse at:                             12:12 a.m.         11:12 p.m.         10:12 p.m.          9:12 p.m.

Total eclipse ends at:                 12:43 a.m.         11:43 p.m.         10:43 p.m.           9:43 p.m.

Partial eclipse ends at:                  1:51 a.m.        12:51 a.m.         11:51 p.m.         10:43 p.m.  

The thin crescent Moon will not interfere with the annual Quadrantid meteor shower. The shower runs from January 1–10 and peaks on the night of January 3-4. An expected 40 meteor meteors per hour will strike the atmosphere about 80 kilometres above the Earth and can produce bright fireballs. The radiant for the Quadrantids is located in an area half way between Draco and the top star of Bootes named Nekkar.

Along with Orion the Hunter, Taurus the Bull rules the winter sky. Within its boundaries we have the even popular Pleiades star cluster. M45 is a fantastic sight in binoculars, a telescope or just with your eyes. Also referred as the Seven Sisters, this cluster also represents the mythical heart of the bull, We then have the “V” shaped Hyades star cluster forming its head and accented by the star Aldebaran, the angry “eye” of the bull. Aldebaran is a actually a foreground star and not part of the cluster.

Follow the long imaginary horn closest to Orion to its end. Not far from here is the first object on Messier’s list. This is M1 or the Crab Nebula and is the remains of a supernova that occurred in the year 1054 A.D. This explosion was so bright, it outshone the moon for a couple of weeks. The Crab Nebula has long since faded to a dim smudge in a telescope eyepiece. It has a pulsar at its centre spinning at 33 times a second.     

The planet Venus still lights up the south east morning sky. It attained greatest elongation (appearing farthest from the Sun as seen from Earth) on December 15 and will be seen a bit lower in the sky each morning. Meanwhile Jupiter is climbing higher throughout the month and on the morning of January 25 both will meet, appearing as “spooky eyes” in the eastern sky. The 16% crescent Moon will be seen between the two on January 31 making a great digital moment.

Until next month, clear skies everyone.

Gary Boyle

Twitter: @astroeducator

Author: Gary BoyleeNews date: Tuesday, January 1, 2019Category: Northern SkiesTweet::  Pages

Create a Logo for CASTOR and Win!

Create a Logo for CASTOR and Win!

Canadian astronomers have established themselves in space-based astronomy by using space telescopes such as Hubble and Chandra. In 2003 Canada’s MOST (Microvariability and Oscillations of Stars) space telescope was launched, and now Canada is a full partner in the James Webb Space Telescope (JWST).

Hubble and Chandra are nearing the end of their lifetimes, and JWST won’t have the long lifetime of Hubble, so Canadian astronomers are already looking at what comes after JWST. The National Aeronautics and Space Administration is developing WFIRST (Wide Field Infrared Survey Telescope) and the European Space Agency is building Euclid.

Since both WFIRST and Euclid will operate in the infrared like JWST, ultraviolet and visible light capabilities in space will be lost when Hubble ceases operations. Because of this problem, many Canadian astronomers are supporting a proposal for a new Canadian space telescope, CASTOR, the Cosmological Advanced Survey Telescope for Optical and ultraviolet Research.

CASTOR is planned to have a primary mirror of a metre in diameter inside a spacecraft weighing about 500 kg. Its camera is planned to have a similar resolution to Hubble, but it would be able to cover a much larger part of the sky than Hubble. 

CASTOR would provide unique data in the ultraviolet part of the spectrum to complement data from JWST, WFIRST and Euclid, assisting in the search for dark energy. It would also challenge and stimulate Canadian industry and Canadian science.

The Canadian Space Agency is conducting a study of CASTOR that Canadian astronomers hope will lead to approval of the mission. While CSA would lead CASTOR, other space agencies would be involved, including NASA and the Indian Space Research Organization, which would provide the launch vehicle.

Now Canadian astronomers are seeking a logo for CASTOR, whose name pays tribute in French to Canada’s national animal, the beaver.

Members of the Royal Astronomical Society of Canada and the Fédération des astronomes amateurs du Québec are invited to submit their designs for a CASTOR logo.

Entries can be sent before February 1, 2019, to: RASC National Office at 203-4920 Dundas St West, Toronto ON M9A 1B7 or at nationaloffice@rasc.ca

They will be judged by a panel of astronomers selected by mission scientists, RASC and FAAQ.

The winner will receive a prize of merchandise from Ingenium: Canada’s Museums of Science and Innovation.

Author: Randy AttwoodeNews date: Wednesday, December 19, 2018Category: AnnouncementseNews Tag: Castor contestTweet::  Pages

The Sky This Month - December 2018

Two Grand Events

This year ends with two fantastic celestial sky shows. First is the long anticipated return of Comet 46P/Wirtanen. Discovered in January 1948 by Carl Wirtanen at the Lick Observatory and one of three he discovered, this 1.2 km wide ice rock was found to have an orbital period of 6.7 years. Close passes in 1972 an 1984 with the planet Jupiter altered its path to its present 5.4 year orbit. Comet Wirtanen comes unusually close this month to within 11.4 million km of earth (0.078 AU) on December 16. This will be just four days after passing the sun. This places Comet Wirtanen in the top ten closest approaches of a comet to the earth in the space age and twentieth in history.

This small and hyperactive comet is now an easy binocular object low in the southern horizon and is climbing quickly. The green coma has already been measured to be larger than the full moon and it is expected to double in size over next coupe weeks. The comet might peak as high as 3rd magnitude making the comet a possible naked eye target from the suburbs and a spectacular object from the countryside. However, comets can be unpredictable in their brightness estimates. On December 15, Wirtanen will be nicely positioned between the Pleiades and Hyades star clusters. The moon will set around midnight local time that night allowing for dark conditions for astrophotographers. On its trek up the sky, the comet comes very close to the star Capella on December 23.

We then have the annual Geminid meteor shower. I consider the Geminids to be the best shower of the year. Factors include its rate of 120 meteors seen per hour and a slow re-entry speed of only 35 km/sec compared to the Perseids seen in August at twice that speed. The Geminids have been known to produce fireballs as larger sized particles completely burn up in the upper atmosphere producing long yellow streaks that can light up the ground. Origin of the meteors or the radiant is located near the star Castor. The shower peaks on the night of December 13/14 with the best viewing time after midnight until dawn. The 36% Moon sets around 10 p.m. local time so the night will remain dark. The only draw back is obviously the cold. As long as the wind stays calm, you should have a great night observing. With wide angle photography centred on the comet, you might capture a Geminid or two in the same field of view.  

The winter sky with Orion the Hunter takes centre stage. Amongst the constellations of Orion, Auriga, Gemini, Canis Minor, Canis Major and Taurus, we see a dozen bright stars. With Orion’s belt located on the celestial equator, the Hunter is perfectly placed to be seen in both the northern and southern hemispheres of the world. Along the imaginary sword the hangs off his belt (3 stars) is a fantastic birthplace of stars – the Orion Nebula. Located 1,500 light years away, this area of gas and dust is slowly forming hundreds of stars.

Mars is still visible low in the western sky and sets at midnight on the 1st.  Compared to is great show this past summer when it was 59 million km on July 31, the red planet is now more than 152 million km from us as we are separating at 12 km/sec. Venus is extremely bright in the morning sky at magnitude -4.9. In a telescope you will see a lovely 27% crescent. On the morning of December 3, the crescent moon will be located north of Venus. Using the moon as a guide, try to follow Venus throughout the day in binoculars or if the blue is a deep blue – with the unaided eye. I once had superb seeing conditions in Kelowna BC years ago and found it a few hours before sunset.

And if a telescope is on your shopping list for yourself or the young astronomer, may I suggest to seek out reputable telescope dealers in your area or on the Internet and try to stay away from camera and big box stores.  

The winter solstice occurs on the 21st at 22:23 Universal Time. New moon occurs on December 7 and the full Cold Moon on the 22nd.

Until next month, clear skies everyone.

Gary Boyle

Author: Gary BoyleeNews date: Saturday, December 1, 2018Category: Northern SkiesFile:  IMG_9552 reduced.jpgTweet::  Pages