Comet ISON at Perihelion (Actual vs. Predicted Paths)


 

I superimposed the actual footage of Comet ISON passing by the Sun onto a graphic simulating its predicted path around the Sun at perihelion. They match!

This is an animation of Comet ISON at perihelion. I superimposed the actual SOHO satellite movie footage, released Friday, Nov 29, onto a still-image sky background (created with Starry Night™ software) that shows the scene at the moment of perihelion, and that displays the predicted orbital path of ISON plus labels the stars.

You’ll see the star fields (real and simulated) register fairly closely (check Antares at lower left) around the time of perihelion. It’s neat how the comet follows its predicted path! Well, of course! Newtonian gravity stills rules the solar system.

But I am amazed at how well the simulation (which is done from the viewpoint of the surface of Earth) lines up with the real movie (which was taken by the SOHO satellite from the L1 point 1.5 million km away from Earth but in the Earth-Sun line).

Click here for a more recent version using the SOHO footage released November 30, available at my Flickr site

— Alan, November 29, 2013, revised Nov. 30 /with credit to StarryNight™/Simulation Curriculum and to NASA/ESA

Comet Lovejoy Beside the Big Dipper


Comet Lovejoy & Big Dipper (Nov 27, 2013)

The handle of the Big Dipper seems to point down to Comet Lovejoy, low in the northern sky.

While the astronomy world waits and watches as Comet ISON rounds the Sun in the next day, another comet is appearing in the evening sky.

This is Comet Lovejoy, aka C/2013 R1, captured in a set of exposures I took about 6:30 pm on Wednesday evening, November 27, when the comet shone off the handle of the Big Dipper. It was not visible to the naked eye but was easy in binoculars. The photo shows Comet Lovejoy as cyan-tinted star at left with a spiky tail pointed away from the Sun.

From my latitude of 51° N Comet Lovejoy sits far enough north to be circumpolar, though just barely. However, as it heads south it will become just a morning sky object, especially for those at more southerly latitudes. In the coming days it will join Comet ISON (or what’s left of it) in the December dawn.

– Alan, November 27, 2013 / © 2013 Alan Dyer

 

 

Sundiving Comet ISON – A Last Look


Comet ISON C/2012 S1 (Nov 21, 2013)

Comet ISON performs its dive toward the Sun, caught in the morning twilight.

This was the infamous and much-hyped Comet ISON (C/2012 S1) as it appeared this morning, November 21, 2013, a week before it performs its hairpin turn around the Sun.

The comet was easy to see in binoculars, though the camera picks up a bit more of its faint tail. ISON was much more photogenic a week ago when it was higher in a darker and moonless sky. But this morning I had to contend with bright moonlight from a waning Moon and the brightening dawn. The inset shows a blow up of just the comet.

ISON is dropping rapidly toward the Sun, making this perhaps the last sighting I’ll have of it until it reappears – we hope! – from behind the Sun in early December. If it survives its perihelion passage it might blossom into brilliance … or fade into obscurity. No one knows.

In the photo above, you can see Mercury at left, shining much brighter than ISON. It was brilliant as it rose into the southeast sky, with the elusive planet now about as well-placed as it gets as a “morning star” for us living at northern latitudes.

Comet Lovejoy C/2013 R1 (Nov 21, 2013)

This morning I was able to shoot not one but two comets.

About half an hour before ISON hove into view I aimed the camera up almost overhead toward Ursa Major, to capture Comet Lovejoy (C/2013 R1) as a bright cyan fuzzball with a short tail. Again, the photo brings out the tail – to the eye the comet was obvious in binoculars but appeared as just a fuzzy star.

I took both shots with the same gear: a 135mm telephoto lens on the Canon 5D MkII on an iOptron SkyTracker. The Lovejoy shot is a stack of 5 x 75 second exposures. The ISON shot is a 4-second exposure, with the colours and contrast boosted for prettiness.

This is certainly proving to be a year of comets. It would be nice if just one of them got really bright!

– Alan, November 21, 2013 / © 2013 Alan Dyer

 

Relaunching Stargazing in Barbados


Observatory Viewing in Barbados (Nov 16, 2013) #1

Barbados is soon to have a new state-of-the-art public observatory for promoting astronomy.

On Saturday night, November 16, I was fortunate and privileged to be the guest speaker at the first event at the newly refurbished Harry Bayley Observatory in Bridgetown, Barbados. A grant from an educational foundation in the UK has allowed the Barbados Astronomical Society to renew the aging 50-year-old facility with a fresh new interior, and all the high-tech fittings of a modern public observatory.

A new dome was lifted into place on top of the 3-storey structure earlier in the week, and the painting and interior finishing was completed just a day or two before my talk, in time for a public RSVP event Saturday night.

Observatory Interior Panorama #1

I gave a talk on The Amazing Sky, showing images and movies from the November 3 total eclipse, among many other photos of the sights anyone can see in the day and night sky. I gave the same talk twice, to two packed houses of 40 people per session in the main floor meeting room/lecture hall. A wonderful spread of local food and drink was served upstairs.

Lots of work remains to complete the refurbishment but the facility was in good enough shape to host a public event. The official opening is in January.

Observatory Viewing in Barbados (Nov 16, 2013) #3

A new Meade 16-inch telescope on a Software Bisque MX2 mount is on its way for installation later this year, equipped with the latest robotic control and digital cameras for public viewing. A hydrogen-alpha solar telescope will also be part of the arsenal of equipment.

This night, members set up a portable Celestron 8-inch telescope outside for viewing the Moon and Jupiter. In contrast to viewing at home at this time of year, observing from 13° North latitude was in shorts and shirt-sleeves.

It was a terrific evening and I’m pleased to have been part of the relaunching of the Observatory and astronomy activities on the island. Many thanks go to my host on the island, Greg Merrick, for making the evening – and my stay this week – possible.

– Alan, November 17, 2013 / © 2013 Alan Dyer

The Green Flash – At Last!


The Green Flash (Nov 15, 2013) from Barbados

At last, I enjoyed a successful attempt to capture the elusive green flash.

During three weeks at sea attempts almost every evening from the ship to sight the green flash always failed, as the Sun set behind low horizon cloud.

But this night, the Sun set into the ocean with a clear horizon. My location was a small public oceanside walkway on Bay Street near Bridgetown, Barbados. It was a great spot to watch the sunset, though our main purpose for stopping there was to pick up some fried chicken at the KFC just steps away!

But the imminent sunset under ideal conditions made it worthwhile sticking around to see if we (I was with two friends from Alberta) could sight the green flash.

We did! I shot a rapid fire sequence – the image above is one frame of many catching the last bit of the Sun remaining above the horizon and turning green.

The infamous green flash is a refraction effect caused by the atmosphere separating out the green light and lifting it higher so it’s the last thing you see as the Sun sets. Conditions aren’t always amenable to seeing the green flash – you need a clear horizon and you also need the atmosphere structured with warm layers near the sea creating a mirage effect.

For more details on the technical explanations see Andrew Young’s page at http://aty.sdsu.edu/ 

… and Les Cowley’s page at http://www.atoptics.co.uk/atoptics/gf1.htm 

Andrew Young has a nice simulation at http://aty.sdsu.edu/explain/simulations/inf-mir/inf-mirSS4GF.html

Sunset from Barbados (Nov 15, 2013)

This was the view moments before, with the lower edge of the setting Sun distorted by atmospheric refraction, a sign that you might see a green flash as the upper edge disappears.

Sunset & Sailing Boat from Barbados

I shot this image a few minutes earlier as a photogenic sailboat drifted into the scene. Red sails in the sunset!

I’m nearing the end of my stay in Barbados and my 4 weeks away from home. There are heavy snowfall warnings out for southern Alberta this weekend so I’m not anxious to return! But winter will be waiting for me next week.

– Alan, November 16, 2013 / © 2013 Alan Dyer

 

The Eclipse in Time-Lapse


Total Solar Eclipse - 2nd Contact Diamond Ring (Nov 3 2013)

Here’s the Atlantic Crossing eclipse in time-lapse from the deck of the spv Star Flyer.

The above image is a still frame from the time-lapse movie I took on November 3, 2013 of the 44-second-long total eclipse of the Sun from the mid-Atlantic Ocean. It shows the first diamond ring (second contact) as totality began.

Below is the full time-lapse.

The movie is from 385 frames shot from before totality until well after. It shows just how lucky were were at seeing this eclipse, with the Sun coming out into a deep blue sky moments before totality and going back into thin cloud just as the total eclipse ends.

You’ll also appreciate the rolling of the ship, sped up here in the time-lapse, with frames taken one second apart.

Below is a still frame of the final diamond ring (third contact). Notice the difference in the brightness of the distant clouds in this image versus the one above. In the main image at top the clouds below the Sun had not yet entered the Moon’s umbral shadow.

But in the image below, the clouds are immersed in the lunar shadow and are about to be lit up again as the shadow races away from us in the direction toward the Sun.

Total Solar Eclipse - 3rd Contact Diamond Ring (Nov 3 2013)

In the time-lapse you can see the shadow enter the scene at top, then depart at the bottom of the frame below the Sun. As it shoots away from us, the shadow darkens the horizon far in the distance further down the path, bringing totality to those on the path to the east.

– Alan, November 11, 2013 / © 2013 Alan Dyer

Red Sky at Night … Sailor’s Delight


Sunset over the Atlantic (Nov 8, 2013) #2

We saw many wonderful sunsets on our sail across the Atlantic, but this was one of the finest.

This was the sky two nights ago, on the evening of November 8, as the Sun, now below the horizon, lit up the clouds to the west. You can see a few people out in the netting of the bow sprit taking in the view.

Sunset and Sails (Nov 8, 2013)

Here was the view looking up into the square rigged sails on the foremast. “The sky is on fire” was the comment I heard from folks on deck.

Red Rainbow over the Atlantic (Nov 8, 2013)

Contributing to our theme of a rainbow eclipse trip, a red rainbow appeared to the east, lit by the light of the setting Sun. What a wonderful sky this was!

Indeed, one of the other astronomers on board tallied up the number of naked eye sky sights he had seen on the voyage. It was an impressive list, equalling what had previously taken him over 30 years of sky gazing to accumulate.

I’m writing this post from back on land, now in Barbados at a latitude of 13° north. However, now that I have high-speed connectivity I can get caught up with posts from the sea voyage, with a couple of more to come from at sea.

– Alan, November 10, 2013 / © 2013 Alan Dyer