Eight exoplanet candidates in SAO survey

Here we present eight new candidates for exoplanets detected by the transit method at the Special Astrophysical Observatory of the Russian Academy of Sciences. Photometric observations were performed with a 50-cm robotic telescope during the second half of 2020. We detected transits with depths of $\Delta m = 0.056-0.173^m$ and periods $P = 18.8^h-8.3^d$ in the light curves of stars with magnitudes of $m = 14.3-18.8^m$. All considered stars are classified as dwarfs with radii of $R_* = 0.4-0.6 R_{sun}$ (with the uncertainty for one star up to $1.1 R_{sun}$). We estimated the candidate radii (all are greater than 1.4 times the Jovian radius), semi-major axes of their orbits ($0.012-0.035 AU$), and other orbital parameters by modelling. We report the light curves with transits for two stars obtained in 2022 based on individual observations.Comment: 16 pages, 14 figures, 3 table

Massive search of spot- and facula-crossing events in 1598 exoplanetary transit lightcurves

We developed a dedicated statistical test for a massive detection of spot- A nd facula-crossing anomalies in multiple exoplanetary transit light curves, based on the frequentist p-value thresholding. This test was used to augment our algorithmic pipeline for transit light curves analysis. It was applied to 1598 amateur and professional transit observations of 26 targets being monitored in the EXPANSION project. We detected 109 statistically significant candidate events revealing a roughly 2 : 1 asymmetry in favor of spots-crossings over faculae-crossings. Although some candidate anomalies likely appear non-physical and originate from systematic errors, such asymmetry between negative and positive events should indicate a physical difference between the frequency of star spots and faculae. Detected spot-crossing events also reveal positive correlation between their amplitude and width, possibly due to spot size correlation. However, the frequency of all detectable crossing events appears just about a few per cent, so they cannot explain excessive transit timing noise observed for several targets.Fil: Baluev, R. V.. Saint Petersburg State University; RusiaFil: Sokov, E. N.. Saint Petersburg State University; Rusia. Russian Academy of Sciences. Central Astronomical Observatory at Pulkovo; RusiaFil: Sokova, I. A.. Saint Petersburg State University; Rusia. Russian Academy of Sciences. Central Astronomical Observatory at Pulkovo; RusiaFil: Shaidulin, V. Sh.. Saint Petersburg State University; RusiaFil: Veselova, A. V.. Saint Petersburg State University; RusiaFil: Aitov, V. N.. Russian Academy of Sciences. Special Astrophysical Observatory; RusiaFil: Mitiani, G. Sh.. Russian Academy of Sciences. Special Astrophysical Observatory; RusiaFil: Valeev, A. F.. Russian Academy of Sciences. Special Astrophysical Observatory; Rusia. Russian Academy of Sciences. Crimean Astrophysical Observatory; RusiaFil: Gadelshin, D.R.. Russian Academy of Sciences. Special Astrophysical Observatory; RusiaFil: Gutaev, A. G.. Russian Academy of Sciences. Special Astrophysical Observatory; Rusia. KazanFederal University (Volga Region); RusiaFil: Beskin, G.M.. Russian Academy of Sciences. Special Astrophysical Observatory; Rusia. KazanFederal University (Volga Region); RusiaFil: Valyavin, G. G.. Russian Academy of Sciences. Special Astrophysical Observatory; Rusia. Russian Academy of Sciences. Crimean Astrophysical Observatory; Rusia. Saint Petersburg State University; RusiaFil: Antonyuk, K.. Russian Academy of Sciences. Crimean Astrophysical Observatory; RusiaFil: Barkaoui, K.. Université de Liège; Bélgica. Cadi Ayyad University; MarruecosFil: Gillon, M.. Université de Liège; BélgicaFil: Jehin, E.. Université de Liège; BélgicaFil: Delrez, L.. Université de Liège; BélgicaFil: Gumundsson, S.. Nes Observatory; IslandiaFil: Dale, H. A.. University of Emory; Estados UnidosFil: Fernandez Lajus, Eduardo Eusebio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Di Sisto, Romina Paula. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Astrofísica La Plata. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas. Instituto de Astrofísica La Plata; ArgentinaFil: Bretton, M.. Baronnies Provençales Observatory; FranciaFil: Wunsche, A.. Baronnies Provençales Observatory; FranciaFil: Hentunen, V. P.. Taurus Hill Observatory; FinlandiaFil: Shadick, S.. University of Saskatchewan; CanadáFil: Jongen, Y.. Observatoire de Vaison la Romaine; FranciaFil: Kang, W.. National Youth Space Center; Corea del SurFil: Kim, T.. National Youth Space Center; Corea del Sur. Chungbuk National University; Corea del SurFil: Pakštienė, E.. Vilnius University; LituaniaFil: Qvam, J. K. T.. Horten Videregående Skole; Norueg

Massive Search for Spot- and Facula-Crossing Events in 1598 Exoplanetary Transit Light Curves

We developed a dedicated statistical test for a massive detection of spot- and facula-crossing anomalies in multiple exoplanetary transit light curves, based on the frequentist p-value thresholding. This test was used to augment our algorithmic pipeline for transit light curves analysis. It was applied to 1598 amateur and professional transit observations of 26 targets being monitored in the EXPANSION project. We detected 109 statistically significant candidate events revealing a roughly 2:1 asymmetry in favor of spots-crossings over faculae-crossings. Although some candidate anomalies likely appear non-physical and originate from systematic errors, such asymmetry between negative and positive events should indicate a physical difference between the frequency of star spots and faculae. Detected spot-crossing events also reveal positive correlation between their amplitude and width, possibly due to spot size correlation. However, the frequency of all detectable crossing events appears just about a few per cent, so they cannot explain excessive transit timing noise observed for several targets