Dr. Michael Catelaz at work on the GAMMA II imaging machine, at the Pisgah Astronomical Research Institute (PARI) in North Carolina.

Dr. Michael Castelaz, the Science Director at the Pisgah Astronomical Research Institute, knows GAMMA II is a sleeping giant.  He just needs a little help waking up the beast.

GAMMA II and its sister, GAMMA I, are legendary imaging machines that were used to create the 19-million strong Guide Star Catalogue for the Hubble Space Telescope (HST).   Think of the Guide Star Catalogue as a souped-up GPS, enabling the Hubble to set its scope on stars thousands of miles away.

Four years ago, the Space Telescope Science Institute at Johns Hopkins University announced it was retiring the image-makers after nearly 20 years of service.

The news swept across the astronomy community and Castelaz and his colleagues at PARI jumped at the opportunity to bring the GAMMA machines to their Western North Carolina campus and reconfigure them for a new cataloging gig.

“It’s old, but it’s still state of the art.  It’s incredible what was done in terms of designing these instruments and getting them going,” Michael Castelaz.

But why bring this beast to PARI? PARI houses a collection of old photographic plates known as the Astronomical Photographic Data Archive, or APDA. Those analog plates contain invaluable data of the night sky, but are not easy to share and use. Catelaz and ADPA director Thurburn Barker believe the re-commissioned GAMMA II can help convert those plates– some of which date back to the 1890s – into new digital maps for future astronomers.  The maps will unlock data on thousands of unclassified stars known to exist in the APDA collection that can then be cataloged by their size, temperature and distance.

When PARI finally obtained the machines they were in pieces: three-tons of granite and lasers awaiting their next mission.  The sheer mass of the machines was intended to absorb vibrations from the floor as well the Earth.  In order to effectively serve the Hubble, GAMMA precisely mapped stars down to the exact micron.  That’s a thousandth of a millimeter to you and me. Castelaz and his cohort eventually reassembled GAMMA II and got all the electronics up and running.  However, do to the jerry-rigging and hand-written code used to reconfigure the original machine, they have not been able to recreate the imaging capacity … yet.

As soon as PARI can get GAMMA humming, the APDA collection will no longer be a black hole.  The meticulous work by generations of astronomers will be ushered into the 21^st century, bringing analog data back to the future.

The Thirty Meter Telescope would be built in Hawaii, atop Mauna Kea at around 13,000 feet. Artist's interpretation courtesy of TMT Observatory Corporation.

Originally reported for KQEDnews.org.

Scientists from the University of California are working with a team of international researchers on one of the most high-profile science projects of this decade: an effort to construct the largest optical telescope on Earth.

The $986 million project is planned for the summit of Mauna Kea, on Hawaii’s Big Island, and will feature a primary mirror 98-feet in diameter.

Scientists working on the project hope to begin construction next year and complete it by 2018 or 2019. They say the facility, dubbed the Thirty Meter Telescope, will allow astronomers to observe with much more clarity some of the earliest stars and galaxies of the universe and investigate what they’re made of.

“We’ll be able to look back at the baby pictures of the universe and trace how it developed,” said Michael Bolte, director of the University of California Observatories and a member of the board of directors for the new telescope.

The telescope won approval last month from the University of Hawaii Board of Regents, which holds the lease to the site.

In addition to exploring the farthest reaches of the universe, the telescope also will be able to routinely and easily produce images of the more than 450 planets that have been discovered orbiting stars outside of our solar system.

Today, the existence of these so-called “exoplanets” can only be inferred by measuring the gravitational tugging forces exerted by the stars they orbit. The telescope also could help determine if some of them have atmospheres similar to Earth’s – the precursor to finding life on another planet.

“It will be one of the most important scientific facilities of the 21st century,” said Bolte, who is also a professor of astronomy at UC-Santa Cruz. “When we look back, it’s going to be the Large Hadron Collider and the Thirty Meter Telescope and I’m not sure what else.”

The project is a joint effort of the University of California, the California Institute of Technology and the Association of Canadian Universities for Research in Astronomy.

A sizable amount of its funding is coming from the Bay Area. The Betty and Gordon Moore Foundation, in Palo Alto, has pledged $200 million toward the telescope’s construction. The University of California and Caltech each plan to raise $50 million. And contributions are expected from the Canadian universities, as well as the governments of China, India and Japan. But 10 to 20 percent of the telescope’s budget still remains to be raised, said Bolte.

The new telescope’s 98-foot (30 meter) mirror would be three times as big as the mirrors on the twin Keck telescopes in Hawaii, currently the biggest in the world, and also owned by the University of California and Caltech. The telescope would produce images three times as sharp as the 33-foot Keck telescopes on Mauna Kea, and would be able to look at objects that are nine times fainter. This would make it possible for scientists to better understand the origins of the universe.

“The universe is 13.7 billion years old and we can see objects that are 13 billion years away, but all we get is fuzzy blobs,” said UC-Santa Cruz astronomer Garth Illingworth, chair of the telescope’s Science Advisory Committee. “We’d like to learn more about these stars and galaxies.”

In January of 2010, Illingworth and his team announced that they had observed the most distant galaxies ever seen. Looking back in time 13 billion years, they found galaxies that were just 600 or 700 million years from the Big Bang. Photographs of these galaxies, which appear as several tiny dots, were made by the Hubble Space Telescope.

Space-based telescopes like Hubble have an advantage over ground telescopes because they don’t have to contend with the blurring caused by the Earth’s atmosphere. But they’re more expensive and therefore, smaller. Hubble’s mirror is less than 8 feet in diameter.

Bigger ground-based telescopes can gather more light than small space-based telescopes. So they make objects that once were faint appear brighter. And the additional light gives researchers information on the chemical composition of objects like stars.

When astronomers understand what a star is made out of, they can better establish its age. And this allows them to plot out the history of the universe more accurately. What’s understood now is that the Big Bang was followed by a period of darkness that astronomers call the Dark Ages. But it’s not clear how long that period lasted.

“There’s controversy about the period before which there were no stars,” said Jerry Nelson, UC-Santa Cruz astronomer and project scientist for the telescope. “The idea is to establish bounds on this. The question is when do you get stars forming that burn holes through this opaque stuff?”

In addition to answering questions about the history of the universe, observers say the telescope could also eventually lead to new energy sources based on the nuclear fusion that fuels stars.

“All those points of light are nuclear furnaces,” said bestselling San Francisco author Timothy Ferris, who wrote “Seeing in the Dark” and other books about astronomy and telescopes. “And they have something to teach us.”

The telescope’s mirror will be made out of 492 closely fit individual hexagonal glass mirrors. The Keck telescopes were the first to use these segmented mirrors to get around the problems created by gigantic individual mirrors. The Keck telescopes were so successful, said Illingworth, that UC and Caltech envisioned the Thirty Meter Telescope as a way to scale-up the Keck model.

TMT Fly-Through from Thirty Meter Telescope on Vimeo.

But big ground-based telescopes have their limitations. Though they can give astronomers more light to study, they can’t by virtue of their size alone make objects appear sharper. To reduce the blurring caused by the atmosphere, scientists use a series of techniques called adaptive optics.

“Adaptive optics is like putting glasses on a big telescope,” said Nelson. A telescope with adaptive optics not only sees sharper images of stars, it also sees more stars.

An expensive and technically complicated process, adaptive optics was used on telescopes for the first time to correct distortions on the Keck telescopes. The technique takes advantage of a layer of the atmosphere that starts about 50 miles above the Earth. This layer is made up of sodium atoms brought in by small meteorites that vaporize as they enter the atmosphere.

Scientists point an orange laser toward the sodium layer. The laser excites the sodium atoms, which become like artificial stars, radiating light back toward the telescope. The process allows researchers to correct for atmospheric turbulence, which causes phenomena such as the twinkle that we see around stars.

Other telescopes in the range of the Thirty Meter Telescope are in the works. An 80-foot mirror called the Giant Magellan Telescope is being spearheaded by a group that includes the Carnegie Institution for Science in Pasadena, Harvard University, the universities of Texas and Arizona and the government of Korea. That telescope is scheduled to be completed in 2018. And Europe is working on the aptly named Extremely Large Telescope, which would have a 138-foot mirror.

“They’re strongly complimentary,” said Bolte. “The Giant Magellan and the European telescope will be in the southern hemisphere, in Chile. So we’ll have access to the entire sky.” Having several of these instruments, he said, would make valuable telescope time more readily available to astronomers.

The Thirty Meter Telescope, which would be built at an elevation of about 13,000 feet, has not been without controversy. Environmentalists say its construction would harm the wekiu bug, a native species that lives atop high Hawaiian peaks. Some Native Hawaiians have come out in opposition, saying that the summit of Mauna Kea is sacred and should not have any more construction.

Scientists hope that the Thirty Meter Telescope will provide answers for many current astronomy questions: What is the invisible matter that makes up 25 percent of universe? What is the mysterious energy that is making it expand faster and faster? But Bolte suspects that just as telescopes in the past surprised scientists by revealing that the planets orbit the Sun and that the universe is expanding, the new telescope’s contributions are impossible to fully predict.

“Every time you build a new telescope with significant new capabilities, you usually solve the problems of the day and find new things you didn’t even know were there,” Bolte said. “The Thirty Meter Telescope will be a bigger jump than any other jump we’ve had, so the new discoveries will be all the more unexpected.”

***

TMT Overview from Thirty Meter Telescope on Vimeo.

Check out these QUEST TV and Radio stories about other University of California astronomy projects:

Illuminating the Northern Lights

Exoplanets

SETI: The New Search for ET

The Planet Hunters

36.9971411 -122.0581762

Image: NASA, ESA, P. Kalas, J. Graham, E. Chiang, E. Kite
(University of California, Berkeley), M. Clampin (NASA Goddard
Space Flight Center), M. Fitzgerald (Lawrence Livermore National
Laboratory), and K. Stapelfeldt and J. Krist (NASA Jet Propulsion
Laboratory)

Exoplanets are planets in other solar systems. Though astronomers have detected over 300 exoplanets since 1995, we only have visible-light images of one of them. These photos of the planet Fomalhaut b, taken by the Hubble Space Telescope, have just been published in Science magazine by UC Berkeley astronomer Paul Kalas. The exoplanet Fomalhaut b orbits the star Fomalhaut (pronounced "foam-a-lot"), and at 25 light years away is the closest exoplanet that we know of.

Up until now, astronomers could only detect exoplanets using indirect methods. To learn more about the star wobbles and dips in starlight that indicate other planets are out there, check out QUEST's radio story, Exoplanets, and QUEST's television story, Planet Hunters. These exoplanets are trillions of miles away, but the research happens close to home at the Lick Observatory near San Jose, and at the Chabot Space and Science Center in Oakland.

Over the next few years, astronomers will likely detect additional exoplanets, and will learn much more about them. In 2009, NASA will launch the satellite telescope Kepler, which will be able to detect smallish Earth-sized planets. And in 2013, the James Webb Space Telescope will go into orbit. As stated in this press release, astronomer Paul Kalas hopes the James Webb Space Telescope will tell us whether there are other planets orbiting Fomalhaut – and whether those planets might be able to sustain life. Who knows – maybe on one of those planets, aliens are collecting snapshots of Earth.

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The project was headed by a group at a university in Toronto and a group at a university in Paris. Canada and France sponsor the 4-meter telescope that is used to discover and observe the supernovae from the point of explosion to the final days when the supernova fades from view. We call this the imaging part of the program. This data constrains the apparent brightness and life cycle of the supernova, and eventually the absolute distance to the supernova.

Our contribution to the project was primarily through our affiliation with Keck Observatory. We were typically awarded four nights a year to observe recently discovered supernovae spectroscopically. The data is used to determine the redshift and the kind of supernova explosion.

The supernovae are used to study the rate of expansion of the universe. It was this type of experiment that was first used to discover that the universe is actually dominated by dark energy.

No one really suspected the presence of dark energy for almost the entirety of the 20^th century. Now, we not only know it exists but are actually trying to understand it in the same way we understand gravity, protons, and electrons. That is where projects like the Supernova Legacy Survey come in. With projects like this, we work to collect enormous samples of well-studied supernovae that can improve our understanding of dark energy.

We use a certain type of supernova as yardsticks to measure distances in the universe. We then model the affects of dark energy on the expansion history of the universe by comparing distances and rates of expansion. This comparison is typically represented in a Hubble Diagram.

The Supernova Legacy Survey has been very successful in its attempts thus far. On the right, I show the Hubble Diagram from the first year of data. This is less than 20% of the full sample. The dotted line outlines the expectations of the 1990's cosmology crowd. The solid line shows the prediction from the more sophisticated cosmologists of the 21^st century. As you can see, the original expectations were pretty far off the mark – the supernovae just don't lie on top of the dotted line.

Now that this program is finishing up, we should be seeing similar figures that are teeming with supernovae. Future programs should do an even better job of making these measurements. Someday we may actually understand this dark energy thing, it may turn out to be something else completely new and unexpected!

Kyle S. Dawson is engaged in post-doctorate studies of distant supernovae and development of a proposed space-based telescope at Lawrence Berkeley National Laboratory.

37.8768 -122.251

Saturn's moon Epimetheus from the Cassini spacecraft.
Credit: Cassini Imaging Team, SSI, JPL, ESA, NASA
and APOD.

On the bus in Denali National Park a few years ago, I found myself sitting next a couple from the East Bay. If you’ve ever been on the Denali bus, you know that it’s a long ride and it was just a matter of time before we struck up a conversation. As often happens, we wound up talking about work and then about astronomy research. Both of them were very interested in the field but were unsure of where to find good information on the web. At the time, I hadn’t really thought about that and wasn’t much help.

Now that I’m writing for QUEST, I am much better suited to answer them. I spend a lot of time surfing the web for images and links to websites to provide the full details for readers who want to follow up on my posts. Over the course of a year or so, I’ve discovered quite a few resources and have settled on a few favorites. Of course, being a Berkeley and Cornell grad, I have a few biases…

First of all, it is common for a university astronomy department to organize a public outreach campaign. I won’t bother with the obvious disclaimers and instead will just say that two of my favorites are “Ask an Astronomer” at Cornell University and the Berkeley Center for Cosmological Physics.

These two sites are quite different. As the name implies, the Cornell site encourages questions and suggestions from readers. The content of the site is therefore governed by the public, covering a wide variety of topics in fairly brief, straightforward language. The Berkeley site is much more structured. They cover the history of cosmology and outline the history of our universe with all the appropriate links (scroll down to see the links). This provides a very detailed and organized explanation of a specific field of astronomy.

In addition to universities, there are quite a few NASA missions that maintain excellent public relations. Almost everyone knows the Hubble Space Telescope and Mars Rovers. Both sites are updated almost daily with galleries, discoveries, and recent news. NASA also has several other large missions at other wavelengths that are probably not as well known. Three examples are the Chandra X-ray observatory, the WMAP mission, and the Spitzer infrared observatory. Like the Hubble and Rover sites, these space-based observatories perform ground-breaking science and do an excellent job explaining their discoveries to the public.

Besides QUEST, there are also quite a few other excellent blogs out there. Each site has a different approach and finds its own balance between astronomy coverage, opinion, and discussion of general science. One of the most popular is the Bad Astro site–we even have a link on the right hand side of the QUEST blog web page. You can also check out About.com's top ten space and astronomy blogs.

Of course, one obvious place to learn about astronomy is from journalists. Two websites that do a very good job of covering the field are Space.com and New Scientist (some content requires subscription).

Finally, if you enjoy beautiful images of the sky, a great place to look is the “Astronomy Picture of the Day." This is where I got my image for today. If you look tomorrow you’re guaranteed to find something just as exciting!

Kyle S. Dawson is engaged in post-doctorate studies of distant supernovae and development of a proposed space-based telescope at Lawrence Berkeley National Laboratory.

latitude: 37.8768, longitude: -122.251

Star or Comet?

Remember the solar wind I wrote about a few weeks ago? This stream of protons does more than create comet tails and aurora, it also destroys all of those fancy electronics we work so hard to put into orbit.

The protons streaming from the sun carry a lot of energy, and they leave a lot of this energy behind as they pass through satellites and astronauts that don’t have the Earth’s atmosphere to protect them. The energy released wrecks havoc on the system, throwing electrons and atoms around like a game of ping-pong. This is one form of radiation damage.

Definitely a comet!
This radiation damage is harmless over short periods of time, much like an occasional X-ray at the dentist. However the solar wind becomes a problem for something like the Hubble Space Telescope or our proposed satellite SNAP which are exposed for many years.

To understand how a telescope degrades from exposure to radiation, let me give an extremely quick explanation of how we gather astronomical images. A telescope is very similar to a camera you buy in the store. The large mirror is equivalent to the lens on your camera. The part that suffers the most radiation damage is the Charge Coupled Device, also known as a CCD.

The CCD is essentially the same as the 8-megapixel chip in your digital camera. This serves as an electronic version of film, recording the image through the photoelectric effect rather than through a chemical reaction. If you can still remember how photography was in the days of film, I'm sure you can appreciate the relief of going digital. Astronomers realized this early on and were pioneers in the use of CCDs.

The photons from the subject of the photograph collide with electrons in the silicon of a CCD, knocking them free from their parent atom. The free electrons are then collected in a well near the site of the collision. Once the exposure is complete, charge is moved one well (or pixel) at a time toward a transistor which then reports the number of electrons found. This process is usually described through the analogy of a bucket brigade passing buckets of water from a reservoir to a fire.

When the CCD is brand new, the bucket brigade performs almost perfectly. If I want to observe a star, the image comes out crystal clear. However, after enough time in space and in the solar wind, the CCD begins to show its wear. The bucket brigade gets sloppy at work and has to contend with an increasingly difficult obstacle course, spilling a little bit of water (or electrons) during each transfer. That same star now leaves a trail of charge behind and begins to look more like a comet.

Now, if I am observing a star, I want my image to look like a star, not like a comet. Is that really too much to ask? Unfortunately, the CCD will inevitably deteriorate in space and astronomers have to find ways to predict and correct for this deterioration. This is what we spent yesterday discussing. We passed around some pretty good ideas but still have a bit of work to do before we can prove a new method for correcting the images. I just hope we it figured out before our satellite launches in 2015!

Kyle S. Dawson is engaged in post-doctorate studies of distant supernovae and development of a proposed space-based telescope at Lawrence Berkeley National Laboratory.

latitude: 37.8768, longitude: -122.251