De Marchi, Guido; Panagia, Nino; Guarcello, M. G.; Bonito, Rosaria
(2013)
Attention is given to a population of 110 stars in the NGC 6611 cluster of the Eagle nebula that have prominent near-infrared excess and optical colours typical of pre-main-sequence (PMS) stars older than 8 Myr. At least ...