Tag Archive for Astronomy Department

Carleo Co-Authors Paper in Nature on Molecular Discovery in Space

Ilaria Carleo, a postdoc working with Associate Professor of Astronomy Seth Redfield, co-authored a paper called “Five carbon- and nitrogen-bearing species in a hot giant planet’s atmosphere,” which details the discovery of six different molecules in the atmosphere of a hot, gas giant exoplanet called HD209458b.

The paper, published in Nature on April 7, discusses known information about the exoplanet, as well as the process by which these molecules were discovered using observations from the Galileo National Telescope.

“Now that the analysis technique has been optimized, we are investigating the presence of these molecules in the atmosphere of other hot-Jupiters and this will help to understand whether all these planets have common formation and evolution history,” Carleo said.

4 Seniors Receive NASA Undergraduate Research Fellowship Awards

space grantsFour members of the Class of 2021 are recipients of NASA Connecticut Space Grant Consortium awards.

Kimberly Paragas ’21, Ben Martinez ’21, Molly Watstein ’21, and Mason Tea ’21 each received a $5,000 Undergraduate Research Fellowship for their ongoing research. They’re among only seven students statewide to receive the honor.

“I have never seen an institution be so successful at these very competitive grants, and was so proud and impressed by the student applicants,” said Seth Redfield, associate professor of astronomy.

Paragras is working with Redfield on her project titled “Gas Giant Atmospheric Mass Loss.” According to the abstract, “Atmospheric mass loss is one of two aspects that influence the evolution of planets, making it essential for understanding their origin. The helium 1083 nm line offers insight into the atmospheric escape of close-in exoplanets, which significantly sculpts their population. This project aims to detect excess helium absorption in the atmosphere of the gas giant HAT-P-18b and estimate its present-day mass loss rate by using transit observations taken with an ultra-narrow band filter. The outcome of this project will provide valuable data for constraining mechanisms of mass loss, as helium outflows have only been detected in 5–6 planets to date.”

Martinez ’21 is working with Ed Moran, chair and professor of astronomy, on a project titled “An Unbiased Survey of Black Hole Activity in the Local Universe.” According to the abstract, “Cosmological simulations have shown that the fraction of low-mass galaxies in today’s universe that contain a nuclear black hole is directly related to the mechanism by which massive black hole seeds formed in the early universe. We have obtained optical emission-line measurements for an unbiased sample of local galaxies using a variety of instruments and will separate the objects into four distinct activity classes. We must remove continuum features from our spectra via the process of starlight subtraction, and examine X-ray and near-IR source catalogs for additional evidence of black-hole accretion to create a comprehensive picture of black hole activity in the nearby universe.”

Watstein ’21 also is working with Moran on a project titled “New Insights into AGN Unification from NuSTAR Observations of Nearby Seyfert 2 Galaxies.” According to the abstract, “Recent X-ray studies have reported a correlation between accretion rate and the presence of a hidden broad-line region in obscured active galactic nuclei (AGNs), suggesting that a substantial revision of the unified model for AGNs is needed. These investigations, however, were based on soft X-ray data, which are unreliable for determining intrinsic luminosities and accretion rates in such objects. Using NuSTAR data in the hard 3-80 keV band, I will determine the intrinsic X-ray luminosities of a large sample of obscured AGNs that have sensitive Keck spectropolarimetry observations, which will afford a definitive test of the accretion-rate hypothesis.”

Tea ’21 is working with Roy Kilgard, associate professor of the practice in astronomy, on a project titled “Analysis, Characterization and Variability of Local, Accreting X-ray Binaries with Archival Chandra Observations.” According to the abstract, “Compact objects are often found in binary systems, emitting X-ray radiation from plasma in their accretion disks as they siphon material from a donor star. Observations of these X-ray binaries (XRBs) in nearby galaxies provide the best opportunity to study the gravitational effects of compact objects on their environment and the high-energy physics powering their emission. In performing a detailed spectral and temporal analysis of the roughly 80 brightest X-ray sources within 15 Mpc, I hope to assess their spectral state and variability in order to more accurately constrain the parameter space and local population of XRBs and black hole binaries (BHBs).”

The NASA Connecticut Space Grant Consortium (CTSGC) is a federally mandated grant, internship, and scholarship program that is funded as a part of NASA education. NASA CTSGC was formed in 1991 in an effort to encourage broader participation in NASA research programs.

Several Wesleyan Faculty, Students Participate in Annual American Astronomical Society Meeting

Four Wesleyan faculty, nine undergraduate students, one graduate student, and one postdoctoral researcher attended the 237th American Astronomical Society meeting virtually Jan. 10–15.

Wesleyan faculty attendees included Ed Moran, chair and professor of astronomy; Seth Redfield, associate professor of astronomy; Meredith Hughes, associate professor of astronomy; and Roy Kilgard, associate professor of the practice in astronomy.

Poster presentations included:
Kimberly Paragas ’21, who is working with Redfield, presented “Metastable Helium Reveals Ongoing Mass Loss for the Gas Giant HAT-P-18b.”

Molly Watstein ’21, who is working with Moran, presented “New Insights into AGN Unification from NuSTAR Observations of Nearby Seyfert 2 Galaxies.”

Hannah Lewis ’23, who is working with Hughes, presented “A Search for Kinematic Signatures of Planets in the Debris Disk Around 49 Ceti.”

Graduate student Megan Delamer, who is working with Hughes, presented “A High-Resolution Study of Spatial and Spectral Variations of Dust Properties in the 49 Ceti Debris Disk.”

Anthony Santini ’18, MA ’19, who is working with Kilgard, presented “An Analysis of X-ray Binary Populations Outside the Visible Extent of Nearby Galaxies.”

Mason Tea ’21, who is working with Kilgard, presented “Circling the Cosmic Drain: Analysis, Characterization and Variability of Local, Accreting X-ray Binaries with Archival Chandra Observations.”

David Vizgan ’21, who is working with Hughes, presented “Tensile Strengths of Bodies in the Collisional Cascade: A Dual-Wavelength Study of the Vertical Structure of the AU Mic Debris Disk.”

Ilaria Carleo, a postdoctoral researcher working with Redfield, presented “TOI-421: A Multiplanet System with a Super-Puffy Mini Neptune.” Carleo’s talk was based on her research cited in AAS Nova.

Ava Nederlander ’22, who is working with Hughes, presented “Resolving Structure in the Debris Disk around HD 206893 with ALMA.”

Seth Larner ’21, who is working with Kilgard, presented “Investigating Transition States in Bright Chandra ACIS X-ray Binaries Exhibiting Intra-Observational Variation.”

Ben Martinez ’21, who is working with Moran, presented “An Unbiased Survey of Black Hole Activity in the Local Universe.”

Anna Fehr ’23, who is working with Hughes, presented “Planet Configurations Carving Gapped Debris Disks.”

Also, Emma Goulet from St. Anselm College, presented “Fitting the Local Interstellar Medium Toward EK Draconis.” Goulet worked under Redfield during the Keck Northeast Astronomy Consortium’s  Research Experiences for Undergraduates (REU) program.

New 24″ Telescope to Provide Better Research Opportunities for Astronomy Students, Faculty

On July 20, the Astronomy Department’s Van Vleck Observatory acquired a state-of-the-art 24-inch telescope that can view galactic objects remotely and autonomously.

“When fully operational, the system will be able to determine if the weather is favorable for observing, open the dome, take calibration observations from a queue, and close down in the morning, all on its own,” explained Roy Kilgard, associate professor of the practice in astronomy. “We’ll be able to conduct remote observations in real time, with a human operator at home or in their office, and make those images available to our students or researchers immediately.”

The new 24-inch PlaneWave CDK24 system replaces a 20-year-old 16-inch Meade LX200GPS Schmidt-Cassegrain in the rooftop dome of the observatory and will allow for student and faculty research and public observation nights. The department hopes to have the telescope fully operational by the start of the fall semester.

At 8 a.m., crews began the installation, which included using a crane to hoist a steel pier, mounting device, and the telescope through the slit in the dome. Photos of the installation are below: (Photos courtesy of Roy Kilgard and Patrick Bohan)

telescope

telescope

Redfield Receives NASA Grant to Study the Properties of Outer Space

Seth Redfield

Associate Professor of Astronomy Seth Redfield will use the Hubble Space Telescope to measure composition, density, temperature, motion, and the spectroscopic signatures of gas and dust.

If a spacecraft were to quickly travel outside the solar system—potentially en route to a nearby exoplanetary system—it would need to pass through an atmosphere unfamiliar to scientists on Earth.

As a recipient of a $415,000 grant from NASA, Seth Redfield, chair and associate professor of astronomy, hopes to learn more about the mysterious makeup of this “outer space.”

“There are several very early designs for an interstellar probe, but first, we need to understand the properties of the space in between the stars if you are traveling through it, especially at high speed,” Redfield said. “Given the vastness of space, even in our nearest cosmic neighborhood of the closest stars, very high speeds are needed. The designs for an interstellar probe involve speeds that range from 11,000 miles per hour to 6 million miles per hour! These require the biggest rockets that NASA has ever built and new propulsion ideas that are still in very early design phases.”

Students, Alumni Attend Meeting of the American Astronomical Society in Hawaii

American Astronomical Society in Hawaii

Ismael Mireles MA ’19, Rachel Marino ’20, Katharine Hesse MA ’20, Justin Perea MA ’20, Gil Garcia ’20, Hunter Vannier ‘20, Fallon Konow ’20, and David Vizgan ’21 gathered for a photo at the American Astronomical Society in Hawaii in January.

Seth Redfield, Hunter Vannier (BA ‘20), Fallon Konow (BA ‘20)

Seth Redfield poses with his students, Hunter Vannier ’20 and Fallon Konow ’20, at a poster session.

Several Wesleyan undergraduate and graduate students, faculty, and alumni attended the 235th American Astronomical Society meeting in Honolulu, Hawaii, Jan. 4–8, 2020.

“The meeting was a huge success, and we were thrilled to have such a large contingent of Wesleyan students able to attend and present their research,” said Seth Redfield, associate professor and chair of astronomy.

Wesleyan McNair Fellow Rachel Marino presented a poster titled “HD106906 Debris Disk Morphology and Origin of an External Perturber.” Her advisor is Meredith Hughes, associate professor of astronomy.

Hunter Vannier ’20 shared his research titled “Mapping the Local Interstellar Medium: Using Hubble to Look Back at the ISM along the Sun’s Historical Trajectory.” His advisor is Seth Redfield.

Wesleyan McNair Fellow Gilberto Garcia ’20 shared his poster titled “From Einstein to Chandra: Dramatic long-term X-ray variability in AGNs.” His advisor is Ed Moran, professor of astronomy.

Fallon Konow ’20 presented “Constructing a Survey of the Local Interstellar Medium using Hubble Spectra.” Her advisor is Seth Redfield.

David Vizgan ’21 presented a project titled “Using [CII] luminosity as a tracer of gas mass @ z=6,” which was based on work from a summer research program in Copenhagen.

Graduate student Justin Perea presented a poster titled, “Emission-line active galaxies and the Cosmic X-ray Background.” His advisor is Ed Moran.

Graduate student Katharine Hesse spoke on “Removing (and Using!) Contaminating Field Stars Around Bright K2 Targets.” Her advisor is Seth Redfield.

Alumni attending included Ismael Mireles MA ’19, Amy Steele MA ’14, Raquel Martinez MA ’13, and Chris Dieck MA ’08.

Redfield and Ilaria Carleo, a postdoctoral researcher in the Astronomy Department, also attended the meeting.

Students, Faculty, Community Observe Rare Complete Transit of Mercury

Visitors use telescopes outside observatory

Individuals gathered outside Van Vleck Observatory to view the transit of Mercury on Nov. 11.

For only the seventh time since Wesleyan’s founding, the planet Mercury passed directly in front of the sun, from the perspective of Earth—and Wesleyan served as a gathering place from which to learn about and observe the event. Faculty and students from Wesleyan’s astronomy department, as well as others from the University and the greater Middletown community, gathered outside the Van Vleck Observatory on Nov. 11 to witness the transit through three telescopes.

The mild weather and partly cloudy conditions—particularly at the beginning and end of the transit (which lasted from 7:35 a.m. to 1:04 p.m.)—made for good viewings through the University’s general-purpose 8-inch telescope, as well as its hydrogen alpha solar telescope, which allows users to observe solar prominences. A second solar telescope, owned by John Sillasen, MALS’07, a local amateur astronomer and member of the Astronomical Society of Greater Hartford, was also available to use as part of the event.

Gilberto Garcia ’20, an astronomy and physics major, was assisting with one of the solar telescopes. “Just seeing Mercury in general is a pretty rare occurrence, so I was pretty excited about it,” Garcia said. Viewed from a telescope, Mercury appeared as a small dot on the sun’s surface.

8 Students Present Research at Northeast Astronomy Consortium

astronomy

Several Wesleyan students and faculty attended the 2019 KNAC Undergraduate Research Symposium at Vassar College.

Eight Wesleyan undergraduates presented results of their summer research to the annual Undergraduate Research Symposium sponsored by the Keck Northeast Astronomy Consortium (KNAC) on Oct. 5.

This year’s symposium was held at Vassar College and attended by 125 astronomy students and faculty, primarily from the consortium colleges (Bryn Mawr, Colgate, Haverford, Middlebury, Swarthmore, Vassar, Wellesley, Wesleyan, and Williams).

Astronomy majors Mason Tea ’21 and Rachel Marino ’20 and sophomores Alex Henton ’22 and Ava Nederlander ’22 gave oral presentations of their projects conducted on campus this summer. In addition, astronomy majors Fallon Konow ’20, Hunter Vannier ’20, Gil Garcia ’20, and Terra Ganey ’21 gave poster presentations of their summer research. The presenters were joined by an equal number of first- and second-year students who went to hear the talks, participate in breakout sessions on various astronomical topics, and network with potential future colleagues.

Both Marino and Garcia are Wesleyan McNair Fellows.

KNAC was founded in 1990 to enhance research opportunities for astronomy students at smaller institutions in the northeast by sharing resources. Today it operates a Research Experiences for Undergraduates (REU) program funded by the National Science Foundation through a grant to Wesleyan.

View additional photos on this Astronomy Department’s Error Bar blog post.

Mason Tea presenting results on a gravitational lensing telescope.

Mason Tea ’21 presents his results on a gravitational lensing telescope.

Ava Nederlander presenting work on a brown dwarf in a debris disk.

Ava Nederlander ’22 presents her work on a brown dwarf in a debris disk.

Gil Garcia presented his work on black holes.

Gil Garcia ’20 presented his study on black holes.

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.”