TESS unveils the phase curve of WASP-33b. Characterization of the planetary atmosphere and the pulsations from the star

We present the detection and characterization of the full-orbit phase curve and secondary eclipse of the ultra-hot Jupiter WASP-33b at optical wavelengths, along with the pulsation spectrum of the host star. We analyzed data collected by the Transiting Exoplanet Survey Satellite (TESS) in sector 18. WASP-33b belongs to a very short list of highly irradiated exoplanets that were discovered from the ground and were later visited by TESS. The host star of WASP-33b is of delta Scuti-type and shows nonradial pulsations in the millimagnitude regime, with periods comparable to the period of the primary transit. These completely deform the photometric light curve, which hinders our interpretations. By carrying out a detailed determination of the pulsation spectrum of the host star, we find 29 pulsation frequencies with a signal-to-noise ratio higher than 4. After cleaning the light curve from the stellar pulsations, we confidently report a secondary eclipse depth of 305.8 +/- 35.5 parts-per-million (ppm), along with an amplitude of the phase curve of 100.4 +/- 13.1 ppm and a corresponding westward offset between the region of maximum brightness and the substellar point of 28.7 +/- 7.1 degrees, making WASP-33b one of the few planets with such an offset found so far. Our derived Bond albedo, A_B = 0.369 +/- 0.050, and heat recirculation efficiency, epsilon = 0.189 +/- 0.014, confirm again that he behavior of WASP-33b is similar to that of other hot Jupiters, despite the high irradiation received from its host star. By connecting the amplitude of the phase curve to the primary transit and depths of the secondary eclipse, we determine that the day- and nightside brightness temperatures of WASP-33b are 3014 +/- 60 K and 1605 +/- 45 K, respectively. From the detection of photometric variations due to gravitational interactions, we estimate a planet mass of M_P = 2.81 +/- 0.53 M$_J.Comment: 19 pages, 15 figure

First Light of Engineered Diffusers at the Nordic Optical Telescope Reveal Time Variability in the Optical Eclipse Depth of WASP-12b

We present the characterization of two engineered diffusers mounted on the 2.5 meter Nordic Optical Telescope, located at Roque de Los Muchachos, Spain. To assess the reliability and the efficiency of the diffusers, we carried out several test observations of two photometric standard stars, along with observations of one primary transit observation of TrES-3b in the red (R-band), one of CoRoT-1b in the blue (B-band), and three secondary eclipses of WASP-12b in V-band. The achieved photometric precision is in all cases within the sub-millimagnitude level for exposures between 25 and 180 seconds. Along a detailed analysis of the functionality of the diffusers, we add a new transit depth measurement in the blue (B-band) to the already observed transmission spectrum of CoRoT-1b, disfavouring a Rayleigh slope. We also report variability of the eclipse depth of WASP-12b in the V-band. For the WASP-12b secondary eclipses, we observe a secondary-depth deviation of about 5-sigma, and a difference of 6-sigma and 2.5-sigma when compared to the values reported by other authors in similar wavelength range determined from Hubble Space Telescope data. We further speculate about the potential physical processes or causes responsible for this observed variabilityComment: 11 pages, 9 figure

IL-6, IL-12, and IL-23 STAT-Pathway Genetic Risk and Responsiveness of Lymphocytes in Patients with Multiple Sclerosis

Multiple sclerosis (MS) is an immune-mediated demyelinating disease characterized by central nervous system (CNS) lymphocyte infiltration, abundant production of pro-inflammatory cytokines, and inappropriate activation of Th1 and Th17 cells, B cells, and innate immune cells. The etiology of MS is complex, and genetic factors contribute to disease susceptibility. Genome-wide association studies (GWAS) have revealed numerous MS-risk alleles in the IL-6/STAT3, IL-12/STAT4, and IL-23/STAT3-pathways implicated in the differentiation of Th1 and Th17 cells. In this study, we investigated the signaling properties of these pathways in T, B, and NK cells from patients with relapsing-remitting MS (RRMS) and healthy controls, and assessed the genetic contribution to the activity of the pathways. This revealed a great variability in the level of STAT-pathway molecules and STAT activation between the cell types investigated. We also found a strong donor variation in IL-6, IL-12, and IL-23 responsiveness of primed CD4+ T cells. This variation could not be explained by a single MS-risk variant in a pathway component, or by an accumulation of multiple STAT-pathway MS-risk SNPs. The data of this study suggests that other factors in cohesion with the genetic background contribute to the responsiveness of the IL-6/STAT3, IL-12/STAT4, and IL-23/STAT3-pathways

Dual-Beam Optical Linear Polarimetry from the Southern Skies : characterisation of CASPOL for high precision polarimetry

We present a characterization of CasPol, a dual-beam polarimeter mounted at the 2.15-m Jorge Sahade Telescope, located at the Complejo Astronómico El Leoncito, Argentina. The telescope is one of the few available meter-sized optical telescopes located in the southern hemisphere hosting a polarimeter. To carry out this work, we collected photopolarimetric data along five observing campaigns, the first one during January 2014, and the remaining ones spread between August 2017 and March 2018. The data were taken through the Johnson?Cousins V, R, and I filters. Along the campaigns, we observed eight unpolarized and four polarized standard stars. Our analysis began characterizing the impact of seeing and aperture into the polarimetric measurements, defining an optimum aperture extraction and setting a clear limit for seeing conditions. Then, we used the unpolarized standard stars to characterize the level of instrumental polarization and to assess the presence of polarization dependent on the position across the charge-coupled device. Polarized standard stars were investigated to quantify the stability of the instrument with wavelength. Specifically, we find that the overall instrumental polarization of CasPol is ∼0.2  %   in the V, R, and I bands, with a negligible polarization dependence on the position of the stars on the detector. The stability of the half-wave plate retarder is about 0.35 deg, making CasPol comparable to already existing instruments. We also provide measurements in the three photometric bands for both the unpolarized and polarized standard stars. Finally, we show scientific results, illustrating the capabilities of CasPol for precision polarimetry of relatively faint objects.Fil: Sosa, Marina S.. Universidad Nacional de La Plata. Facultad de Ciencias Astronómicas y Geofísicas; ArgentinaFil: von Essen, Carolina. Stellar Astrophysics Centre, Aarhus University; DinamarcaFil: Andruchow, Ileana. 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: Cellone, Sergio Aldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; ArgentinaFil: Mammana, Luis Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Complejo Astronómico "El Leoncito". Universidad Nacional de Córdoba. Complejo Astronómico "El Leoncito". Universidad Nacional de la Plata. Complejo Astronómico "El Leoncito". Universidad Nacional de San Juan. Complejo Astronómico "El Leoncito"; Argentin

Testing connections between exo-atmospheres and their host stars: GEMINI-N/GMOS ground-based transmission spectrum of Qatar-1b

Till date, only a handful exo-atmospheres have been well characterized, mostly by means of the transit method. Some classic examples are HD 209458b, HD 189733b, GJ-436b, and GJ-1214b. Data show exoplanet atmospheres to be diverse. However, this is based on a small number of cases. Here we focus our study on the exo-atmosphere of Qatar-1b, an exoplanet that looks much like HD 189733b regarding its host star's activity level, their surface gravity, scale height, equilibrium temperature and transit parameters. Thus, our motivation relied on carrying out a comparative study of their atmospheres, and assess if these are regulated by their environment. In this work we present one primary transit of Qatar-1b obtained during September, 2014, using the 8.1 m GEMINI North telescope. The observations were performed using the GMOS-N instrument in multi-object spectroscopic mode. We collected fluxes of Qatar-1 and six more reference stars, covering the wavelength range between 460 and 746 nm. The achieved photometric precision of 0.18 parts-per-thousand in the white light curve, at a cadence of 165 s, makes this one of the most precise datasets obtained from the ground. We created 12 chromatic transit light curves that we computed by integrating fluxes in wavelength bins of different sizes, ranging between 3.5 and 20 nm. Although the data are of excellent quality, the wavelength coverage and the precision of the transmission spectrum are not sufficient to neither rule out or to favor classic atmospheric models. Nonetheless, simple statistical analysis favors the clear atmosphere scenario. A larger wavelength coverage or space-based data is required to characterize the constituents of Qatar-1b's atmosphere and to compare it to the well known HD 189733b. On top of the similarities of the orbital and physical parameters of both exoplanets, from a long Hα photometric follow-up of Qatar-1, presented in this work, we find Qatar-1 to be as active as HD 189733.Facultad de Ciencias Astronómicas y GeofísicasInstituto de Astrofísica de La Plat

Broad-band spectrophotometry of the hot Jupiter HAT-P-12b from the near-UV to the near-IR

The detection of trends or gradients in the transmission spectrum of extrasolar planets is possible with observations at very low spectral resolution. Transit measurements of sufficient accuracy using selected broad-band filters allow for an initial characterization of the atmosphere of the planet. We obtained time series photometry of 20 transit events and analyzed them homogeneously, along with eight light curves obtained from the literature. In total, the light curves span a range from 0.35 to 1.25 microns. During two observing seasons over four months each, we monitored the host star to constrain the potential influence of starspots on the derived transit parameters. We rule out the presence of a Rayleigh slope extending over the entire optical wavelength range, a flat spectrum is favored for HAT-P-12b with respect to a cloud-free atmosphere model spectrum. A potential cause of such gray absorption is the presence of a cloud layer at the probed latitudes. Furthermore, in this work we refine the transit parameters, the ephemeris and perform a TTV analysis in which we found no indication for an unseen companion. The host star showed a mild non-periodic variability of up to 1%. However, no stellar rotation period could be detected to high confidence.Comment: 13 pages, 6 figures, Accepted for publication in A&

High pathogen prevalence in an amphibian and reptile assemblage at a site with risk factors for dispersal in Galicia, Spain

Ranaviruses are agents of disease, mortality and population declines in ectothermic vertebrates and emergences have been repeatedly linked to human activities. Ranaviruses in the common midwife toad ranavirus lineage are emerging in Europe. They are known to be severe multi-host pathogens of amphibians and can also cause disease in reptiles. Recurrent outbreaks of ranavirus disease and mortality affecting three species have occurred at a small reservoir in north-west Spain but no data were available on occurrence of the pathogen in the other amphibian and reptile species present or at adjacent sites. We sampled nine species of amphibians and reptiles at the reservoir and nearby sites and screened for ranavirus presence using molecular methods. Our results show infection with ranavirus in all nine species, including first reports for Hyla molleri, Pelophylax perezi, Rana iberica, and Podarcis bocagei. We detected ranavirus in all four local sites and confirmed mass mortality incidents involving Lissotriton boscai and Triturus marmoratus were ongoing. The reservoir regularly hosts water sports tournaments and the risks of ranavirus dispersal through the translocation of contaminated equipment are discussed