New ephemeris of two W Uma-type binaries: BQ Ari and V1370 Tau

International audienceThe new light curve and ephemeris of two eclipsing binary systems BQ Ari and V1370 Tau are presented. The observation was made with CCD through C filter and we used the Czech astronomical society's database to extract raw data, to obtain the time of minimums we used Table Curve software and then calculate O-C with the new ephemeris

Formación de sepiolita-paligorskita en litofacies lutítico-carbonáticas en el sector de Borox-Esquivias (cuenca de Madrid)

According to lithological composition three units were stablished in the area studied: a) Clayey unit. Green and pinkish clays with sandy beds and early formation of calcretes. Clay minerals association: smectite-mixed-layers (kerolite-stevensite) sepiolite-illite-kaolinite. b) Clayey calcareous unit Green clays with calcretes and a sandy level at bottom of the unit. Clay minerals association: smectite-illite-palygorskite-sepiolite-kaolinite. c) Clayey-dolomitic unit. Green clays with dolomicrites. Clay minerals association: smectiteillite-palygorskite-sepiolite. Results let us to stablish a sepiolite and palygorskite genesis related to lacustrine paludine environments where pedodiagenetic processes (v.s. carbonation, dolomitization, silicification, vertic features) were responsible of smectite instability, with development of palygorskite or sepiolite, according to their respectively di or triocthedral character.En el área estudiada, desde un punto de vista litológico se han diferenciado tres tramos: a) Lutítico. Lutitas verdes y rosáceas con intercalaciones samíticas e incipiente desarrollo de calcretas. la asociación de minerales de la arcilla es: esmectita-interestratificados (kerolitaestevensita)-sepiolita-illita-caolinita. b) Lutítico-calcáreo. Lutitas verdes y calcretas con un nivel samítico en la base del tramo. La asociación de minerales de la arcil1a es: esmectita-illita-paligorskita-sepiolita-eaolinita. c) Lutítico-dolomítico. Lutitas verdes y dolomicritas. La asociación de minerales de la arcilla es: esmectita-illita-paligorskita-sepiolita. Los resultados permiten establecer una génesis de sepiolita y paligorskita en relación con ambientes lacustres-palustres, donde los procesos edafodiagenéticos (carbonatación, dolomitización, silicificación, vertisolización) provocan la desestabilización de fases esmectíticas precursoras. De acuerdo con el carácter di o trioctaédrico de la esmectita se propicia la formación de paligorskita o sepiolita, respectivamente

Ephemeris Updates for Seven Selected HATNet Survey Transiting Exoplanets

We refined the ephemeris of seven transiting exoplanets HAT-P-6b, HAT-P-12b, HAT-P-18b, HAT-P-22b, HAT-P-32b, HAT-P-33b, and HAT-P-52b. We observed 11 transits from eight observatories in different filters for HAT-P-6b and HAT-P-32b. Also, the Exoplanet Transit Database (ETD) observations for each of the seven exoplanets were analyzed, and the light curves of five systems were studied using Transiting light Exoplanet Survey Satellite (TESS) data. We used Exofast-v1 to simulate these ground- and space-based light curves and estimate mid-transit times. We obtained a total of 11, 175 and 67 mid-transit times for these seven exoplanets from our observations, ETD and TESS data, respectively, along with 155 mid-transit times from the literature. Then, we generated transit timing variation (TTV) diagrams for each using derived mid-transit times as well as those found in the literature. The systems' linear ephemeris was then refined and improved using the Markov Chain Monte Carlo (MCMC) method. All of the studied exoplanets, with the exception of the HAT-P-12b system, displayed an increasing trend in the orbital period in the TTV diagrams.Comment: 11 Pages, submitted to the Astrophysics journa