A SEARCH FOR CIRCUMSTELLAR DUST AROUND HR-10, A PROPOSED BETA-PICTORIS STAR

We present archival IRAS data and recent IUE observations of the A shell star HR 10 (HD 256). HR 10 is detected in the IRAS Faint Source Survey and ADDSCAN data at 12 and 25-mu-m and marginally detected at 60-mu-m. The IUE data indicate a spectral type of A2 with 0.1 mag of UV selective extinction following a galactic average extinction law. HR 10 shows an infrared excess, compared to normal A stars of the same spectral type, beginning at 12-mu-m and extending to longer wavelengths. The IR excess is consistent with free-free emission and a suggestion of CS dust. The IR colors for this star differ significantly from those of beta Pic and are closer to those of Vega. The absence of circumstellar selective extinction shortward of 3200 angstrom suggests that the circumstellar grain size distribution does not resemble that of the interstellar medium, but may be more like the grains around Vega and beta-Pic.