23 research outputs found
Doppler confirmation of TESS planet candidate TOI1408.01: grazing transit and likely eccentric orbit
We report an independent Doppler confirmation of the TESS planet candidate
orbiting an F-type main sequence star TOI-1408 located 140 pc away. We present
a set of radial velocities obtained with a high-resolution fiber-optic
spectrograph FFOREST mounted at the SAO RAS 6-m telescope (BTA-6). Our
self-consistent analysis of these Doppler data and TESS photometry suggests a
grazing transit such that the planet obscures its host star by only a portion
of the visible disc. Because of this degeneracy, the radius of TOI-1408.01
appears ill-determined with lower limit about 1 R,
significantly larger than in the current TESS solution. We also derive the
planet mass of ~ and the orbital period
days, thus making this object a typical hot Jupiter, but with a significant
orbital eccentricity of . Our solution may suggest the planet is
likely to experience a high tidal eccentricity migration at the stage of
intense orbital rounding, or may indicate possible presence of other unseen
companions in the system, yet to be detected.Comment: 5 pages, 3 figure
Clinical pattern, diagnosis and treatment of flu and ARVI
Flu and ARVI are among the most dangerous infectious diseases recorded in Russia, both in terms of the financial burden and the damage they cause to the health of the population. In outpatient therapeutic practice, incidence of visits related to acute respiratory viral infections is about 6% of all visits, while during the epidemic it increases 8-10 times. Timely diagnosis and adequate therapy could prevent the progression of the disease and its complications
Emergency prevention of tick-borne encephalitis
On the territory of the Russian Federation tick-borne encephalitis (TBE) is registered in over 1.550 administrative districts of 41 regions, territories and autonomous republics. Over the entire period of observations since the official start of records in 1939, the manifestations have remained seasonal (May, August) with regular periods of rise in morbidity (9-11 years) caused by changes of the total quantity and percentage of infected ticks in the total [1, 2]
High-Resolution Fiber-Fed Spectrograph for the 6-m Telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences: Assessment of Efficiency
International audienceWe report the results of laboratory tests of the first version of the high-resolution fiber-fed spectrograph designed for the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS). During laboratory tests a spectral resolution of about 70 000 was achieved. The peak efficiency of the entire optical path of the spectrograph (without light losses at the CCD, primary mirror of the 6-m telescope, and in the atmosphere) at 620 nm and with the equivalent slit widths of the 1″.5 and 0″.75 are equal to 8% and 4%, respectively. The resolving power R = 70 000 and 100 000 can be reached with the sky aperture 0″.75 and 0″.4 respectively. In the current version of the spectrograph these regimes of operation are implemented by mechanic aperturing of the slit. A dedicated projecting camera has been developed and is currently manufactured to operate with a collimated 200-mm diameter beam, which will make it possible to increase the spectral resolution up to 100 000. A two-beam image slicer will be used to maintain the luminous efficiency of the instrument at least at the 6% level
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
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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