Hello world! Welcome to the documentation for orbitize, a Python package for fitting orbits of directly imaged planets.

orbitize packages two back-end algorithms into a consistent API. It’s written to be fast, extensible, and easy-to-use. The tutorials below will walk you through the code and introduce some technical stuff, but we suggest learning about the Orbits for the Impatient (OFTI) algorithm and MCMC algorithms (we use this one) before diving in. Our contributor guidelines document will point you to more useful resources.

orbitize is designed to meet the needs of the exoplanet imaging community, and we encourage community involvement. If you find a bug, want to request a feature, etc. please create an issue on GitHub.

orbitize is patterned after and inspired by radvel.



orbitize is under active development, and we’ve still got a lot to do! To get involved, check out our contributor guidelines, look over our issues list, and/or reach out to Sarah. We’d love to have you on our team!

Some major planned updates:

  • fit orbits of multiple objects in one system

  • fit Gaia astrometry & RVs

  • marginalize over instrumental uncertainties


1.11.1 (2020-6-11)

  • Fixed a string formatting bug causing corner plots to fail for RV+astrometry fits

1.11.0 (2020-4-14)

  • Multiplanet support!

  • Changes to directory structure of sample data files

  • Fixed a bug that was causing corner plots to fail on loaded results objects

1.10.0 (2020-3-6)

  • Joint RV + relative astrometry fitting capabilities!

  • New tutorial added

1.9.0 (2020-1-24)

  • Require astropy>=4

  • Minor documentation upgrades

  • This is the first Python 2 noncompliant version

1.8.0 (2020-1-24)

  • Bugfixes related to numpy and astropy upgrades

  • This is the last version that will support Python 2

1.7.0 (2019-11-10)

  • Default corner plots now display angles in degrees instead of radians

  • Add a keyword for plotting orbits that cross PA=360

1.6.0 (2019-10-1)

  • Mikkola solver now implemented in C-Kepler solver

  • Fixed a bug with parallel processing for OFTI

  • Added orbit vizualisation jupyter nb show-me-the-orbit to docs/tutorials

  • New methods for viewing/chopping MCMC chains

  • Require emcee<3 for now

1.5.0 (2019-9-9)

  • Parallel processing for OFTI.

  • Fixed a bug converting errors in RA/Dec to sep/PA in OFTI.

  • OFTI and MCMC now both return likelihood, whereas before one returned posterior.

  • Updated logic for restricting Omega and omega bounds.

1.4.0 (2019-7-15)

  • API change to lay the groundwork for dynamical mass calculation.

  • JeffreysPrior -> LogUniformPrior

  • New tutorials.

  • Added some informative error messages for input tables.

  • Bugfixes.

1.3.1 (2019-6-19)

  • Bugfix for RA/Dec inputs to the OFTI sampler (Issue #108).

1.3.0 (2019-6-4)

  • Add ability to customize date of tau definition.

  • Sampler now saves choice of tau reference with results.

  • Default tau value is now Jan 1, 2020.

  • Small bugfixes.

1.2.0 (2019-3-21)

  • Remove unnecessary astropy date warnings.

  • Add custom likelihood function.

  • Add progress bar for ptemcee sampler.

  • Add customizable color axis for orbit plots.

  • Small bugfixes.

1.1.0 (2019-1-6)

  • Add sep/PA panels to orbit plot.

  • GaussianPrior now operates on only positive numbers by default.

1.0.2 (2018-12-4)

  • Expand input reading functionality.

  • Bugfixes for MCMC.

1.0.1 (2018-11-20)

  • Bugfix for building on CentOS machines.

1.0.0 (2018-10-30)

  • Initial release.