54 research outputs found
First results of the Kourovka Planet Search: discovery of transiting exoplanet candidates in the first three target fields
We present the first results of our search for transiting exoplanet
candidates as part of the Kourovka Planet Search (KPS) project. The primary
objective of the project is to search for new hot Jupiters which transit their
host stars, mainly in the Galactic plane, in the magnitude range of 11 to
14 mag. Our observations were performed with the telescope of the MASTER
robotic network, installed at the Kourovka astronomical observatory of the Ural
Federal University (Russia), and the Rowe-Ackermann Schmidt Astrograph,
installed at the private Acton Sky Portal Observatory (USA). As test
observations, we observed three celestial fields of size deg
during the period from 2012 to 2015. As a result, we discovered four transiting
exoplanet candidates among the 39000 stars of the input catalogue. In this
paper, we provide the description of the project and analyse additional
photometric, spectral, and speckle interferometric observations of the
discovered transiting exoplanet candidates. Three of the four transiting
exoplanet candidates are most likely astrophysical false positives, while the
nature of the fourth (most promising) candidate remains to be ascertained.
Also, we propose an alternative observing strategy that could increase the
project's exoplanet haul.Comment: 11 pages, 16 figures; Accepted for publication in Monthly Notices of
the Royal Astronomical Society 201
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
WASP-12 b and WASP-4 b: Planets Falling onto the Host Star?
We present results of a homogeneous analysis of more than thousand transit lightcurves of 17 exoplanets.Представлены результаты однородной обработки более тысячи кривых блеска экзопланетных прохождений для 17 экзопланет.Работа выполнена при поддержке гранта РНФ 19-72-10023
Ephemeris refinement of 21 Hot Jupiter exoplanets with high timing uncertainties
Transit events of extrasolar planets offer a wealth of information for planetary characterization. However, for many known targets, the uncertainty of their predicted transit windows prohibits an accurate scheduling of follow-up observations. In this work, we refine the ephemerides of 21 Hot Jupiter exoplanets with the largest timing uncertainty. We collected 120 professional and amateur transit light curves of the targets of interest, observed with 0.3m to 2.2m telescopes, and analyzed them including the timing information of the planets discovery papers. In the case of WASP-117b, we measured a timing deviation compared to the known ephemeris of about 3.5 hours, for HAT-P-29b and HAT-P-31b the deviation amounted to about 2 hours and more. For all targets, the new ephemeris predicts transit timings with uncertainties of less than 6 minutes in the year 2018 and less than 13 minutes until 2025. Thus, our results allow for an accurate scheduling of follow-up observations in the next decade
Multiple shadow electromagnetic-acoustic technique of the cylindrical objects testing
Implementation method of multiple shadow techniques for testing of cylindrical objects (bars, tubes) using electromagnetic-acoustic transducers of bulk and Rayleigh waves are presented. Approaches to the signal analysis based on spectral, probabilistic and statistical analysis, correlation analysis methods are proposed and informative parameters of the testing are proved. Examples of the technique practical implementation for nondestructive testing of flows and structure analysis and geometry of the spring steel rods.Представлены способы реализации методов многократной тени для контроля цилиндрических объектов (прутков, труб) с использованием электромагнитно-акустических преобразователей объемных и рэлеевских волн. Предложены подходы к анализу сигналов, основанные на методах спектрального, вероятностно-статистического, корреляционного анализа, обоснованы информативные параметры контроля. Приведены примеры практической реализации метода для дефектоскопии, структуроскопии и геометрии прутков из рессорно-пружинной стали.Работа выполнена в рамках проекта № 15-19-00051 Российского научного фонда
ОПЫТ ЛЕЧЕНИЯ ГОРМОНОЗАВИСИМОГО РАКА ПРЕДСТАТЕЛЬНОЙ ЖЕЛЕЗЫ АНТАГОНИСТОМ ЛГРГ ДЕГАРЕЛИКСОМ
Moscow developmental program results on assessment of luteinizing hormone-releasing hormone (gonadotrophinreleasing hormone) antagonist degarelix efficacy and tolerance in patients with prostate cancer received drug treatment in specialized outpatient polyclinic institutions of Moscow are provided in the original publication. In total 307 patients were included in the study and assigned in 3 groups: 1st (n=174) – patients with progressing prostate cancer after radical treatment (prostatectomy, radiation therapy); 2d (n=92) – patients with prostate cancer had cardiovascular diseases in history; 3d (n=41) – patients with prostate cancer with early castration refractivity occurred on the background of continuous hormone therapy by luteinizing hormone-releasing hormone antagonists. In all groups degarelix was prescribed in standard therapeutic regimen (240 mg/80 mg). Degarelix was effective in all test groups that was manifested by PSA level decrease on the background of one-year drug treatment, high control of testosterone castration level. Treatment by degarelix allowed increasing time before chemotherapy prescription (up to 12 months) in certain group of patients with biochemical progression on the background of luteinizing hormone-releasing hormone analogues administration. Degarelix tolerance was good even in patients with clinically significant cardiovascular pathology in history. In 4% of cases significant reactions were observed in the injection site after start dose administration.В оригинальной публикации представлены результаты Московской исследовательской программы по оценке эффективности и переносимости антагониста ЛГРГ дегареликса у больных РПЖ, получавших медикаментозное лечение в профильных амбулаторно-поликлинических учреждениях г. Москвы. Всего в исследование было включено 307 пациентов, которые были распределены на 3 группы: 1-я (n=174) – больные РПЖ с прогрессированием болезни после радикального лечения (простатэктомия, лучевая терапия) без кардиоваскулярной патологии в анамнезе; 2-я (n=92) – пациенты, имеющие РПЖ и сердечно-сосудистые заболевания в анамнезе; 3-я (n=41) – больные РПЖ с ранней кастрационной рефрактерностью, возникшей на фоне непрерывной гормональной терапии агонистами ЛГРГ. Во всех группах дегареликс назначался в стандартном терапевтическом режиме (240 мг/80 мг). Дегареликс был эффективен во всех группах наблюдения, что проявлялось снижением ПСА на фоне годичного приема препарата, высоким контролем кастрационного уровня тестостерона. Терапия дегареликсом позволила увеличить время до назначения химиотерапии (до 12 месяцев) в определенной группе пациентов с биохимическим прогрессированием на фоне приема аналогов ЛГРГ. Переносимость дегареликса была хорошей даже у пациентов с клинически значимой кардиоваскулярной патологией в анамнезе. В 4% случаев наблюдались значимые реакции в месте введения препарата после введения стартовой дозировки
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
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