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 

 

Big Dipper Over Castle Mountain


Big Dipper over Castle Mountain, Banff (Aug 24, 2013)

The famous stars of the Big Dipper dip behind the moonlit crags of Castle Mountain.

I just got back from four days in Banff, always a great place to be, even if it is cloudy. And it was!

I lost one night to forest fire smoke and another to rain clouds. On Saturday and Sunday nights I managed to seek out some clearer skies for nighttime shooting. This is a shot from Saturday, from a favourite photo stop on the Bow Valley Parkway overlooking the cliffs of Castle Mountain.

Despite the dew from rains earlier in the day I managed to shoot a time-lapse here. These two shots are frames from the movie which pans slowly across the scene.

Iridium Flare over Castle Mountain

This frame catches an Iridium satellite flare above the Dipper.

Light from the waning gibbous Moon, which was in and out of clouds itself, illuminates the scene and nicely cross-lights the Castle cliffs.

– Alan, August 26, 2013 / © 2013 Alan Dyer

 

Star and Satellite Trails


Big Dipper Star Trails and Iridium Flares (July 12, 2013)

A long exposure captures streaks from the turning stars and passing satellites.

This was a busy sky. The feature photo stacks a dozen images taken over 6 minutes.

During that time the northern stars around the Big Dipper turned about the celestial pole just off frame at upper right.

Meanwhile, two satellites passed through the field, both flaring in brightness briefly, tracing tapered streaks from left to right above the treetops. These may have been Iridium satellites, infamous for producing sunglint flares as they momentarily reflect the Sun from their mirror-like antenna panels.

A magenta aurora tints the northern sky as well.

Big Dipper & Purple Aurora (July 12, 2013)

This image is from the same sequence of 300 or so I took last night for a time-lapse movie, but this is a single 30-second exposure so the stars look more natural and pinpoint. Now you can make out the familiar pattern of the Big Dipper.

I shot several sequences last night, until the clouds rolled in and curtailed photography. However, skies are clearing again and the forecast is for several clear nights to come over the Cypress Hills. I’ve got a few locations picked out for time-lapse shooting if the skies cooperate.

– Alan, July 12, 2013 / © 2013 Alan Dyer