Weekly Colloquium

Most weeks during the semester, we host a scholar for a one-day visit. The visit culminates with a public talk on a topic of contemporary physics or astronomy. Students are welcome to these talks, and seniors are required to attend at least nine over the course of a year. Near the end of each semester, honors thesis students give public lectures on their work.  We gather before the talks for tea, coffee, and cookies at 3:45, Ground Lobby of Science Center followed by the talk at 4:00 pm in A011.

Our Astronomy program is part of the Five College Astronomy Department, which hosts its own colloquium series Thursdays at 3:45 pm at UMass in LGRT 1033. 

  • If you would like to be mailed seminar announcements, please send an email to physics@amherst.edu.
  • Contact colloquium organizer Alice Simmoneau (asimmoneau@amherst.edu) with any questions about colloquia.

Tuesday, March 3, 2020

Tue, Mar 3, 2020

Daniella Bardalez Gagliuffi, American Museum of Natural History: “Identifying Observational Signatures of Brown Dwarf and Giant Planet Formation”

Brown dwarfs are the critical link between the products of stellar and planetary formation pathways; hence, their population properties and compositions can inform on the likelihood of either formation history. In particular, multiplicity is a direct outcome of formation, yet it is challenging to measure it in a consistent way, since each binary detection technique is sensitive to a different range of separations and mass ratios.

In this talk, I will present results from a volume-limited spectroscopic sample, including a new binary fraction straddling the hydrogen-burning minimum mass, which separates stars from brown dwarfs. I will discuss future directions for a comprehensive characterization of both the statistical distributions of the population of multiple systems and the fundamental properties of their individual components as a function of age. These are crucial steps to identify spectroscopic signatures of formation.