Benchmarking the power of amateur observatories for TTV exoplanets detection

We perform an analysis of ~80 000 photometric measurements for the following 10 stars hosting transiting planets:WASP-2, -4, -5, -52, Kelt-1, CoRoT-2, XO-2, TrES-1, HD 189733, GJ 436. Our analysis includes mainly transit light curves from the Exoplanet Transit Database, public photometry from the literature, and some proprietary photometry privately supplied by other authors. Half of these light curves were obtained by amateurs. From this photometry we derive 306 transit timing measurements, as well as improved planetary transit parameters. Additionally, for 6 of these 10 stars we present a set of radial velocity measurements obtained from the spectra stored in the HARPS, HARPS-N and SOPHIE archives using the HARPS- TERRA pipeline. Our analysis of these transit timing and radial velocity data did not reveal significant hints of additional orbiting bodies in almost all of the cases. In the WASP-4 case, we found hints of marginally significant TTV signals having amplitude 10-20 s, although their parameters are model dependent and uncertain, while radial velocities did not reveal statistically significant Doppler signals.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

Determination of themean orbit for meteoroid streams

В данной работе представлен математический аппарат вычисления средней орбиты семейства тел с помощью метрик Холшевникова. На его основе разработан программный комплекс для исследования эволюции метеорных потоков. Для примера проведено исследование метеорного потока Геминиды, который на сегодняшний день является одним из самых интенсивных. Результаты для выборок разных годов демонстрируют одинаковые результаты, при том что выборки не пересекаются. Помимо прочего удалось оценить возраст потока Геминиды.This paper presents a mathematical apparatus for calculating the average orbit of a family of bodies using Kholshevnikov metrics. Based on it, a software package has been developed for studying the evolution of meteor showers. As an example, a study was conducted of the Geminid meteor shower, which is one of the most intense today. The results for samples from different years show the same results, despite the fact that the samples do not overlap. Among other things, we calculated the age of the Geminids stream

Benchmarking the power of amateur observatories for TTV exoplanets detection

This document is the Accepted Manuscript version of the following article: Roman v. Baluev, et al, ‘Benchmarking the power of amateur observatories for TTV exoplanets detection’, Monthly Notices of the Royal Astronomical Society, Vol. 450(3): 3101-3113, first published online 9 May 2015. The version of record is available at doi: https://doi.org/10.1093/mnras/stv788 © 2015 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.We perform an analysis of ~80000 photometric measurements for the following 10 stars hosting transiting planets: WASP-2, -4, -5, -52, Kelt-1, CoRoT-2, XO-2, TrES-1, HD 189733, GJ 436. Our analysis includes mainly transit lightcurves from the Exoplanet Transit Database, public photometry from the literature, and some proprietary photometry privately supplied by other authors. Half of these lightcurves were obtained by amateurs. From this photometry we derive 306 transit timing measurements, as well as improved planetary transit parameters. Additionally, for 6 of these 10 stars we present a set of radial velocity measurements obtained from the spectra stored in the HARPS, HARPS-N, and SOPHIE archives using the HARPS-TERRA pipeline. Our analysis of these TTV and RV data did not reveal significant hints of additional orbiting bodies in almost all of the cases. In the WASP-4 case, we found hints of marginally significant TTV signals having amplitude 10-20 sec, although their parameters are model-dependent and uncertain, while radial velocities did not reveal statistically significant Doppler signals.Peer reviewe

Homogeneously derived transit timings for 17 exoplanets and reassessed TTV trends for WASP-12 and WASP-4

We homogeneously analyse ∼3.2 × 105 photometric measurements for ∼1100 transit lightcurves belonging to 17 exoplanet hosts. The photometric data cover 16 years 2004–2019 and include amateur and professional observations. Old archival lightcurves were reprocessed using up-to-date exoplanetary parameters and empirically debiased limb-darkening models. We also derive self-consistent transit and radial-velocity fits for 13 targets. We confirm the nonlinear TTV trend in the WASP-12 data at a high significance, and with a consistent magnitude. However, Doppler data reveal hints of a radial acceleration about ( − 7.5 ± 2.2) m/s/yr, indicating the presence of unseen distant companions, and suggesting that roughly 10 per cent of the observed TTV was induced via the light-travel (or Roemer) effect. For WASP-4, a similar TTV trend suspected after the recent TESS observations appears controversial and model-dependent. It is not supported by our homogeneus TTV sample, including 10 ground-based EXPANSION lightcurves obtained in 2018 simultaneously with TESS. Even if the TTV trend itself does exist in WASP-4, its magnitude and tidal nature are uncertain. Doppler data cannot entirely rule out the Roemer effect induced by possible distant companions

Benchmarking the power of amateur observatories for TTV exoplanets detection

We perform an analysis of ~80 000 photometric measurements for the following 10 stars hosting transiting planets:WASP-2, -4, -5, -52, Kelt-1, CoRoT-2, XO-2, TrES-1, HD 189733, GJ 436. Our analysis includes mainly transit light curves from the Exoplanet Transit Database, public photometry from the literature, and some proprietary photometry privately supplied by other authors. Half of these light curves were obtained by amateurs. From this photometry we derive 306 transit timing measurements, as well as improved planetary transit parameters. Additionally, for 6 of these 10 stars we present a set of radial velocity measurements obtained from the spectra stored in the HARPS, HARPS-N and SOPHIE archives using the HARPS- TERRA pipeline. Our analysis of these transit timing and radial velocity data did not reveal significant hints of additional orbiting bodies in almost all of the cases. In the WASP-4 case, we found hints of marginally significant TTV signals having amplitude 10-20 s, although their parameters are model dependent and uncertain, while radial velocities did not reveal statistically significant Doppler signals.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

Collocation integrator based on Legendre polynomials

This paper presents the implementation of a collocation integrator for system of first-order ordinary differential equations. At each step, we construct the interpolation polynomial represented by a linear combination of the Legendre polynomials. Such a representation allows us to make an effective algorithm for calculating the coefficients of the interpolation polynomial and the result of integration at each step. The accuracy of the integrator is determined by the set of intermediate nodes selected to construct the interpolation polynomial.В данной работе представлена реализация коллокационного интегратора для систем обыкновенных дифференциальных уравнений первого порядка. На каждом шаге строится интерполяционный полином, который представляется линейной комбинацией по полиномам Лежандра. Такое представление позволяет построить эффективный алгоритм вычисления коэффициентов интерполяционного полинома и результата интегрирования на каждом шаге. Точность интегратора определяется набором промежуточных узлов, выбираемых для построения интерполяционного полинома.Работа выполнена при поддержке гранта РНФ 19-72-10023

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