simultaneous wavelength calibration (i.e. the on-sky calibration fiber) to ensure that the bluer spectral regions would not be contaminated by the calibration lamp, that provides a much stronger flux for any instrumental setup.. The exposure time was set to 900 s for ESO programs 198.C-0838 and 1102.C-0339, and to 1[,]{}200 s for ESO program 0101.C-0510, translating in a median signal-to-noise ratio per spectral pixel of 51 and 70 at 650 nm, respectively. A single spectrum on October 1, 2018, had an exposure time of 609 s for an unknown reason. A total of 47 HARPS spectra were collected, ending with observations on December 19, 2018.

HARPS spectra were acquired in roughly three packs of data separated in time by about 40 days. This sampling is reflected in the window function presented in Figure \[fig:GLSP\]. Two archival spectra of L 168-9 are available at the ESO database. However, a radial velocity offset was introduced on May 2015 because the vacuum vessel was opened during a fiber upgrade [@LoCurto2015]. As this offset is not yet well characterized for M dwarfs, we decided to disregard those two points (from July 2008 and June 2009) in our subsequent analysis.

The HARPS Data Reduction Software 