Free Access

Fig. 2


Comparison of an average-combined spectrum and its individual exposures for β UMi (K4III). Thex-axes are wavelengths in Å. The 22 individual exposures are shown as lines, the average combined “deep spectrum” as dots. Panel a: a 0.8-Å section showing the 22 exposures of the K I 7699 Å line profile. The y-axis is relative intensity. No differences can be seen at this plot scale. Panel b: a zoom into a 0.08-Å subsection of the line core. The spacing of the dots represent the CCD pixel dispersion. Panel c: S/N per pixel in the K I line core for the same spectral window as in panel b.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.