starrotate is a tool for measuring stellar rotation periods using Lomb-Scargle (LS) periodograms, autocorrelation functions (ACFs) and Gaussian processes (GPs). It uses the astropy implementation of Lomb-Scargle periodograms, and the exoplanet implementation of fast celerite Gaussian processes.

starrotate is compatible with any light curve with time, flux and flux uncertainty measurements, including Kepler, K2 and TESS light curves. If your light curve is has evenly-spaced (or close to evenly-spaced) observations, all three of these methods: LS periodograms, ACFs and GPs will be applicable. For unevenly spaced light curves like those from the Gaia, or ground-based observatories, LS periodograms and GPs are preferable to ACFs.

Example usage

import starrotate as sr

rotate = sr.RotationModel(time, flux, flux_err)
lomb_scargle_period = rotate.LS_rotation()
acf_period = rotate.ACF_rotation()
gp_period = rotate.GP_rotation()

License & attribution

Copyright 2018, Ruth Angus.

The source code is made available under the terms of the MIT license.

If you make use of this code, please cite this package and its dependencies. You can find more information about how and what to cite in the citation documentation.