Using a numerical simulation, a new approach to determine the wave structure function, and therefore the astronomical seeing, is presented and discussed. This method is based on the study of the ...diffraction pattern produced by a double slit at the focus plane of a telescope. The phase screens are simulated using a fast Fourier transform (FFT) based method and Kolmogorov's law regarding atmospheric turbulence. From the scattered wave intensity, the wave structure function is calculated by taking into account both phase and amplitude fluctuations. This means that we can obtain a seeing value that is independent of the propagation distance between the turbulent layers and the ground level (Fresnel diffraction effect). Indeed, the seeing is related to the refractive-index structure constant (C
n
2) inside the turbulent layers and thus should be independent of the aforementioned propagation distance.
ABSTRACT
We present the discovery of four new giant planets from the Wide Angle Search for Planets-South (WASP-South), three hot Jupiters and one bloated sub-Saturn mass planet: WASP-169b, WASP-171b, ...WASP-175b, and WASP-182b. Besides the discovery photometry from WASP-South we use radial velocity measurements from CORALIE and HARPS and follow-up photometry from EulerCam, TRAPPIST-North and -South, and SPECULOOS. WASP-169b is a low-density Jupiter ($M=0.561 \pm 0.061\,{M_{\rm Jup}},\ R=1.304^{+0.150}_{-0.073}\,{R_{\rm Jup}}$) orbiting a V = 12.17 F8 subgiant in a 5.611 d orbit. WASP-171b is a typical hot Jupiter ($M=1.084 \pm 0.094\,{M_{\rm Jup}},\ R=0.98^{+0.07}_{-0.04}\,{R_{\rm Jup}}$, P = 3.82 d) around a V = 13.05 G0 star. We find a linear drift in the radial velocities of WASP-171 spanning 3.5 yr, indicating the possibility of an additional outer planet or stellar companion. WASP-175b is an inflated hot Jupiter (M = 0.99 ± 0.13 MJup, R = 1.208 ± 0.081 RJup, P = 3.07 d) around a V = 12.04 F7 star, which possibly is part of a binary system with a star 7.9 arcsec away. WASP-182b is a bloated sub-Saturn mass planet (M = 0.148 ± 0.011 MJup, R = 0.850 ± 0.030 RJup) around a metal-rich V = 11.98 G5 star (Fe/H = 0.27 ± 0.11). With an orbital period of P = 3.377 d, it sits right in the apex of the sub-Jovian desert, bordering the upper and lower edge of the desert in both the mass–period and radius–period plane. WASP-169b, WASP-175b, and WASP-182b are promising targets for atmospheric characterization through transmission spectroscopy, with expected transmission signals of 121, 150, and 264 ppm, respectively.
We report the discovery of a Neptune-like planet (LP 714-47 b, P = 4.05204 d, mb = 30.8 ± 1.5M⊕, Rb = 4.7 ± 0.3 R⊕) located in the “hot Neptune desert”. Confirmation of the TESS Object of Interest ...(TOI 442.01) was achieved with radial-velocity follow-up using CARMENES, ESPRESSO, HIRES, iSHELL, and PFS, as well as from photometric data using TESS, Spitzer, and ground-based photometry from MuSCAT2, TRAPPIST-South, MONET-South, the George Mason University telescope, the Las Cumbres Observatory Global Telescope network, the El Sauce telescope, the TÜBİTAK National Observatory, the University of Louisville Manner Telescope, and WASP-South. We also present high-spatial resolution adaptive optics imaging with the Gemini Near-Infrared Imager. The low uncertainties in the mass and radius determination place LP 714-47 b among physically well-characterised planets, allowing for a meaningful comparison with planet structure models. The host star LP 714-47 is a slowly rotating early M dwarf (Teff = 3950 ± 51 K) with a mass of 0.59 ± 0.02M⊙ and a radius of 0.58 ± 0.02R⊙. From long-term photometric monitoring and spectroscopic activity indicators, we determine a stellar rotation period of about 33 d. The stellar activity is also manifested as correlated noise in the radial-velocity data. In the power spectrum of the radial-velocity data, we detect a second signal with a period of 16 days in addition to the four-day signal of the planet. This could be shown to be a harmonic of the stellar rotation period or the signal of a second planet. It may be possible to tell the difference once more TESS data and radial-velocity data are obtained.
To reach a suitable limiting magnitude with a multi-aperture interferometer, we need to cophase the different telescopes using a reference source. The latter should be located in the same isopistonic ...domain as the science source. We developed a direct analytical expression of deducing the isopistonic angle from atmospheric optical parameters as seeing, isoplanatic angle and outer scale. All of these atmospheric turbulence parameters are measured by the Generalized Seeing Monitor (GSM). The first statistics of the isopistonic angle obtained from the GSM data are presented and comparison between the major sites over the world are discussed (La Silla, Cerro Pachon, Paranal, San Pedro, Mt Palomar, Mauna Kea, La Palma, Oukaïmeden, Maydanak, Dome C). Implications of these isopistonic angle statistics on large interferometers cophasing in terms of sky coverage and limiting magnitude are discussed.
A network of meteor stations is being deployed in Morocco with the aim to determine meteor trajectories and their relationships with possible parent bodies. Several meteor showers may be related to ...known parent bodies, such as the the comet 109P/Swift-Tuttle, which is associated to Perseids. Two stations of meteor observations with Watec cameras were recently installed in Morocco as part of this network, one at the Oukaimeden Observatory and the other at Marrakech. This paper presents the implementation of a software to determine the orientation of the camera, and the preliminary results obtained with the two stations.
Through Spectroscopy, we aim to develop the field of pulsating stars, especially the atmospheric dynamics of high amplitude pulsators such as RR Lyr and R Scuti, in order to establish new models of ...the mechanical and thermal behavior of their atmospheres (shock waves, relaxation time, energy loss…). We used high-resolution spectra over a total of 81 nights from made with the spectrograph Eshell during years 2013 and 2015 runs from Oukaïmeden observatory in the High Atlas mountains (Morocco) completed with made with the spectrograph ELODIE (Haute Provence observatory, France) during years 1994–1997. A detailed analysis of line profile variations over the whole pulsation cycle is performed. Shock wave velocity and lines intensity were used as indicators of atmospheric dynamics activities. We have obtained and compared our results with those obtained by the large telescopes, we have obtained thanks to our site very satisfactory results, Indeed : For RR lyr: For the first time the second apparition of Helium (D3) was detected using our Telescope (0.35m) at Oukaïmeden Observatory. For the first time, during the phase of expansion of the star, the emission of the line D3 is visible on various phases Blazhko, including during the minimum of the cycle Blazhko. Also, we presented the results of a long- term, high-resolution spectroscopic study of the variable star R Sct. We analyzed the features of the optical spectra of this object and found RSct shows irregular behavior in its slight variations for much of the time that it was observed. Its average period is close to 142 d, but some- times the irregularities are so strong that it is not possible to define a periodic variation.
TRAPPIST-North (TRAnsiting Planets and PlanetesImals Small Telescope) is a 60-cm robotic telescope that was installed in May 2016 at the Oukaimeden Observatory 1. The project is led by the University ...of Liège (Belgium) and the Caddi Ayad University of Marrakech (Morocco). This telescope is a twin of the TRAPPIST-South telescope, which was installed at the ESO La Silla Observatory in 2010 2. The TRAPPIST telescopes are dedicated to the detection and characterization of planets orbiting stars other than our Sun (exoplanets) and the study of comets and other small bodies in our solar system. For the comets research, these telescopes have very sensitive CCD cameras with complete sets of narrow band filters to measure the production rates of several gases (OH, NH, CN, C3 and C2) and the dust 3. With TRAPPIST-North we can also observe comets that would not be visible in the southern hemisphere. Therfore, with these two telescopes, we can now observe continuously the comets around their orbit. We project to study individually the evolution of the activity, chemical composition, dust properties, and coma morphology of several comets per year and of different origins (New comets and Jupiter Family comets) over a wide range of heliocentric distances, and on both sides of perihelion. We measure the production rates of each daughter molecules using a Haser model 4, in addition to the Afρ parameter to estimate the dust production in the coma. In this work, we present the first measurements of the production rates of comet C/2013 X1 (PANSTARRS) observed with TN in June 2016, and the measurements of comet C/2013 V5 (Oukaimeden) observed in 2014 with TRAPPIST-South.
This paper aims at studying the wind at 200 mbar over the Moroccan observatory Oukaimeden, as high-altitude winds have been adopted as a useful parameter for site characterization in terms of the ...suitability of a site for the development of some adaptive optics techniques. The data used come from the National Center for Environmental Prediction/National Center for Atmospheric Research (NCEP/NCAR) reanalysis data base, which is widely acknowledged as being reliable. Statistical analyses of 200-mbar wind speed since 1983 are performed. Comparison with some of the main observatory sites worldwide qualifies Oukaimeden as one of the best observatory sites in terms of 200-mbar wind statistics. Our analysis of a record of seeing measurements during the years 2003 and 2004 concludes that while 200-mbar wind speed can be used as a parameter for ranking astronomical sites in term of their suitability for adaptive optics, it cannot be used for the whole atmospheric seeing prediction. A comparison of monthly values of the seeing parameter at Oukaimeden, La Silla and Paranal demonstrates the high seeing quality of Oukaimeden, as the seeing values measured were lower than those of La Silla and Paranal for most of the time during the comparison period. Furthermore, a statistical analysis of atmospheric stratified seeing, wavefront coherence time and isoplanatic angle measured with a Multi-Aperture Scintillation Sensor instrument over Paranal from 2004 to 2007 have been performed. We found good correlations between 200-mbar wind velocity and levels 4, 5 and 6 seeing, wavefront coherence time and isoplanatic angle, with corresponding correlation coefficients of 0.74, 0.79, 0.70, 0.97 and 0.78.
We present the observation of a transit of the exoplanet TrES-3b by the newly commissioned robotic telescope TRAPPIST-North located at Oukaimeden Observatory (Morocco). The obtained light curve ...reaches a photometric precison 600 ppm. Its Bayesian analysis with a Markov Chain Monte Carlo code enables us to refine the radius of the planet to R p = 1.346 − 0.050 + 0.065 R J u p . These results demonstrate the high potential of TRAPPIST-North for high-photometry of exoplanet transits.
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