A dim candidate companion to ε Cephei

Abstract

Using a vector vortex coronagraph behind the 1.5 m well-corrected subaperture (WCS) at Palomar, we detected a second object very close to ε Cephei, a δ Scuti F0 IV star. The candidate companion, 50 times fainter than ε Cephei, if physically associated, is a late-type K or early M star, and lies at an angular separation of 330mas, or 1.1 λ/D for the WCS, making it the smallest angle detection ever realized with a coronagraph in terms of λ/D units. The projected separation of the putative companion is 8.6 AU, most likely on a highly eccentric orbit. The recently detected near-infrared excess is thus likely not due to hot dust. Moreover, we also show that the previously reported IRAS 60 μm excess was due to source confusion on the galactic plane. © 2011. The American Astronomical Society. All rights reserved.