Searching for Candidates of Orbital Decays among Transit Exoplanets

Transit observations have become an important technique to probe exoplanets. Therefore, there are many projects carrying on organized observations of transit events, which make a huge amount of light-curve and transit timing data available. We consider this as an excellent opportunity to search for possible orbital decays of exoplanets from this big number of mid-transit times through data-model fitting with both fixed-orbit and orbit-decay models. In order to perform this task, we collect mid-transit-time data from several sources and construct the most complete database up to date. Among 144 hot Jupiters in our study, HAT-P-51b, HAT-P-53b, TrES-5b, WASP-12b are classified as the orbit-decay cases. Thus, in addition to reconfirming WASP-12b as an orbit-decay planet, our results indicate that HAT-P-51b, HAT-P-53b, TrES-5b are potential orbit-decay candidates.Comment: 12 pages, 5 figures, 5 tables, accepted by New Astronom

Revisiting the Transit Timing and Atmosphere Characterization of the Neptune-mass Planet HAT-P-26 b

We present the transit timing variation (TTV) and planetary atmosphere analysis of the Neptune-mass planet HAT-P-26~b. We present a new set of 13 transit light curves from optical ground-based observations and combine them with light curves from the Wide Field Camera 3 (WFC3) on the Hubble Space Telescope (HST), Transiting Exoplanet Survey Satellite (TESS), and previously published ground-based data. We refine the planetary parameters of HAT-P-26 b and undertake a TTV analysis using 33 transits obtained over seven years. The TTV analysis shows an amplitude signal of 1.98 $\pm$ 0.05 minutes, which could result from the presence of an additional $0.02 M_{Jup}$ planet at the 1:2 mean-motion resonance orbit. Using a combination of transit depths spanning optical to near-infrared wavelengths, we find that the atmosphere of HAT-P-26 b contains $2.4^{+2.9}_{-1.6}$% of H$_2$O with a derived temperature of $590^{+60}_{-50}$ K.Comment: 34 pages, accepted by A

Pulsations in Algols

We present a brief review of the recent results of photometric and spectroscopic surveys and 3-D hydrodynamic simulations of the mass- transfer for the class of oscillating mass-accreting components of Algols (oEA stars). These ground-based spectroscopic and space-based photometric surveys are aimed at detecting and studying the spectra of non- radial oscillations, to get precise orbits and parameters of the binaries, and studying the spectroscopic and the hydrodynamic nature of the mass- transfer. We discovered 47 new oEA stars in TESS data and carried out follow up spectroscopic observations of known and new oEA stars with the SALT telescope. We found that the co-existence of excitation of high-degree non-radial modes with a wide spectrum of low-degree modes is a common phenomenon in oEA stars

Pulsations in Algols

We present a brief review of the recent results of photometric and spectroscopic surveys and 3-D hydrodynamic simulations of the mass- transfer for the class of oscillating mass-accreting components of Algols (oEA stars). These ground-based spectroscopic and space-based photometric surveys are aimed at detecting and studying the spectra of non- radial oscillations, to get precise orbits and parameters of the binaries, and studying the spectroscopic and the hydrodynamic nature of the mass- transfer. We discovered 47 new oEA stars in TESS data and carried out follow up spectroscopic observations of known and new oEA stars with the SALT telescope. We found that the co-existence of excitation of high-degree non-radial modes with a wide spectrum of low-degree modes is a common phenomenon in oEA stars