SkyNews - Astronomy & Stargazing Magazine of Canada
SkyNews, the magazine of astronomy and stargazing, is your guide to observing the night sky. On our website you can find out what's up in the sky this week and a collection of resources for amateur astronomers.
The Swan Nebula, also known as M17, resides within a rich swath of summer Milky Way in northern Sagittarius. The nebula can be seen in binoculars and is a delight in a small telescope, which reveals the swan (or “check-mark”) shape readily. (The Swan is swimming upside down in this north-up shot.) In a larger instrument equipped with a narrow-band filter, some of the intricate detail and faint nebulosity shown in long-exposure photographs becomes visible.
The Swan is nicely presented in this image by Ontario astrophotographer Rick Saunders, who captured the nebula on June 13, 2018, while attending the Cherry Springs Star Party in Pennsylvania. Rick combined 9, 240-second exposures recorded at ISO 1600 with a Nikon D810A DSLR camera and an Orion 10-inch f/3.9 astrographic reflector telescope (fitted with a Baader MPCC Mark III coma corrector) for the final result shown here.
Getting a shot of the northern lights is extremely challenging at the moment. For one thing, summer nights are very short. Secondly, solar activity is currently low, which means few auroral displays are triggered. But “challenging” isn’t the same as “impossible,” as this photo by John Andersen proves. In spite of the unfavourable circumstances, he was able to capture the scene presented above in the early morning hours of June 18, 2018, from a location east of Crossfield, Alberta—a town with a latitude of 51 degrees north. Indeed, twilight’s persistent glow on this near-solstice “night” adds colour to the sky and makes the scene all the more attractive.
John used a Canon EOS 6D DSLR camera fitted with a Tamron 15-30mm f/2.8 zoom lens (set to 15mm) for this 8-second exposure at ISO 3200.
High overhead on summer nights is Cygnus, the celestial swan—a constellation also more prosaically known as the Northern Cross. With the Milky Way running the full length of Cygnus, it’s not surprising that the region is rich with deep-sky treasures. One of the best known is the North America Nebula, much of which is shown in the photo above. Particularly conspicuous is the way the nebula suggests the west coast of Central America and Mexico—a feature informally dubbed the Cygnus Wall.
This nicely detailed narrow-band photo of the region was captured by Ian Barredo from his backyard in Regina, Saskatchewan. He used a ZWO ASI1600 monochromatic camera and a set of Astronomik filters with a Sky-Watcher 80mm ED refractor telescope (fitted with a 0.85× focal reducer) to obtain the data used for this image.
With the solstice having just occurred on June 21, summer has officially begun in the northern hemisphere. For some, that date also brings with it the less happy realization that the days are now growing shorter as we once again begin the long march toward winter. Another, less obvious (but related) effect is that the point of sunrise will now begin to drift southward. This shift is nicely illustrated in this composite image by Luca Vanzella. His photo shows sunrise near three key dates in 2017 (from left to right): the summer solstice, the autumn equinox and the winter solstice. Luca’s home city of Edmonton, Alberta, is on the horizon.
Each individual exposure in Luca’s photo was captured with a Canon EOS Rebel 3Ti DSLR camera and a wide-angle zoom lens set to 10mm focal length. The sun images (spaced 5 minutes apart) were made with a solar filter mounted on the front of the lens.
Galaxies are by far the most numerous deep-sky objects, and the deeper you go, the more you find. But even the Messier catalogue, which is heavily skewed toward the brightest celestial showpieces, lists 40 galaxies. Face-on spiral, M101, in the constellation Ursa Major is one of the finest examples. It can be found under dark skies by following a string of stars curving eastward from Mizar, the middle star in the Big Dipper’s handle. With a good-sized telescope, you can make out M101’s main spiral arms, but the finest details only show up in photographs, like this one by Raphaël Dubuc. Among the details in this image are several additional galaxies—all distant and faint. The most conspicuous of these is NGC5473, at lower left. (North is to the left in this 1.3-degree wide image.)
Raphaël captured this M101 portrait from a dark-sky location in Saint-Camille, Quebec. He used an Explore Scientific 127mm, f/7.5 ED refractor and a modified Canon EOS Rebel T3i DSLR camera equipped with a Astrodon IR/UV cut filter. Total exposure was 3¾ hours.
Revisiting Mars stirs memories of past encounters and stokes anticipation.
SkyNews illustration based on Schiaparelli 1877-86 Mars map
Some of my fondest astronomical memories are of the red planet. The Mars of Giovanni Schiaparelli and Percival Lowell was the one that excited my youthful imagination. The idea that primitive plant life existed on Mars’ parched, dusty surface seemed entirely plausible—indeed, probable. And who knew what may have existed in the remote past? Perhaps there never were Martians like those described by H.G. Wells or Ray Bradbury, but still . . . what if? When you’re 10 years old, lots of things are possible.
My earliest recollection of seeing Mars for myself was during the favourable August 1971 opposition. My dad had probably heard a sensationalistic item on the radio about the planet being unusually close (some things never change), and he woke me in the middle of the night so that I could witness the “once-in-a-lifetime” spectacle. Unaware of the hype, I was, nonetheless, impressed by the brilliant, vividly orange beacon low in the southern sky. All close oppositions of Mars are notable, but some such as that 1971 encounter—are more memorable than others.
It was during the 1988 summer opposition that I truly got to know Mars with a telescope. At the time, I was living in downtown Vancouver, British Columbia, and did most of my observing with a 6-inch reflector on my sixth-floor, southwest-facing apartment balcony—the scope’s short (f/6) focal ratio made it ideal for such cramped confines. Even so, I had to coordinate my viewing sessions to start when Mars cleared the corner of the balcony directly above me. To my amazement, I discovered that during the quiet hours of the early morning, big-city seeing conditions can be surprisingly steady. Night after night, I peered into my scope’s eyepiece, thrilling at the views and sketching what I saw.
Some of my most exciting Mars observing came during the 2001 close approach, when I was an editor at Sky & Telescope magazine, in Cambridge, Massachusetts. Being responsible for the observing section, I helped shepherd into production an article by noted planet observers Tom Dobbins and Bill Sheehan. Bill and Tom discussed short-lived specular flares—glints of sunlight reflecting off the Martian surface—that might be visible when conditions were just right. As their article described, there had been some credible flare observations in the 1950s, but the reality and nature of the phenomenon was far from certain.
Armed with a table of predictions, then editor-in-chief Rick Fienberg and I flew to the Florida Keys to take advantage of the region’s famously steady seeing conditions. We set up our gear at Tippy D’Auria’s house along with a few other observers, including Tom and ace planet imager Don Parker, who planned to record the hoped-for flares with video equipment attached to his telescope. To our great delight, on the third night of our Florida stay, we witnessed a succession of starlike flashes on the Martian surface—events that we were able to relive later when we reviewed Parker’s video recording. It was a remarkable night that ultimately resulted in one of the few occasions my name has appeared in an International Astronomical Union Circular.
So here we are on the eve of another great opposition. For just the fourth time in my life, Mars will come within 60 million kilometres of Earth. I’ll be out with my scope every clear night this summer getting reacquainted with my old friend. At some point, I’m sure I’ll pause to reflect on how much has happened since our first meeting in 1971. I’m a much more experienced observer now, with half a lifetime under my belt, while Mars has been extensively mapped and explored by numerous robotic probes since Mariner 4’s initial visit, in 1965. But in spite of everything, I know that when I peer into the eyepiece at that peachy orange Martian disc, looking back will be the same mysterious world that sparked so much excitement in me decades ago.
Check out the July/August 2018 issue of SkyNews for an expanded version of Gary’s Editor’s Report.
Although many of us enjoy using a telescope to view challenging targets, such as faint galaxies and nebulas, or to glimpse elusive detail on Jupiter or Mars, there’s nothing quite like stepping back to take in the big-picture perspective. Naked-eye astronomy has many rewards. The enjoyment derived from leisurely identifying constellations and asterisms is hard to beat—and the only gear you need to enhance the experience is a comfortable reclining chair. This photo of the Big Dipper over the Skitchine Lodge in North Kamloops, British Columbia, evokes the simple pleasure of looking up at a starry night.
Tom Evans of Calgary, Alberta, captured this view last July, and spent nearly a year learning the ins and outs of image processing before arriving at the result shown here. He used a tripod-mounted Canon EOS 6D DSLR camera at ISO 3200, with a Canon 16-35mm zoom lens (set to 16mm). The photo combines a total of 41 exposures to capture the full dynamic range of the scene. The star “points” were added in post-processing using the StarSpikes Pro 4, a PhotoShop plug-in filter.
Central Cygnus is awash in nebulosity—so much so that individual objects can be difficult to appreciate, or even locate. But NGC6888 (popularly known as the Crescent Nebula) is fairly easy to spot in this long-exposure image by astrophotographer Tudor Chibacu. The nebula’s distinctive shape and relative brightness are also the reason it’s a popular target for deep-sky observers. However, seeing the Crescent for yourself requires dark skies and a telescope equipped with a narrow-band eyepiece filter.
Tudor captured this 3-degree-wide view of the Crescent and surrounding region from Kingston, Ontario. He used a William Optics 71mm apochromatic refractor telescope (working at f/4.7) and a QHY163M camera to record 5 hours of exposure data with a H-alpha filter and 6 hours with an OIII filter for this bicolour image.
Near the top of every observer’s must-see list for late spring is M13, otherwise known as the Great Hercules Cluster. At magnitude 5.8, it can be perceived with the naked eye and is an easy binocular find. However, like all globular star clusters, M13 really comes into its own in a telescope. The object is impressive in small apertures, but the increased resolution of bigger instruments show the cluster to even greater effect. In a large backyard scope, M13 is a spectacular swarm of luminous pinpoints.
Haneytown, New Brunswick, astrophotographer Scott Champion captured this beautifully detailed image of M13 with a MallinCam VRC-8 Ritchey-Chrétien astrograph fitted with an Astro-Physics CCDT67 focal reducer for a working f-ratio of f/5.4. Scott used a Atik 383L + monochromatic CCD camera shooting through Baader Planetarium filters to acquire a total of 82 minutes exposure data.