Constraints on the Evolution of Remnant Protostellar Dust Debris around HR 4796

Abstract

We have obtained optical spectra and J, H, K, and 20 μm photometry of the components of HR 4796, whose component A (m V =5.8 mag) is a main-sequence A-type star with a large fractional infrared excess (L IR /L * =5×10 −3 ), produced by circumstellar dust. Component B (m V =12.7 mag), located 7″.7 away from component A, is an early M-type star. During the past 60 years, it appears that HR 4796A and B have had nearly the same proper motion; they are likely to be a physical pair. The luminosity of HR 4796B is about 0.15 L ○. , and with T eff ∼3300 K, it lies well above the main sequence, and thus has an estimated age of about 3×10 6 years