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Intensity interferometry removes the stringent requirements on mechanical precision and atmospheric corrections that plague all amplitude interferometry techniques at the cost of severely limited sensitivity. A new idea we recently introduced, very high redundancy, alleviates this problem. It enables the relatively simple construction (∼1 cm mechanical precision) of a ground-based astronomical facility able to transform a two-dimensional field of point-like sources to a three-dimensional distribution of microarcsec resolved systems, each imaged in several optical bands. Each system will also have its high-resolution residual timing, high-quality (inside each band) spectra and light curve, emergent flux, effective temperature, polarization effects and perhaps some thermodynamic properties, all directly measured. All the above attributes can be measured in a single observation run of such a dedicated facility. We conclude that after three decades of abandonment, optical intensity interferometry deserves another review, also as a ground-based alternative to the science goals of space interferometers. 相似文献
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C. Cavarroc C. Moutou D. Gandolfi B. Tingley M. Ollivier S. Aigrain R. Alonso J.-M. Almenara M. Auvergne A. Baglin P. Barge A. S. Bonomo P. Bordé F. Bouchy J. Cabrera S. Carpano L. Carone W. D. Cochran S. Csizmadia H. J. Deeg M. Deleuil R. F. Díaz R. Dvorak M. Endl A. Erikson M. Fridlund M. Gillon E. W. Guenther T. Guillot A. Hatzes G. Hébrard L. Jorda A. Léger H. Lammer T.-O. Lev C. Lovis P. J. MacQueen T. Mazeh A. Ofir H. Parviainen T. Pasternacki M. P?tzold D. Queloz H. Rauer D. Rouan B. Samuel A. Santerne J. Schneider J. Weingrill G. Wuchterl 《Astrophysics and Space Science》2012,337(2):511-529
CoRoT is a space telescope which aims at studying internal structure of stars and detecting extrasolar planets. We present here a list of transits detected in the light curves of stars observed by CoRoT in two fields in the anti-center direction: the LRa03 one observed during 148 days from 3 October 2009 to 1 March 2010 followed by the SRa03 one from the 5 March 2010 to the 29 March 2010 during 25 days. 5329 light curves for the LRa03 field and 4169 for the SRa03 field were analyzed by the detection team of CoRoT. Then some of the selected exoplanetary candidates have been followed up from the ground. In the LRa03 field, 19 exoplanet candidates have been found, 8?remain unsolved. No secured planet has been found yet. In the SRa03 field, there were 11 exoplanetary candidates among which 6 cases remain unsolved and 3 planets have been found: CoRoT-18b, CoRoT-19b, CoRoT-20b. 相似文献
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A. Ofir 《Monthly notices of the Royal Astronomical Society》2008,387(4):1597-1604
Transiting planets manifest themselves by a periodic dimming of their host star by a fixed amount. On the other hand, light curves of transiting circumbinary (CB) planets are expected to be neither periodic nor to have a single depth while in transit. These propertied make the popular transit-finding algorithm Box Least Squares (BLS) almost ineffective so a modified version of BLS for the identification of CB planets was developed – CB-BLS. We show that using this algorithm it is possible to find CB planets in the residuals of light curves of eclipsing binaries that have noise levels of 1 per cent and more – quality that is routinely achieved by current ground-based transit surveys. Previous searches for CB planets using variation in eclipse times minima of CM Dra and elsewhere are more closely related to radial velocity than to transit searches and so are quite distinct from CB-BLS. Detecting CB planets is expected to have significant impact on our understanding of exoplanets in general, and exoplanet formation in particular. Using CB-BLS will allow to easily harness the massive ground- and space-based photometric surveys in operation to look for these hard-to-find objects. 相似文献
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Aviv Cohen 《The Journal of geography》2018,117(2):51-63
Guided by the assumption that geography teaching is connected to nationalism and civic education, this study focused on the manifestation of different citizenship conceptions in the teaching of the land of Israel as implemented in the Israeli educational system. This historical content analysis of Israeli curricula resulted in a division into three periods. Whereas the first two periods reflected specific citizenship conceptions—nationalistic in the former and individualistic in the latter, the third period is characterized by an amalgamation of contradictory conceptions. These findings point to the potential and challenges facing geography education in creating a truly democratic space. 相似文献
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