Imaging & Spectroscopy

nuance: Efficient Detection Of Planets Transiting Active Stars

By Keith Cowing
Status Report
February 14, 2024
Filed under , , , , , ,
nuance: Efficient Detection Of Planets Transiting Active Stars
Rate of true positives for the 4000 simulated light curves. The color scale represents the fraction of true positives, white if all injected transits are recovered in a given portion of the (τ, δ) parameter space, black if none are recovered. — astro-ph.EP

The detection of planetary transits in the light curves of active stars, featuring correlated noise in the form of stellar variability, remains a challenge. Depending on the noise characteristics, we show that the traditional technique that consists of detrending a light curve before searching for transits alters their signal-to-noise ratio, and hinders our capability to discover exoplanets transiting rapidly-rotating active stars.

We present nuance, an algorithm to search for transits in light curves while simultaneously accounting for the presence of correlated noise, such as stellar variability and instrumental signals. We assess the performance of nuance on simulated light curves as well as on the TESS light curves of 438 rapidly-rotating M dwarfs.

For each dataset, we compare our method to 5 commonly-used detrending techniques followed by a search with the Box-Least-Square algorithm. Overall, we demonstrate that nuance is the most performant method in 93% of cases, leading to both the highest number of true positives and the lowest number of false positive detections.

Although simultaneously searching for transits while modeling correlated noise is expected to be computationally expensive, we make our algorithm tractable and available as the JAX-powered Python package nuance, allowing its use on distributed environments and GPU devices.

Finally, we explore the prospects offered by the nuance formalism, and its use to advance our knowledge of planetary systems around active stars, both using space-based surveys and sparse ground-based observations.

Lionel Garcia, Daniel Foreman-Mackey, Catriona A. Murray, Suzanne Aigrain, Dax L. Feliz, Francisco J. Pozuelos

Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2402.06835 [astro-ph.EP] (or arXiv:2402.06835v1 [astro-ph.EP] for this version)
Submission history
From: Lionel Garcia
[v1] Fri, 9 Feb 2024 23:45:35 UTC (1,962 KB)

Explorers Club Fellow, ex-NASA Space Station Payload manager/space biologist, Away Teams, Journalist, Lapsed climber, Synaesthete, Na’Vi-Jedi-Freman-Buddhist-mix, ASL, Devon Island and Everest Base Camp veteran, (he/him) 🖖🏻