tokens: We are grateful to Dr J. S. Jenkins for discussions that led to important improvements of this Letter. C.L. acknowledges the financial support of the Swiss National Science Foundation (SNSF). This research made use of Astropy 2 (Astropy Collaboration 2013) , and of the SIMBAD (Wenger et al. 2000) , VIZIER (CDS, Strasbourg, France) and NASA’s Astrophysics Data System databases.
ner_tags: O O O O B-Person I-Person I-Person I-Person O O O O O O O O O O B-Person O O O O O O B-Organization I-Organization I-Organization I-Organization B-Organization O O O O O B-Software I-Software B-Citation I-Citation I-Citation O O O O B-Database B-Citation I-Citation I-Citation I-Citation O B-Database B-Organization B-Location I-Location O B-Archive I-Archive I-Archive I-Archive O