Conjunctions, Satellites & Auroras, Oh My!


Friday the 13th Aurora Title

October has brought clear skies and some fine celestial sights. Here’s a potpourri of what was up from home. 

We’ve enjoyed some lovely early autumn weather here in southern Alberta, providing great opportunities to see and shoot a series of astronomical events.


Conjunctions

Venus & Mars in Close Conjunction #2 (Oct 5, 2017)
Venus and Mars in close conjunction in the dawn sky on October 5, 2017. Venus is the brightest object; Mars is below it; while the star above Venus is 4th magnitude Sigma Leonis. The foreground is illuminated by light from the setting Full Moon in the west. This is a single 1-second exposure with the 135mm lens at f/2 and Canon 60Da at ISO 800. 

On October 5, Venus and Mars appeared a fraction of a degree apart in the dawn twilight. Venus is the brightest object, just above dimmer but red Mars. This was one of the closest planet conjunctions of 2017. Mars will appear much brighter in July and August 2018 when it makes its closest approach to Earth since 2003.


Satellites: The Space Station

Overhead Pass of the Space Station in Moonlight
An overhead pass of the ISS on October 5, 2017, with the Full Moon rising in the east at left. The ISS is moving from west (at right) to east (at left), passing nearly overhead at the zenith at centre. North is at the top, south at bottom in this fish-eye lens image with an 8mm Sigma fish-eye lens on the Canon 6D MkII camera. This is a stack of 56 exposures, each 4 seconds long at an interval of 1 second. 

The Space Station made a series of ideal evening passes in early October, flying right overhead from my site at latitude 51° N. I captured it in a series of stacked still images, so it appears as a dashed line across the sky. In reality it looks like a very bright star, outshining any other natural star. Here, it appears to fly toward the rising Moon.


Satellites: Iridiums

Twin Iridium Satellite Flares (October 9, 2017)
A pair of nearly simultaneous and parallel Iridium satellite flares, on October 9, 2017, as they descended into the north. The left or westerly flare was much brighter and with a sharp rise and fall in brightness. While it was predicted to be mag. -4.4 I think it got much brighter, perhaps mag -7, but very briefly. These are Iridium 90 (left) and Iridium 50 (right). This is a stack of 40+ exposures each, 2 seconds at 1-second intervals, with the Sigma 24mm lens at f/1.4 and Nikon D750 at ISO 6400.

Often appearing brighter than even the ISS, Iridium satellite flares can blaze brighter than even Venus at its best. One did so here, above, in another time-lapse of a pair of Iridium satellites that traveled in parallel and flared at almost the same time. But the orientation of the reflective antennas that create these flares must have been better on the left Iridium as it really shot up in brilliance for a few seconds.


Auroras

Aurora and Circumpolar Star Trails (Oct, 13, 2017)
A circumpolar star trail composite with Northern Lights, on October 13, 2017, shot from home in southern Alberta. The Big Dipper is at bottom centre; Polaris is at top centre at the axis of the rotation. The bottom edge of the curtains are rimmed with a pink fringe from nitrogen. This is a stack of 200 frames taken mostly when the aurora was a quiescent arc across the north before the substorm hit. An additional single exposure is layered in taken about 1 minute after the main star trail set to add the final end point stars after a gap in the trails. Stacking was with the Advanced Stacker Plus actions using the Ultrastreaks mode to add the direction of motion from the tapering trails. Each frame is 3 seconds at f/2 and ISO 6400 wth the Sigma 14mm lens and Nikon D750.

Little in the sky beats a fine aurora display and we’ve had several of late, despite the Sun being spotless and nearing a low ebb in its activity. The above shot is a composite stack of 200 images, showing the stars circling the celestial pole above the main auroral arc, and taken on Friday the 13th.

Aurora from October 13, 2013
A decent aurora across the north from home in southern Alberta, on Friday the 13th, October, 2017, though these frames were taken after midnight MDT. 3 seconds at f/2 and ISO 6400 wth the Sigma 14mm lens and Nikon D750.

This frame, from some 1300 I shot this night, October 13, captures the main auroral arc and a diffuse patch of green above that pulsed on and off.

You can see the time-lapse here in my short music video on Vimeo.

Friday the 13th Aurora from Alan Dyer on Vimeo.

It’s in 4K if your monitor and computer are capable. It nicely shows the development of the aurora this night, from a quiescent arc, through a brief sub-storm outburst, then into pulsing and flickering patches. Enjoy!


What all these scenes have in common is that they were all shot from home, in my backyard. It is wonderful to live in a rural area and to be able to step outside and see these sites easily by just looking up!

— Alan, October 16, 2017 / © 2017 Alan Dyer / AmazingSky.com 

 

Dawn Sky Delights


Aldebaran About to be Occulted by the Moon

It was one of those mornings when the sky was full of wonder.

After days and nights of smoke from unfortunate fires burning not far away, including in my favourite national park of Waterton Lakes, the sky cleared enough this morning, September 12, to reveal some fine sights.

At 6 a.m. the waning gibbous Moon passed in front of the star Aldebaran in Taurus. It is performing many such occultations of Aldebaran this year, but most aren’t well seen from any one location. This one was ideal, right from my backyard.

The lead image is a “high dynamic range” stack of several exposures showing the waning Moon and star set in some high haze adding the sky colours.

The star winked out behind the Moon’s bright limb as the Moon advanced from right to left (west to east) against the background sky.

Occultation of Aldebaran
Aldebaran nearing the limb of the Moon.
This shows a composite sequence, with images of the star taken every four minutes blended with a single image of the Moon. While it looks like the star is moving, it is really the Moon that is edging closer to Aldebaran.

The star reappeared from behind the dark limb of the Moon, but five minutes after sunrise, with the Moon in a bright blue sky. Still, the star stood out nicely in binoculars and in the telescope for this view.

Aldebaran Near the Moon in Day Sky
Aldebaran off the dark limb of the Moon.
Aldebaran is the point of light at right, just off the invisible edge of the Moon.

I shot stills and video, and compiled them into this short video.

Enlarge it to full screen to view it properly.

Meanwhile, over to the east the twilight sky was awash in planets.

Rocky Planets at Dawn with Labels (Sept. 12, 2017)
The line of dawn planets, with labels.
All the three inner terrestrial worlds were there: Venus, at top, Mercury below Regulus, and Mars lowest of the trio. Of course, a fourth terrestrial world is in the photo, too – Earth!

Mercury was at its greatest western elongation this morning, placing it as far from the Sun and as high in the sky as it gets, with this autumn appearance the best of 2017 for a morning showing for Mercury. Even so, you can see how Mercury is always low and easy to miss. However, this morning it was obvious to the naked eye.

Mars and Mercury will be in close conjunction at dawn on the morning of September 16.

Rocky Planets at Dawn (Sept. 12, 2017)

It was a fine morning to be up early and enjoy the solar system show.

— Alan, September 12, 2017 / © 2017 Alan Dyer / amazingsky.com

 

End of Year Skies


New Moon for a New Year

The crescent Moon rises into the western evening sky as 2016 ends, while Venus shines bright, and Orion rises into the east.

Getting clear skies is a rare treat of late, but these are images from two such nights this week. On December 30, the thin waxing Moon appeared in the colourful twilight of a winter night. Despite the clouds and the Moon’s low altitude, the dark side of the Moon is plainly visible illuminated by Earthshine.

Venus in Twilight over Pioneer Grain Elevators

Venus is now brilliant as an evening star in the southwest. Here is it over the old wood grain elevators at Mossleigh, Alberta, some of the few of these landmarks left standing on the prairies.

Fainter Mars shines above Venus and over the month of January, Venus will climb up to meet Mars by month’s end for a fine conjunction with the crescent Moon as well. Watch through January as Venus and Mars converge.

Orion and Pioneer Grain Elevators

As the planets set into the southwest, Orion the Hunter rises into the east. Here it is over the Mossleigh elevators, illuminated by local lights.

Enjoy the winter skies as clouds permit!

Clear skies and Happy New Year!

— Alan, December 31, 2016 / © 2016 Alan Dyer / www.amazingsky.com

 

Free 2016 Sky Calendar


2016 Calendar Cover

Plan your cosmic year with my free 2016 Sky Calendar.

My Calendar lists all the best sky events for 2016, plus Moon phases, to help you plan your astronomical year.

Coming up we have:

• A fairly close approach of Mars

• A rare transit of Mercury

• A photogenic gathering of Mars, Saturn and Antares

… among many other sky events.

You can download the free PDF at

http://www.amazingsky.com/about-alan.html

Feel free to share the link to this page.

Happy New Year to all!

— Alan, December 29, 2015 / © 2015 Alan Dyer

Heads Up! – A Comet in the December Dawn


Dec 7 Venus & Moon

A new comet is coming into our morning sky, for our binocular viewing pleasure.

Comet Catalina, aka C/2013 US10, has emerged from behind the Sun and is beginning to rise into our northern hemisphere dawn sky. The new comet promises to be visible in binoculars, but likely won’t be obvious to the unaided eyes.

On the morning of December 7 the comet sits within a binocular field of the waning crescent Moon which itself sits just above brilliant Venus. That in itself will be a remarkable view, best appreciated in binoculars, and a fine photogenic sight for the camera.

The close conjunction of the crescent Moon with Venus alone will be enough of an attraction on December 7, but the comet should add to the scene.

December 7 Venus Occultation

Even more, later in the day the Moon actually passes in front of, or “occults,” Venus in the daytime sky for most of North America.

That occultation happens in the morning for western North America and in the early afternoon for eastern North America. However, you’ll need a telescope to see it well, and very clear blue skies.

Stellarium Occultation

Use planetarium software (the free Stellarium program, for example, shown above, if you do not own astronomy software) to simulate the sky and provide the occultation times for your location. Zoom into the Moon and run time back and forth on December 7 to see when Venus goes behind the Moon and reappears. The screen shot above is for Calgary.

Back to the Comet

Comet Catalina was discovered in October 2013 at the Catalina Observatory in Arizona. The comet spent the last few months in the southern hemisphere sky, but is now coming north and into our sky, but at dawn.

Comet Catalina Path

It rises higher and higher each morning  through December and into the new year. It may remain at fifth magnitude, bright enough to be easily visible in binoculars from a dark site, but likely not naked eye.

The chart above plots the comet at daily intervals, from December 4 to January 1. The comet is shown for December 15. Note that on the morning of January 1 it sits within a telescope field of the bright star Arcturus.

The distance from Earth to the comet decreases through December and early January, keeping the comet at a constant brightness even as it recedes from the Sun. We are closest to Catalina on January 17, at a far distance of 108 million km. But in late January the comet fades rapidly to become a telescope target.

To see Comet Catalina this month, get up 1 to 2 hours before sunrise and look southeast to east. But you will need dark skies to see it well. This will not be a good urban comet.

Nevertheless, as far as we know, this will be the best comet of 2016.

— Alan, December 2, 2015 / © 2015 Alan Dyer / www.amazingsky.com

 

Four Planets Along the Morning Ecliptic


Four planets in the morning sky, on October 20, 2015, along the ecliptic from bottom to top:  - Mercury (close to the horizon at lower left) - Mars (dim, below Jupiter) - Jupiter (fairly bright at upper right) - Venus (brightest of the four) I shot this from home in southern Alberta. This is a composite stack of 5 exposures from 15 seconds to 1 second to contain the range of brightness from the bright horizon to the dimmer sky up higher. All with the 35mm lens and Canon 6D at ISO 800.

Four planets appear in the dawn sky outlining the morning ecliptic.

This morning, October 20, I was able to capture four planets in the morning sky, arrayed along the ecliptic.

From bottom to top they are: Mercury (just past its point of greatest elongation from the Sun), dim Mars, bright Jupiter, and very bright Venus (just 6 days away from its point of greatest elongation from the Sun). Above Venus is Regulus, in Leo.

I’ve added in the labels and the line of the ecliptic, rising steeply out of the east in the autumn dawn sky.

Of course, there is a fifth unlabelled planet in the scene, quite close in the foreground.

The image below is an unlabeled version.

Four planets in the morning sky, on October 20, 2015, along the ecliptic from bottom to top:  - Mercury (close to the horizon at lower left) - Mars (dim, below Jupiter) - Jupiter (fairly bright at upper right) - Venus (brightest of the four) I shot this from home in southern Alberta. This is a composite stack of 5 exposures from 15 seconds to 1 second to contain the range of brightness from the bright horizon to the dimmer sky up higher. All with the 35mm lens and Canon 6D at ISO 800.

Mercury will be disappearing from view very quickly now as it drops back down toward the Sun.

But over the next week the three higher planets will converge into a tight triangle just 4.5 degrees apart. We won’t see these three planets this close together in a darkened sky until November 2111.

For more information on this week’s dawn sky planet dance see my previous blog entry.

TECHNICAL:
I shot the scene from home in southern Alberta. The image is a composite stack, with manually created masks (not an HDR stack), of 5 exposures, from 15 seconds to 1 second, to contain the range of brightness from the bright horizon to the dimmer star-filled sky higher up. All are with the 35mm lens and Canon 6D at ISO 800.

— Alan, October 20, 2015 / © 2015 Alan Dyer / www.amazingsky.com

Heads Up! — Planet Dance in the Dawn


Oct 17 Dawn Sky

Watch a trio of planets converge in the dawn sky. 

You might have already seen Venus shining brightly in the morning sky. And perhaps you’ve seen a slightly less bright object below it. That’s Jupiter.

But there’s a third, even dimmer planet accompanying Venus and Jupiter — reddish Mars. On the morning of Saturday, October 17 (chart above ⬆️) Mars and Jupiter pass just 1/2 degree apart, for a mismatched double “star” at dawn.

The planets put on an even better show in the following 10 days as all three converge to form a tight triangle of worlds in the morning sky.

Oct 23 Dawn Sky

On October 23 ⬆️, Venus, Mars and Jupiter appear in a close grouping just 4.5 degrees apart, close enough to each other to be easily contained in the field of typical binoculars, the circle shown in these charts.

Oct 25 Dawn Sky

Two mornings later, on October 25 ⬆️, Venus and Jupiter are at their closest apparent separation, just 1 degree apart, for a brilliant double “star” in the morning twilight. If you miss this morning, on the next morning, October 24, the two planets appear about the same distance apart as well.

Oct 28 Dawn Sky

By October 28 ⬆️, the three planets have switched positions, as Venus drops lower but Jupiter climbs higher. But they again appear in a triangle, 4.5 degrees wide.

The motion you’re seeing from day to day is due to a combination of the planets’ own orbital motions around the Sun, as well as our planet’s motion.

Keep in mind, the planets aren’t really close together in space. They lie tens, if not hundreds, of millions of kilometres apart. They appear close to each other in our sky because they lie along the same line of sight.

Do try to get up early enough — between 6 a.m. and 6:30 a.m. should do it — to look east to see the changing configuration of planets as they dance at dawn. Binoculars will provide the best view.

This is a rare sight! We won’t see these three planets this close to each other in a darkened sky until November 20, 2111!

— Alan, October 16, 2015 / © 2015 Alan Dyer / www.amazingsky.com