A crucial test for astronomical spectrograph calibration with frequency combs

  title={A crucial test for astronomical spectrograph calibration with frequency combs},
  author={Rafael A. Probst and Dinko Milakovi{\'c} and B. Toledo-Padr{\'o}n and G. Lo Curto and Gerardo {\'A}vila and Anna Brucalassi and B. L. Canto Martins and Izan de Castro Le{\~a}o and Massimiliano Esposito and Jonay I. Gonz{\'a}lez Hern{\'a}ndez and Frank Grupp and Theodor W. H{\"a}nsch and Hanna Kellermann and Florian Kerber and Olaf Mandel and Antonio Manescau and Eszter Pozna and Rafael Rebolo and Jos{\'e} R. de Medeiros and Tilo Steinmetz and A. Su{\'a}rez Mascare{\~n}o and Thomas Udem and Josefina Urrutia and Yuanjie Wu and Luca Pasquini and Ronald Holzwarth},
  journal={Nature Astronomy},
Laser frequency combs (LFCs) are well on their way to becoming the next-generation calibration sources for precision astronomical spectroscopy 1 – 6 . This development is considered key in the hunt for low-mass rocky exoplanets around solar-type stars whose discovery with the radial-velocity method requires cm s –1 Doppler precision 7 . In order to prove such precise calibration with an LFC, it must be compared to another calibrator of at least the same precision. Being the best available… 

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