March 1, 2022
Speaker: Suvrath Mahadevan (in-person)
Contact Information: suvrath@astro.psu.edu
Title: Pathways to Earth-Mass Planets with Precision Spectroscopy
Abstract: Modern astronomical spectrometers are approaching the exquisite sensitivity to detect the signature of an Earth-mass planet around stars like the Sun. I shall discuss the challenges involved in making these difficult measurements with the Doppler radial velocity technique, and the evolution of the design of these instruments as they seek ever-tighter control of environmental parameters, and increased measurement precision. A suite of new technologies like frequency stabilized laser combs, low drift etalons, and deeper understanding of the detectors is enabling a new level of precision in radial velocity measurements - as well as illustrating new challenges. I will use two such instruments we have built to illustrate some of the underlying physics and measurement challenges. I will then discuss how the stars themselves are the remaining challenge, as magnetically driven processes create ‘stellar activity’ noise that can masquerade as planets and obfuscate their detection. I shall highlight a few paths we are exploring to mitigate this – using our star, the Sun, as a guide, and discuss whether the goal of discovering and characterizing terrestrial mass planets capable of hosting liquid water on their surfaces is now within reach.
Visitor's room: 125
Visit Schedule:
Tuesday (1 Mar. 2022):
9:00 a.m.: Chris Spalding (Peyton 128)
9:30 a.m.:
10:00 a.m.: Michael Strauss (113)
10:30 a.m.: Preparation for the Colloquium
11:00 a.m.: Colloquium
12:30 p.m.: Bahcall Lunch
2:00 p.m.: Tansu Daylan (125)
2:30 p.m.: Samuel Yee (017 -- basement)
3:00 p.m.: Grad Students/Grad Tea (033)
3:30 p.m.: Grad Students /Grad Tea (033)
4:00 p.m.: Dan Tamayo (110)
4:30 p.m.: Robert Lupton
5:00 p.m.: Allison Strom (125)
5:30 p.m.: Sarah Millholland (125)
6:00 p.m.: DINNER - meet in Grand Central
Dinner Sign-up - add your name here:
Suvrath Mahadevan
Faculty host: Robert Lupton
Postdoc host: Guðmundur Stefánsson [unfortunately can not join dinner tonight, so someone can take my spot]
Sam Yee
Tansu Daylan
Gaspar Bakos
Sarah Millholland (but happy to give the spot to a student)
Nadia Zakamska
PLEASE NO MORE THAN 8 PEOPLE (it is more difficult to properly interact with the speaker with larger groups). STUDENTS HAVE PRIORITY.