ISM DUST GRAINS AND N-BAND SPECTRAL VARIABILITY IN THE SPATIALLY RESOLVED SUBARCSECOND BINARY UY Aur
- Steward Observatory, Department of Astronomy, University of Arizona, Tucson, AZ 85721 (United States)
- NASA Ames Research Center, Moffett Field, CA 94035 (United States)
- Space Telescope Science Institute, Baltimore, MD 21218 (United States)
The 10 {mu}m silicate feature is an essential diagnostic of dust-grain growth and planet formation in young circumstellar disks. The Spitzer Space Telescope has revolutionized the study of this feature, but due to its small (85 cm) aperture, it cannot spatially resolve small/medium-separation binaries ({approx}<3''; {approx}< 420 AU) at the distances of the nearest star-forming regions ({approx}140 pc). Large, 6-10 m ground-based telescopes with mid-infrared instruments can resolve these systems. In this paper, we spatially resolve the 0.''88 binary, UY Aur, with MMTAO/BLINC-MIRAC4 mid-infrared spectroscopy. We then compare our spectra to Spitzer/IRS (unresolved) spectroscopy, and resolved images from IRTF/MIRAC2, Keck/OSCIR, and Gemini/Michelle, which were taken over the past decade. We find that UY Aur A has extremely pristine, interstellar medium (ISM)-like grains and that UY Aur B has an unusually shaped silicate feature, which is probably the result of blended emission and absorption from foreground extinction in its disk. We also find evidence for variability in both UY Aur A and UY Aur B by comparing synthetic photometry from our spectra with resolved imaging from previous epochs. The photometric variability of UY Aur A could be an indication that the silicate emission itself is variable, as was recently found in EX Lupi. Otherwise, the thermal continuum is variable, and either the ISM-like dust has never evolved, or it is being replenished, perhaps by UY Aur's circumbinary disk.
- OSTI ID:
- 21394300
- Journal Information:
- Astrophysical Journal, Vol. 711, Issue 2; Other Information: DOI: 10.1088/0004-637X/711/2/1280; ISSN 0004-637X
- Country of Publication:
- United States
- Language:
- English
Similar Records
Circumbinary ring, circumstellar disks, and accretion in the binary system UY Aurigae
Variable accretion processes in the young binary-star system UY Aur