Identifying False Positive Signals in Exoplanet Searches
A recent paper titled "A false positive transit candidate for EPIC 211101996 from K2 and TESS data identified as background eclipsing binary Gaia DR3 66767847894609792" by René Heller, Milena Hüschen, Jan-Vincent Harre, and Stefan Dreizler discusses the identification of a false positive signal in the search for transiting exoplanets. The study focuses on EPIC 211101996, a cool M dwarf star located in the Pleiades open cluster, which is estimated to be around 100 million years old.
The researchers initially detected a transit-like signal in the K2 light curve of this star. However, upon further analysis using the Wōtan software for detrending and the Transit Least Squares algorithm for transit searching, they concluded that the signal originated from a background eclipsing binary, specifically Gaia DR3 66767847894609792, which is situated approximately 20 arcseconds west of the target star.
The light curve of the contaminant displayed a V-like shape with an eclipse depth of about 15%, indicating it is a grazing eclipsing binary. This finding is significant as it highlights the challenges in detecting transiting planets around young stars, where stellar activity can complicate observations. The paper emphasizes the importance of careful analysis to avoid misidentifying signals that may lead to incorrect conclusions about the presence of exoplanets.
This research contributes to the broader understanding of exoplanet detection methods and the complexities involved when observing young stellar environments. The findings underscore the necessity for rigorous data analysis techniques in astrophysics, particularly in the context of distinguishing between genuine planetary transits and false signals caused by other celestial phenomena.
The paper can be cited as follows: Heller, R., Hüschen, M., Harre, J., & Dreizler, S. (2024). A false positive transit candidate for EPIC 211101996 from K2 and TESS data identified as background eclipsing binary Gaia DR3 66767847894609792. arXiv:2408.16797.