The evolution of PUCHEROS from a basic to a competitive tool for stellar astrophysics

We present PUCHEROS +, a new spectrograph developed as an enhanced version of PUCHEROS (Pontificia Universidad Catolica High Echelle Resolution Optical Spectrograph), which was the first high-resolution spectrograph built at the Pontificia Universidad Catolica de Chile (UC). With respect to its predecessor, PUCHEROS + includes a substantial number of improvements, mainly: a new scientific detector, improved objective optics, calibration system, guiding, active thermal control, and remote observing mode. These upgrades convert our early prototype into a much more powerful instrument for science. With a spectral resolution of R = 18000, a spectral range between 400 and 730 nm and an instrument efficiency of about 30 per cent, PUCHEROS + was tested at the ESO (European Southern Observatory) 1.52-m telescope where it has reached a limiting magnitude of about 12 in V band and radial velocity precision of about 30 m/s. The instrument was conceived as a pathfinder for the high-resolution echelle spectrograph PLATOSpec and at the same time, it demonstrates that a compact, relatively low-cost spectrograph can be efficiently employed for long-term monitoring campaigns and as support facility for space missions, in particular if operated remotely at relatively small- or medium-sized telescopes.