Tag Archive for Astronomy Department

Herbst and Greenwood in The Conversation: The Tell-Tale Clue to How Meteorites Were Made

Wesleyan faculty frequently publish articles based on their scholarship in The Conversation US, a nonprofit news organization with the tagline, “Academic rigor, journalistic flair.” In a new article, John Monroe Van Vleck Professor of Astronomy Bill Herbst and Assistant Professor of Earth and Environmental Sciences James Greenwood write about the model they’ve proposed for how the most common kind of meteorites form—a mystery that has dogged scientists for decades.

The tell-tale clue to how meteorites were made, at the birth of the solar system

April 26, 1803 was an unusual day in the small town of L’Aigle in Normandy, France – it rained rocks.

Over 3,000 of them fell out of the sky. Fortunately, no one was injured. The French Academy of Sciences investigated and proclaimed, based on many eyewitness stories and the unusual look of the rocks, that they had come from space.

The Earth is pummeled with rocks incessantly as it orbits the Sun, adding around 50 tons to our planet’s mass every day. Meteorites, as these rocks are called, are easy to find in deserts and on the ice plains of Antarctica, where they stick out like a sore thumb. They can even land in backyards, treasures hidden among ordinary terrestrial rocks. Amateurs and professionals collect meteorites, and the more interesting ones make it to museums and laboratories around the world for display and study. They are also bought and sold on eBay.

Despite decades of intense study by thousands of scientists, there is no general consensus on how most meteorites formed. As an astronomer and a geologist, we have recently developed a new theory of what happened during the formation of the solar system to create these valuable relics of our past. Since planets form out of collisions of these first rocks, this is an important part of the history of the Earth.

This meteor crater in Arizona was created 50,000 years ago when an iron meteorite struck the Earth. It is about one mile across. W. Herbst, CC BY-SA

This meteor crater in Arizona was created 50,000 years ago when an iron meteorite struck the Earth. It is about one mile across. (Photo by Bill Herbst, CC BY-SA)

The mysterious chondrules

Natural Sciences and Mathematics Division Hosts Celebration of Science Theses

On April 26, honors and graduate students in the Natural Sciences and Mathematics Division presented posters at the Celebration of Science Theses.

On April 26, honors and graduate students in the Natural Sciences and Mathematics Division presented posters at the Celebration of Science Theses.

Han Yang Tay presented a poster titled "Rich Club and Diverse Club in Structural and Functional Neuroimaging Data." His advisor is Psyche Loui

Han Yang Tay ’19 speaks to Barbara Juhasz, associate professor of psychology, about his study titled “Rich Club and Diverse Club in Structural and Functional Neuroimaging Data.” His advisor is Psyche Loui, assistant professor of psychology.

Study by Herbst, Greenwood Presents New Theory on How Meteorites Formed

A paper by John Monroe Van Vleck Professor of Astronomy William Herbst and Assistant Professor of Earth and Environmental Sciences James Greenwood will be published in the September 2019 issue of Icarus, published by Elsevier. The paper is available online.

The paper, titled “Radiative Heating Model for Chondrule and Chondrite Formation,” presents a new theory of how chondrules and chondrites (the most common meteorites) formed. It suggests a new approach to thinking about these rocks that populate the meteorite collections on Earth. It includes both theory and experiments (completed in Greenwood’s lab in Exley Science Center).

These laboratory experiments demonstrate that porphyritic olivine chondrules, the most voluminous type of chondrule, can be made using heating and cooling curves predicted by the “flyby” model. View a schematic diagram here.

“The problem of how chondrules and chondrites formed has been around for decades—more than a century, really. We cannot yet claim to have solved the problem but we have provided a new idea about the solution that passes many tests,” Herbst explained.

The basic idea, Herbst said, involves heating of small fluffy “rocks” in space as they fly past molten lava eruptions on larger asteroids, during the first few million years of the solar system’s existence.

Herbst, Greenwood, and Postdoctoral Research Associate Keniche Abe, will present this research at meetings this summer in Europe and Japan.

Students, Faculty, Alumni Present Research at 50th Annual Planetary Science Conference

Jeremy Brossier presented a talk titled "Radiophysical Behaviors of Venus’ Plateaus and Volcanic Rises: Updated Assessment." He also presented a poster titled "Complex Radar Emissivity Variations at Some Large Venusian Volcanoes."

At left, earth and environmental sciences postdoctoral research associate Jeremy Brossier presented a poster titled “Complex Radar Emissivity Variations at Some Large Venusian Volcanoes” during the Lunar and Planetary Science Conference in Texas.

Several Wesleyan students, faculty, and alumni attended the 50th Lunar and Planetary Science Conference (LPSC) March 18-22 in The Woodlands, Texas. Members of the Wesleyan Planetary Sciences Group presented their research on a range of planetary bodies.

This annual conference brings together international specialists in petrology, geochemistry, geophysics, geology, and astronomy to present the latest results of research in planetary science.

Earth and environmental studies major Emmy Hughes ’20 presented a poster titled “Observations of Transverse Aeolian Ridges in Digital Terrain Models” during a session on “Planetary Aeolian Processes.”

Earth and environmental science graduate student Reid Perkins MA ’19 presented a talk titled “A Reassessment of Venus’ Tessera Crater Population and Implications for Tessera Deformation” and a poster titled “Volumes and Potential Origins of Crater Dark Floor Deposits on Venus.”

Klusmeyer Receives a Chambliss Award for Astronomy Research

After a star forms, a dusty ring of space debris may begin orbiting around a star. These circumstellar disks are composed of asteroids or collision fragments, cosmic dust grains, and gasses.

Astronomy graduate student Jessica Klusmeyer is interested in understanding the molecular composition of the debris disk gas. “It has important implications not only for our knowledge of debris disks but also for planet formation,” she said.

Klusmeyer joined more than 25 Wesleyan affiliates and shared her research during the 233rd American Astronomical Society Meeting Jan. 6-10 in Seattle, Wash. The American Astronomical Society (AAS) awarded Klusmeyer a Chambliss medal for her poster presentation titled, “A Deep Search for Five Molecules in the Debris Disk around 49 Ceti.”

The Astronomy Achievement Student Awards recognize exemplary research by undergraduate and graduate students who present at one of the poster sessions at the meetings of the AAS. Awardees are honored with a Chambliss medal or a certificate.

Klusmeyer competed for the Chambliss award against hundreds of graduate and PhD students from research universities around the country.

A second-year masters student, Klusmeyer is working on the project with her advisor, Meredith Hughes, assistant professor of astronomy and assistant professor, integrative sciences.

“Professor Hughes has a very active and supportive research group that covers a wide variety of circumstellar disks and planet formation topics,” Klusmeyer said. “She works in radio wavelengths of light and the group often utilizes data from the world-class Atacama Large Millimeter/submillimeter Array (ALMA) telescope.”

Klusmeyer joined Hughes’s group during her first year of graduate school and is working on unlocking the molecular composition of a nearby debris disk surrounding 49 Ceti, a star located in the constellation of Cetus. Cetus, which is named after a Greek sea monster, resembles the shape of a whale and can be viewed from campus (or as far away as Chile!).

Scientists once thought that debris disks would lose their gas composition after planet formation, however, more than 20 debris disks containing molecular carbon monoxide gas have already been detected by astronomers.

“Our project wants to understand the nature of this gas,” Klusmeyer explained. “Is it leftover material from when the star formed, or is it constantly being produced in collisions from exocomets or other small bodies orbiting around 49 Ceti?”

If a debris disk has gas, “it may provide a longer period of time for gas giant planet formation or we could detect other molecules commonly found in comets and have the first glance at the molecular composition of comets around other stars,” she said.

Girish Duvvuri ’17 received a Chambliss medal in 2018. Read more.

Students, Faculty, Alumni Attend American Astronomical Society Meeting

Mark Popinchalk ’13

Roy Kilgard and Mark Popinchalk ’13.

More than 25 Wesleyan affiliates attended the 233rd American Astronomical Society Meeting Jan. 6-10 in Seattle, Wash. All current Wesleyan students who attended presented posters of their research.

Campus attendees included: Bill Herbst, the John Monroe Van Vleck Professor of Astronomy and professor, integrative sciences; Roy Kilgard, associate professor of the practice in astronomy and associate professor of the practice, integrative sciences; Michael Henderson ’19; Allison Quintana ’19; graduate student Jessica Klusmeyer; graduate student Ismael Mireles; and graduate student Anthony Santini ’18.

Alumni included Hannah Fritze ’18, Aylin Garcia Soto ’18, Prajwal Niraula MA ’18, Amy Steele MA ’14, Nicole Arulanantham MA ’15, Mark Popinchalk ’13, Marshall Johnson ’11, Anna Williams ’09, Ken Rumstay MA ’77, Taft Armandroff ’82, Phil Choi ’95, Anil Seth ’98, Evan Tingle ’08, MA ’09, Diana Windemuth MA ’13, Trevor Dorn-Wallenstein ’15, Clara Moskowitz ’05, Emily Leiner ’10.

Diana Windemuth MA ’13 and Aylin Garcia Soto ’18

Diana Windemuth MA ’13 and Aylin Garcia Soto ’18.

Former graduate student Colin Littlefield, and former post-doctoral researchers Vicki Sarajedini and John Cannon also attended.

In addition, five college students who participated in the Keck Northeast Astronomy Consortium’s (KNAC) summer Research Experiences for Undergraduate (REU) program at Wesleyan attended the meeting. Karina Cooper, Sadie Coffin, Aleezah Ali, Katie Chapman, and Diego Garcia worked at Wesleyan’s observatory last summer and were under the direction of Wesleyan faculty and students.

View additional photos of the meeting in this Van Vleck Observatory blog.

5 Students Receive NASA Connecticut Space Grant Consortium Fellowships, Awards

Two graduate students and three undergraduate students are recipients of Fall 2018 NASA Connecticut Space Grant Consortium (CTSGC) awards. They are among 39 students from 13 CTSGC academic affiliate institutions to be honored.

NASA CTSGC is a federally mandated grant, internship, and scholarship program that is funded as a part of NASA Education. There are Space Grant Consortia in all 50 states, plus Washington, D.C., and Puerto Rico.

Earth and environmental science graduate student Christina Cauley received an $8,000 Graduate Research Fellowship for her project “Chemistry and Biology of Giant Hydrothermal Mounds in Paulina Lake, Oregon.” Her advisor is Joop Varekamp, the Harold T. Stearns Professor of Earth Science and Smith Curator of Mineralogy and Petrology of the Joe Webb Peoples Museum of Natural History. Varekamp also is professor of earth and environmental sciences; professor, environmental studies; and professor, Latin American studies.

Astronomy major Hunter Vannier ’20 received a $5,000 Undergraduate Research Fellowship for his project titled “Using Hubble to Look Back at the Sun’s Historical Trajectory Through the Local Interstellar Medium.” Vannier’s advisor is Seth Redfield, chair and associate professor of astronomy. Redfield also is associate professor, integrative sciences, and co-coordinator, planetary science.

Three other students received $1,000 Student Travel Grants, which covered travel expenses to attend the American Astronomical Society Meeting in Seattle, Wash., in January.

At the meeting, Astronomy major Michael Henderson ’19 presented his senior thesis research titled “High Precision Photometry of Faint White Dwarf Stars from K2 Data.” Henderson’s advisor is Seth Redfield.

Astronomy graduate student Ismael Mireles, presented his master’s thesis research on “Searching for planets around the brightest stars in K2.” Mireles’s advisor is Seth Redfield.

And astronomy graduate student Anthony Santini ’18 presented his BA/MA thesis research titled “Determining Fundamental Properties of Galaxies with X-ray Binary Correlations.” Santini’s advisor is Roy Kilgard, associate professor of the practice in astronomy and associate professor of the practice, integrative sciences.

Wesleyan in the News

In this recurring feature in The Wesleyan Connection, we highlight some of the latest news stories about Wesleyan and our alumni.

Recent Wesleyan News

1. Los Angeles Times“As the World Warms, Deadly and Disfiguring Tropical Diseases Are Inching Their Way Toward the U.S.”

In this op-ed, Professor of Biology Frederick Cohan and Isaac Klimasmith ’20, both in the College of the Environment, write that infectious disease is a growing threat, resulting from climate change, that humans may find hard to ignore. Cohan is also professor, environmental studies and professor, integrative sciences.

2. Hartford Courant: “Trump’s Immoral Response to Climate Report”

Gary Yohe, the Huffington Foundation Professor of Economics and Environmental Studies, writes in this op-ed that it is “irresponsible” and “immoral” to ignore the findings of a major new report on climate change. Delaying action to mitigate and adapt to climate change will be increasingly damaging and expensive, he writes. Yohe is also professor of economics and professor, environmental studies, and was a reviewer on the new National Climate Assessment. He also recently co-authored an op-ed in HuffPost titled “People Are Already Dying by the Thousands Because We Ignored Earlier Climate Change Warnings.” 

3. National Geographic: “Both of NASA’s Voyager Spacecraft Are Now Interstellar. Where to Next?”

With both of NASA’s twin Voyager spacecraft now having crossed the threshold into interstellar space, Seth Redfield, associate professor and chair of astronomy, comments on what the spacecraft are likely to encounter on their journey. Redfield is also associate professor, integrative sciences, and co-coordinator of Planetary Science.

4. Inside Higher Ed: “Ordinary Education in Extraordinary Times”

President Michael Roth writes in this op-ed that in uncommon times, “traditional educational practices of valuing learning from people different from ourselves have never been more important.”

Recent Alumni News

  1. The Takeaway; WNYC Studios: “Politics with Amy Walter: Pentagon’s First-Ever Audit Exposes Massive Accounting Fraud”

David Lindorff ’71, the investigative journalist who wrote an exclusive on the topic for The Nation, joins Walter’s guests—including Staff Sergeant Patricia King, Ambassador Eric Edelman, and Dr. Isaiah Wilson III, a retired Army colonel and senior lecturer with Yale University’s Jackson Institute for Global Affairs—to discuss military spending and its alignment with the military’s strategic goals.

Redfield Speaks at California Academy of Sciences

Seth Redfield

Seth Redfield

On Oct. 15, Seth Redfield, associate professor and chair of astronomy, gave a lecture at the Morrison Planetarium at the California Academy of Sciences. He was invited to speak as part of the Benjamin Dean Astronomy Lecture series. The title of his talk was, “Exploring Our Galactic Neighborhood.” The talk will be posted to the Academy’s iTunes University site.

Redfield is also associate professor, integrative sciences, and co-coordinator, planetary science.

 

Sundial Sculpture Installed on Van Vleck Observatory

Seth Redfield, chair and associate professor of astronomy, associate professor of integrative sciences, and artist Robert Adzema observe a sundial's installation July 16 at the Van Vleck Observatory. Adzema, a maker of site-specific sundials, designed the sculpture to be placed at its exact location on the telescope's wall.

Seth Redfield, chair and associate professor of astronomy, associate professor of integrative sciences, along with artist Robert Adzema observed the sundial’s installation July 16 at the Van Vleck Observatory. Adzema, a maker of site-specific sundials, designed the sculpture for this exact location below the telescope’s dome.

The campus community now has the ability to tell time the way Egyptians did more than 3.500 years ago—by using light and shadows.

A modern-day sundial, which mimics those used throughout history, now hangs on the south side of the Van Vleck Observatory’s 24-inch Perkin telescope. The six-foot-square structure is fabricated from 3/16-inch thick Muntz metal bronze with stainless steel reinforcing.

“Campus doesn’t have enough outside art,” said Joyce Jacobsen, provost and senior vice president for academic affairs. “A sundial is a perfect piece because it’s not only aesthetically pleasing but it’s functional too.”

Bill Herbst, John Monroe Van Vleck Professor of Astronomy, along with Jacobsen, had been pitching the idea of a sundial to the Wesleyan administration for many years. In 2016, the plan was approved by all involved parties, including the President’s Office and Physical Plant-Facilities. Jacobsen and Herbst commissioned sundial creator and artist Robert Adzema of New York to design and build a sundial for Wesleyan’s campus. After visiting campus six times and crafting multiple paper and wooden models, Adzema completed the time-telling sculpture in 18 months.

“Sundials can be designed for almost any fixed surface that receives sunlight,” Adzema said. “The most precise dials, as is this dial, here at Wesleyan, are made to the exact longitude and latitude of the site.”

On July 16, crews from New Jersey traveled to campus and began installing the 650-pound sundial. Adzema also attended to offer guidance and direction.

“It’s a great location in terms of being visible without being intrusive,” Jacobsen said. “We will also have an entry now in the online listing for sundials around the world, so now maybe we will have yet more people visit campus, drawn here by the sundial!”

Photos of the sundial’s installation are below: (Photos by Olivia Drake)

Crews used a scissor lift to lift and install the 650-pound sundial.

Duvvuri ’17 Awarded Chambliss Award for Astronomy Research

Girish Duvvuri ’17 presented his research titled “Necroplanetology: Disrupted Planetary Material Transiting WDII45+017.” His advisor is Seth Redfield, associate professor of astronomy.

Girish Duvvuri ’17 presented his research titled “Necroplanetology: Disrupted Planetary Material Transiting WDII45+017″ at a poster session in 2017.

In recognition of his exemplary research at Wesleyan, astronomy major Girish Duvvuri ’17 has been awarded a Chambliss medal from the American Astronomical Society (AAS).

Duvvuri, who majored in astronomy, physics, and English, received the award during the 232nd AAS Meeting June 3–7 in Denver, Colo.

There, he presented a study that formed much of his senior thesis at Wesleyan. Seth Redfield, associate professor and chair of astronomy, associate professor of integrative sciences, and co-coordinator of planetary science, served as Duvvuri’s advisor.

To be eligible for an award, work featured on a poster must have been done within the past year and while the presenter was an undergraduate or graduate student.

Duvvuri is currently a PhD student in astronomy at the University of Colorado in Boulder.

Students Receive Research Awards from NASA

Three undergraduates and one graduate student received NASA Connecticut Space Grant Awards from the NASA Connecticut Space Grant Consortium (CTSGC). The CTSGC is a federally mandated grant, internship, and scholarship program that aims to inspire the pursuit of careers in science, technology, engineering, and mathematics.

Astronomy and math major Nicole Zalewski ’20 received a $5,000 undergraduate research fellowship to pursue her study on “Measurement of the Radar Properties of the Oldest Rocks on Venus to Constrain Mineralogy.” Her advisor is Martha Gilmore, the George I. Seney Professor of Geology, professor of earth and environmental sciences, co-coordinator of planetary science, and director of graduate studies.