A cluster of class I/f/II young stellar objects discovered near the Cepheid SU Cas


E-mail: dmajaess@cygnus.smu.ca


Preliminary constraints are placed on a cluster of young stellar objects (J2000 02:54:31.4 +69:20:32.5) discovered in the field of the classical Cepheid SU Cas. The Wide-field Infrared Survey Explorer (WISE) 3.4-, 4.6-, 12- and 22-μm images reveal that the cluster deviates from spherical symmetry and exhibits an apparent diameter of 3 × 6 arcmin. Spectral energy distributions constructed using the Two Micron All Sky Survey (2MASS) Ks (2.2 μm) and WISE photometry indicate that 19 (36 per cent) class I, 21 (40 per cent) class f and 13 (25 per cent) class II objects lie r < 3 arcmin from the cluster centre. Conversely, 11 (18 per cent) class I, 13 (21 per cent) class f and 37 (61 per cent) class II objects were detected for r > 3 arcmin. Approximately 50 per cent of the class I sources within r < 3 arcmin were classified solely using WISE photometry owing to the absence of detections by 2MASS.