Koen, C.2021-02-082021-02-082020Koen, C. (2020). Properties of CVSO 30 from TESS measurements: probably a binary T Tauri star with complex light curves and no obvious planets. Monthly Notices of the Royal Astronomical Society, 494(3), 4349–43561365-2966https://doi.org/10.1093/mnras/staa1038http://hdl.handle.net/10566/5866‘Transiting Exoplanet Survey Satellite’ (TESS) photometry of CVSO 30 spanned 21.8 d, with a single large gap of 1.1 d. This allows alias-free determination of the two periodicities in the data. It is confirmed that both of these are non-sinusoidal: the dominant P1 = 0.4990 d has two detectable harmonics and P2 = 0.4486 d has seven. The large number of harmonics in the second periodicity characterizes a very complex light curve shape. One of the features in the light curve is a sharp dip of duration ∼2 h: this is probably the source of the previously claimed planetary transit signature. The star is a member of a small group of T Tauri stars with complex light curves, which have recently been exhaustively studied using Kepler and TESS observations. The two non-commensurate periods are most simply interpreted as being from two stars, i.e. CVSO 30 is probably a binary.enStars: individual: CVSO 30Stars: variables: T Tauri 1 INTRODUCTIONStellar rotation periodSinusoidalArticle