The near-infrared and ice-band variability of Haro 6-10

¹ Max-Planck-Institut für Astronomie, Königstuhl 17, 69117 Heidelberg, Germany
² State University of New York at Stony Brook, Stony Brook, NY 11974-3800, USA
³ Visiting Astronomer at the Infrared Telescope Facility, which is operated by the University of Hawaii under contract to the National Aeronautics and Space Administration
⁴ University of Wyoming, Laramie, WY 82071, USA

Corresponding author: Ch. Leinert, leinert@mpia-hd.mpg.de

Received: 1 December 2000
Accepted: 19 January 2001

Abstract

We have monitored the angularly resolved near infrared and 3.1 μm ice-band flux of the components of the young binary Haro 6-10 on 23 occasions during the years 1988 to 2000. Our observations reveal that both the visible star Haro 6-10 (Haro 6-10S) and its infrared companion (Haro 6-10N) show significant variation in flux on time scales as short as a month. The substantial flux decrease of Haro 6-10S over the last four years carries the reddening signature of increased extinction. However, a comparable K-band flux increase observed in the IRC is associated with a dimming in the H-band and cannot be explained by lower extinction. Absorption in the 3.1 μm water-ice feature was always greater towards the IRC during our observations, indicating a larger amount of obscuring material along its line of sight. We detect variability in the ice-band absorption towards Haro 6-10S and Haro 6-10N, significant at the 3.5σ and 2.0σ levels, respectively.