51 Eri is well known for hosting a directly imaged giant planet and for its membership to the
We analyzed 20 s cadence Transiting Exoplanet Survey Satellite time-series photometry of the exoplanet host star HR 8799 collected in Sector 56. The amplitude spectrum shows Gamma Doradus (
- Publication Date:
- NSF-PAR ID:
- 10389795
- Journal Name:
- Research Notes of the AAS
- Volume:
- 7
- Issue:
- 1
- Page Range or eLocation-ID:
- Article No. 2
- ISSN:
- 2515-5172
- Publisher:
- DOI PREFIX: 10.3847
- Sponsoring Org:
- National Science Foundation
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Abstract β Pictoris moving group. Using 2 minute cadence photometry from the Transiting Exoplanet Survey Satellite (TESS), we detect multiperiodic variability in 51 Eri that is consistent with pulsations of Gamma Doradus (γ Dor) stars. We identify the most significant pulsation modes (with frequencies between ∼0.5 and 3.9 cycles day−1and amplitudes ranging between ∼1 and 2 mmag) as dipole and quadrupole gravity modes, as well as Rossby modes, as previously observed in Keplerγ Dor stars. Our results demonstrate that previously reported variability attributed to stellar rotation is instead likely due toγ Dor pulsations. Using the mean frequency of theℓ = 1 gravity modes, together with empirical trends of the Keplerγ Dor population, we estimate a plausible stellar core rotation period of days for 51 Eri. We find no significant evidence for transiting companions around 51 Eri in the residual light curve. The detection ofγ Dor pulsations presented here, together with follow-up observations and modeling, may enable the determination of an asteroseismic age for this benchmark system. Future TESS observations would allow a constraint on the stellar core rotation rate, which in turn traces the surface rotation rate, andmore » -
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