Revised Astrometric Calibration of the Gemini Planet Imager

Authors

• Robert J. De Rosa, European Southern Observatory Santiago
• Meiji M. Nguyen, University of California, Berkeley
• Jeffrey Chilcote, University of Notre Dame
• Bruce MacIntosh, Stanford University
• Marshall D. Perrin, Space Telescope Science Institute
• Quinn Konopacky, Center for Astrophysics & Space Sciences
• Jason J. Wang, California Institute of Technology
• Gaspard Duchêne, University of California, Berkeley
• Eric L. Nielsen, Stanford University
• Julien Rameau, Université Grenoble Alpes
• S. Mark Ammons, European Southern Observatory Santiago
• Vanessa P. Bailey, European Southern Observatory Santiago
• Travis Barman, European Southern Observatory Santiago
• Joanna Bulger, European Southern Observatory Santiago
• Tara Cotten, European Southern Observatory Santiago
• Rene Doyon, Institut de Recherche sur les Exoplanètes
• Thomas M. Esposito, University of California, Berkeley
• Michael P. Fitzgerald, European Southern Observatory Santiago
• Katherine B. Follette, European Southern Observatory Santiago
• Benjamin L. Gerard, European Southern Observatory Santiago
• Stephen J. Goodsell, Stanford University
• James R. Graham, University of California, Berkeley
• Alexandra Z. Greenbaum, Stanford University
• Pascale Hibon, European Southern Observatory Santiago
• Li Wei Hung, Stanford University
• Patrick Ingraham, Stanford University
• Paul Kalas, University of California, Berkeley
• James E. Larkin, European Southern Observatory Santiago
• Jérôme Maire, Center for Astrophysics & Space Sciences
• Franck Marchis, Stanford University
• Mark S. Marley, Stanford University
• Christian Marois, European Southern Observatory Santiago
• Kimberly Ward-Duong, Amherst CollegeFollow
• et al, Various Institutions

Document Type

Article

Publication Date

1-1-2020

Publication Title

Journal of Astronomical Telescopes, Instruments, and Systems

Abstract

We present a revision to the astrometric calibration of the Gemini Planet Imager (GPI), an instrument designed to achieve the high contrast at small angular separations necessary to image substellar and planetary-mass companions around nearby, young stars. We identified several issues with the GPI data reduction pipeline (DRP) that significantly affected the determination of the angle of north in reduced GPI images. As well as introducing a small error in position angle measurements for targets observed at small zenith distances, this error led to a significant error in the previous astrometric calibration that has affected all subsequent astrometric measurements. We present a detailed description of these issues and how they were corrected. We reduced GPI observations of calibration binaries taken periodically since the instrument was commissioned in 2014 using an updated version of the DRP. These measurements were compared to observations obtained with the NIRC2 instrument on Keck II, an instrument with an excellent astrometric calibration, allowing us to derive an updated plate scale and north offset angle for GPI. This revised astrometric calibration should be used to calibrate all measurements obtained with GPI for the purposes of precision astrometry.

Keywords

astrometric calibration, data processing, Gemini Planet Imager, high-contrast imaging

Volume

6

Issue

1

DOI

https://doi.org/10.1117/1.JATIS.6.1.015006

ISSN

23294124

Version

Version of Record

Recommended Citation

De Rosa, Robert J.; Nguyen, Meiji M.; Chilcote, Jeffrey; MacIntosh, Bruce; Perrin, Marshall D.; Konopacky, Quinn; Wang, Jason J.; Duchêne, Gaspard; Nielsen, Eric L.; Rameau, Julien; Ammons, S. Mark; Bailey, Vanessa P.; Barman, Travis; Bulger, Joanna; Cotten, Tara; Doyon, Rene; Esposito, Thomas M.; Fitzgerald, Michael P.; Follette, Katherine B.; Gerard, Benjamin L.; Goodsell, Stephen J.; Graham, James R.; Greenbaum, Alexandra Z.; Hibon, Pascale; Hung, Li Wei; Ingraham, Patrick; Kalas, Paul; Larkin, James E.; Maire, Jérôme; Marchis, Franck; Marley, Mark S.; Marois, Christian; Ward-Duong, Kimberly; and al, et, "Revised Astrometric Calibration of the Gemini Planet Imager" (2020). Astronomy: Faculty Publications, Smith College, Northampton, MA.
https://scholarworks.smith.edu/ast_facpubs/114