[Dan's blog] Try on a pair of NuSTARs!

Sara’s note: Please join us in welcoming our newest guest blogger, Dr. Dan Wik! You might have heard our interview with Dan in our podcast NASA’s Newest X-Ray Eyes, and we’re excited to get more behind-the-scenes coverage of NuSTAR and Dan’s research in his blog posts.

Imagine you are usually confined inside your home – like we are on the surface of the Earth – but when you do make it outside at night, you forget your glasses despite having terrible vision. Looking up at the sky, you can see a few blurry stars and a diffuse glow, but you can’t tell if the glow is really diffuse or just made up of many fainter stars. Next time you make it outside, you resolve to remember your glasses to find out. If the light is coming from the X-ray part of the spectrum, then on the next trip outside you’ll be wearing a pair of NuSTARs.

NuSTAR is the first observatory capable of focusing the bluest colors of X-ray light, in a bandwidth where the X-ray sky is the brightest. Since its launch last summer, it has been surveying the sky in order to detect the source of this glow, which is thought to be made up of many discrete objects. These are not stars, but massive black holes in the hearts of galaxies billions of light years away. In fact, we’ve already resolved the redder part of the X-ray sky with the Chandra X-ray Observatory, which is how we know what these objects are. However, the kind of black holes we see with Chandra cannot produce the light at the bluest end of the X-ray spectrum. We still think they’re massive black holes, but there’s something intrinsically different about them. Once we find them with NuSTAR, we’ll learn exactly why they’re different and what that means for the growth of black holes over cosmic time. These massive black holes at the centers of galaxies – millions of times more massive than the Sun – appear to grow as the galaxy around them grows and changes, a process that depends on their galactic neighborhoods and the larger cosmic web — seeded just after the Big Bang — in which all galaxies are ensnared.

A model of NuSTAR at Caltech. The part closest to the camera holds the mirrors (the two “eyes” – looks remarkably like a face), and the detectors and rest of the spacecraft are on the far end of the boom. Credit: Caltech/JPL/NASA

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[Brian's blog] A Look into the Building Blocks of Life

Maggie’s note: Please welcome a new guest blogger, astronomer Brian Williams!

Most of the stars in the universe will, like our Sun, live steadily for billions of years before ending in relative serenity. However, a select few will go out in a blaze of glory called a supernova, the explosion of an entire star. These cosmic blasts are among the most powerful events in the universe, and can be seen at distances of billions of light years; releasing, in a matter of seconds, an amount of energy equal to the Sun’s output over billions of years. In the past few decades, observations of distant supernovas helped astronomers pin down the expansion rate of the universe, allowing the determination that the universe is not, as was previously expected, slowing down in its expansion, but speeding up, due to the presence of a mysterious force known as “dark energy.”

Nearly all of the matter in the universe that we understand is made of hydrogen and helium, the simplest elements, created in the Big Bang. The rest, including the oxygen that we breath, the carbon, calcium, and iron in our bodies, sodium and choride on our dinner tables, and the silicon in our computer chips were forged in the cores of stars: hot and powerful element factories that convert lighter elements into heavier ones. The gravity that holds stars together generally keeps these elements locked deep inside their interiors, never to be spread throughout the universe. Luckily, supernova explosions provide a mechanism to do just this, liberating these fundamental building blocks of planetary systems and, indeed, life itself, throughout the universe. It is no exaggeration to say that we owe our entire existence to the life, and death, of stars that existed before our Sun and solar system were even created.

In my research at NASA’s Goddard Space Flight Center, the fading of a supernova from view marks only the beginning of my interests. I study the fiery aftermath of the explosion, which remains visible for thousands of years. An exploding star doesn’t simply dissipate into nothingness; rather, it forms a nebula known as a supernova remnant, a cloud of gas expanding at speeds of several million miles per hour. The gas cloud is made up of both material that has been ejected from the now exploded star and particles of gas and dust tenuously floating in the interstellar medium, the scientific name for the space between the stars. An example of a supernova remnant is shown below. This remnant, the remains of a star that exploded in 1604 A.D, is known as Kepler’s SNR, named for the famous German astronomer who kept detailed records of “De Stella Nova” (the New Star).

Kepler’s Supernova remnant, as seen by NASA’s Spitzer Space Telescope (red), Hubble Space Telescope (yellow), and Chandra X-ray Observatory (green and blue). Credit: NASA, R. Sankrit (NASA Ames) and W.P. Blair (Johns Hopkins Univ.)

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[Maggie's blog] Infrared: Beyond the Visible

As many of you know, aside from Blueshift, I work on the James Webb Space Telescope, which will be the successor the Hubble Space Telescope. It’s not a replacement, partly because Hubble isn’t going anywhere anytime soon, but also because the Webb is primarily an infrared telescope. Astronomers use something called a Decadal Survey to decide what the priorities are in astronomy for the next decade. During one of these surveys, it was decided that the astronomical community should study galaxy, star and planet formation in the Universe.

To see the very first stars and galaxies form in the early Universe, we have to look deep into space to look back in time. This is because it takes light time to travel from there to here and the farther out we look, the further we look back in time. The Universe is expanding, and therefore the farther we look, the faster objects are moving away from us, redshifting the light. Redshift means that light that is emitted as ultraviolet or visible light is shifted more and more to redder wavelengths, into the infrared part of the electromagnetic spectrum.

Because of this, Webb was designed as an infrared telescope.

In order to explain the above in terms anyone can understand, our friends at the Space Telescope Science Institute created this video called “Infrared: Beyond the Visible.” Here is how they explain the video.

The James Webb Space Telescope will be the most powerful infrared telescope ever launched into space … but do you know why that matters? Check out “Infrared: Beyond the Visible,” in which we explain everything you’ll ever need to know about infrared astronomy via paper cutouts. It has galaxies. Planets. Redshifting. Swimming aliens. Paranoid astronomers. Watch it now, before everyone else knows more about infrared than you do.

We chatted briefly with Stephanie Smith and Tracy Vogel, two of the video’s creators, and asked them, “Why make a cartoon about infrared astronomy?” Here’s their answer:

We want to communicate to as many people as possible why the James Webb Space Telescope is important, in large part because in explaining it we are also educating them about how the universe we live in works. But to truly understand some of these concepts requires a lot of different information that we knew a big portion of the audience who loves and appreciates Hubble’s images doesn’t necessarily have. We needed a primer that starts from the basics and works its way up from there. It’s a lot of information to take in all at once, so we knew it’d have to be energetic and entertaining if we wanted people to watch it — and pay attention! — all the way through. Making the science case for Webb’s unique capabilities involves some fairly complex concepts. Cartoons are a great way to break down complicated ideas into their simplest form to help visualize and focus in on what’s really going on. Folks have been making educational cartoon for years for the same reasons, and those efforts were a big inspiration for our own project.

But this is just a starting point. We had so much to cover, we couldn’t cover any of it in great depth. That’s why we’ve put together a resource page with links to other videos and websites that have more information about infrared astronomy and the Webb telescope, including some great videos from the Spitzer Space Telescope and other NASA missions, for anyone who wants to explore further.

You can download this video and see these resources about infrared astronomy at Space Telescope Science Institute’s original page for this video.

Read the NASA feature.

[Blog] Awesomeness Round-Up – 6/11/2012

On Tuesday, June 5, Venus passed in front of the Sun – an event that was visible on seven continents for those that were fortunate enough to have clear weather. These “transits” of Venus are very rare, coming in pairs separated by more than a hundred years. This June’s transit, the second of a 2004-2012 pair, won’t be repeated until the year 2117.

Credit: NASA/SDO, AIA

Credit: JAXA/NASA/Lockheed Martin

The first image is a composite of images taken by the Solar Dynamics Observatory that shows the path that Venus took across the disk of the Sun. The second is a close-up image taken by Hinode – a joint JAXA/NASA mission to study the connections of the sun’s surface magnetism, primarily in and around sunspots.
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[Blog] Awesomeness Round-Up – 2/13/2012

Credit: ESA/Herschel/PACS/SPIRE/Hill, Motte, HOBYS Key Programme Consortium

This beautiful, infrared image shows a new view of the Eagle nebula captured by the European Herschel Space Observatory. In 1995, Hubble famously captured a visble-light image of the “Pillars of Creation,” a region of star-formation. That image is below – in the above image, that region is shown within the circle.

Credit: NASA, Jeff Hester, and Paul Scowen (Arizona State University)

Infrared light is needed to see into the opaque clouds of dust and gas within which stars form. You can read more about what astronomers are learning from this new view of the nebula in the NASA feature.

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[Sara's blog] The Helix Nebula in New Light… Again!

Credit: NASA, ESA, C.R. O’Dell (Vanderbilt University), and M. Meixner, P. McCullough

The Helix Nebula is an iconic astronomical object – it’s been imaged again and again, by a variety of satellites. It’s one of those objects that gets turned into desktop wallpapers, posters, and postcards. It was even featured on a postage stamp issued in Great Britain in 2007. It’s one of those inspiring, mysterious images of space that people like to look at. And guess what – scientists like to look at it too!

The image above combines observations of the Helix from the the Advanced Camera for Surveys aboard the Hubble Space Telescope and the ground-based Cerro Tololo Inter-American Observatory in Chile (you can download it from HubbleSite). There are many similar images of the Helix in visible light, and others across a variety of wavelengths. Many satellites and ground-based observatories have turned their eyes towards the Helix Nebula.
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[Blog] Weekly Awesomeness Round-up – 10/11/10

There’s a time in nearly every satellite’s life where a decision has to be made – continue or game over? For NASA’s Wide-field Infrared Survey Explorer, or WISE, this question arose when the satellite reached the end of its onboard frozen hydrogen coolant. This wasn’t a surprise, but WISE used that coolant to make its detectors more sensitive to infrared light. However, NASA decided to continue the mission. Even without coolant, two of WISE’s infrared detectors can still operate and look a little closer to home for comets and asteroids.  This has been dubbed the NEOWISE Post-Cryogenic Mission.  And there’s still plenty of data for scientists to study from the mission’s cooler period.

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