L1551NE - Discovery of a Binary Companion

Abstract

L1551NE is a very young (class 0 or I) low-mass protostar located close to the well-studied L1551 IRS5. We present here evidence, from 1.3mm continuum interferometric observations at ~1&#39;&#39; resolution, for a binary companion to L1551NE. The companion, whose 1.3mm flux density is ~1/3 that of the primary component, is located 1.43&#39;&#39; (~230 A.U. at 160pc) to the southeast. The millimeterwave emission from the primary component may have been just barely resolved, with deconvolved size ~0.82&#34;x0.70&#34; (~131x112 A.U.). The companion emission was unresolved (<100 A.U.). The pair is embedded within a flattened circum-binary envelope of size ~5.4&#39;&#39; x 2.3&#39;&#39; (~860 x 370 A.U.). The masses of the three components (i.e. from the cicumstellar material of the primary star and its companion, and the envelope) are approximately 0.044, 0.014 and 0.023 Mo respectively.