Stellar activity and magnetism studied by optical interferometry
نویسندگان
چکیده
منابع مشابه
Optical Path Stability and Fringe Tracking in Optical Stellar Interferometry
In this paper we analyze the problems of fringe pattern estimation in optical stellar interferometry that are associated with optical path errors. Our rst nding is that an optimal fringe tracking system must track with path length errors of less than about one-eighth of the coherence length. The second is that if phase closure estimation is to be achieved at the lowest possible light levels, th...
متن کاملDifferential path considerations in optical stellar interferometry.
A formulation of the differential-air-path problem for a large-baseline optical interferometer is presented. Because air is a dispersive medium, each wavelength has a different optical path length. This can be corrected to a large extent if an extra piece of glass is placed in each arm of the interferometer. The problem then becomes analogous to the doublet-achromat design, in which, in this ca...
متن کاملFemtosecond spectral interferometry of optical activity: theory.
Optical activities such as circular dichroism (CD) and optical rotatory dispersion (ORD) are manifested by almost all natural products. However, the CD is an extremely weak effect so that time-resolved CD spectroscopy has been found to be experimentally difficult and even impossible for vibrational CD with current technology. Here, we show that the weak-signal and nonzero background problems ca...
متن کاملOptical qubit by conditional interferometry
We suggest a method to prepare any chosen superposition a0|0〉 + a1|1〉 of the vacuum and one-photon states. The method is based on a conditional double-interferometer fed by an one-photon state and a coherent state. The scheme involves only linear optical elements and avalanche photodetectors, and therefore it should be realizable with current technology. A realistic description of the triggerin...
متن کاملNew model and application to stellar interferometry
Measurement of a star’s apparent diameter with an intensity interferometer yields its geometrical radius and its effective temperature when one knows or measures the specific centre to limb-darkening. This paper presents a formulation that (1) makes use of a single parameter and (2) is well suited for the interpretation and comparison of centre to limb darkening. Subsequently, this result is ap...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2004
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:20040151