On February 7, ESA released the first test image taken by the CHEOPS (Characterizing ExOPlanet Satellite) space telescope. In the center of the image can be seen the star HD 70843. It is a yellow dwarf located 150 light-years from the Sun. The star was chosen as the first subject for shooting because of its brightness and convenient position.
It should be noted that the CHEOPS image is out of focus. This is done on purpose. The telescope will take such images to distribute the starlight over as many pixels as possible. This makes it possible to smooth out errors caused by vibrations of the telescope itself and deviations between pixels, which makes it possible to increase the accuracy of photometric measurements.
The mission said the first CHEOPS images were smoother and more symmetrical than simulated images taken in laboratory conditions. In the coming weeks, engineers will continue to test surveys to ensure that the telescope's optical system is operating as intended. It is expected to begin its main scientific program in early April.
CHEOPS is designed to search for exoplanets by the transit method. The device will track small changes in the brightness of stars that occur during the passage of exoplanets across its disk. The main objectives of the observations will be objects with masses in the range between the mass of the Earth and Neptune. The emphasis will be on the study of already known worlds. CHEOPS will have to clarify their dimensions. Combined with spectrometric observations, this will allow astronomers to calculate their average densities and find out if they are rocky bodies (like our Earth), or if gases prevail in their composition and they resemble Jupiter or Neptune.