Direct Imaging Confirmation and Characterization of a Dust-Enshrouded Exoplanet Orbiting Fomalhaut
Abstract
We present Subaru/IRCS J band data for Fomalhaut and a (re)reduction of archival 2004--2006 HST/ACS data first presented by Kalas et al. (2008). We confirm the existence of a candidate exoplanetary companion, Fomalhaut b, in both the 2004 and 2006 F606W data sets at a high signal-to-noise. Additionally, we confirm the detection at F814W and present a new detection in F435W. Fomalhaut b's space motion may be consistent with it being in an apsidally-aligned, non debris ring-crossing orbit, although new astrometry is required for firmer conclusions. We cannot confirm that Fomalhaut b exhibits 0.7-0.8 mag variability. The new, combined optical SED and IR upper limits confirm that emission identifying Fomalhaut b originates from starlight scattered by small dust, but this dust must be bound to a massive body. The new Subaru upper limits and IRAC/4.5 μm upper limits imply M < 2 M_{J}, but this is still consistent with the range of Fomalhaut b masses it would need to sculpt the disk. Much like for the protoplanet LkCa 15 b, Fomalhaut b is very plausibly ``a planet identified from direct imaging" even if current images of it do not, strictly speaking, show thermal emission from a directly imaged planet.
- Publication:
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American Astronomical Society Meeting Abstracts #221
- Pub Date:
- January 2013
- Bibcode:
- 2013AAS...22132405C