The Stellar Triangle of Summer




When the Summer Triangle sinks into the west, we know summer has come to an end. While the stars of the Summer Triangle are now high overhead from northern latitudes as the sky gets dark, by late evening the Summer Triangle is setting into the west.

These three bright stars are an example of stellar variety:

– At bottom is Altair in Aquila the eagle. It’s a white main-sequence star 17 light years away, fairly nearby by stellar standards. Leslie Nielson and his crew went to Altair in the 1950s movie Forbidden Planet.

– At top right is Vega, in Lyra the harp, a hotter and more luminous blue-white star than Altair, making it appear brighter than Altair, despite Vega being farther away, at 25 light years distant. Jodi Foster went to Vega in the movie Contact.

– But the third member of the Triangle, Deneb, at top left, is an extreme star. It appears a little fainter than Vega, but looks can be deceiving. Deneb is actually a luminous supergiant star, putting out 54,000 times the energy of our Sun. Deneb is about 1,400 light years away and yet, due to its fierce output of light, appears almost as bright as Vega. Light from Deneb left that star in the 6th century. I don’t know of any movie heroes who went to Deneb. The name means “tail of the Swan,” hardly a romantic destination for space-faring adventurers.

Look toward the Summer Triangle and you are looking down the spiral arm of the Milky Way that we live in. The stars of that arm appear as a packed stellar cloud running through Cygnus the swan, the constellation that contains Deneb.

I took this shot Saturday night, from home, on what turned out to be a very clear night, once some clouds got out of the way in the early evening. This is a 4-image stack of 8-minute exposures, at f/4 with the 35mm Canon lens, a favourite of mine, on the Canon 5D MkII at ISO 800. I added in exposures taken through a soft-focus filter to give the added glows around the stars to help make the bright stars and their colours more visible.

— Alan, September 25, 2011 / Image © 2011 Alan Dyer

Happy Equinox!


 

This is a shot I’ve been after for several years, usually from this same location, looking west toward the setting Sun.

This is sunset at the autumnal equinox, with the Sun going down due west, something it does only at the two equinoxes. September’s usually the one with clear skies, as it was this night, Sept 23, 2011. Except for some annoying clouds at the horizon over the Rockies to the west. I was hoping for a clear shot of the Sun right at sunset at the end of Highway 1, the Trans-Canada Highway. But it’s close. Better luck next year!

After today, the Sun will be setting south of west, and the days will become shorter than the nights.

This is a 6-image HDR stack to capture both the bright and dark parts of the scene. It worked, but Photoshop refused to properly remove the “ghosts” — images from cars moving from shot to shot. But if I hadn’t told you about it, you might not have noticed!

— Alan, September 23, 2011 / Image © 2011 Alan Dyer

 

September Milky Way


 

This was the scene from my rural backyard on Tuesday night, September 20, with the Milky Way at its best across the sky.

September usually brings the best nights of the year for dark-sky observing and shooting the Milky Way. Nights are clear, dry, and transparent. The Milky Way stretches across the sky from southwest to northeast in the early evening.

Under clear skies on Tuesday the dark lanes and structure of the Milky Way really stood out, both to the eye and to the camera. Image processing for contrast does bring out the dust lanes, including the subtle patches off the main Milky Way band.

The centre of the image contains the three bright stars of the Summer Triangle. They frame the bright Cygnus starclouds and glowing red nebulas that mark the spiral arm that we live in. Above, at top left in the image, is a bluer section of the Milky Way formed by the more distant Perseus spiral arm, the one further out from us in the Galaxy.

I took this shot with the Canon 5D MkII and Canon 15mm lens, for a stack of five 6-minute exposures at f/4 and ISO 800.

— Alan, September 21, 2011 / Image © 2011 Alan Dyer

 

Saturday Night Stargazing


It was a marvellous night for the Milky Way … and some Saturday Night Stargazing.

This was the scene at the University of Calgary’s Rothney Astrophysical Observatory on Saturday night (Sept 17, 2011) as a crowd of about 250 people took in the wonders of the night sky at one of the Observatory’s monthly Open Houses. Skies were excellent and a late moonrise left dark skies early on for views of the Milky Way, a seldom seen part of nature for city-dwellers. A dozen volunteers from the local chapter of the Royal Astronomical Society of Canada provided telescopes and expertise to tour people around night sky wonders, from comets to star clusters. Many people are delighted just to have the constellations pointed out, so they can identify the patterns whose names they have heard of but have never seen.

What always impresses me about such events is how much interest the public shows, and how much the kids in attendance know about astronomy and space. One young man, age 10 or so, in seeing some of the images, like this one, that I was taking pop up on my camera screen, asked if I do piggyback photography! At his age I’m not sure I knew about piggyback photography!

We see all ages at our public stargazing events, all expressing the same “Wow! That’s cool!” reaction. Hearing the comments gives us astronomers a charge — we get as much back from the guests as we hope we provide them.

— Alan, Sept. 18, 2011 / Image © 2011 Alan Dyer

 

Time-Lapse Test: Adding Motion Control


Here’s the movie I show being taken in my previous blog. This is my first attempt at a motion-control time-lapse.

In this movie the camera shifted position during the 3 hours of shooting by sliding along a rail, with the movement controlled by a little computer box that opened and closed the shutter (in this case for 15 seconds for each frame), then between each exposure it pulsed the motor to shift the camera a centimetre or so down the dolly’s rail. 

Pretty nifty! And until this unit, the Stage Zero Dolly, came along this capability would have cost much more money, from some Hollywood cinema supplier.

This was only a test, and I did mess up at one point (where I appear in the frame in the previous blog’s movie) as I tried to adjust the speed in mid-track, resulting in some dead motion for a few frames. So the motion comes to a halt briefly. It will take some learning to know how to set the speed right for the number of frames and exposure times I typically shoot.

But the ramping up in speed at the beginning of this movie is intentional, and is one of the motion control variables you can program in. 

The Stage Zero Dolly unit is from Dynamic Perception LLC. Lots of time-lapse shooters are employing it now, for their cinema-like pans and moves. I’ve been inspired by the work of Randy Halverson at http://dakotalapse.com/ . Amazing stuff — representing a whole new level of time-lapse techniques. 

So now I know what I’ll be doing now on moonlit evenings! 

— Alan, September 12, 2011 / Movie © 2011 Alan Dyer

Time-Lapse of a Time-Lapse


I’ve been taking lots of time-lapse movies of late. But this one is a time-lapse movie of my other camera taking a time-lapse movie.

Here you see my Canon 7D camera riding aboard my latest tool (or toy!), a motion-control dolly. The camera takes its series of still images (that will be later stitched together into a movie) while it tracks down a rail, riding on a motorized cart.

The unit is called the Stage Zero Dolly, from Dynamic Perception LLC. It is a nifty device that fires the camera shutter for the exposure time and interval you desire. In between each exposure it also moves the camera a small amount down the track. The result can be seen in the next blog, a time-lapse movie with a changing perspective, giving a cinema-style dolly shot. Except, I took this one over 3 hours.

While this scene might look like I took it during the day, it is the middle of the night (witness the moving stars). The blue sky is due to moonlight, from an almost Full Moon on September 10.

The Stage Zero Dolly takes some work to set up and program right, but the results open up a whole new dimension (literally!) in time-lapse shooting.

— Alan, September 12, 2011 / Movie © 2011 Alan Dyer

A Super Star Party Sky


This is the kind of sky that makes astronomers smile. Clear and painted with twilight colours.

This was the scene two weekends ago, on August 26, at the annual Starfest star party in southern Ontario. Starfest is Canada’s biggest annual astronomy gathering and this year attracted about 700 people, filling the campground with tents, trailers and telescopes.

I was fortunate enough to be able attend this year, as one of the guest speakers in a pretty full program of afternoon and evening talks. I presented two talks, on the “Great Southern Sky” and on “Ten Tips for Better Pix,” plus presented a laser tour of “my sky” after dark on the Friday.

Starfest, as with other star parties I’ve been to lately, hasn’t fared well for weather in the last few years, but this year the clouds (mostly!) stayed away and people enjoyed a fabulous weekend under the Milky Way and summer stars.

This is a roughly 180° panorama taken at twilight, showing the rising dark blue arc of Earth’s shadow at left, with a strangely bright glow in the atmosphere above it. At right is the glow of sunset and some crepuscular rays (shadows from distant clouds) visible as bright and dark bands across the sky.

Starfest is a great star party. Anyone in eastern Canada interested in astronomy should make a point of attending. Next year’s event is August 16-19, 2012.

— Alan, Sept 11, 2011 / Image © 2011 Alan Dyer