Another criteria of an Earth analog is that it should orbit a solar analog, that is, a star much like our Sun, similar photometrically or in terms of spectral type.
12.
Heweliusz photometrically measures low-level oscillations and temperature variations in stars brighter than visual magnitude ( 4.0 ), with unprecedented precision and temporal coverage not achievable through terrestrial based methods.
13.
For that reason, a spectroscopic redshift is conventionally regarded as being necessary for an object's distance to be considered definitely known, whereas photometrically determined redshifts identify " candidate " very distant sources.
14.
All graphic elements ( images and text ) are first converted from given gamma space ( according to known or assumed gamma information in PNG, JPEG etc . ) through known user gamma setting into a 48 bits per pixel photometrically linear space where they are resampled with bilinear resampling to the target size, possibly taking aspect ratio correction into account.
