Stellar Cartography

Singular Spectrum Analysis of Exoplanetary Transits

By Keith Cowing
Status Report
April 9, 2024
Filed under , , , , , , ,
Singular Spectrum Analysis of Exoplanetary Transits
Figure (a) and (c) show the initial light curve and the river plot for TOI-4622, respectively. The light curve is folded over seven transits and the river plot shows the evolution of the noisy periodic transit signals over the course of the entire light curve. Figure (b) and (d) show the denoised versions of these plots after the implementation of SSA. The SNR of the transit has increased from 13.37 to 15.59. — astro-ph.EP

Transit photometry is currently the most efficient and sensitive method for detecting extrasolar planets (exoplanets) and a large majority of confirmed exoplanets have been detected with this method.

The substantial success of space-based missions such as NASA’s Kepler/K2 and Transiting Exoplanet Survey Satellite (TESS) has generated a large and diverse sample of confirmed and candidate exoplanets. Singular Spectrum Analysis (SSA) provides a useful tool for studying photometric time series and exoplanetary transits.

SSA is a technique for decomposing a time series into a sum of its main components, where each component is a separate time series that incorporates specific information from the behavior of the initial time series. SSA can be implemented for extracting important information (such as main trends and signals) from the photometry data or reducing the noise factors.

The detectability and accurate characterization of an exoplanetary transit signal is principally determined by its signal-to-noise ratio (SNR). Stellar variability of the host star, small planet to star radius ratio, background noises from other sources in the field of observations and instrumental noise can cause lower SNRs and consequently, more complexities or inaccuracies in the modeling of the transit signals, which in turn leads to the inaccurate inference of the astrophysical parameters of the planetary object.

Therefore, implementing SSA leads to a more accurate characterization of exoplanetary transits and is also capable of detecting transits with low SNRs (SNR<10). In this paper, after discussing the principles and properties of SSA, we investigate its applications for studying photometric transit data and detecting low SNR exoplanet candidates.

Hossein Fatheddin, Sedighe Sajadian

Comments: 11 pages, 5 figures
Subjects: Earth and Planetary Astrophysics (astro-ph.EP); Instrumentation and Methods for Astrophysics (astro-ph.IM)
Cite as: arXiv:2404.05323 [astro-ph.EP] (or arXiv:2404.05323v1 [astro-ph.EP] for this version)
Focus to learn more
Submission history
From: Sedighe Sajadian
[v1] Mon, 8 Apr 2024 09:13:08 UTC (10,067 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) πŸ––πŸ»