ASU School of Life Sciences selects new director

July 19, 2019

Professor Kenro Kusumi, a genome biologist, has been selected as the new director for Arizona State University’s School of Life Sciences, effective immediately. Kusumi served as interim director for the school for the past six months.

He joined ASU in 2006 as an associate professor and has held additional leadership positions, including associate dean of research and digital initiatives and associate dean of graduate programs. His lab uses genomic approaches to address questions about animal evolution, with direct impact on biomedical and environmental challenges. Along with ASU colleagues, Kusumi is uncovering the molecular instructions required for regeneration in the lizard. By deciphering the genome of the desert tortoise, a hallmark animal of the American Southwest, his group is working with state and federal agencies to help conserve this threatened species. Professor Kenro Kusumi, a genome biologist, has been selected as the new director for Arizona State University’s School of Life Sciences. Photo by Charlie Leight/ASU Now Download Full Image

“Professor Kusumi brings an outstanding record of scientific research, teaching and strong leadership to his new role as director of the School of Life Sciences,” said Nancy Gonzales, dean of natural sciences with The College of Liberal Arts and Sciences. “We are confident in his ability to help build even stronger collaborations of interdisciplinary research, as well as support top-notch degree programs in the life sciences. Also, we are grateful to Professor Bert Jacobs for his years of service and dedication to the success of the School of Life Sciences.”

The school is the largest academic unit within The College, housing dozens of graduate and undergraduate degree programs, as well as thousands of students, both on campus and online. The school is known for innovation in education. It recently launched the country’s first completely online Bachelor of Science biological sciences degree program.

“The School of Life Sciences is an educational innovator, creating entirely new approaches for learning in the 21st century,” Kusumi said. “By breaking down barriers, we have been able to foster transformative and interdisciplinary research in the life sciences. This is an exciting and pivotal time for our school, and I am truly honored to have the opportunity to serve as director.”

He received his doctorate from MIT and completed his postdoctoral training at the National Institute for Medical Research in London. Before coming to ASU, he taught at the University of Pennsylvania School of Medicine and the Children’s Hospital of Philadelphia, where he served as director of pediatric orthopedic basic research.

“In his leadership roles at The College, we’ve come to know Professor Kusumi’s complete dedication not only to the job at hand, but also to ASU’s charter for inclusion, advancing research and discovery, and assuming the fundamental responsibility for the communities we serve,” said Patrick Kenney, dean of The College. “With his leadership experience, as well as scientific and teaching expertise, we are confident he will lead the school to even greater success.”

Along with his directorship, Kusumi will also assume a new role in The College as associate dean of strategic partnerships.

Professor Kenro Kusumi, the new director of the ASU School of Life Sciences, talks with Jennifer Cox, a senior business operations manager at the school. Photo by Charlie Leight/ASU Now

About the school

Established in 2003 as the first interdisciplinary school in President Michael Crow’s vision for a New American University, the School of Life Sciences serves as a hub for interdisciplinary centers, institutes and attracting research talent. Dynamic laboratories, state-of-the-art technologies and a vast expansion of research infrastructure now support more than 4,000 students and 100 faculty members. From Pulitzer Prize winners to young entrepreneurial thought leaders, life sciences faculty pursue discovery and translational research, providing an entrepreneurial climate to bring the best research ideas to fruition.

Sandra Leander

Assistant Director of Media Relations, ASU Knowledge Enterprise

480-727-3396 sandra.leander@asu.edu

Astronomers make first calculations of magnetic activity in 'hot Jupiter' exoplanets

Gas-giant planets orbiting close to other stars have powerful magnetic fields, many times stronger than our own Jupiter, according to a new study by a team of astrophysicists. It is the first time the strength of these fields has been calculated from observations.The team, led by Wilson Cauley of the University of Colorado, also includes associate professor Evgenya Shkolnik of Arizona State Univ...

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Astronomers make first calculations of magnetic activity in 'hot Jupiter' exoplanets

July 22, 2019

The team, led by Wilson Cauley of the University of Colorado, also includes associate professor Evgenya Shkolnik of Arizona State University's School of Earth and Space Exploration. The other researchers are Joe Llama of Lowell Observatory and Antonino Lanza of the Astrophysical Observatory of Catania in Italy. Their report was published July 22 in Nature Astronomy. This illustration shows a hot Jupiter orbiting so close to a red dwarf star that the magnetic fields of both interact, triggering activity on the star. Astrophysicists have for the first time used observations of such activity to calculate field strengths in four hot Jupiter star-and-planet systems. Image credit: NASA, ESA and A. Schaller (for STScI) Download Full Image

"Our study is the first to use observed signals to derive exoplanet magnetic field strengths," said Shkolnik. "These signals appear to come from interactions between the magnetic fields of the star and the tightly orbiting planet."

Many worlds

More than 3,000 exoplanet systems containing over 4,000 planets have been discovered since 1988. Many of these star systems include what astronomers call "hot Jupiters." These are massive gaseous planets presumed to be like the sun's Jupiter but orbiting their stars at close distances, typically about five times the star's diameter, or roughly 20 times the moon's distance from Earth.

Such planets travel well inside their star's magnetic field, where interactions between the planetary field and the stellar one can be continual and strong.

Previous studies, the team says, have placed upper limits on exoplanet magnetic fields, for example from radio observations or derived purely from theory.

"We combined measurements of increased stellar emission from the magnetic star-planet interactions together with physics theory to calculate the magnetic field strengths for four hot Jupiters," lead author Cauley said.

The magnetic field strengths the team found range from 20 to 120 gauss. For comparison, Jupiter’s magnetic field is 4.3 gauss and Earth's field strength is only half a gauss, although that is strong enough to orient compasses worldwide.

Hot Jupiters (red dots) are large planets similar to our Jupiter, but orbiting close to their stars. Four hot Jupiters have magnetic field strengths much greater than that of Earth, Saturn, Uranus or Neptune — or even Jupiter itself. The left scale shows field strength in gauss, the bottom scale shows orbital distance from the star in astronomical units; Earth orbits the sun at 1 AU.

Credit: Wilson Cauley/Iniversity of Colorado

This simulation shows how a hot Jupiter's magnetic field would interact with its host star's magnetic field. The new study found such interactions are enhanced because at least four hot Jupiters have larger calculated magnetic field strengths than previously thought.

Credit: Antoine Strugarek/CEA Saclay/Université de Montréal

Triggering activity

The astrophysicists used telescopes in Hawaii and France to acquire high-resolution observations of emission from ionized calcium (Ca II) in the parent stars of the four hot Jupiters. The emission comes from a star's hot, magnetically heated chromosphere, a thin layer of gas above the cooler stellar surface. The observations let the team calculate how much energy was being released in the stars' calcium emission.

Said Shkolnik, "We used the power estimates to calculate magnetic field strengths for the planets using a theory for how the planets' magnetic fields interact with the stellar magnetic fields."

Cauley explained, "Magnetic fields like to be in a state of low energy. If you twist or stretch the field like a rubber band, this increases the energy stored in the magnetic field." Hot Jupiters orbit very close to their parent stars and so the planet's magnetic field can twist and stretch the star's magnetic field.

"When this happens," Cauley said, "energy can be released as the two fields reconnect, and this heats the star's atmosphere, increasing the calcium emission."

Probing deep

Astrophysicists have suspected that hot Jupiters would, like our own Jupiter, have magnetic fields produced deep inside them. The new observations provide the first probe of the internal dynamics of these massive planets.

"This is the first estimate of the magnetic field strengths for these planets based on observations, so it's a huge jump in our knowledge," Shkolnik noted. "It's giving us a better understanding of what is happening inside these planets."

She adds that it should also help researchers who model the internal dynamos of hot Jupiters. "We knew nothing about their magnetic fields — or any other exoplanet magnetic fields — and now we have estimates for four actual systems."

Surprisingly powerful

The field strengths, the team says, are larger than one would expect considering only the rotation and age of the planet. The standard dynamo theory of planetary magnetic fields predicts field strengths for the sampled planets that are much smaller than what the team found.

Instead, the observations support the idea that planetary magnetic fields depend on the amount of heat moving through the planet's interior. Because they are absorbing a lot of extra energy from their host stars, hot Jupiters should have larger magnetic fields than planets of similar mass and rotation rate.

"We are pleased to see how well the magnitude of the field values corresponded to those predicted by the internal heat flux theory," Shkolnik said. "This may also help us work toward a clearer understanding of magnetic fields around temperate rocky planets."

Robert Burnham

Science writer, School of Earth and Space Exploration

480-458-8207 Robert.Burnham@asu.edu