The Sky This Month - April 2021

Distant Islands

Longer days and shorter nights are telltale signs winter are all but gone. As Orion and Taurus are sinking in the west, disappearing by midnight, we now focus on the abundance of galaxies available. We can observe and photograph a few classic groupings in Leo the Lion such as the Leo Triplet consisting of M65/M66/NGC 3628 or the combination of M95/M96/M105. This pales in comparison to the swarm of galaxies found from Virgo through Coma Berenices and up into Ursa Major.

An observing challenge would to locate the dwarf spheroidal galaxy Leo 1. It is estimated to be 820,000 light-years away with a diameter of around 2,000 light-years across. As irregulars go, it has no structure whatsoever and glows at eleventh magnitude. One problem spotting this smudge in the eyepiece of a telescope is the galaxy’s proximity of a mere 20 arcseconds from the bright star Regulus, blazing at magnitude 1.4. Putting this bright sun out of the field of view is key to viewing Leo 1.

Galaxies are distant islands containing hundreds of millions of stars just like our Milky Way. A great object to observe and image is M64 - the Blackeye Galaxy. Catalogued as a type 2 Seyfert Galaxy, this spiral resides only 17 million light-years from us and has a distinctive thick band of dust hiding part of the bright nucleus thus giving the galaxy its name. This object should be on your observing list.

With this vast region populated with so many galaxies, groupings are very common. With a wide-angle eyepiece, locate the duo of M84/86 measuring 66 and 57 million light-years respectively and you should see about half a dozen fainter objects closeby These members are part of “Markarian’s Chain”. Wide-angle photography will allow you to catch extended portions of the chain. More than 15 galaxies are associated with this amazing collection.

As for the planets, Mars has now dimmed to magnitude +1.3 and sets after 1 a.m. at the beginning of the month. The moon will appear below it on the 16th. Jupiter and Saturn are now emerging out of the solar glare and visible low in the southeast before 5 a.m. A digital moment of these two gas giants and the 20% waning moon occurs on April 7 as dawn is just about to start.

April 22 is the peak night of the annual Lyrid meteor shower. The Leonids produce about 20 meteors per hour but you will be battling a 70% lit moon that only sets after 4 a.m. This month’s new moon occurs on April 11 (lunation 1216) with the Full Pink Full lighting up the sky on the 26th.

Until next month, clear skies everyone.

Gary Boyle

Author: Gary BoyleeNews date: Thursday, April 1, 2021Category: Northern SkiesTweet::  Pages

The Sky This Month - March 2021

Signs of Spring

With the icy grip of snow, ice and bone-chilling temperatures keeping most of us indoors at night, the change of season on the way this month. The Spring Equinox occurs on March 20 at 9:37 UT. The Equinox both Spring and Fall are the best chance to glimpse the ghostly Zodiacal Light, a slanted triangle column of interplanetary dust scattered by the sun. For two weeks starting March 1, you can glimpse or even photograph this elusive glow seen after evening twilight. Dark country skies and the absence of all light sources including moonlight will reward you with faint light appearing to point to the Pleiades star cluster. Another two-week period occurs at the end of the month after the full moon.

The Messier list is a collection of 110 celestial objects comprised of open star clusters, globular clusters, nebulae and remote galaxies. This number represents the brightest or near brightest as seen in earlier telescopes of antiquity. This is a far cry from the countless hundreds of objects modern scopes and photography can see and image. Many of the Messier objects are the favourite targets at public star parties and a great way for beginners to hunt the wonders of the night.

One roadblock to seeing a certain object is its proximity to the sun. If a particular object is too close to the solar glare, one must wait a few weeks for the earth to move away from the glare in its yearly orbit around the sun. But there is a time of year where all 110 objects can be glimpsed if you are up for the Messier Marathon.

March is always the month but the optimal night varies as to when the moon is at new phase. The marathon usually takes place on a weekend closest to the new moon. This is an all-night event from dusk till dawn and would be difficult to achieve when you must wake up for work or school. This year’s weekend of choice is the night of March 13/14 which happens to coincide with the exact date of the new moon. However, time is of the essence and following an exact order of objects (link above) maximizes your chances of accomplishing the marathon in one night. You must begin with the spiral galaxy M77 as the sky darkens in the west and battling a brightening eastern sky as dawn approaches by ending the list with the globular cluster M30. This is the same weekend that most of Canada will be advancing the clocks by one hour as we move Daylight Saving Time (DST).

Another change you will notice is the constellations themselves. As of the beginning of March Scorpius is seen low in the southeast and Cygnus low in the northeast around 3:30 a.m. and appear two hours earlier by April 1. From a dark location, you should be able to glimpse the Milky Way stretching above the treetops from the countryside. As weeks and months tick by, the band of stars will rise earlier and will be swatting mosquitoes before you know it.

The Full Worm Moon occurs on March 28 at 18:48 UT. With that said Easter is one of the holidays that varies with the lunar cycle. It always occurs on the Sunday after the full moon following the Spring Equinox. This year we will be celebrating Easter on April 4.           

Until next month, clear skies everyone.

Gary Boyle

Author: Gary BoyleeNews date: Monday, March 1, 2021Category: Northern SkiesTweet::  Pages

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