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Gemini Planet Imager observational calibrations V: astrometry and distortion

Konopacky, Quinn M. and Hinkley, Sasha (2014) Gemini Planet Imager observational calibrations V: astrometry and distortion. In: Ground-based and Airborne Instrumentation for Astronomy V. Proceedings of SPIE. No.9147. Society of Photo-Optical Instrumentation Engineers , Bellingham, WA, Art. No. 914784. ISBN 978-0-8194-9615-7.

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We present the results of both laboratory and on sky astrometric characterization of the Gemini Planet Imager (GPI). This characterization includes measurement of the pixel scale* of the integral field spectrograph (IFS), the position of the detector with respect to north, and optical distortion. Two of these three quantities (pixel scale and distortion) were measured in the laboratory using two transparent grids of spots, one with a square pattern and the other with a random pattern. The pixel scale in the laboratory was also estimate using small movements of the artificial star unit (ASU) in the GPI adaptive optics system. On sky, the pixel scale and the north angle are determined using a number of known binary or multiple systems and Solar System objects, a subsample of which had concurrent measurements at Keck Observatory. Our current estimate of the GPI pixel scale is 14.14 ± 0.01 millarcseconds/pixel, and the north angle is -1.00 ± 0.03°. Distortion is shown to be small, with an average positional residual of 0.26 pixels over the field of view, and is corrected using a 5th order polynomial. We also present results from Monte Carlo simulations of the GPI Exoplanet Survey (GPIES) assuming GPI achieves ~1 milliarcsecond relative astrometric precision. We find that with this precision, we will be able to constrain the eccentricities of all detected planets, and possibly determine the underlying eccentricity distribution of widely separated Jovians.

Item Type:Book Section
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URLURL TypeDescription DOIArticle
Konopacky, Quinn M.0000-0002-9936-6285
Hinkley, Sasha0000-0001-8074-2562
Additional Information:© 2014 SPIE. The Gemini Observatory is operated by the Association of Universities for Research in Astronomy, Inc., under a cooperative agreement with the NSF on behalf of the Gemini partnership: the National Science foundation (United States), the National Research Council (Canada), CONICYT (Chile), the Australian Research Council (Australia), Ministério da Ciência, Tecnologia e Inovação (Brazil), and Ministério de Ciência, Tecnologia e Innovacíon Productiva (Argentina). This publication makes use of data obtained at the W.M. Keck Observatory, which is operated as a scientific partnership among the California Institute of Technology, the University of California and the National Aeronautics and Space Administration. The Observatory was made possible by the generous financial support of the W.M. Keck Foundation. P.K. and J.R.G. thank support from NASA NNX11AD21G, NSF AST-0909188, and the University of California LFRP-118057. Q.M.K is a Dunlap fellow at the Dunlap Institute for Astronomy & Astrophysics, University of Toronto. The Dunlap Institute is funded through an endowment established by the David Dunlap family and the University of Toronto.
Funding AgencyGrant Number
W. M. Keck FoundationUNSPECIFIED
University of CaliforniaLFRP-118057
Dunlap Institute for Astronomy and AstrophysicsUNSPECIFIED
Subject Keywords:Gemini Planet Imager, GPI, distortion, astrometry, calibration, integral field spectroscopy, planetary dynamics, high contrast imaging
Series Name:Proceedings of SPIE
Issue or Number:9147
Record Number:CaltechAUTHORS:20150622-111956472
Persistent URL:
Official Citation:Quinn M. Konopacky ; Sandrine J. Thomas ; Bruce A. Macintosh ; Daren Dillon ; Naru Sadakuni ; Jérôme Maire ; Michael Fitzgerald ; Sasha Hinkley ; Paul Kalas ; Thomas Esposito ; Christian Marois ; Patrick J. Ingraham ; Franck Marchis ; Marshall D. Perrin ; James R. Graham ; Jason J. Wang ; Robert J. De Rosa ; Katie Morzinski ; Laurent Pueyo ; Jeffrey K. Chilcote ; James E. Larkin ; Daniel Fabrycky ; Stephen J. Goodsell ; Ben R. Oppenheimer ; Jenny Patience ; Leslie Saddlemyer ; Anand Sivaramakrishnan; Gemini planet imager observational calibrations V: astrometry and distortion. Proc. SPIE 9147, Ground-based and Airborne Instrumentation for Astronomy V, 914784 (July 28, 2014); doi:10.1117/12.2056646
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:58400
Deposited By: Tony Diaz
Deposited On:22 Jun 2015 20:05
Last Modified:10 Nov 2021 22:04

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