An Etymological Dictionary of Astronomy and Astrophysics
English-French-Persian

In an → image, the degree of distinction between areas with different → brightness levels; in other words, the → ratio of the brightness between light and → dark areas.

From Fr. contraster, from It. contrastare "stand out against," from V.L. *contrastare "to withstand," from L. → contra- "against" + stare "to stand," (cf. Pers. istâdan "to stand," O.Pers./Av. sta- "to stand, stand still; set," Skt. sthâ- "to stand," Gk. histemi "put, place, weigh," PIE base *sta- "to stand").

Pâdsâni, from pâd- "agianst," → contra- + sân "manner, semblance," variant sun, Mid.Pers. sân "manner, kind," Sogdian šôné "career" + -i noun suffix.

The → extreme adaptive optics system and → coronagraphic facility at the → European Southern Observatory (ESO) → Very Large Telescope (VLT) (UT3) available from May 2014. Its primary science goal is imaging, low-resolution spectroscopic, and polarimetric characterization of → exoplanetary system at → visible and → near-infrared wavelengths (0.5-2.32 μm). SPHERE is capable of obtaining → diffraction-limited images at 0''.02 to 0''.08 resolution depending on the wavelength. Its → spectral resolution is 30 to 350, depending on the mode.

→ spectro-; → polarimetric; → high; → contrast; → exoplanet.