Astrophysicist contributes to discovery on birth of stars

NEW HAVEN — In astrophysics, collision can create new life.

Dana Casetti, an adjunct faculty member at Southern Connecticut State University and research scientist at Yale University, was part of a team of researchers that used NASA’s Hubble Telescope and made a discovery that could potentially lead to more knowledge about star birth.

In March, NASA announced that the team appeared to have solved a mystery regarding two satellite dwarf galaxies — the Large Magellanic Cloud and the Small Magellanic Cloud — that share an “arm” of gas between them directing the tug-of-war nature of their orbit. The team used ultraviolet light to conclude that the composition of the arm resembles the Small Magellanic Cloud.

Casetti said young stars at the edge of the Milky Way Galaxy, caused by a collision between the two

clouds and the disk of the Milky Way, create an opportunity to learn more about star birth as the researchers apply their discovery to knowledge of how gas enters galaxies.

“If you don’t understand stars, you have incorrect inferences about the planets around them,” she said. “From here on, we (will) better understand applications

for cosmology.”

In June, Casetti lectured about astrophysics at the Vatican.

Casetti was selected as one of four lecturers on the topic of “Stellar Variability in the Era of Large Surveys” at the Vatican Observatory Summer School, a highly selective, prestigious, global program for doctoral students, postdoctoral researchers and accomplished astrophysics undergraduates.

“Stellar variability is

anything from a star’s brightness to its motion,” she said. “You can learn a tremendous amount from how stars vary, their ages, their dynamics and their distances scales.”

Casetti said she would consider the beginning of the “large survey” era in astrophysics to be earlier this decade, roughly correlating with the launch of the Gaia spacecraft in 2013. Gaia’s second data release occurred in April, and constitutes almost two years of observations on more than 1 billion stars.

Now that astrophysics is in the large survey era, Casetti said there are still many questions remaining to answer.

While at Yale, where she earned her doctorate in 1998, she recalls discussions surrounding dark matter and the belief that discoveries about its composition were imminent.

“Twenty years later and we still don’t know what it is,” she said.

Peter Hvizdak / Hearst Connecticut Media Southern Connecticut State University and Yale astrophysicist Dana Casetti was part of a research team whose discovery could lead to greater knowledge of how stars are born.