Finding hidden text in historical documents
document restoration

Mar. 21, 2016
Susan Gawlowicz

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Roger Easton, professor of imaging science, is the go-to guy for imaging cultural artifacts in various states of deterioration. He and his students have enhanced manuscripts all over the world. (Photo courtesy of A. Sue Weisler)

The direction of RIT professor Roger Easton’s research changed in 1998 when a manuscript scholar working for Christie’s of New York came to the Chester F. Carlson Center for Imaging Science with a palimpsest in her backpack.

Underneath the text of a 12th-century Christian prayer book lay the erased 10th-century transcriptions of mathematical treatises written by Archimedes in the third century BCE. The palimpsest, or overwritten book, was bound from random pages of discarded manuscripts scraped clean. Copies of Archimedes’ writings had wound up in a medieval recycling bin.

The erased manuscripts in the palimpsest include the only extant copy of Archimedes’ Method of Mechanical Theorems and the only version of his best-known work, On Floating Bodies, written in the original Greek. The Christie’s scholar wanted a sampling of images from the seven treatises for the auction catalog, and she needed the RIT team to disentangle and enhance the undertext.

Easton spent one day that August imaging the manuscript with the late Robert Johnston, archeologist and retired RIT dean of the then-College of Fine Arts. Their collaborator, Keith Knox, then a scientist at Xerox Corp., helped. His sister-in-law at Christie’s had referred the scholar to the group.

They captured a sample of images from the manuscript under ultraviolet and infrared light and processed the information to reveal text and diagrams containing Archimedes’ concepts.

The manuscript sold at auction for $2 million and spent a decade under conservation at the Walters Art Gallery, now Museum. The preservation of Archimedes’ treatises—and other important historical and philosophical writings recovered on the palimpsest—culminated in a 2011 symposium and exhibition and a two-volume catalogue of images enhanced largely by Easton and Knox.

The project gained RIT entry into an inner circle of scholars and conservators. Today, Easton is the go-to guy for imaging manuscripts, maps, musical scores and other cultural artifacts in various states of deterioration.

Demand for the digital recovery of historical artifacts has taken Easton to Egypt, England, France, Germany, the Republic of Georgia, Italy and India to image documents too precious and fragile to move.

He and his students have enhanced religious manuscripts found in a back room at St. Catherine’s Monastery in Mount Sinai, Egypt, the African diaries of Victorian explorer David Livingstone and the 15th century Martellus Map, which may have influenced Christopher Columbus. Discover magazine ranked the multispectral imaging of the Martellus Map at Yale University as No. 74 in its list of the top 100 science stories of 2015. Chet Van Duzer, an independent scholar, led the project.

“The Archimedes palimpsest was the driving force that showed people what could be done and also taught us how to do it,” said Easton, a professor of imaging science. “We had to learn how to collect the data better and process it. The Archimedes is arguably the most significant surviving manuscript in the history of science.”

Urgent need

Spectral imaging recovers faded or erased text by capturing details about the ink and the parchment at different wavelengths. And because different wavelengths of light convey information unique to that spectrum, traces of iron ink, for instance, appear one way in infrared light, another way in ultraviolet, and, perhaps, not at all in visible light. Multispectral imaging collects the different information and recombines them into composite spectral signatures.

Easton uses the near-infrared wavelength to reveal ink in darkened or charred parchment and the ultraviolet wavelength to enhance the visibility of faded text with fluorescence. Instead of reflecting light, a document imaged under ultraviolet absorbs and re-emits light, making the parchment glow beneath the ink.

The collaborator’s imaging system has evolved since the early days of the Archimedes project. The current setup includes a 50-megapixel digital camera, a spectral lens that provides a sharp focus from near ultraviolet to near infrared wavelengths, and different panels of light emitting diodes in 12 bands of color. The camera has optical filters that allow illumination of the object with one color and imaging with another.

“War and climate are the two biggest threats to these documents,” Easton said. “Mali rebels burned the public library in Timbuktu, while ISIS did the same in Mosul (Iraq). There is an urgent need to preserve and document and to have multiple repositories of data.”

One of his collaborators, Gregory Heyworth, a humanities professor at the University of Mississippi, estimates that Europe alone has 60,000 manuscripts in need of attention.

Easton thinks the number is modest. The overwhelming amount of work to be done is compounded by the lack of trained people to do it, he said.

“The Archimedes took us 10 years. That was one manuscript, 177 leaves. It had lots of issues. Then, 161 palimpsested manuscripts at St. Catherine’s Monastery. We started out planning for 135, but we found more during the imaging over the course of the five-year project.”

A happy accident

The emerging field of spectral imaging of historical documents gives RIT an opportunity to capitalize on its imaging expertise and become an international leader and a resource in this area, said David Messinger, director of the Center for Imaging Science.

“We could develop new imaging modalities and new image processing tools and techniques that could be transitioned to the teams that go out into the field,” Messinger said. “Funded graduate students could be doing the cutting-edge research and permanent staff could support both the students and people outside RIT.”

Already students are making a difference.

During work on the Archimedes palimpsest, Kevin Bloechl ’12, ’14 (imaging science) developed processing techniques that Easton now applies to every new project. The story is one of Easton’s favorite anecdotes.

At the time, Bloechl, then a first-year student, asked Easton for something to do over the 2008 winter break instead of bagging groceries. Easton had just received an email from the curator at Walters Art Museum asking him to spend his holiday working on a section of the Archimedes palimpsest the scholars wanted to read. Easton handed the project to Bloechl.

“I said, ‘Here. Go do this,’ figuring he wouldn’t have any luck,” Easton said. “Within four hours, he stumbled upon it. With those images we were able to recover the text that was completely invisible to our normal methods. The scholars described the results as ‘miraculous.’”

Bloechl used one color image composed of red, green and blue light generated by fluorescence from the ultraviolet illumination. The text became legible to scholars after processing those three bands of the color image.

“It was the red-green-blue difference where the text was but only in this one undertext,” he said. “This was a commentary on Aristotle’s ‘Categories’ that was part of the palimpsest.”

His breakthrough changed Easton’s approach. From then on, Easton always imaged the color of the ultraviolet fluorescence. The manuscript absorbed the ultraviolet and emitted light mostly in the blue, some in the green and a little in the red, Easton explained.

Bloechl describes his contribution as a happy accident.

“The pages of the palimpsest had been imaged under illumination at various wavelengths, and all of these wavelengths were being used in processing,” he said. “I forgot to include all of the wavelengths on one attempt. This yielded the initial results that I’d come up with, and noticing improved results, I continued to use this processing over a full page of the palimpsest.”

David Kelbe ’10, ’15 (imaging science) is another student who has advanced the science of imaging historical documents. Kelbe, now a research scientist at Oak Ridge National Laboratory, introduced principles of remote sensing to the statistical analysis of different spectral colors. His techniques analyze the different brightness and wavelengths of light and recombine them to accentuate the contrast of the undertext, he explained.

“Remote sensing has benefited from huge amounts of resources and development over the last decades for the intelligence community,” Kelbe said. “The cultural heritage domain doesn’t have that expertise, but we can bring the same methods and technology to this domain and there is a lot of potential there.”

Kelbe will continue teaching scholars in Vienna and Athens to image documents they wish to recover. He is also ensuring continuity at RIT by teaching his techniques to fourth-year imaging science undergraduates Liz Bondi and Kevin Sacca.

Sacca is exploring solutions for scholars with his senior project. He is developing an inexpensive portable imaging system for scholars to use on site. Sacca will demonstrate a prototype of his imaging-software tool kit at the Imagine RIT: Innovation and Creativity Festival on May 7. Easton looks forward to Sacca’s results.

Messinger sees the potential to connect the dots among the College of Science, the College of Imaging Arts and Sciences, the College of Liberal Arts’ museum studies and digital humanities and social sciences programs, and the Cary Graphic Arts Collection in The Wallace Center. Steven Galbraith, curator of the Melbert B. Cary Jr. Graphic Arts Collection, proposed and championed the idea.

This fall, a new Laboratory for Imaging of Historical Artifacts was established by the Chester F. Carlson Center for Imaging Science with $300,000 from the Chester and Dorris Carlson Charitable Fund. The laboratory will position RIT to advance the science behind imaging historical documents and train more people.

“With the number of manuscripts that need imaging, we need many more systems and many more groups out there doing this work,” Easton said. “We need tech-savvy scholars who can image documents and affordable, user-friendly equipment for them to use. And we need to close the loop between scholars and scientists. It’s really an example of how the humanities and the sciences can work together.”

Past projects

Cultural heritage objects imaged:

  • Palimpsests (erased and overwritten manuscripts)
  • Archimedes palimpsest 10th century
  • Syriac-Galen palimpsest ninth century
  • St. Catherine’s Monastery (“New Finds” project administered by the Early Manuscripts Electronic Library)
  • David Livingstone’s African diaries
  • Scythia, 11th century palimpsest, from the National Library of Austria
  • Codex Vercellensis (“Codex A”)
  • Les Eschéz d’Amour (The Chess of Love), a 31,000-line, 14th-century French epic poem damaged in 1945 during bombing raids on Dresden


  • Vercelli Mappamundi c. 1220
  • Waldseemüller Cosmographica Universalis 1507
  • Martellus World Map c. 1491

Coming up

Roger Easton will present his research this year at several forums. He and collaborator Keith Knox will present the keynote address at the Imaging Science and Technology Society: Digital Archiving Conference at the National Archives in Washington, D.C., April 20, and participate in a forum about the Syriac Galen palimpsest in Philadelphia April 29-30.

Robert Johnston’s legacy

RIT’s foray into the spectral imaging of historical documents was initiated in the 1990s by the late archeologist Robert Johnston, a former dean of RIT’s College of Fine Arts and director of the Chester F. Carlson Center for Imaging Science from 1992-1994.

He was among the first to suggest the use of digital imaging technology to decipher the Dead Sea Scrolls, ancient Jewish texts that hold clues to the development of Christianity.

RIT’s contributions were featured in documentaries produced by British Broadcasting Corp. and the Discovery Channel celebrating the 50th anniversary of the scrolls’ discovery.




Scholars were unable to read the cartouche on Henricus Martellus’ World Map until Roger Easton processed the images.

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Original Source: University News

NIH study seeks to improve quality-of-life measure for deaf and hard-of-hearing people RIT leads $1.6 million study to enhance disability and outcomes research

Mar. 28, 2016
Susan Gawlowicz

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Poorna Kushalnagar

Improving the health of the deaf and hard-of-hearing population through accessible patient-reported outcome measures is the goal of a $1.6 million National Institutes of Health-funded study, led by Rochester Institute of Technology.

Researchers and providers will, for the first time, have a tool for assessing their deaf and hard-of-hearing patients’ health-related quality-of-life outcomes in American Sign Language. Resulting data will lend new insights in patient outcomes research and improve prevention and treatment models for the underserved deaf and hard-of-hearing population, said Poorna Kushalnagar, a health psychologist and research associate professor in RIT’s Chester F. Carlson Center for Imaging Science.

Patient assessments evaluate symptoms, well-being and life satisfaction, as well as physical, mental and social health. Surveys designed for English speakers present a language barrier for many users of American Sign Language and accessible services, Kushalnagar said.

She and her colleagues at Northwestern University, University of Arkansas Little Rock and Gallaudet University have developed a new profile based on the standard Patient Reported Outcome Measurement Information System, or PROMIS, used in clinical outcomes research. The team modified the PROMIS domains to reflect the experiences of deaf and hard-of-hearing people in English and ASL. The resulting PROMIS-Deaf profile has undergone rigorous cognitive testing with deaf and hard-of-hearing adults and is being used to gather data from a nationwide sample.

A large sample of 650 participants will allow researchers to analyze data from several subgroups within the deaf and hard-of-hearing population, such as by hearing-level, language, gender, ethnicity, race and identification with the lesbian, gay, bisexual, transgender and gay community.

“This project will yield the largest, most representative quality-of-life data set on deaf and hard-of-hearing adults with early deafness,” said Kushalnagar, director of the Deaf Health and Communication and Quality of Life Center in RIT’s Center for Imaging Science.

The NIH grant and supplemental research funding supports three undergraduate researchers and a post-baccalaureate diversity fellow at RIT, as well as a graduate assistant researcher at the University of Arkansas Little Rock.

Kushalnagar’s team includes David Cella, chair and professor of medical social science in the Feinberg School of Medicine at Northwestern University, and Samuel Atcherson, associate professor of audiology at the University of Arkansas Little Rock.

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Original Source: University News

Growing Up With the Space Race
Cultural Artifact and Document Imaging

Mar. 17, 2016
Roger Easton Jr

Back in December, Motherboard published a short post about the 58th anniversary of the 1957 Vanguard TV-3 (Test Vehicle 3) launch, which was the first American attempt to send a satellite into orbit. We were pleasantly surprised when Roger Easton Jr. reached out with his thoughts on the mission. An accomplished scientist in his own right, Dr. Easton is also the son of Roger Lee Easton, who led Project Vanguard during the 1950s, and later went on to become the inventor and designer of the Global Positioning System (GPS) that has become so ingrained in our everyday lives today.

Dr. Easton graciously obliged to share his memories of growing up alongside Project Vanguard in a post for Motherboard. Fittingly, today is the 58th anniversary of the launch of Vanguard 1, which is now the oldest satellite in orbit. Enjoy.

—Becky Ferreira


Among the strongest and clearest memories from my early childhood in the 1950s was being taken outside into the yard early one evening in October 1957 by Mom and Dad to see a moving light in the sky—in the southwest, if I recall correctly. It was the burned-out top stage of the Soviet rocket that launched Sputnik 1.

My other memories of that time are far more vague, but my sister reminds me constantly that Dad wasn’t home much that week, because he was working with his team to switch over the Minitrack satellite tracking system at Blossom Point, MD to pick up radio signals from Sputnik at 20.005 MHz (right next to the US WWV time signal) and 40.002 MHz.

Minitrack was designed to “listen in” at 108.0 MHz and 108.3 MHz, just above the FM radio band, which was much lessoccupied in the 1950s than it is now. The frequency conversion was said to be very difficult, but was eventually successful after some days of frantic effort. It apparently required stringing up an untidy nest of RF coaxial cables. As Dad told it, a Navy liaison officer was somewhat offended by the “unshipshape” nature of that building-wide web of cables, so he took on the personal task of “straightening up” the mess—and the system never worked again (which is a metaphor of some sort).

Blossom Point, Maryland, 1956. Image: Naval Research Laboratory

Dad grew up in rural Vermont, where his father was the town doctor at the time of the Spanish Flu and the Depression. Dad was attracted to science, and was assigned to the Naval Research Laboratory (NRL) after graduating from Middlebury College in 1943. A decade later, he became involved in the early US space program, including “Project Vanguard.”

This phrase had a very fuzzy meaning for me until my second-grade year. The December 1957 issue of National Geographic magazine had a photo of Dad holding the “grapefruit” test satellite. Within a week, the story became even more interesting, when the Vanguard Test Vehicle 3 (TV-3) exploded in spectacular fashion, damaging America's hope of taking back some of the spotlight from the Soviets after their successful launches of Sputniks 1 and 2.

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RIT researchers among group whose work confirms Einstein’s theories

Detection by international LIGO Collaborative opens new window on the universe with detection of gravitational waves from colliding black holes

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Research at the Center for Computational Relativity and Gravitation at Rochester Institute of Technology explores extreme astrophysical phenomena through Albert Einstein’s general theory of relativity. Several members of the center contributed research to the LIGO Scientific Collaboration that helped confirm Einstein’s prediction of the existence of gravitational waves. Members of the center include, left to right in the front row, Jam Sadiq, John Whelan, Jason Nordhaus, Monica Rizzo, Carlos Lousto and Manuela Campanelli, director; in the second row, Joshua Faber, Brennan Ireland and Naixin (Chris) Kang; in the third row, Yosef Zlochower, Yuanhao (Harry) Zhang and Richard O’Shaughnessy; in the fourth row, Dennis Bowen and Jake Lange; and in the fifth row, Zachary Silberman, Hans-Peter Bischof and James Healy.  (Elizabeth Lamark/RIT Production Services)

Feb. 11, 2016
Susan Gawlowicz

Six Rochester Institute of Technology researchers are among the authors of a paper announcing what may be the most important scientific discovery in a century—findings that confirm the existence of gravitational waves predicted in Albert Einstein’s general theory of relativity.

For the first time, scientists have observed ripples in the fabric of spacetime called gravitational waves, arriving at the Earth from a cataclysmic event in the distant universe. This confirms a major prediction of Albert Einstein’s 1915 general theory of relativity and opens an unprecedented new window onto the cosmos.

Gravitational waves carry information about their dramatic origins and about the nature of gravity that cannot otherwise be obtained. Physicists have concluded that the detected gravitational waves were produced during the final fraction of a second of the merger of two black holes to produce a single, more massive spinning black hole. This collision of two black holes had been predicted but never observed.

The gravitational waves were detected on Sept. 14, 2015, at 5:51 a.m. Eastern Daylight Time (9:51 UTC) by both of the twin Laser Interferometer Gravitational-wave Observatory (LIGO) detectors, located in Livingston, La., and Hanford, Wash. The LIGO Observatories are funded by the National Science Foundation and were conceived, built, and are operated by Caltech and Massachusetts Institute of Technology. The discovery, accepted for publication in the journal Physical Review Letters, was made by the LIGO Scientific Collaboration (which includes the GEO Collaboration and the Australian Consortium for Interferometric Gravitational Astronomy) and the Virgo Collaboration using data from the two LIGO detectors.

RIT researchers listed as co-authors of the paper to be published in Physical Review Letters are John Whelan, associate professor in RIT’s School of Mathematical Sciences and principal investigator of RIT’s group in the LIGO Scientific Collaboration; Richard O’Shaughnessy, assistant professor in the School of Mathematical Sciences; Carlos Lousto, professor in the School of Mathematical Sciences and an American Physical Society Fellow; James Healy, post-doctoral research fellow; and graduate students in RIT’s astrophysical sciences and technology program Jacob Lange and Yuanhao Zhang. They are all members of RIT’s Center for Computational Relativity and Gravitation, a research hub in the College of Science and an RIT Research Center of Excellence, led by Manuela Campanelli, director of the center, professor in the School of Mathematical Sciences and an American Physical Society Fellow.

RIT President Bill Destler lauded the team for its role in this scientific revelation.

“This is a historic day in science, and RIT is thrilled that our researchers played such an important role in this collaboration's profound discovery,” Destler said. “Their commitment to their field and to their research exemplifies what we set out to do at RIT. We are delighted that our university has been able to facilitate their work and look forward to supporting them as they continue their research.”

The LIGO paper prominently cites 2005 landmark research done by Campanelli and her team on binary black hole mergers. Based on this milestone work, Lousto and Healy numerically modeled the merger of a pair of black holes and simulated gravitational waveforms that match the one which LIGO detected.

Campanelli’s team was one of the first to solve Einstein’s strong field equations describing the inspiral, merger and ringdown of binary black hole systems—and simulate colliding black holes on a supercomputer. Her collaborators were Lousto and Yosef Zlochower, an associate professor in RIT’s School of Mathematical Sciences, and Pedro Marronetti, program director of the division of gravitational physics at the National Science Foundation.

Hans-Peter Bischof, RIT professor of computer science and a member of the center and the LIGO Scientific Collaboration, has produced scientific visualizations of their seminal research and subsequent work.

“The LIGO announcement is both a historical and a very emotional moment in science, especially for us, since our research contributed to the identification of the first gravitational wave observation as a binary black hole merger,” Campanelli said.

Whelan and O’Shaughnessy specialize in analyzing gravitational wave data and developing methods for detecting and interpreting gravitational wave signals.

“This discovery kicks off the field of gravitational wave astronomy,” said Whelan, principal investigator of RIT’s group in the collaboration. “For the first time, we’ve observed the universe through the new window opened up by Advanced LIGO.”

O’Shaughnessy’s research connects the gravitational-wave signatures observed by LIGO to the astrophysical sources that produced them. He estimates both the nature of these sources—in this case, a binary black hole—and how they formed.

“LIGO has just made the first direct observation of binary black holes,” O’Shaughnessy said. “The next year or two, as LIGO accumulates more data and makes the first census of binary black holes in the universe, will really transform our understanding of how these systems are made.”

O’Shaughnessy works closely with Lousto and Healy, who use supercomputers to produce accurate numerical simulations of binary black hole systems like the one detected by LIGO.

“It is incredibly exciting to see that our predictions for the merger of two black holes have been so neatly verified by direct observation,” Lousto said.

Black holes are massive stars that have collapsed into compact objects whose gravity is too strong for light to escape. Collisions of black holes produce gravitational waves that ripple through space at the speed of light.

The detection of the first gravitational wave follows the centennial celebration in 2015 of Einstein’s general theory of relativity, which predicted the existence of these waves. They result from strongly gravitating masses like black hole mergers, highly spinning neutron stars and stellar explosions—and from the Big Bang.

Although these waves carry extreme amounts of energy, they couple weakly to matter, and only highly sensitive detectors like LIGO can observe them. Analysis of the shape of gravitational waves can reveal information about the systems that generated them.

LIGO research is carried out by the LIGO Scientific Collaboration, a group of more than 1,000 scientists from universities around the United States and in 14 other countries. More than 90 universities and research institutes in the collaboration develop detector technology and analyze data; approximately 250 students are strong contributing members of the collaboration.

The LIGO Scientific Collaboration’s detector network includes the LIGO interferometers and the GEO600 detector. The GEO team includes scientists at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, AEI), Leibniz Universität Hannover, along with partners at the University of Glasgow, Cardiff University, the University of Birmingham, other universities in the United Kingdom, and the University of the Balearic Islands in Spain.

LIGO was originally proposed as a means of detecting these gravitational waves in the 1980s by Rainer Weiss, professor of physics, emeritus, from MIT; Kip Thorne, Caltech’s Richard P. Feynman Professor of Theoretical Physics, emeritus; and Ronald Drever, professor of physics, emeritus, also from Caltech.

Virgo research is carried out by the Virgo Collaboration, consisting of more than 250 physicists and engineers belonging to 19 different European research groups: six from Centre National de la Recherche Scientifique (CNRS) in France; eight from the Istituto Nazionale di Fisica Nucleare (INFN) in Italy; two in the Netherlands with Nikhef; the Wigner RCP in Hungary; the POLGRAW group in Poland and the European Gravitational Observatory (EGO), the laboratory hosting the Virgo detector near Pisa in Italy.

The discovery was made possible by the enhanced capabilities of Advanced LIGO, a major upgrade that increases the sensitivity of the instruments compared to the first generation LIGO detectors, enabling a large increase in the volume of the universe probed—and the discovery of gravitational waves during its first observation run.

The U.S. National Science Foundation leads in financial support for Advanced LIGO. Funding organizations in Germany (Max Planck Society), the U.K. (Science and Technology Facilities Council, STFC) and Australia (Australian Research Council) also have made significant commitments to the project. Several of the key technologies that made Advanced LIGO so much more sensitive have been developed and tested by the German UK GEO collaboration.

For more information on the RIT team:

For information on CCRG: and

For information on RIT's Black Hole Lab:

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Original Source: University News

Observing planet formation at close range: Gemini Planet Imager’s view of the TW Hya disk
Astronomy and Space Science

Dec. 22, 2015
Joel Kastner


Investigations of star and planet formation have long focused on the rich stellar nurseries of Taurus, Ophiuchus, Chamaeleon, and a handful of similarly nearby (but lower mass) molecular clouds. These regions, which lie just beyond 100 pc, are collectively host to hundreds of low-mass, pre-main sequence (T Tauri) stars with ages of a few million years and less. They hence provide large samples of stars with orbiting circumstellar disks that span a wide range of evolutionary stages.

Examples of protoplanetary disks that lie closer than ~100 pc to Earth are far fewer and farther between. However — because their proximity affords the maximum possible linear spatial resolution — these nearby disks provide unique opportunities to test theories describing the planet formation process (see Furthermore, the T Tauri star-disk systems within 100 pc of the Sun tend to be older, on average, than the large numbers of star-disk systems that are still found in or near their natal dark clouds. Hence, circumstellar disks orbiting the nearest known young stars are particularly informative about the late stages of planet formation, as disks disperse and any planets born therein are reaching their final masses (for a brief overview of the study of nearby young stars, see 2015arXiv151000741K).

TW Hydrae was the first of these nearby T Tauri stars to be identified, and remains the best-studied such system. At just 54 pc from Earth and a ripe young age of roughly 8 million years, this nearly solar-mass star and its orbiting, circumstellar disk of dust and gas has become a “go-to” target for new imaging facilities seeking to demonstrate their capabilities. For example, TW Hya has already been the subject of a significant number of ALMA First Light and Early Science programs aimed at investigating the chemistry and structure of its 200-AU-diameter disk.

Hence, when Gemini Planet Imager (GPI) became available for Early Science observations last year, TW Hya beckoned. Given GPI’s potential to perform diffraction-limited, coronagraphic near-infrared imaging on the 8-meter Gemini South telescope, GPI imaging of TW Hya offered the chance to image a protoplanetary disk in its giant planet and Kuiper Belt formation (~10-50 AU) regions at a jaw-dropping ~1.5 AU resolution. In combination with GPI’s polarimetric capability, such observations can tease out the faint signature of starlight scattered off circumstellar dust, potentially yielding an unprecedently detailed view of the surface of the nearly face-on disk.

Our team’s observations of TW Hya were challenging for GPI; the star lies at the faint end of the useful range of its adaptive optics (AO) unit. But our team had successfully imaged the circumbinary disk orbiting the close binary T Tauri system V4046 Sgr with GPI (Rapson et al. 2015ApJ…803L..10R), a system very similar to TW Hya in many respects (including its I magnitude). So we had hope for TW Hya as well.


The GPI observations of TW Hya did not disappoint. These new GPI coronagraphic/polarimetric AO images confirm the presence of a dark gap in the TW Hya disk at 23 AU that was previously tentatively identified via near-infrared imaging with the Subaru telescope (Akiyama et al. 2015ApJ…802L..17A). The GPI imaging furthermore clearly resolve the disk gap, allowing us to measure its width (~5 AU) and depth (~50%) and thereby facilitating direct comparison with detailed numerical simulations of planets forming in circumstellar disks. The comparisons we have carried out thus far (see above) indicate that the 5-AU-wide gap’s observed structure could be generated by a sub-Jupiter-mass planet orbiting within the disk at a position roughly equivalent to that of Uranus in our solar system. For the gory details, see Rapson et al. (2015ApJ…815L..26).

Further scrutiny of the TW Hya disk with GPI and SPHERE in their differential coronagraphic imaging modes may yield direct detection of the planet(s) that appears to be actively carving a gap in the TW Hya disk — especially if the putative planet is still actively accreting gas from the disk. There are other possible explanations for the formation of gaps and rings in disks, however. In particular, dust grain fragmentation and ice condensation rates may change rapidly with disk radius, yielding sharp variations in small grain surface densities and/or reflective properties that can produce the appearance of disk gaps when imaged in scattered starlight. Or the inner regions of the disk may be partially shadowing exterior regions. ALMA imaging of the TW Hya disk should provide definitive tests of these alternative scenarios for the gap at 23 AU seen in our GPI imaging.

-Joel Kastner (Center for Imaging Science and School of Physics & Astronomy, Rochester Institute of Technology)

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Campus Spotlight

campus spotlight photo

Jan. 14, 2016
A. Sue Weisler

Roger Easton, professor in the Chester F. Carlson Center for Imaging Science, uses multispectral imaging to uncover hidden text from historical objects. He is spending the intersession in Chartres, France, imaging fragments of manuscripts damaged in WWII bombings.

Getting looped: RIT engineering and imaging science students move on to next phase of SpaceX Hyperloop competition
Student Stories

Two undergraduate teams make the cut with designs for futuristic tube travel

Dec. 11, 2015
Michelle Cometa

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Team Two is Tyler Kuhns, second-year imaging science, Hamburg, N.Y.; Ryan Hartzell, second-year imaging science, Danielsville, Pa.; Zachary Assenmacher, second-year physics, Danielsville, Pa.; Jeff Maggio, second-year imaging science, Cincinnati, Ohio; Nate Dileas, second-year imaging science, Buffalo, N.Y.; Emily Faw second-year motion picture science, Sellersville, Pa.; Catherine Meininger, second-year motion picture science, Oklahoma City, Okla.; and Kristina Carucci second-year imaging science, Massapequa Park, N. Y. Faculty advisors are imaging professors Harvey Rhody and Joe Pow.

Two teams of undergraduates from Rochester Institute of Technology beat out universities, companies and individuals from around the world and had their preliminary designs accepted for the SpaceX Hyperloop Pod Competition Design Weekend. Of the 1,200 designs submitted, only 318 teams from 162 universities in 16 countries are advancing to the first phase of the design process and presenting their unique designs Jan. 29-30 atTexas A & M University.

The Hyperloop is a futuristic high-speed rail system with multi-passenger, solar-powered “pods,” or capsules, speeding through a series of depressurized tubes. Elon Musk first proposed the Hyperloop idea in 2013, and his company, SpaceX, is one of several seeking to accelerate the development of a system prototype. He proposed a national challenge—to build a scaled-down pod model and necessary sub-systems. After several competition phases, Musk intends to hold a final contest in June at SpaceX headquarters in Hawthorne, Calif., where a Hyperloop test track is being built.

Trying to get from this first design phase to the finals are two groups of undergraduates from RIT’s Kate Gleason College of Engineering and the Chester F. Carlson Center for Imaging Science. All are only second or third-year students who have yet to start co-ops or major design projects within their programs, but who believe their Hyperloop ideas have the potential to make an impact on high-speed travel, said Willow Baker, a mechanical engineering major and leader for RIT Team One.

“This whole competition is just a large brainstorm for this really huge idea. Get as many minds on a problem as you can, and it’s going to be solved that much faster, with that many more different approaches to the problem,” Baker said.

The six engineering students she is working with are designing a full pod. They are fine-tuning a full proposal complete with designs for the levitation system with a flexible barrier they call the “skirt” to maintain the air bearings, and a modular regenerative braking system.

“We were able to make comparisons for our system to other things we found in the real world like the takeoff and landing gears on airplanes, or like an air hockey table with the little openings that release air and try to trap the air under the game pieces so that they levitate. The Hyperloop is a new application that combines a lot of pre-existing technology,” said Baker, who is from Blue Bell, Pa.

Teams have the option of presenting a full-pod proposal or details related to one of the Hyperloop’s sub-systems. They will be required to present a working prototype plan, as well as the process to build the equipment, materials used and cost estimates for manufacturing the pod. They will be judged by university and corporate engineers.

Led by Kristina Carucci, RIT Team Two developed two sub-systems: a high-speed communications system and a sensor system to detect faults in the walls of the tube that could impede the motion of the pod. Both are relatively new technologies being enhanced so they can be applied to a higher speed environment, she said.

“It is an entirely imaging-based method. Other traditional methods that are used to scan tubes, like oil pipelines, would not work in this case,” said Carucci, a second-year imaging science student from Massapequa Park, N. Y. “Scanning the walls of the tube will use what is called ‘structured light,’ and it is commonly used to make 3D maps of stationary objects for scientific purposes. But it has never been used at such high speeds.

“Our proposed optical communications system will far exceed the current communications model in place. Not to mention, this would be the first time a system like ours could be used in a environment like the Hyperloop tube.”

Each of the teams had access to faculty from their colleges and took advantage of that expertise to learn more about successfully building mathematical models and to act as panelists similar to the ones that will question them at the Challenge in Texas about their new technologies. Over RIT’s holiday break in December, both teams will finalize designs, cost estimates, specifications and 3D models of components as well as simulations to verify that designs could work.

But futuristic models still have some real-world concerns. As both teams refine design specs they are also strategizing how to get to Texas for the competition. Managing prescribed budgets for a project plan is different than finding funds—and each team recognized that it is a different skill set and that they could be successful if they joined forces.

“The first thing I said to the team was, ‘Guys, we don’t know much, but there’s very little that we can’t learn.’ So we went and found what we needed to know—and it wouldn’t have been possible without the Internet,” said Baker, laughing. “It was just attempting to use our brains and the Internet, and going for it. And we are all attempting to see if we can figure out together how to get there.”

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University News

USRA Announces 2015 Scholarship Award Winners
Student Stories

CIS senior Elizabeth Bondi wins prestigous McGetchin Award

Oct. 14, 2015
Dr. James Lochner

Image:Left to Right: Risa Robinson (Professor, Mechanical Engineering, RIT); Anthony Hennig (Student, Mechanical Engineering); Zoran Ninkov (Professor, Center for Imaging Science, COI Representative, Rochester Institute of Technology); Elizabeth Bondi (Student, Center for Imaging Science); Mihail Barbosu (Professor, Mathematics). 

The Universities Space Research Association (USRA) is proud to announce the 2015 winners of the annual USRA Scholarship Awards. USRA's scholarship selection committee has chosen an outstanding group of students in physical science and engineering disciplines from universities across the United States. These students have shown deep interest in space-related careers and research.

Among the winners is Ms. Elizabeth Bondi, a senior imaging science major at the Rochester Institute of Technology, who won the Thomas R. McGetchin Memorial Scholarship Award, which honors Dr. McGetchin's contributions to planetary science. Bondi is a highly-motivated, in-depth learner, and has applied her imaging science expertise to historical documents and planetary imagery. As an intern at NASA's Jet Propulsion Laboratory, she characterized landing sites for the Insight Mars mission and also planned the test flight program for the proposed Mars Helicopter for the Mars 2020 Rover. She has also presented papers at STEM education conferences on project based learning and peer evaluations. 

Original Source: USRA Press Release