Erika Camacho represents ASU New College at STEM leadership training

June 12, 2018

Erika Camacho, associate professor in Arizona State University's School of Mathematical and Natural Sciences, in the New College of Interdisciplinary Arts and Sciences, represented ASU at the SACNAS – HHMI Advanced Leadership Institute to participate in advanced leadership training to increase STEM leaders of color. 

The SACNAS – HHMI Advanced Leadership Institute is led by Society for Advancement of Chicanos/Hispanics and Native Americans in Science (SACNAS) and the Howard Hughes Medical Institute (HHMI). Dr. Erika Camacho ASU Associate Professor Erika Camacho conducts research at the interface of mathematical applications to biology and sociology. Download Full Image

The institute, held June 4–7 at HHMI in Chevy Chase, Maryland, was an intensive advanced course for graduates of the Linton-Poodry SACNAS Leadership Institute (LPSLI). Participants tackled topics including: career success factors; increasing spheres of influence; challenges in organizational leadership; leading and managing policy initiatives; and decision making and team dynamics in executive teams.

HHMI is the ideal partner to help established leaders deepen their skills, said Rolando Madrid, SACNAS director of programs.

“HHMI has a strong legacy of supporting diversity, inclusion, mentoring and scientific excellence in the highest caliber of America’s STEM professionals,” he said.

Sonia Zárate, president-elect of SACNAS, said, “For 45 years, SACNAS has been a leader in diversifying the STEM enterprise. Like all challenges, changing the face of science to reflect current demographics requires a multipronged approach that includes training individuals and working to change the environment that the individuals are in. The SACNAS suite of leadership programs, which includes the LPSLI and the ALI, serve to empower participants as agents of change — the overall goal of these two programs being to prepare a cadre of diverse scientific leaders that will help drive diversity, equity and inclusion at all levels in their home institutions.”

Clifton Poodry, a founding member of SACNAS and co-founder with Marigold Linton of the LPSLI, said, “The scientific enterprise of the country, whether in academia, industry or government, benefits from the values and expertise embodied in the diverse membership of SACNAS. The LPSLI and ALI are designed to hone the skills of a group that will change the face of science.”

Camacho conducts research at the interface of mathematical applications to biology and sociology. Some of her projects include mathematically modeling the transcription network in yeast, the interactions of photoreceptors, social networks, and fungal resistance under selective pressure. She serves as co-director of the Applied Mathematical Sciences Summer Institute (AMSSI) and was co-principal investigator for two grants from the National Security Agency providing funding for the summer institute. Camacho has received various awards including a citation from the U.S. National Security Agency for her excellent work in mentoring and guiding undergraduate research. 

What's up with Tabby's Star? Still an enigma, says ASU astronomer

June 12, 2018

Dubbed by some as "the strangest star in the universe," the star known as KIC 8462852, Boyajian's Star, or Tabby's Star, is a little hotter than the sun and a bit brighter intrinsically. The star lies almost 1,500 light-years away from Earth in the constellation of Cygnus the Swan.

Sounds pretty ordinary, right? A hypothetical view of the enigma known as Tabby's Star, which dims and brightens in irregular ways that astronomers are still trying to understand. Current models envision the star surrounded by a lumpy ring of dust that lies in our line of sight to it. The star may also have several comets, which is consistent with studies finding evidence for cometary activity within the system. Credit: NASA/JPL-Caltech Download Full Image

Not at all. What makes this star so notable are large changes in its apparent brightness, by up to 20 percent. Moreover, these changes occur at irregular intervals and last days or weeks. In addition, the star also appears to be dimming and brightening steadily over a scale of years.

Citizen scientists using data from the Kepler Space Telescope first discovered brightness dips in 2015. Since then the star has been observed with ground-based telescopes around the world.

"Tabby's Star continues to pose puzzles," said Eva Bodman, a postdoctoral astronomer at Arizona State University's School of Earth and Space Exploration. She recently reported on observations of the star at the American Astronomical Society's summer meeting in Denver.

Last year, a ground-based monitoring campaign of the star with the Las Cumbres Observatory Global Telescope led by astronomer Tabetha Boyajian of Louisiana State University (and funded by Kickstarter backers) identified four brightness dips. These were named Elsie, Celeste, Skara Brae, and Angkor. Earlier this year two more dips were spotted and dubbed Caral-Supe and Evangeline.

"Our observations show that the dips that come and go over a few weeks are produced by dust," Bodman said. Dust is likely also the cause of the more gradual changes in brightness, but there's an important difference between the two kinds of dust.

"These new dips were observed at multiple wavelengths and clearly showed deeper dips at blue wavelengths than in red and in the near infrared," Bodman noted. "Larger depths at shorter, bluer wavelengths indicates small-grain dust."

The light curve for Tabby's Star in 2017 displays two kinds of changes in apparent brightness. The highlighted and named parts show brief drops in brightness. But there is also a more gradual change (black line) where the brightness slowly decreases and then returns. Even though these both happen at the same time, the different kinds of brightness changes are caused by different kinds of dust. Credit: Eva Bodman/ASU

That suggests that whatever process is creating these dust particles is going on currently.

As Bodman explained, "The dust is very small — like smoke particles from a campfire — and that means it was created recently. Particles that small get blown out of a star's vicinity in a year or so, driven away by the pressure of starlight."

On the other hand, the dust causing the more gradual brightness changes has a different spectrum which points to larger grains and probably a different origin. However, as with the small dust grains, astronomers are not sure what is producing it.

In the same scientific session as Bodman's presentation was one by two high-school students from the Thacher School in Ojai, California. Their data were collected independently, yet were consistent with the results Bodman found.  

So where do these details leave astronomers' picture of Tabby's Star?

"This all suggests that the dust cloud obscuring the star is extremely complex along our line of sight to it," Bodman said. "We're seeing different parts of the dust cloud as they drift in front of the star.

"We need more observations to explain how the dust is being produced and to develop a clear astrophysical picture of what's happening at Tabby's Star."

Stay tuned.

Robert Burnham

Science writer, School of Earth and Space Exploration