T arget: Epsilon Eridani (aka Rán)
Target Description: Solar-analog debris disk

Instrument: FORCAST
Spectral Elements: FOR_F348 (Single channel mode)
Central Wavelength: 34.8 microns
Bandwidth: 3.8 microns
Exposure times: 302 minutes total on-source
Observation dates: January, February, and November 2015

Proposal ID: 03_0092, 04_0015
Program PI: K. Su
Publication: Su et al., 2017, AJ, 153, 5
[DOI] https://doi.org/10.3847/1538-3881/aa696b


Technical Note

FORCAST was used with its 34.8-micron filter to obtain a deep mid-infrared image of the disk of eps Eri, which was resolved by approximately 2 beam widths (where the resolution of SOFIA at 34.8 microns is ~3.4”). Compared to the radial profile of the observed calibrators, the eps Eri profile is more extended in the 4”-10” (10-16 AU) range from the star, and this excess emission region is consistent with the in-situ dust distribution produced either (1) a single planetesimal belt at 3-21 AU or (2) by two narrower planetesimal belts at 1.5-2 AU (or 3-4 AU) and 8-20 AU. The observed disk profile is not consistent with proposed models where there is constant inward dust flow due to Poynting-Robertson and stellar wind drag from an outer cold Kuiper-belt analog located at a distance of 64 AU.