Origin and Evolution of the Cepheus Bubble

The Cepheus bubble is a giant shell with a diameter of about 120pc, discovered by Kun (1987) from IRAS sky flux maps. We have imaged this 10° × 10° region in the CO J=1-0 line, using the FCRAO Quarry system with sample spacing equal to the 45″ FWHM beam width. We estimate the total molecular gas mass to be ∼105 solar masses and a total kinetic energy ∼1051 ergs. We find 49 O and B0–B2 type stars in the Cepheus bubble region, most belong to the CepOB2 association. 120 IRAS point sources, selected according to color criteria representative of young stellar objects, fall within our map. Many of these sources are associated with the globules and filamentary structures seen in the CO emission, similar to the situation found in IC1396 (Patel et al. 1995). These stars, which are still associated with dense molecular gas plausibly represent the third and youngest generation of stars in this region.