Archive for the ‘Astronomy’ Category

Big Bang Monday: DNS Pulsar

Monday, May 4th, 2015

DNS in this case stands for “double neutron star” and a pulsar in the widest known orbit around another neutron star was discovered by two high school students.

In the summer of 2012, during a Pulsar Search Collaboratory workshop, two high-school students discovered J1930−1852, a pulsar in a double neutron star (DNS) system. Most DNS systems are characterized by short orbital periods, rapid spin periods and eccentric orbits. However, J1930−1852 has the longest spin period (Pspin∼185 ms) and orbital period (Pb∼45 days) yet measured among known, recycled pulsars in DNS systems, implying a shorter than average and/or inefficient recycling period before its companion went supernova. We measure the relativistic advance of periastron for J1930−1852, ω˙=0.00078(4) deg/yr, which implies a total mass (Mtot=2.59(4) M⊙) consistent with other DNS systems. The 2σ constraints on Mtot place limits on the pulsar and companion masses (mp1.30 M⊙ respectively). J1930−1852’s spin and orbital parameters challenge current DNS population models and make J1930−1852 an important system for further investigation.

A P–P˙ diagram showing all pulsars in DNS systems (stars/squares) and all other known pulsars (dots). Measured P and P˙ come from the ATNF Pulsar Catalog (Hobbs et al. 2004) and lines of characteristic age and surface magnetic field are shown with dot-dash and dashed lines, respectively. Recycled DNS pulsars (stars) appear between the normal and millisecond pulsar populations and are listed in Table 2. Despite its significantly longer spin period, J1930−1852 clearly belongs in the population of recycled DNS pulsars, unlike J1906+0746 and J0737−3039B (squares) – neither of which have undergone recycling.

With so many astronomers engaged in this type of work, it’s inspirational to find younger ones with no inhibitions and lots of hope continues to reap the rewards of discovery.

 

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Big Bang Monday: Fly Through Andromeda

Monday, January 19th, 2015

Via EarthSky, a 1.5 billion pixel image of Andromeda galaxy, interpreted as a “fly-through.” The image is huge (69,536 x 22,230).


Geminid Meteor Shower

Tuesday, December 23rd, 2014

Via Blue Dog Films on Vimeo

Geminids meteor shower December 2014…. a slightly different perspective!
I filmed some time lapse images over 2 nights around the 14th of December 2014. Intrigued by the Geminid meteor shower, I decided to make a short film/ animation to explain (very simply) how it comes about.
You have to watch the time lapse sequences a few times and more of the meteor streaks will reveal themselves. They are very subtle bright streaks.

Time lapses shot on a Canon 5d, compositing in After Effects and 3d work in Modo.


Big Bang Monday: Astronomy Photographer of the Year

Monday, September 22nd, 2014

The winning image by James Woodend was of a green aurora pictured in Iceland’s Vatnajokull National Park. The light reflected almost symetrically in Jokulsrlon Glacier lagoon. A complete lack of wind and currrent combine in this sheltered lagoon scene to create an arresting mirror effect giving the image a sensation of utter stillness. © James Woodend

As reported by The Daily Mail

From clouds dancing across the Milky Way to a stunning solar eclipse over Kenya, the annual competition showcasing the mysterious depths of our universe has revealed some incredible images.

West Midlands-based photographer James Woodend beat over a thousand amateur and professional photographers from around the world to win the title of Astronomy Photographer of the Year 2014.

As well as securing the £1,500 ($2,440) top prize, his image takes pride of place in the exhibition of winning photographs opening today at the Royal Observatory Greenwich.
The judges were mesmerised by Woodend’s shot portraying a vivid green aurora dancing across the Icelandic night sky and reflected symmetrically in the glacial Jökulsarlon lagoon of Vatnajökull National Park.

Competition judge and Royal Observatory Public Astronomer, Dr Marek Kukula said: ‘I love the combination of whites and blue in the glacier with the chilly green of the aurora in this wonderfully icy picture.

‘We’ve had some amazing aurora pictures in the competition over the last six years, but this is the first time a photo of the Northern Lights has actually won the Astronomy Photographer of the Year prize.

‘We were all completely in awe of the colours and symmetry of James’ shot.’

That really is a stunning image! Some of the others receiving commendation include the Horsehead Nebula, IC 1340 (part of the Veil Nebula), Helix Nebula, NGC 1999 and the surface of the Sun.

They’re on display now at the Royal Observatory’s Astronomy Centre in Greenwich (18 September 2014 to 22 February 2015).


Big Bang Monday: Aurora Over Scotland

Monday, September 15th, 2014

Scotland’s vote for independence on 18 September 2014 is an interesting proposition. Although Sir Paul is in favor of “staying together, it is an immensely complicated proposition (defense, currency/banking, oil rights, etc.). Contrary to what you may remember from Trainspotting, Scotland was not “colonized by wankers.”

Let’s move on to the other spectacle in Scotland recently: the aurora borealis! You’ve got to see Maciej Winiarczyk’s beautiful photos!

Aurora Panorama from Noss Head

Loch Killimster, Caithness, Scotland


Aurora Space Vine

Thursday, September 4th, 2014

Nice vine from Reid Wiseman. Here’s the full version…


Big Bang Monday: Comet of the Month

Monday, August 18th, 2014

Comet 67P/Churyumov-Gerasimenko activity on 2 August 2014. The image was taken by Rosetta’s OSIRIS wide-angle camera from a distance of 550 km. The exposure time of the image was 330 seconds and the comet nucleus is saturated to bring out the detail of the comet activity. Note there is a ghost image to the right. The image resolution is 55 metres per pixel.

ESA’s Rosetta Mission is sending back some very interesting images, especially for those who were curious about what these big rocks look like. It’s the first spacecraft to rendezvous with a comet.

The one from 7 August 20014 gave us a pretty good close-up…

Comet 67P/Churyumov-Gerasimenko imaged by Rosetta’s OSIRIS narrow angle camera on 7 August from a distance of 104 km.

Not as exciting as we’d expect, yet it’s most fascinating.

So how big is this comet? Thanks to @quark1972, now we now. Here’s the comet next to Los Angeles.


Big Bang Monday: The White Hole

Monday, August 11th, 2014

Check out this abstract

While most of the singularities of General Relativity are expected to be safely hidden behind event horizons by the cosmic censorship conjecture, we happen to live in the causal future of the classical big bang singularity, whose resolution constitutes the active field of early universe cosmology. Could the big bang be also hidden behind a causal horizon, making us immune to the decadent impacts of a naked singularity? We describe a braneworld description of cosmology with both 4d induced and 5d bulk gravity (otherwise known as Dvali-Gabadadze-Porati, or DGP model), which exhibits this feature: The universe emerges as a spherical 3-brane out of the formation of a 5d Schwarzschild black hole. In particular, we show that a pressure singularity of the holographic fluid, discovered earlier, happens inside the white hole horizon, and thus need not be real or imply any pathology. Furthermore, we outline a novel mechanism through which any thermal atmosphere for the brane, with comoving temperature of 20% of the 5D Planck mass can induce scale-invariant primordial curvature perturbations on the brane, circumventing the need for a separate process (such as cosmic inflation) to explain current cosmological observations. Finally, we note that 5D space-time is asymptotically flat, and thus potentially allows an S-matrix or (after minor modifications) AdS/CFT description of the cosmological big bang.

Got your head wrapped around it yet? Probably not. Our friends at Science Daily explain it a little more…

What we perceive as the big bang, they argue, could be the three-dimensional “mirage” of a collapsing star in a universe profoundly different than our own.

“Cosmology’s greatest challenge is understanding the big bang itself,” write Perimeter Institute Associate Faculty member Niayesh Afshordi, Affiliate Faculty member and University of Waterloo professor Robert Mann, and PhD student Razieh Pourhasan.

Conventional understanding holds that the big bang began with a singularity — an unfathomably hot and dense phenomenon of spacetime where the standard laws of physics break down. Singularities are bizarre, and our understanding of them is limited.

“For all physicists know, dragons could have come flying out of the singularity,” Afshordi says in an interview with Nature.

The problem, as the authors see it, is that the big bang hypothesis has our relatively comprehensible, uniform, and predictable universe arising from the physics-destroying insanity of a singularity. It seems unlikely.

So perhaps something else happened. Perhaps our universe was never singular in the first place.

Their suggestion: our known universe could be the three-dimensional “wrapping” around a four-dimensional black hole’s event horizon. In this scenario, our universe burst into being when a star in a four-dimensional universe collapsed into a black hole.

In our three-dimensional universe, black holes have two-dimensional event horizons — that is, they are surrounded by a two-dimensional boundary that marks the “point of no return.” In the case of a four-dimensional universe, a black hole would have a three-dimensional event horizon.

In their proposed scenario, our universe was never inside the singularity; rather, it came into being outside an event horizon, protected from the singularity. It originated as — and remains — just one feature in the imploded wreck of a four-dimensional star.

The researchers emphasize that this idea, though it may sound “absurd,” is grounded firmly in the best modern mathematics describing space and time. Specifically, they’ve used the tools of holography to “turn the big bang into a cosmic mirage.” Along the way, their model appears to address long-standing cosmological puzzles and — crucially — produce testable predictions.

Of course, our intuition tends to recoil at the idea that everything and everyone we know emerged from the event horizon of a single four-dimensional black hole. We have no concept of what a four-dimensional universe might look like. We don’t know how a four-dimensional “parent” universe itself came to be.

But our fallible human intuitions, the researchers argue, evolved in a three-dimensional world that may only reveal shadows of reality.

They draw a parallel to Plato’s allegory of the cave, in which prisoners spend their lives seeing only the flickering shadows cast by a fire on a cavern wall.

“Their shackles have prevented them from perceiving the true world, a realm with one additional dimension,” they write. “Plato’s prisoners didn’t understand the powers behind the sun, just as we don’t understand the four-dimensional bulk universe. But at least they knew where to look for answers.”

Still interested? I bet you are! Read more here. Relax: there’s a video on the Perimeter Institute site.


Big Bang Monday: 10 Years Gone for Cassini

Monday, June 30th, 2014

Today marks ten years since the Cassini spacecraft arrived at Saturn. The image above is one of my personal favorites (similar images also available via BigBangPrints.com).

The team of scientists at Cassini have selected their own “top 10″ list of images. More importantly, their list of the top ten discoveries is far more impressive…

  1. The Huygens probe makes first landing on a moon in the outer solar system (Titan)
  2. Discovery of active, icy plumes on the Saturnian moon Enceladus
  3. Saturn’s rings revealed as active and dynamic — a laboratory for how planets form
  4. Titan revealed as Earth-like world with rain, rivers, lakes and seas
  5. Studies of the great northern storm of 2010-2011
  6. Radio-wave patterns shown not to be tied to Saturn’s interior rotation as previously thought
  7. Vertical structures in the rings imaged for the first time
  8. Study of prebiotic chemistry on Titan
  9. Mystery of the dual bright-dark surface of Iapetus solved
  10. First complete view of the north polar hexagon and discovery of giant hurricanes at both of Saturn’s poles

I love the preview of what we can expect in the coming years…


Big Bang Monday: Four-Eyed Astronomy Photos

Monday, June 23rd, 2014

Photographer Vincent Brady made a contraption with four cameras, each fitted with fish-eye lenses, which he set up to do 360-degree panoramas. He calls them “Planetary Panoramas” and the results are amazing!

While experimenting with different photography tricks and techniques back in 2012, I was shooting 360 degree panoramas in the daytime and long exposures of the stars streaking in the sky at night. It suddenly became clear that the potential to combine the two techniques could be a trip! Since the Earth is rotating at a steady 1,040 mph I created a custom rig of 4 cameras with fisheye lenses to capture the entire night-sky in motion. Thus the images show the stars rotating around the north star as well as the effect of the southern pole as well and a 360 degree panorama of the scene on Earth. Each camera is doing nonstop long exposures, typically about 1 minute consecutively for the life of the camera battery. Usually about 3 hours. I then made a script to stitch all the thousands of these panoramas into this time-lapse. I created my rig in January of 2013 while in my final semester at Lansing Community College before receiving an associates degree in photography. Given it was winter in Michigan, I didn’t get to chase the notorious clear moonless night sky as much as I had hoped as the region has lots of cloud cover that time of year. Though I was ready on the rare night to go experiment. After graduating in May I had built up quite the urge to hit the road. My rig has taken me to firefly parties in Missouri, dark eerie nights at Devils Tower, through Logan Pass at Glacier National Park, up the mountains of British Columbia, and around the amazing arches and sandstone monuments in the Great American Southwest.

These are the images I created on the cold, dark, sleepless nights under awe-spiring skies.

The music is composed and recorded by my very good friend, the acoustic fingerpicking guitar prodigy Brandon McCoy! Brandon who is also from the greater Lansing area in Mid-Michigan is quite the acoustic instrumentalist. The song chosen for this time-lapse is called ‘One Letter From Lady.’ I moved to Michigan when I was 15 and Brandon was the first friend I made. He was the cool kid playing Pink Floyd licks on a $2 guitar at the time. Soon, after he had spent his cold, dark, sleepless nights perfecting his craft, he started coming up with his very own instrumentals. Some of which are upbeat by mixing picking, slapping, and drumming on the guitar while other compositions of his are calm and soothing and can put you in a meditative trance if you just close your eyes. It has been a great experience watching each other grow as artist for over the past 10 years, and you better believe we will be collaborating on projects like this in the very near future.

Phil Plait does an extraordinary job of explaining what’s going on here…

First are the weird star trails you see in many of the scenes. I’ve explained this before, but briefly: When you face north, east is to your right and west to your left, so the stars rise and set in a counterclockwise manner. If you face south, the reverse is true (west on your right, east on your left, and the stars move clockwise). If you look due east, the stars rise straight up, going over you head. Face west, and they move straight down to the horizon.

Normally, since you can only look in one direction at a time, you don’t have to deal with all these different movements all at once. But in the video we’re seeing the whole sky at the same time, with all those weird motions combined. So near the sky’s north pole the stars make little circles one way, and near the south pole (which is below the horizon in Michigan, where these shots were taken) they move the opposite way.

But there’s more! Once the images are stitched together, they can be mapped into different shapes. Just like you can take a map of the Earth and turn that into a spherical globe, a flattened Mercator projection, or any number of other types of shapes, you can do that with the sky as well. Brady reshaped the pictures several ways in the video, including using a (more or less) flat horizon facing east (at the 0:15 mark), which makes the stars rise out of the middle of the frame, and the same thing but facing south (at the 1:55 mark) and west (at the 2:19 mark) — all of which make the sky look very odd indeed.

But he also used something called the “Little Planet” effect, which is really weird. This takes the flat horizon and wraps it around into a circle, making the left side of the image touch the right, like rolling a rectangle up into a cylinder (or, more accurately a cone). The technique is pretty simple, and the end result is that it’s like you’re looking down on a tiny little planet or asteroid with the sky wrapped around it. This also tends to distort taller objects, lengthening them, so the arches (at the 0:30 mark) and hoodoos (at the 1:27 mark) look like they’re reaching toward you.

I’ll note that this is the opposite of the “all-sky” effect (at the 1:14 mark) where it looks like you’re looking up into the entire sky.

What fun! And all of this just from looking in all directions at once, and applying a little math to the result. I have to admit, I found it very disorienting (in a fun way) trying to pick out constellations and familiar landmarks in the sky during the video.

This is really cool and I hope he registers a patent!