Results 71 to 80 of about 3,877 (212)

The Surprising Evolution of the Shadow on the TW Hya Disk

The Astrophysical Journal, 2023
We report new total-intensity visible-light high-contrast imaging of the TW Hya disk taken with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope.
John Debes, Rebecca Nealon, Richard Alexander, Alycia J. Weinberger, Schuyler Grace Wolff, Dean Hines, Joel Kastner, Hannah Jang-Condell, Christophe Pinte, Peter Plavchan, Laurent Pueyo   +10 more
doaj   +1 more source

Observing Strategies for the NICI Campaign to Directly Image Extrasolar Planets

, 2008
We discuss observing strategy for the Near Infrared Coronagraphic Imager (NICI) on the 8-m Gemini South telescope. NICI combines a number of techniques to attenuate starlight and suppress superspeckles: 1) coronagraphic imaging, 2) dual channel imaging ...
Artigau, Etienne, Biller, Beth, Chun, Mark R., Close, Laird M., Ftaclas, Christ, Hartung, Markus, Hayward, Thomas, Liu, Michael, Toomey, Douglas W., Wahhaj, Zahed   +9 more
core   +1 more source

The coronagraphic Modal Wavefront Sensor: a hybrid focal-plane sensor for the high-contrast imaging of circumstellar environments [PDF]

, 2016
The raw coronagraphic performance of current high-contrast imaging instruments is limited by the presence of a quasi-static speckle (QSS) background, resulting from instrumental non-common path errors (NCPEs).
Keller, Christoph U., Korkiakoski, Visa, Pietrow, Alexander G. M., Snik, Frans, Wilby, Michael J.   +4 more
core   +3 more sources

Compatibility of a Diffractive Pupil and Coronagraphic Imaging [PDF]

Publications of the Astronomical Society of the Pacific, 2013
Detection and characterization of exo-earths require direct-imaging techniques that can deliver contrast ratios of 10(exp 10) at 100 milliarc-seconds or smaller angular separation. At the same time, astrometric data is required to measure planet masses and can help detect planets and constrain their orbital parameters. To minimize costs, a single space
Eduardo Bendek, Ruslan Belikov, Eugene Pluzhnik, Olivier Guyon   +3 more
openaire   +1 more source

Direct Measurement of Extinction in a Planet-hosting Gap

The Astronomical Journal
Recent disk observations have revealed multiple indirect signatures of forming gas giant planets, but high-contrast imaging has rarely confirmed the presence of the suspected perturbers.
Gabriele Cugno, Stefano Facchini, Felipe Alarcon, Jaehan Bae, Myriam Benisty, Anna-Christina Eilers, Gene C. K. Leung, Michael Meyer, Laurent Pueyo, Richard Teague, Edwin Bergin, Julien Girard, Ravit Helled, Jane Huang, Jarron Leisenring   +14 more
doaj   +1 more source

SPHERE: the exoplanet imager for the Very Large Telescope [PDF]

, 2019
Observations of circumstellar environments to look for the direct signal of exoplanets and the scattered light from disks has significant instrumental implications.
A. Baruffolo, A. Bazzon, A. Boccaletti, A. Costille, A. Delboulbé, A. Origné, A. Pavlov, A. Roux, A. Sevin, A. Vigan, A. Zurlo, A.-M. Lagrange, B. Le Ruyet, B. Salasnich, C. Dominik, C. Fabron, C. Ginski, C. Gry, C. Moutou, C. Petit, C. Soenke, D. Fantinel, D. Gisler, D. Le Mignant, D. Maurel, D. Mesa, D. Mouillet, D. Perret, D. Segransan, D. Tiphène, E. Cascone, E. Fedrigo, E. Giro, E. Hugot, E. Lagadec, E. Santambrogio, E. Stadler, F. Chapron, F. Madec, F. Ménard, F. Rigal, F. Vakili, F. Wildi, G. Chauvin, G. Farisato, G. Lessio, G. Rousset, G. Zins, H. Le Coroller, H. M. Schmid, J. Antichi, J. Baudrand, J. Charton, J. de Boer, J. Girard, J. Milli, J. Parisot, J. Pragt, J. Ramos, J.-F. Sauvage, J.-L. Beuzit, J.-L. Lizon, J.-M. Reess, K. Dohlen, L. Abe, L. B. F. M. Waters, L. Gluck, L. Lundin, L. Weber, M. Carbillet, M. Carle, M. Downing, M. Feldt, M. Jaquet, M. Kasper, M. Langlois, M. Llored, M. Marteaud, M. Saisse, M. Suarez, M. Turatto, N. Hubin, O. Dupuis, O. Möller-Nilsson, P. Baudoz, P. Bernardi, P. Blanchard, P. Bruno, P. Feautrier, P. Gigan, P. Martinez, P. Puget, P. Rabou, R. Barette, R. Brast, R. Claudi, R. Gratton, R. Roelfsema, R. Siebenmorgen, S. Desidera, S. Incorvaia, S. Rochat, S. Scuderi, S. Udry, T. Buey, T. Fusco, T. Henning, T. Moulin, U. Anselmi, V. De Caprio, Y. Magnard, Z. Wahhaj   +111 more
core   +3 more sources

Coronagraphic Data Post-processing Using Projections on Instrumental Modes

The Astrophysical Journal
Directly observing exoplanets with coronagraphs is impeded by the presence of speckles from aberrations in the optical path, which can be mitigated in hardware with wave front control, as well as in post-processing. This work explores using an instrument
Yinzi Xin, Laurent Pueyo, Romain Laugier, Leonid Pogorelyuk, Ewan S. Douglas, Benjamin J. S. Pope, Kerri L. Cahoy   +6 more
doaj   +1 more source

Speckle Space–Time Covariance in High-contrast Imaging

The Astronomical Journal, 2023
We introduce a new framework for point-spread function subtraction based on the spatiotemporal variation of speckle noise in high-contrast imaging data where the sampling timescale is faster than the speckle evolution timescale.
Briley Lewis, Michael P. Fitzgerald, Rupert H. Dodkins, Kristina K. Davis, Jonathan Lin   +4 more
doaj   +1 more source

Review of small-angle coronagraphic techniques in the wake of ground-based second-generation adaptive optics systems [PDF]

, 2012
Small-angle coronagraphy is technically and scientifically appealing because it enables the use of smaller telescopes, allows covering wider wavelength ranges, and potentially increases the yield and completeness of circumstellar environment - exoplanets
Barrett, Harrisson, Baudoz, Pierre, Belikov, Ruslan, Beuzit, Jean-Luc, Boccaletti, Anthony, Devaney, Nicolas, Girard, Julien, Gladysz, Szymon, Guyon, Olivier, Kasper, Markus, Krist, John, Lawson, Peter, Macintosh, Bruce, Marois, Christian, Mawet, Dimitri, Mennesson, Bertrand, Milli, Julien, Mouillet, David, Mugnier, Laurent, Murakami, Naoshi, Oppenheimer, Ben, Poyneer, Lisa, Pueyo, Laurent, Savransky, Dmitri, Serabyn, Eugene, Traub, Wesley, Trauger, John, Vérinaud, Christophe, Wallace, James K.   +28 more
core   +3 more sources

Mapping Ground-based Coronagraphic Images to Helioprojective-Cartesian Coordinate System by Image Registration

The Astrophysical Journal
A few ground-based solar coronagraphs have been installed in western China for observing the low-layer corona in recent years. However, determining the helioprojective coordinates for the coronagraphic data with high precision is an important but ...
Feiyang Sha, Yu Liu, Lidong Xia, Yao Chen, Qing Zhou, Yangrui Chen, Chuyu Zhong, Xuefei Zhang, Tengfei Song, Mingzhe Sun, Xiaoyu Yu, Haitang Li, Jacob Oloketuyi, Qiang Liu, Xinjian Wang, Qiwang Luo, Xiaobo Li   +16 more
doaj   +1 more source