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orbitize!: A Comprehensive Orbit-fitting Software Package for the High-contrast Imaging Community

Blunt, Sarah and Wang, Jason and Angelo, Isabel and Ngo, Henry and Cody, Devin and De Rosa, Robert J. and Graham, James R. and Hirsch, Lea and Nagpal, Vighnesh and Nielsen, Eric L. and Pearce, Logan and Rice, Malena and Tejada, Roberto (2020) orbitize!: A Comprehensive Orbit-fitting Software Package for the High-contrast Imaging Community. Astronomical Journal, 159 (3). Art. No. 89. ISSN 1538-3881.

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orbitize! is an open-source, object-oriented software package for fitting the orbits of directly imaged objects. It packages the Orbits for the Impatient (OFTI) algorithm and a parallel-tempered Markov Chain Monte Carlo (MCMC) algorithm into a consistent and intuitive Python API. orbitize! makes it easy to run standard astrometric orbit fits; in less than 10 lines of code, users can read in data, perform one fit using OFTI and another using MCMC, and make two publication-ready figures. Extensive pedagogical tutorials, intended to be navigable by both orbit-fitting novices and seasoned experts, are available on our documentation page. We have designed the orbitize! API to be flexible and easy to use/modify for unique cases. orbitize! was designed by members of the exoplanet imaging community to be a central repository for algorithms, techniques, and know-how developed by this community. We intend for it to continue to expand and change as the field progresses and new techniques are developed, and call for community involvement in this process. Complete and up-to-date documentation is available at, and the source code is available at

Item Type:Article
Related URLs:
URLURL TypeDescription Paper Itemorbitize! ItemCode
Blunt, Sarah0000-0002-3199-2888
Wang, Jason0000-0003-0774-6502
Angelo, Isabel0000-0002-9751-2664
Ngo, Henry0000-0001-5172-4859
De Rosa, Robert J.0000-0002-4918-0247
Hirsch, Lea0000-0001-8058-7443
Nielsen, Eric L.0000-0001-6975-9056
Pearce, Logan0000-0003-3904-7378
Rice, Malena0000-0002-7670-670X
Additional Information:© 2020 The American Astronomical Society. Received 2019 October 1; revised 2019 November 17; accepted 2019 November 18; published 2020 February 5. The authors thank those at academic and telescope facilities whose labor maintains spaces for scientific inquiry, particularly those whose communities are excluded from the academic system. This package was born and developed at the winter 2018 and 2019 AAS Hack Days, and the authors wish to thank the organizers of these events. S.B. would like to thank Logan Cody for superb video editing. The authors would also like to thank Dillon Dong, Jasmine Garani, Melisa Tallis, and Daniel Yahalomi for their time and initial work on orbitize!, and Junellie Gonzalez, Kelly Kosmo O'Neil, Ryan Rubenzahl, and Jean-Baptiste Ruffio for participating in our hackathons and for their anticipated future contributions to orbitize! S.B. would like to thank Andrew Howard, B.J. Fulton, and Erik Petigura for helpful conversations. Finally, we thank the anonymous individual who unknowingly named orbitize! at the 2018 AAS Hack Day.
Funding AgencyGrant Number
NSF Graduate Research FellowshipUNSPECIFIED
Heising-Simons Foundation51 Pegasi b Fellowship
Subject Keywords:Open source software ; Coronographic imaging ; Orbit determination
Issue or Number:3
Classification Code:Unified Astronomy Thesaurus concepts: Open source software (1866); Orbit determination (1175)
Record Number:CaltechAUTHORS:20191120-112746352
Persistent URL:
Official Citation:Sarah Blunt et al 2020 AJ 159 89
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:99958
Deposited By: Tony Diaz
Deposited On:20 Nov 2019 19:35
Last Modified:16 Apr 2020 14:56

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