Don't Twinkle, Little Star: How a Laser-Shooting Robot is Taming the Atmosphere and Bringing Space-based Astronomy to Earth
Like an art historian studying the Sistine Chapel from the bottom of a swimming pool, an Earth-bound astronomer's view of the cosmos is blurred and distorted by our turbulent atmosphere. In recent decades, however, a technique called adaptive optics has begun to correct our telescopes' vision: by introducing a small mirror whose surface can deform, adaptive optics systems restore the shape of a mangled light beam to nearly space-based perfection. For astronomical objects that are too dim for the calculation of the correct deformable mirror shape, powerful lasers are shot into the sky to act as artificial reference sources. Today, adaptive optics systems have been installed on most of the world's largest telescopes, but among their drawbacks are: 1) the time needed to set up new adaptive optics observations drastically reduces the amount of time available for taking science data, and 2) they are only employed for a fraction of the time on a fraction of the world's telescopes.
Robo-AO is a robotic adaptive optics system that was designed to overcome these drawbacks, enabling observations of 250+ targets per night at high resolution. By automating each step of the adaptive process and employing a low-maintenance ultraviolet laser, Robo-AO reduces the ``startup time" between scientific observations from 5-20 minutes (typical of previous adaptive optics systems) to less than two minutes. In 2015, our group installed Robo-AO at the 2.1-m telescope on Kitt Peak, Arizona, where it's now observing every clear night -- the first full-time adaptive optics observatory. In the months since commissioning, I have used Robo-AO to newly resolve dozens of binary stars in the Pleiades, a familiar winter-time star cluster whose youth and proximity make for a natural star formation laboratory. These observations are opening the door to long-standing questions in stellar and planetary astrophysics, including the influence of a binary companion on a planet-forming disk.
Rebecca Jensen-Clem presenting.
Refreshments available prior to the lecture.
The Everhart Lecture Series is a forum encouraging interdisciplinary interaction among graduate students and faculty, the sharing of ideas about research developments, as well as a space to discuss controversies. Everhart Lectures allow for the recognition of individual Caltech student's exemplary presentation and research abilities. Lecturers discuss scientific topics and research topics of concern to graduate students and faculty.
Each Fall, graduate student lecturers are selected to present their ideas as part of a series of lectures.