PI: Arpita Roy, aroy@stsci.edu
Website: https://arpita.space/
Grad Student Project Duration: 2 years of funding available (with potential for thesis project)
Project Abstract: In the overarching quest for habitable worlds, the field of radial velocity (RV) exoplanet detection stands at a highly potent juncture as a new generation of “extreme precision” planet hunting spectrographs is deployed. Once these sophisticated systems are able to overcome prior instrumental limits, astrophysical noise or ‘jitter’ caused by stellar magnetic activity will become the fundamental obstacle to the detection of small planetary signatures. This research project will use NASA and NSF's flagship Doppler RV instrument, NEID, to study the Sun as our best target for detailed activity characterization. The PI is part of the NEID team, as well as several other extreme precision radial velocity (EPRV) instruments — therefore, this project will also involve collaboration across some of the leading exoplanet research groups as we combine resources towards a common goal.
Figure 1: First light at NEID, looking at the star 51 Peg in memory of the first exoplanet discovery. This image shows high-resolution spectra across the large wavelength range of NEID, which will help us disentangle chromatic stellar activity from "colorless" bulk motion of the star caused by the presence of a planet. We also see the simultaneous wavelength calibration provided by the cutting edge technology of a laser frequency comb. Image from NEID team, part of press releases made by NOIRLab, and NASA JPL.
Figure 2: NEID observations of the sun as a star. (Left) Simultaneous image of the sun showing quiescent phase. (Right) NEID radial velocity observations while still in the laboratory, showing excellent precision over short timescales. Analysis by PI, as part of NEID Pre-Ship Review.
Student work: The student will systematically classify the NEID solar spectra into regions that are sensitive and insensitive to magnetic activity. We will then further scrutinize the sensitive regions to understand the exact line profile perturbations caused by different kinds of activity. This will enable the development of a new kind of line-profile based activity indicators that we will define against canonical activity diagnostics such as the Ca H&K lines. Finally, the student will use this knowledge to improve the NEID radial velocity pipeline, and lead/contribute to multiple publications along the way. The student will also have the opportunity to travel to Kitt Peak Observatory in Arizona to see NEID in operation and gain on-site experience, and to Pasadena to work closely with collaborators at Caltech and NASA JPL. Previous experience with exoplanets or spectroscopy is a bonus but not a prerequisite — however, a successful student will start the project with some fluency in Python.
