Collaborators @ UT: Tom Allen (Ph.D. student: project lead), Nicole Karnath (Ph.D. student),  Tyler Frey (Undergraduate), Tom Megeath

With approximately 3000 members, the Cepheus OB3b is one of the two most massive, young (< 6 Myr) clusters known within 1 kpc of the Sun.  At a distance of 700 pc, it appears to be similar to the Orion Nebula Cluster (ONC) in size and number of young stars.  However, it has mostly cleared its gas and appears to be older than the ONC (3-4 Myr vs 1-2 Myr median age).   We have embarked on a program to study this cluster through imaging and spectroscopy using Spitzer, Chandra, Herschel, NOAO 0.9 meter, DCT and MMT telescopes.  These data are providing a detailed study of the properties of the stars, the age of the cluster, and the evolution of disks around the member stars.  The publications can be found here.

Image: visible light image of Cep OB3b obtained by Tom Allen with mosaic imager on NOAO 0.9 meter