ABSTRACT When a projectile at hyper-velocity impacts the Moon a transient luminous phenomenon occ... more ABSTRACT When a projectile at hyper-velocity impacts the Moon a transient luminous phenomenon occurs (impact flash). Here we present the research environment of our network. We highlight some results of the analysis of the first Lunar Meteoroids impacts detected in Morocco. On February 6, 2013, at 06:29:56.7 UT and April 14, 2013, 20:00:45.4 we observed two flashes produced by kilogram-size meteoroids striking the lunar surface. In addition to providing intensity and duration of the flash, and estimates of the mass of the meteoroids, we report on the first developments of techniques to determine accurately the position of the flash.
ABSTRACT Morocco is known to a region of frequent witness of meteorite falls and/or recovery. Thi... more ABSTRACT Morocco is known to a region of frequent witness of meteorite falls and/or recovery. This dictate the necessity to create the first Moroccan meteor network. This paper presents the results of the 2012 Geminid observation campaign performed at the Atlas Golf Marrakesh, Marrakesh, Morocco. It was found that the Geminids duration is generally correlated to their magnitude. Moreover, we analyse a Geminid spectrum showing a normal class spectrum, with high sodium content. Morocco is found to be an excellent place for meteor observation and future work and collaboration are presented.
ABSTRACT In this paper we describe a new technique of circular aperture apodization. It is produc... more ABSTRACT In this paper we describe a new technique of circular aperture apodization. It is produced by interferometry. The light, which is diffracted by a circular aperture, is split into two beams of different amplitudes where one of them has undergone an homothety to change its radial dimensions, by using an afocal optical system. The two beams are then combined coherently to form an apodized point spread function (PSF). This procedure allows us to reduce the diffraction wings of the PSF with different reduction factors depending on the combination parameters.
In this paper we report the all exoplanets that are discovered to date by the transit method. Als... more In this paper we report the all exoplanets that are discovered to date by the transit method. Also, we present the limit of detection by this method using the small instruments, and the specific information that can be deducted from the transit method. In addition, we present the detection and characterization of HD 189733b, the peculiarity of this exoplanet is that the flow of the target star is decreased significantly (~3%) during the transit. We determined the radius of the exoplanet 1.27 ± 0.03 RJ, the impact parameter 0.70 ± 0.02, and the inclination of the orbit 85.4 ± 0.1°. The transit of the extrasolar planet HD 189733b is already done using the larger telescope. In this study, we used during the observation a telescope of modest size.
In this work we describe an apodization technique of a circular telescope aperture . The apodizat... more In this work we describe an apodization technique of a circular telescope aperture . The apodization procedure introduced here consists of splitting a PSF image into two PSF images, using optical systems, where one of them has undergone a homothety to change its radial dimensions. After a coherent recombination of these two PSFs, we obtain an apodized image. This procedure allows us to reduce the diffraction wings of the PSF with different reduction factors depending on the combination parameters. In laboratory this apodization aproach can be realized by using an interferometric assembly based on Mach-Zender interferometer . We present here the simulation results and we show that the technique HACA reduce the diffraction wings. This technique can be combined with coronagraphy.
ABSTRACT As part of the conceptual and preliminary design processes of the Extremely Large Telesc... more ABSTRACT As part of the conceptual and preliminary design processes of the Extremely Large Telescope (ELT), the ELT site-testing team at Morocco has spent the last two years measuring the atmospheric properties at Aklim site as another 4 candidate mountains in North and South hemisphere, Aklim is the per-selected site for the ELT, is located in Moroccan Anti-Atlas at the geographic coordinates 30°7'39" N, 08°18'39" W. In this paper we present the isoplanatic angle theta0 and the isopistonic angle thetap, measurements at Aklim site, statistics of the mentioned parameters are obtained from the whole data recorded from April 2008 to December 2009 using the Multi Aperture Scintillation Sensor (MASS) - Differential Image Motion Monitor (DIMM) system, more representative results and statistics are shown hereafter.
Proceedings of the International Astronomical Union, 2006
The ELT project is currently under way in Europe and North America. Astronomical sites depend cri... more The ELT project is currently under way in Europe and North America. Astronomical sites depend critically on sky transparency and on aerosol loadings. A quantitative survey of aerosol optical properties at candidate ELT sites is an essential part of the site selection process. There are basically two methods to characterize aerosol properties: ground based measurements and satellite measurements. In this paper we will establish a full climatology of two sites very close to each other, but at a difference of 2300m in altitude: Izaña and Santa Cruz located in the Canary Islands. Both have sun photometers from the AERONET network. We also use the aerosol index determined from TOMS satellite data to determine how aerosol optical properties vary with altitude. We establish a correlation between the TOMS index and the aerosol optical thickness in both sites. Aerosol optical properties show very good correlation between Izaña and Santa Cruz. As a result we establish a set of relationships h...
ABSTRACT When a projectile at hyper-velocity impacts the Moon a transient luminous phenomenon occ... more ABSTRACT When a projectile at hyper-velocity impacts the Moon a transient luminous phenomenon occurs (impact flash). Here we present the research environment of our network. We highlight some results of the analysis of the first Lunar Meteoroids impacts detected in Morocco. On February 6, 2013, at 06:29:56.7 UT and April 14, 2013, 20:00:45.4 we observed two flashes produced by kilogram-size meteoroids striking the lunar surface. In addition to providing intensity and duration of the flash, and estimates of the mass of the meteoroids, we report on the first developments of techniques to determine accurately the position of the flash.
ABSTRACT Morocco is known to a region of frequent witness of meteorite falls and/or recovery. Thi... more ABSTRACT Morocco is known to a region of frequent witness of meteorite falls and/or recovery. This dictate the necessity to create the first Moroccan meteor network. This paper presents the results of the 2012 Geminid observation campaign performed at the Atlas Golf Marrakesh, Marrakesh, Morocco. It was found that the Geminids duration is generally correlated to their magnitude. Moreover, we analyse a Geminid spectrum showing a normal class spectrum, with high sodium content. Morocco is found to be an excellent place for meteor observation and future work and collaboration are presented.
ABSTRACT In this paper we describe a new technique of circular aperture apodization. It is produc... more ABSTRACT In this paper we describe a new technique of circular aperture apodization. It is produced by interferometry. The light, which is diffracted by a circular aperture, is split into two beams of different amplitudes where one of them has undergone an homothety to change its radial dimensions, by using an afocal optical system. The two beams are then combined coherently to form an apodized point spread function (PSF). This procedure allows us to reduce the diffraction wings of the PSF with different reduction factors depending on the combination parameters.
In this paper we report the all exoplanets that are discovered to date by the transit method. Als... more In this paper we report the all exoplanets that are discovered to date by the transit method. Also, we present the limit of detection by this method using the small instruments, and the specific information that can be deducted from the transit method. In addition, we present the detection and characterization of HD 189733b, the peculiarity of this exoplanet is that the flow of the target star is decreased significantly (~3%) during the transit. We determined the radius of the exoplanet 1.27 ± 0.03 RJ, the impact parameter 0.70 ± 0.02, and the inclination of the orbit 85.4 ± 0.1°. The transit of the extrasolar planet HD 189733b is already done using the larger telescope. In this study, we used during the observation a telescope of modest size.
In this work we describe an apodization technique of a circular telescope aperture . The apodizat... more In this work we describe an apodization technique of a circular telescope aperture . The apodization procedure introduced here consists of splitting a PSF image into two PSF images, using optical systems, where one of them has undergone a homothety to change its radial dimensions. After a coherent recombination of these two PSFs, we obtain an apodized image. This procedure allows us to reduce the diffraction wings of the PSF with different reduction factors depending on the combination parameters. In laboratory this apodization aproach can be realized by using an interferometric assembly based on Mach-Zender interferometer . We present here the simulation results and we show that the technique HACA reduce the diffraction wings. This technique can be combined with coronagraphy.
ABSTRACT As part of the conceptual and preliminary design processes of the Extremely Large Telesc... more ABSTRACT As part of the conceptual and preliminary design processes of the Extremely Large Telescope (ELT), the ELT site-testing team at Morocco has spent the last two years measuring the atmospheric properties at Aklim site as another 4 candidate mountains in North and South hemisphere, Aklim is the per-selected site for the ELT, is located in Moroccan Anti-Atlas at the geographic coordinates 30°7'39" N, 08°18'39" W. In this paper we present the isoplanatic angle theta0 and the isopistonic angle thetap, measurements at Aklim site, statistics of the mentioned parameters are obtained from the whole data recorded from April 2008 to December 2009 using the Multi Aperture Scintillation Sensor (MASS) - Differential Image Motion Monitor (DIMM) system, more representative results and statistics are shown hereafter.
Proceedings of the International Astronomical Union, 2006
The ELT project is currently under way in Europe and North America. Astronomical sites depend cri... more The ELT project is currently under way in Europe and North America. Astronomical sites depend critically on sky transparency and on aerosol loadings. A quantitative survey of aerosol optical properties at candidate ELT sites is an essential part of the site selection process. There are basically two methods to characterize aerosol properties: ground based measurements and satellite measurements. In this paper we will establish a full climatology of two sites very close to each other, but at a difference of 2300m in altitude: Izaña and Santa Cruz located in the Canary Islands. Both have sun photometers from the AERONET network. We also use the aerosol index determined from TOMS satellite data to determine how aerosol optical properties vary with altitude. We establish a correlation between the TOMS index and the aerosol optical thickness in both sites. Aerosol optical properties show very good correlation between Izaña and Santa Cruz. As a result we establish a set of relationships h...
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Papers by Zouhair Benkhaldoun