Abstract

Spectrophotometry of the common-proper-motion pair ESO 440-55a/55b indicates that 440-55a (mV ≈ 19.3) is a DZ 7 showing lines of Ca II, Ca I, Mg I, and Fe I, with no He or H lines present, while 440-55b is an M5 red dwarf with mV ≈ 20.2. Its proper motion μ = 0.22±0.04arcsec/yr (θ = 273°) at an estimated distance of 120 pc implies a tangential velocity vT = 125 km s-1 and a separation between the stars of 9.4×1015cm.