Signatures of rocky planet engulfment in HAT-P-4 - Implications for chemical tagging studiesC. Saffe, E. Jofré, E. Martioli, M. Flores, R. Petrucci and M. Jaque ArancibiaA&A, 604 (2017) L4DOI: https://doi.org/10.1051/0004-6361/201731430