The debris disk of HR 8799: do we need an extra planet?
Abstract
HR 8799 is so far the only system where multiple planets have been directly imaged. The planetary system is surrounded by an extremely faint debris disk, which detailed observations are now within reach thanks to the sensitivity and resolution power of ALMA. Prior observations of this disk at low ( 3) SNR in Band 6 (1.3 mm) led two different teams to derive two different values for the location of the disk inner edge: one result suggests that an additional planet should be present beyond the outermost planet HR 8799 b to carve this inner edge. The other one finds an inner edge location that is, on the contrary, compatible with HR 8799 b carving this inner edge. We present here new high angular resolution observations of this debris disk in Band 7 with ALMA, the most sensitive that were obtained so far, thanks to which we derive an inner edge consistent with the largest value derived from the modeling of the Band 6 emission, and thus confirm that the inner edge of the debris disk would require an additional planet beyond HR 8799 b to have been carved at this distance.
- Publication:
-
AAS/Division for Extreme Solar Systems Abstracts
- Pub Date:
- August 2019
- Bibcode:
- 2019ESS.....450106F