Oh now this is VERY cool! Denis+ on “Cold and eccentric: a high-spectral resolution view of 51 Eri b with VLT/HiRISE” where radial velocity measurements of the exoplanet enable a determination of the 3D orbit, and therefore you can calculate the PHASE as seen by Earth! #astrodon #exoplanet ☄

Possible orbits for the exoplanet 51 Eri b drawn around the star, along with the planet at two locations in its orbit showing a dayside illuminated disk and a nightside disk.
Matthew Kenworthy @kenworthy