We have studied the photo-fragmentation of the HBC cation -C42H18+- a large PAH cation of potential astrophysical interest. HBC cation photo-fragment patterns are measured upon irradiation by an unfocused Nd:YAG laser (532 nm) for different experimental conditions, using quadrupole ion trap, time-of-flight mass spectrometry. Both stepwise dehydrogenation of C42H18+ and C-2/C2H2 loss pathways are identified as relevant photodissociation routes. (C) 2013 Elsevier B.V. All rights reserved.