Discovery of an Extremely Red Object in the Field of HD 155826

Abstract

We have discovered an extremely red object, LSF 1, located 7" southwest (P.A. 217 degrees) of the bright spectroscopic binary system HD 155826. Originally reported by IRAS as one source detected at 12-60 ?m, and found as a single 6-25 ?m source of similar flux in the Midcourse Space Experiment Galactic plane survey, two bright point sources were found in arcsecond resolution infrared images obtained with the MIRLIN camera at the Infrared Telescope Facility and confirmed by the Long Wavelength Spectrometer camera on Keck I. While HD 155826 itself was easily detected in all the broadband and narrowband filters from 0.9 to 12 ?m that we used, the new counterpart, LSF 1, is only visible at 10 ?m. In Gunn z, J, H, and K', the upper limit to the new object's magnitude is ~14. The detection of the new bright IR source explains the confusing [K]-[N] IRAS colors that originally implied that HD 155826 was a possible Vega-like system. The ``anomalous long-wavelength emission'' is found to arise entirely from the new source. Without mid-IR extension or excess long-wavelength emission, HD 155826 should no longer be classified as a Vega-like system. We suspect LSF 1 to be either a highly reddened carbon star or a Class II YSO, with no association with the high proper motion HD 155826 system.