Results 81 to 90 of about 3,877 (212)

A Binary Shaped Mask Coronagraph for a Segmented Pupil [PDF]

, 2010
We present the concept of a binary shaped mask coronagraph applicable to a telescope pupil including obscuration, based on previous works on binary shaped pupil mask by \citet{Kasdin2005} and \citet{Vanderbei1999}.
Abe, L., Enya, K.
core   +1 more source

Joint Diagnostics of Circumsolar Sky Brightness Using Coronagraphic Measurements and Aerosol Optical Inversions at Maunaloa

The Astrophysical Journal
Atmospheric aerosols strongly influence daytime sky quality for solar coronal imaging, yet few studies directly link aerosol properties and sky brightness measurements within ∼2° of the Sun. Here, we compare externally occulted coronagraphic measurements
Thomas A. Schad, Paul Bryans, André Fehlmann, Sarah Gibson, David M. Harrington, Lucas A. Tarr, Steven Tomczyk, Jeffrey G. Yepez   +7 more
doaj   +1 more source

High Performance Lyot and PIAA Coronagraphy for Arbitrarily shaped Telescope Apertures

, 2013
Two high performance coronagraphic approaches compatible with segmented and obstructed telescope pupils are described. Both concepts use entrance pupil amplitude apodization and a combined phase and amplitude focal plane mask to achieve full ...
Belikov, Ruslan, Cady, Eric, Guyon, Olivier, Hinz, Philip H., Martinache, Frantz   +4 more
core   +2 more sources

Resolving the delta Andromedae spectroscopic binary with direct imaging [PDF]

, 2015
We present a direct image of the innermost companion to the red giant delta Andromedae using the Stellar Double Coronagraph at the Palomar Observatory.
Bottom, Michael, Kuhn, Jonas, Mawet, Dimitri, Mennesson, Bertrand, Serabyn, Eugene, Shelton, Jean C., Wallace, J. Kent   +6 more
core   +2 more sources

Subaru AO Coronagraphic and Direct Imaging of YSOs [PDF]

Symposium - International Astronomical Union, 2004
A cold near-infrared stellar coronagraph combined with adaptive optics (CIAO) is introduced. As an open-use instrument on the Subaru 8.2-m telescope, it has been used for several star formation studies with high spatial resolutions (from natural seeing of about 0.6 arcsec down to 0.07 arcsec with adaptive optics).
Motohide Tamura, Misato Fukagawa, Masahiko Hayashi   +2 more
openaire   +1 more source

Notch‐Filter Masks: Practical Image Masks for Planet‐finding Coronagraphs [PDF]

The Astrophysical Journal, 2003
An ideal coronagraph with a band-limited image mask can efficiently image off-axis sources while removing identically all of the light from an on-axis source. However, strict mask construction tolerances limit the utility of this technique for directly imaging extrasolar terrestrial planets. We present a variation on the basic band-limited mask design--
Kuchner, Marc J., Spergel, David N.
openaire   +2 more sources

The Lyot Project Direct Imaging Survey of Substellar Companions: Statistical Analysis and Information from Nondetections [PDF]

, 2010
The Lyot project used an optimized Lyot coronagraph with Extreme Adaptive Optics at the 3.63m Advanced Electro-Optical System telescope (AEOS) to observe 86 stars from 2004 to 2007.
Aime, Anand Sivaramakrishnan, Baraffe, Ben R. Oppenheimer, Biller, Biller, Brown, Butler, Carson, Carson, Carson, Carson, Digby, Douglas Brenner, Fischer, Fitzgerald, Gilles Chabrier, Heinze, Hinkley, Hinkley, Hinkley, Isabelle Baraffe, James P. Lloyd, James R. Graham, Jeffrey Kuhn, Johnson, Jurić, Jérémy Leconte, Lafrenière, Lafrenière, Lewis C. Roberts, Lloyd, Lowrance, Lyot, Malbet, Marois, Marois, Marois, Marshall D. Perrin, Masciadri, Metchev, Metchev, Michal Simon, Neil Zimmerman, Nielsen, Nielsen, Oppenheimer, Oppenheimer, Oppenheimer, Perrin, Robert A. Brown, Russell Makidon, Rémi Soummer, Sasha Hinkley, Scharf, Sivaramakrishnan, Sivaramakrishnan, Soummer, Soummer   +58 more
core   +2 more sources

Exoplanet Imaging with a Phase‐induced Amplitude Apodization Coronagraph. III. Diffraction Effects and Coronagraph Design

The Astrophysical Journal, 2006
Properly apodized pupils can deliver point-spread functions (PSFs) free of Airy rings and are suitable for high dynamical range imaging of extrasolar terrestrial planets (ETPs). To reach this goal, classical pupil apodization (CPA) unfortunately requires most of the light gathered by the telescope to be absorbed, resulting in poor throughput and low ...
Eugene A. Pluzhnik, Olivier Guyon, Stephen T. Ridgway, Frantz Martinache, Robert A. Woodruff, Celia Blain, Raphael Galicher   +6 more
openaire   +1 more source

A Comprehensive Spectroscopic Reference of the Solar System and Its Application to Exoplanet Direct Imaging

The Planetary Science Journal
We present a calibrated database of reflectance spectra for the solar system planets (i.e., Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune) and for Titan, spanning from the ultraviolet to the near infrared.
Allison Payne, Geronimo L. Villanueva, Vincent Kofman, Thomas J. Fauchez, Sara Faggi, Avi M. Mandell, Aki Roberge, Eleonora Alei   +7 more
doaj   +1 more source

A Decade of Coronagraphic and Spectroscopic Studies of CME-Driven Shocks

, 2012
Shocks driven by Coronal Mass Ejections (CMEs) are primary agents of space weather. They can accelerate particles to high energies and can compress the magnetosphere thus setting in motion geomagnetic storms.
Bemporad, Alessandro, Vourlidas, Angelos
core   +1 more source