The Sky This Month - January 2021

Orion’s Many Colours - part 1

As the bright stars of the winter sky rise in the east, we witness a great mythological battle that has been raging for thousands of years. With his mighty shield and raised club, Orion the Hunter has been locked in this imaginary confrontation with Taurus the Bull. The constellation Orion is one of the most iconic groupings of distant suns.

It is truly amazing seeing the majestic lineup of the three sparkling belt stars (which the ancient pyramids were oriented to) and the star-forming region called the Orion Nebula. Aka M42 is found in the imaginary sword hanging from Orion’s belt. Alone they are impressive to the naked eye but the magic of astrophotography reveals the true colours of this amazing region of space.

We first start with the Orion Nebula. Located 1,500 light-years away, M42 is a stellar nursery that spans about 25 light-years across and is condensing and compressing individual pockets of gas and dust to form thousands of new stars. The Hubble Space Telescope has imaged some of these pockets forming disks or protostars. Images of the nebula show pallets of red, pink, blue and grey.

The brighter members of the constellation are hot blue stars except for the top left shoulder star called Betelgeuse appearing bright orange. Opposed the star-forming region of the Orion Nebula, Betelgeuse is at the end of its life and has entered the red giant stage. It has been a highly energetic star in its early life, consuming its fuel in only 10 million years. By comparison, our sun lives at a quieter pace and has a life expectancy of 10 billion years which is presently halfway. Betelgeuse has ballooned out to 950 times that of the sun or if it were at the centre of the solar system would reach out to the orbit of Jupiter. It will explode anytime in the next few hundred years and appear as bright as the full moon.

As we take longer and multiple exposures of the belt stars, the camera reveals the Flame Nebula located east of the left-most belt star named Alnitak located 1,100 light-years away. At about 1,300 light-years away, the Flame is another star-forming region just like M42 but has an obscuring cloud hiding the centre bright stars which are responsible for lighting up the gas and dust thus giving the overall appearance of a flame. This object appears bright beige.

Not too far below Alnitak is the elusive vertical region called the Horsehead Nebula. Long exposure photography is the key to seeing the dark silhouette of this dense dust cloud known as Lynds 1630 thus resembling a horse’s head in front of a hydrogen gas star-forming region. There are no bright areas, just black in front of the deep red hydrogen. This object is difficult to observe visibly and requires very large telescopes and is a challenge to image.

The Quadrantid meteor shower is the first shower of the year. The event is best seen on the night of January 2 into the morning of January 3 with a very sharp peak period that will only last a few hours. According to Pierre Martin, an experienced meteor observer, this narrow peak is predicted to occur around 9:30 a.m. eastern time on the 3rd when the radiant between Bootes, Ursa Major and Hercules is up high. However, the sun will be well up meaning the east coast might have the best chance of seeing the maximum amount of the usual 20 to 30 meteors per hour.

However, based on the modelling by Jenniskens and Peter Brown, the 2021 Quadtantids might be above average. The theoretical filament looks thicker than it did in 2009 which was a great year with the zenithal hourly rates (ZHR) equalling 150. Pierre was able to see the rising rates during the 2009 shower before dawn with 197 meteors seen in just two hours. That shower had the same peak prediction as this year’s event. The downside is the waning gibbous moon will lighten the sky and drown out many meteors. But if you can, try and observe this weekend event as the number of meteors might be high.

I hope you have had the opportunity to observe and photograph the great conjunction of Jupiter and Saturn leading up to the December 21 event. Now separating, the two are sinking lower in the southwest sky and will be lost in the solar glare in the second half of the month but move to the morning sky in February. Venus is now low in the southeast sky and is also moving closer to the solar glare.

The only visible planet seen for part of the night is Mars. At the beginning of the month, it sets at 1:50 a.m. local time and about 1 a.m. by month’s end. Although not as spectacular as last month’s conjunction, Mars and Uranus will come closest together on January 20. They will but 1.6 degrees apart or a little more than three full moons lined up. Mars is still close to magnitude zero while Uranus remains at its usual brightness of magnitude +5.8. It will be to the lower left of Mars and appear as a fuzzy bluish-green star. The first quarter moon will also be in the area, below the pair.

The new moon occurs on January 13 and the Full Wolf Moon lighting up the night on January 28.

Until next month, clear skies everyone.

Gary Boyle

Author: Gary BoyleeNews date: Friday, January 1, 2021Category: Northern SkiesTweet::  Pages

The Sky This Month - December 2020

The Great Conjunction

Looking back on 2020, the entire world has been and is still suffering high levels of stress and anxiety from this pandemic. Normal life came to a screaming halt as we had to find different ways to entertain ourselves such as reading, doing crafts and binge-watching TV for hours on end while others learned something new. As did early civilizations millennia ago, people have started looking at the night sky as an escape. There are news reports that telescope sales are way up showing interest in astronomy is mounting.

Over this year there were a few great celestial events that drew us out of our homes and looked up. If we ever needed a prime example of a comet, along came Neowise in July that was bright enough to be seen naked eye in the moonlight. Millions of people around the globe enjoyed seeing and photographing this interstellar visitor.

The first week of October saw our favourite planet Mars making its brightest and closest approach to earth since 2003. Mars is still seen overhead for most of the night appearing bright orange. Over the weeks and months, we will notice Mars dimming ever so slowly as our distance increases with each passing day.   

Closing off December the Geminid meteor shower peaks on the night of the 13/14. This is one of the best displays of the year, producing 120 slow-moving meteors per hour with the occasional bright fireball. The new moon will not interfere with this year’s display which brings us to this very special conjunction of Jupiter and Saturn.

Every 20 years the two gas giants of the solar system meet up in a great conjunction. On December 21 the two will have a separation of only six arc minutes or one-fifth the size of the full moon. Both will be visible in a telescope along with their moons. This will be a truly unique image to see and photograph. We also celebrate the solstice on the 21st. Also on the 21st, the normally weak Ursids meteor shower might produce a series of outbursts possibly producing up to several meteors per minute around 10 to 11 p.m. and then 1 a.m. eastern time. 

The new moon occurs on December 14 and the Full Cold Moon on December 29.

Until next month, clear skies everyone.

Gary Boyle

Author: Gary BoyleeNews date: Tuesday, December 1, 2020Category: Northern SkiesTweet::  Pages

The Sky This Month - September 2020

Rising Pegasus,

The Great Square of Pegasus depicting the mythological winged horse is now high in the eastern sky. Pegasus is one of the original 48 constellations listed by Ptolomy sometime after 150 BC and was part of the story of the “Royal Family of Constellations”. The story depicts King Cepheus and Queen Cassiopeia sacrificing their daughter Andromeda to the sea creature Cetus to appease the angry gods. Our hero Perseus the Hunter saves Andromeda and they both ride off on Pegasus.

The celestial square is quite obvious in the sky and is home to a few interesting and challenging deep-sky objects. First is the spiral galaxy NGC 7331 nicknamed the ‘Deerlick’ which can be located a little more than four degrees north of the star Matar. Matar has a spectral class of G5, so it is a bit cooler than the sun. It is a double star or quadruple star system – a double-double located about 230 light-years. At 47 million light-years, NGC 7331 is a common target for astrophotographers. Close to this galaxy are a few fainter and much farther galaxies aka ‘The Fleas’. They are NGC 7335 magnitude 13.5 and 310 million ly away, NGC 7336 magnitude 15.6 and 430 million ly distant, NGC 7337 also magnitude 15.6 but 320 million ly away and NGC 3740 at magnitude 14.6 and 320 million ly from us. Not far is ‘Stephen’s Quintet’ with members around the 14th magnitude range and locate 2080 to 320 million ly away.

The most famous and a favourite shown at stars parties is the Andromeda Galaxy. This is the closest neighbouring galaxy other than our satellite Megallantic Clouds. A truly amazing object to observe with a telescope but is bright enough to be seen on a clear moonless night in the countryside without optical aid. The galaxy is only 2.25 million ly away so the photons of light you see, left the galaxy when Homo Habilus was walking the earth. M31 possesses a couple of satellite galaxies namely M32 and M 110. Today’s modern telescopes along with state of the art CCD cameras can image globular clusters in the galaxy. How many can you find?

There are a couple of naked-eye stars that are known to harbour exoplanets. The first is 51 Pegasi located 50 light-years from earth and in 1995 was the first sun-like star discovered to harbour a planet. It has been officially named Dimidium and has a magnitude of 5.4. Over in Andromeda, look for the star Upsilon Andromedae located 44 light-years away. The parent star to four exoplanets is a bit brighter at magnitude 3.8.

After a memorable month of July Comet 2020 F3 (NEOWISE) is rapidly dimming and is now located low in the western sky after sunset. By month’s end, it will be near Virgo and an eleventh magnitude smudge. It is currently magnitude 8.7 and returns 6,700 years from now.

Aside from the above-mentioned objects, the bright planets own the night. Jupiter and Saturn are well up in the southern sky after sunset. Be sure to consult the RASC Observer’s Handbook 2020 for the ephemeris of moon transits and eclipses. Mars is up in the eastern sky by 9:30 p.m. local time with brilliant Venus seen in the northeast by 3 a.m. Sure signs of winter knocking at the door in a few months is seeing the constellation Orion well up in the east and along with Venus, the Hyades and Pleiades. This is something to witness on a clear moonless morning.

The equinox occurs on September 22 at 13:31 UT signifying the beginning of Fall in the northern hemisphere and Spring in the south. The equinox is also time to look for the elusive zodiacal light in the eastern sky before the first glimmer of dawn. The zodiacal light is caused by reflected sunlight of dust grains in the inner solar system. Your two-week window to capture this begins September 15. Dark sky locations and moonless mornings are a must to see this tilted wedge of light. Try imaging the lights with a DSRL on a tripod. The Full Corn Moon occurs on September 2 and New Moon will occur on September 17.

Until next month, clear skies everyone.

Gary Boyle

Author: Gary BoyleeNews date: Thursday, October 1, 2020Category: Northern SkiesTweet::  Pages