3406 20180116112342.0 10.1051/epjconf/201715205010 DOI SCART-2018-0019 Irrgang, A. The evolved slowly pulsating B star 18 Peg. A testbed for upper main sequence stellar evolution 2017 The predicted width of the upper main sequence in stellar evolution models depends on the empirical calibration of the convective overshooting parameter. Despite decades of discussions, its precise value is still unknown and further observational constraints are required to gauge it. Irrgang et al. ([1]) showed that the B3 III giant 18 Peg is one of the most evolved members of the class of slowly pulsating B (SPB) stars and, thus, bears tremendous potential to derive a tight lower limit for the width of the upper main sequence. In addition, 18 Peg turns out to be part of a single-lined spectroscopic binary system with an eccentric, more than 6-year orbit. The orbital solution, in combination with the absence of additional signatures of the secondary component in the spectroscopic data and the spectral energy distribution, lead to the conclusion that all the observations of 18 Peg are fully compatible with the assumption that the secondary component is either a main-sequence star with a mass of 1-4 M⊙ or a neutron star. NO De Cat, P. Tkachenko, A. EPJ Web of Conferences 152 2017 id. 05010 1-2 peter@observatoire.be https://www.epj-conferences.org/articles/epjconf/abs/2017/21/epjconf_puls2017_05010/epjconf_puls2017_05010.html 134748 http://publi2-as.oma.be/record/3406/files/Irrgang2017_EPJWC152_05010.pdf 3983 http://publi2-as.oma.be/record/3406/files/Irrgang2017_EPJWC152_05010.gif?subformat=icon icon 4304 http://publi2-as.oma.be/record/3406/files/Irrgang2017_EPJWC152_05010.jpg?subformat=icon-180 icon-180 published in NONREF