The Down Under Waxing Moon


Earthshine on Australian Waning Crescent Moon (HDR)

To northern eyes this looks like an old Moon in the morning sky, but this is really a young Moon in the evening sky – seen from Australia.

This was the waxing crescent Moon a few nights ago in the early evening sky. Because I took this from a latitude of 30° south, the Moon is turned over almost 90° from the way northern hemisphere viewers would see it from Canada or the northern U.S.

For this image, I shot ten exposures from 1/30s to 15 seconds and merged them into one “high dynamic range” composite using Photomatix Pro software. The result is an image with detail in both the bright sunlit crescent and in the dark side of the Moon visible here lit by Earthshine, sunlight reflected off the Earth. The resulting “HDR image” compressed the wide range of brightness into one image, to show the Moon the way your eye would see it but that photo technology is still not capable of recording in one exposure.

– Alan, December 20, 2012 / © 2012 Alan Dyer

 

The Colourful Clouds of Orion – #2


The Nebulas of Orion v2

Swirls of pink, red and blue nebulas surround the Belt and Sword of Orion the Hunter.

For this closeup of Orion I used a 135mm telephoto lens under dark Australian skies to grab long exposures to reveal not only the bright Orion Nebula at bottom in Orion’s Sword, but also the Horsehead Nebula (below the left star of Orion’s Belt), Barnard’s Loop (at left) and the mass of red nebulosity between the Loop and the Belt & Sword. At right is a faint blue nebula reflecting the light of the hot blue stars in the area.

This is a gorgeous area of sky for the camera, but only the brightest nebulas, the tip of the cosmic iceberg, are visible to the eye even with the aid of a telescope.

– Alan, December 19, 2012 / © 2012 Alan Dyer

 

The Colourful Clouds of Orion – #1


Orion from Australia (50mm 5DII)

The constellation Orion is a hotbed of star formation, from masses of colourful clouds.

I shot this portrait of Orion the Hunter a few nights ago in Australia where Orion stands upside down compared to our view from up north. But I’ve turned around the photo here to put him right side up with head at the top and feet at the bottom.

The three stars in a row in the middle are his famous Belt stars. Below shines the nebulas that outline his Sword, among them the Orion Nebula, the subject of an earlier post last week

The giant arc is Barnard’s Loop, a bubble blown in space by the winds from hot new stars. The bubble around Orion’s head at top is a similar interstellar bubble. Most stars here are blue-white and hot, but the distinctively orange star is the red giant Betelgeuse, a good candidate for a supernova explosion.

Orion stands high in the sky at midnight these nights, summer here in Australia, but winter at home in Canada.

– Alan, December 19, 2012 / © 2012 Alan Dyer

 

Remains of a Star: The Vela Supernova Remnant


Vela Supernova Remnant and Gum Nebulas

Amid a maze of glowing nebulas sits a tracery of magenta and cyan that was once a star.

This image takes in the Vela Supernova Remnant. You can see it as the lacework of gas in the centre of the field. Oddly enough, it sits in the middle of the vast Gum Nebula, the subject of my previous post, an object also thought to be a supernova remnant but one much older and closer. The Vela Supernova Remnant here likely comes from a supergiant star that exploded about 10,000 years ago. It, too, would have been quite a sight to the earliest of civilizations.

The field in the southern constellation of Vela also contains many other classic red and pink nebulas, but ones that are forming new stars, not the remains of dead ones. Most carry designations from astronomer Colin Gum’s catalog from the 1950s and have no numbers from the more familiar NGC or IC catalogs amateur stargazers refer to in their scanning of the skies. Yet, these Gum nebulas show up easily in photos.

I used a 135mm telephoto lens to take this image and it encompasses a field similar to what binoculars would frame. Except, it takes long exposure photos to show these nebulas. I looked last night at the Vela SNR with my 25cm reflector telescope and could just barely see the main arc of nebulosity as a grey ghost in the eyepiece. And that was under perfect dark Australian sky conditions.

– Alan, December 18, 2012 / © 2012 Alan Dyer

 

Giant Bubble in the Southern Sky


Gum Nebula in Vela

 

The southern sky contains what must be the largest nebula in our sky, a giant bubble spanning a wide swath of the Milky Way.

This is the object known as the Gum Nebula. You can see it in my previous post, in the ultrawide view of the southern sky. Here I’m framing it with a normal 50mm lens that covers about 50° of sky. The Gum Nebula is completely invisible to the eye and shows up only on photos. It wasn’t even discovered until the 1950s, by Australian astronomer Colin Gum. It is #12 in his catalog of southern sky nebulas. I’ve always thought this was an example of an interstellar bubble, blown by intense winds from hot blue stars, of which there are many in this part of the Milky Way in Vela and Puppis. At left are the four stars of the False Cross in Carina and Vela.

But some sources claim this is a supernova remnant, the blasted remains of a star that blew up 1 to 2 million years ago. It is big because it is close by, just 450 to 1500 light years away depending on what side if the remnant you measure. If that’s the case, the star that exploded would have been quite a shadow-casting sight in our prehistoric sky, assuming it was that close to us when it blew up and was in the night sky at the time.

Either way, it is a great target for amateur photographers, and now with digital cameras it is easy to record. This night, some haze moving through added the photogenic glows around all the stars to bring out their colours.

– Alan, December 18, 2012 / © 2012 Alan Dyer

 

 

Ultrawide Southern Sky


Ultrawide Angle Southern Milky Way - December 2012

This horizon-to-horizon image takes in a broad sweep of the southern Milky Way from Orion to the Southern Cross.

At upper left shines bright Jupiter in Taurus and the stars of Orion, upside down. To the right of Orion is Sirius in Canis Major, the brightest star in the night sky. To the right of Sirius above the Milky Way is Canopus, the second brightest star in the night sky and one we don’t see from up north. The two satellite galaxy Magellanic Clouds are at upper right. Below them is the bright Milky Way through Carina and Crux, the Southern Cross. Alpha and Beta Centauri are just above the dark trees at right. This is the entire Milky Way you see on an early austral summer night from down under.

What stands out is the huge red bubble of gas called the Gum Nebula in Vela and Carina. It is strictly a photographic object but shows up well on red-sensitive digital cameras.

I shot this with a filter-modified Canon 5D Mark II camera and a 15mm wide-angle lens on a mount tracking the stars. It is a stack of four 6-minute exposures, shot from Australia a few nights ago under nearly perfect sky conditions.

– Alan, December 17, 2012 / © 2012 Alan Dyer

 

The Amazing Orion Nebula


Orion Nebula Complex, M42, M43, NGC 1973-5-7

My Australian nights are proving to be frequently and thankfully clear enough that I’ve got the luxury of shooting some familiar “home sky” objects. This is the famous Orion Nebula in the Sword of Orion, about 1500 light years away.

I’ve shot this nebula many times from the northern hemisphere but my Australian skies are darker than at home, and the nights a lot warmer than when this object is up in our winter sky.

The Orion Nebula is a complex consisting of Messier 42, the main nebula, M43, a small nebula attached to the north (above) and the bluish Running Man Nebula (can you see his dark figure?) at top that is officially catalogued as NGC 1973-5-7. Together, these make up the largest region of star formation in our corner of the Milky Way. It’s easy to see with the unaided eye on a dark night.

To shoot this, I blended three different exposures, short (4 x 1 minute), medium (4 x 5 minutes) and long (4 x 15 minutes), to preserve all the details from the intensely bright core our to the faint tendrils extending into deep space. I stacked the 4 frames taken at each of the exposure times, then blended those stacks using masks in Photoshop CS6 (and its wonderful and editable Refine Mask function) to mask out the overexposed area of the longer exposure and let the shorter exposure content shine through. The result is that the core still shows the little cluster of stars, the Trapezium, and the characteristic green tint of the core. But I applied lots of Curves to bring out the fainter bits and swirls in the periphery.

I shot this through my Astro-Physics Traveler 105mm refractor at f/5.8 using the filter-modified Canon 5D MkII camera, at ISO 400. This turned out to be certainly my best shot of Orion yet in my library.

– Alan, December 13, 2012 / © 2012 Alan Dyer