Part of a SPIRou frame recorded from the red dwarf star AD Leonis. Each group of three vertical bars corresponds to one spectral order, covering a
small region of the spectral domain. The two left-most vertical bars of each order contain the spectrum of the star (in two polarization states), whereas the right-most one contains a Fabry-Perot spectrum ensuring that velocimetric variation of the star can be monitored with sufficient precision. The spectral lines (along with telluric lines from the Earth’s atmosphere) show up as
darker horizontal bands in the image, forming a "cosmic barcode" of information about the star and any potential planets. Image: SPIRou team/CFHT. |