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Scientists Photographed Our ‘Galactic Bulge’ Using a Dark Energy Camera

In an effort to research how the center of the Milky Way Galaxy formed what is known as a “galactic bulge,” Scientists used a Dark Energy Camera to survey a portion of the sky and capture a photo of billions of stars.

NASA’s Hubblesite describes our galaxy as “shaped like two fried eggs glued back-to-back.” This depiction makes clear the central bulge of stars that sits in the middle of a sprawling disk of stars that we usually see in two-dimensional drawings. You can get a better idea of how that looks thanks to a rendering from the ESA below:

This makeup is thought to be a common feature among myriad spiral galaxies like the Milky Way, and scientists desired to study how the bulge was formed. Were the stars within the bulge born early in our galaxy’s history, 10 to 12 billion years ago, or did the bulge build up over time through multiple episodes of star formation?

“Many other spiral galaxies look like the Milky Way and have similar bulges, so if we can understand how the Milky Way formed its bulge then we’ll have a good idea for how the other galaxies did too,” said co-principal investigator Christian Johnson of the Space Telescope Science Institute in Baltimore, Maryland.

The team surveyed a portion of our sky covering more than 200 square degrees – an area approximately equivalent to 1,000 full Moons – using the Dark Energy Camera (DECam) on the Victor M. Blanco 4-meter Telescope at the Cerro Tololo Inter-American Observatory in Chile, a Program of NSF’s NOIRLab.

This image shows a wide-field view of the center of the Milky Way with a pull-out image taken by the DECam.

The scientific sensor array on the DECam is made up of 62 separate 2048×4096 pixel backside-illuminated CCD sensors, totaling 520 megapixels. An additional 12 2048×2048 pixel CCD sensors (50 megapixels) are used to guide the telescope, monitor focus, and help with alignment.

This wide-field camera is capable of capturing 3 square degrees of sky in a single exposure and allowed the team to collect more than 450,000 individual photographs. From that data the team was able to determine the chemical compositions for millions of stars. The image below contains billions of stars:

You can view a pannable and zoomable version of this image here. It uses the same interface as the giant 2.5 gigapixel image of the Orion Constellation taken by Matt Harbison.

For this particular study, scientists looked at a subsample of 70,000 stars from the above image. It had been previously believed that the stars in the bulge were born in two separate “waves” early in the history of the galaxy, but thanks to data gleaned from the study, now scientists think that a vast majority were formed at about the same time nearly 10 billion years ago.

According to Nasa, the researchers are looking into the possibility of measuring stellar distances to make a more accurate 3D map of the bulge. They also plan to seek correlations between their metallicity measurements and stellar orbits. That investigation could locate “flocks” of stars with similar orbits, which could be the remains of disrupted dwarf galaxies or identify signs of accretion like stars orbiting opposite the galaxy’s rotation.

(Via Hubblesite and SyFy)

NASA Turns Space Photos Into Music

NASA has a new project that turns space photos into sounds. Using sonification, images obtained from telescopes are turned into “music” that sounds like what you’d hear when your operating system boots up.

The creative project is being carried out by scientists at NASA’s Chandra X-ray Observatory.

“Telescopes give us a chance to see what the Galactic Center looks like in different types of light,” NASA writes. “By translating the inherently digital data (in the form of ones and zeroes) captured by telescopes in space into images, astronomers create visual representations that would otherwise be invisible to us.

“But what about experiencing these data with other senses like hearing?”

Sonification is the process of translating data into sound. Starting on the left side of images and moving toward the right, NASA’s sonification system reads in the vertical rows of pixels and creates sounds that represent the position and brightness of things seen.

“The light of objects located towards the top of the image are heard as higher pitches while the intensity of the light controls the volume,” NASA says regarding the Milky Way photo and music in the 1-minute video above. “Stars and compact sources are converted to individual notes while extended clouds of gas and dust produce an evolving drone.

“The crescendo happens when we reach the bright region to the lower right of the image. This is where the 4-million-solar-mass supermassive black hole at the center of the Galaxy, known as Sagittarius A* (A-star), resides, and where the clouds of gas and dust are the brightest.”

Here are the sounds created from other photos:

Now NASA just needs to release these songs as galactic ringtones for our smartphones.

(via NASA via Laughing Squid)

NASA Shares Time-Lapse of Exploding Star that Outshone Its Entire Galaxy

NASA has just published a stunning, one-of-a-kind time-lapse captured by the Hubble telescope. The short video shows an exploding star (AKA a supernova) in a galaxy 70-million light-years from Earth—a fireworks show so bright it outshone every other star in its galaxy before fading into oblivion.

In total, the time-lapse captures a full year of observations from February 2018 to February 2019. During this time, the supernova in galaxy NGC 2525 reached peak brightness, outshining every other star in its own galaxy, before “fading into obscurity” as humans watched on from million of light years away.

As Nobel Laureate Adam Riess put it in a blog post on the Hubble website, “no Earthly fireworks display can compete with this supernova, captured in its fading glory by the Hubble Space Telescope.”

You can see a wide-angle view of the full galaxy below, with the supernova very obviously shining on the outer edge of one of its spiral arms:

According to NASA, the energy released was “equal to the radiance of 5 billion Suns,” a light show worth capturing to be sure. However, Hubble wasn’t just interested in this supernova because NASA is eager to share celestial fireworks with the public; this kind of supernova is important in measuring our distance to its host galaxy and answering questions about the expansion of the universe.

“Because supernovae of this type all peak at the same brightness, they are known as ‘standard candles,’ which act as cosmic tape measures,” explains NASA. “Knowing the actual brightness of the supernova and observing its brightness in the sky, astronomers can calculate the distances of their host galaxies. This allows astronomers to measure the expansion rate of the universe.”

To learn more about this process or see more images of this supernova, head over to the Hubble website or check out the time-lapse video up top. Whether or not you’re interested in the science behind the photograph though, you have to admit that NASA captured something truly incredible here.

(via Engadget)


Credits: Photos and videos by ESA/Hubble & NASA, M. Kornmesser, M. Zamani, A. Riess and the SH0ES team.

This Tilt-Shift Photo of Andromeda Was Shot Using a DIY Adapter

The Royal Observatory Greenwich’s Insight Investment 2020 Astrophotographer of the Year, Nicolas Lefaudeux, has revealed his technique and the simple DIY adapter that made his award-winning image of the Andromeda galaxy possible.

As some photographers were locked in a discussion about whether or not the French optical engineer and part-time astrophotographer used Photoshop techniques or genuine photography to capture his acclaimed photo, Lefaudeux took to his personal website to share his method.

Constraints and hardware limitations forced Lefaudeux to think outside the box and work with what was available. The result? A stunning new perspective on one of our closest galactic neighbors.

“Shooting Andromeda was a consequence of having the hardware that I had,” Lefaudeux explained to me by phone from his home in France on Monday. “With the telescope I have, which is not that big, you end up with not that many potential targets. Andromeda is the first one that comes to mind… it’s a natural object to choose for it.”

Andromeda’s width would fill the field of view of his telescope. With his target in mind, he turned to creating the blur effect that would fulfill his creative vision.

Software effects like Photoshop blurring didn’t provide a satisfactory look for Lefaudeux, so he got to work fabricating an appropriate mount to connect his camera to the telescope at enough of an angle to create a tilt lens look.

With its orientation, Andromeda offers the perfect plane to try this effect, he said, and by aligning his focal plane with the galactic center, he was able to simulate a foreground and background comprised of defocused stars.

But the small diameter mount of his Sony a7S camera limited the angle with which he could create the focal plane thus constraining the depth of field.

“The bayonet [flange] is super tight… at a certain angle, you begin not to see the sensor, because the bayonet is higher than the sensor and it blocks some part of the sensor,” Lefaudeux says.

Because of Sony’s narrower mount, he saw shadows on the sensor while it was tilted away from the telescope’s eyepiece, at worst blocking the image entirely or creating a harsh vignette. Larger flanges would offer steeper angles, he said, resulting in a shallower depth of field.

The solution came with a unique, yet simple, angled camera to telescope adapter. By implementing a modest 25-degree pitch to offset the camera sensor, Lefaudeux had enough tilt to allow the line of focus to include the plane of the galaxy while creating a foreground and background of blurred out, multicolored orbs.

The adapter in use between the camera and telescope.

For those who still contend that Lefaudeux used a filter, or software technique to create the effect, he offered some insight to explain why the camera technique is possible, and ultimately better than using Photoshop to emulate it.

“When you know a bit about how the effect is obtained, you understand why it [software] is not giving this effect,” he said. “The stars don’t get saturated, and when you blur them you don’t get their real brightness, they just appear darker than they appear in camera.”

“For bright, colorful bokeh you require defocus acquisition,” he said, adding that the idea is similar to lens-whacking with a cheap lens to achieve defocus. He illustrated this point on his website, where he demonstrated an attempt to create the effect in Photoshop compared with the image in question. The contrast was obvious: defocus was clearly superior.

Though the idea itself seems simple enough, he added that the winning image required hundreds of long-exposure frames compiled in a stack to bring out the detail and color of the final shot.

A single uncalibrated frame shot using the adapter.

Lefaudeux’s technique and final image were enough to earn him the title of Astrophotographer of the Year and net him a cash award of £10,000 (~$12,800). Asked what he intended to do with the prize money he offered only a neutral reply, “It opens possibilities…” he said.

Expect to see Lefaudeux chasing eclipses around the world once travel restrictions begin to lift, and keep up with his work at his website.


If you’re interested in hearing my conversation with Lefaudeux in its entirety, you can listen to Episode 3 of my photography podcast The Image File.

You can also read Lefaudeux’s blog post to find out more about the technical details of this DIY adapter and how he created the winning photo.


About the author: Chris Koehn is a former newspaper journalist turned videographer. With independent documentary and corporate video production experience, Chris helped newsrooms adopt video content strategies as media convergence and DSLR film making transformed the online news landscape. His video work earned nominations and national news awards in Canada for election coverage. Chris is now working in independent journalism and documentary while freelancing for Canadian news outlets. You can connect with him on Twitter.


Image credits: Photographs by Nicolas Lefaudeux and used with permission