相关论文: High Dynamic Range and the Search for Planets

We conducted a number of multi-band coronagraph experiments using a vacuum chamber and a binary-shaped pupil mask which in principle should work at all wavelengths, in the context of the research and development on a coronagraph to observe…

We use a Lucky Imaging system to obtain I-band images with much improved angular resolution on a ground-based 2.5m telescope. We present results from a 10-night assessment campaign on the 2.56m Nordic Optical Telescope and quantify the…

High contrast imaging searches for exoplanets have been conducted on 2.4-10 m telescopes, typically at H band (1.6 microns) and used exposure times of ~1 hr to search for planets with semi-major axes of > ~10 AU. We are beginning to plan…

The scientific interest in directly image and identifying Earth-like planets within the Habitable Zone (HZ) around nearby stars is driving the design of specialized direct imaging mission such as ACESAT, EXO-C, EXO-S and AFTA-C. The inner…

We propose and evaluate the feasibility of a new strategy to search for planets via microlensing observations. This new strategy is designed to detect planets in "wide" orbits, i.e., with orbital separation, a, greater than ~1.5 R_E.…

We describe a new series of band-limited image masks for coronagraphy that are insensitive to pointing errors and other low-spatial-frequency optical aberrations. For a modest cost in throughput, these ``eighth-order'' masks would allow the…

So far, most of the about 5700 exoplanets have been discovered mainly with radial velocity and transit methods. These techniques are sensitive to planets in close orbits, not being able to probe large star--planet separations. $\mu$-lensing…

Searching for extrasolar planets by direct detection is extremely challenging for current instrumentation. Indirect methods, that measure the effect of a planet on its host star, are much more promising and have indeed led to the discovery…

The vast majority of known extrasolar planets orbit stars with a narrow range of masses (0.7-1.3 M_sun). Recent years have seen rapid growth in our knowledge about the properties of planetary systems with host stars significantly more…

A modified version of the folded aplanatic Gregory telescope equipped with a spherical two-lens corrector is proposed for observations requiring a high signal-to-noise ratio. The basic telescope model has an aperture of 400 mm (f/3.0), its…

Gravitational microlensing is a new technique that allows low-mass exoplanets to be detected at large distances of ~7kpc. This paper briefly outlines the principles of the method and describes the observational techniques. It shows that…

This study is focused on the very high dynamic imaging field, specifically the direct observation of exoplanetary systems. The coronagraph is an essential technique for suppressing the star's light, making it possible to detect an exoplanet…

In this paper is presented an analytical study of the azimuthal phase-mask coronagraph currently envisioned for detecting and characterizing extra-solar planets. Special emphasis is put on the physical and geometrical interpretation of the…

Our understanding of extra-solar planet systems is highly driven by advances in observations in the past decade. Thanks to high precision spectrograph, we are able to reveal unseen companions to stars with the radial velocity method. High…

We summarize the scientific potential of high contrast optical space imaging for studies of extrasolar planets, debris disks, and planet formation. The unique scientific capabilities offered by a 2-m class optical telescope, the technical…

A measurement by microlensing of the planetary mass function of planets with masses ranging from 5M_E to 10M_J and orbital radii from 0.5 to 10 AU was reported recently. A strategy for extending the mass range down to (1-3)M_E is proposed…

Phase masks coronagraphs can be seen as linear systems that spatially redistribute, in the pupil plane, the energy collected by the telescope. Most of the on-axis light must ideally be rejected outside the aperture to be blocked with a Lyot…

Several mission concepts are being studied to directly image planets around nearby stars. It is commonly thought that directly imaging a potentially habitable exoplanet around a Sun-like star requires space telescopes with apertures of at…

Several Extreme Adaptive Optics (XAO) systems dedicated to the detection and characterisation of the exoplanets are currently in operation for 8-10 meter class telescopes. Coronagraphs are commonly used in these facilities to reject the…

With sub-microarcsecond angular accuracy, the \theia telescope will be capable of revealing the architectures of nearby exoplanetary systems down to the mass of Earth. This research addresses the challenges inherent in space astrometry…