Top: Hɑ region of the second observation of 5235 from 5 May 2002, reduced as described here (black) and with default reduction parameters (red). One can clearly see the spurious emission on the blue side of the stellar Hɑ line core. Bottom: Hβ region of the observation of 7788 from 12 June 2002, reduced as described here (black) and with default reduction parameters (red). One can clearly see the spurious emission on the blue side of the stellar Hβ line core.