Transit Timing Variations for AU Microscopii b & c
Abstract
AU Mic is a relatively bright, nearby (9.7 pc), young (22 Myr) M1V pre-main sequence star hosting two transiting exoplanets AU Mic b and c and a spatially-resolved outer dusty debris disk. This research explores the transit timing variations (TTVs) of AU Mic b and c. For AU Mic b, we present three Spitzer/IRAC (4.5 μm) transits (two new), five TESS Cycle 1 and 3 transits, 11 LCO transits, one PEST-0.30m transit, one Brierfield-0.36m transit, and two transit timing measurements from Rossiter-McLaughlin observations; for AU Mic c, we present three TESS Cycle 1 and 3 transits. We use EXOFASTv2 to jointly model the transits and to obtain the midpoint transit times. We then construct an O-C diagram to map the TTVs. We model the TTVs for AU Mic b and c with Exo-Striker to recover constraints on the mass for AU Mic c. We compare the TTV-derived constraints to a recent radial-velocity mass determination. The results demonstrate that the AU Mic planetary system is dynamically interacting producing detectable TTVs, and the implied orbital dynamics may inform future constraints on the formation mechanisms for this young planetary system. However, stellar activity from flares and rotational spot modulation complicate our analysis of this young system. We recommend future TTV observations of AU Mic b and c to further constrain the dynamical masses and to search for additional planets in the system.
- Publication:
-
Posters from the TESS Science Conference II (TSC2)
- Pub Date:
- July 2021
- DOI:
- 10.5281/zenodo.5114040
- Bibcode:
- 2021tsc2.confE...7W
- Keywords:
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- Exoplanets;
- Stars: activity;
- Stars: individual: AU Mic;
- Techniques: photometric;
- Techniques: transit;
- Techniques: transit timing variation;
- Zenodo community tsc2