DMPP-4: candidate sub-Neptune mass planets orbiting a naked-eye star
We present radial velocity measurements of the very bright (V ∼ 5.7) nearby F star, DMPP-4 (HD 184960). The anomalously low Ca II H&K emission suggests mass-loss from planets orbiting a low activity host star. Periodic radial velocity variability with ∼10 m s−1 amplitude is found to persist over...
| Autores: | , , , , , , , , , , , |
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| Formato: | artículo |
| Estado: | Versión publicada |
| Fecha de publicación: | 2023 |
| País: | España |
| Recursos: | Consejo Superior de Investigaciones Científicas (CSIC) |
| Repositorio: | DIGITAL.CSIC. Repositorio Institucional del CSIC |
| OAI Identifier: | oai:digital.csic.es:10261/347649 |
| Acesso em linha: | http://hdl.handle.net/10261/347649 |
| Access Level: | acceso abierto |
| Palavra-chave: | Methods: observational Techniques: photometric Techniques: radial velocities Techniques: spectroscopic Planets and satellites: detection Stars: late-type |
| Resumo: | We present radial velocity measurements of the very bright (V ∼ 5.7) nearby F star, DMPP-4 (HD 184960). The anomalously low Ca II H&K emission suggests mass-loss from planets orbiting a low activity host star. Periodic radial velocity variability with ∼10 m s−1 amplitude is found to persist over a >4 yr time-scale. Although the non-simultaneous photometric variability in four TESS sectors supports the view of an inactive star, we identify periodic photometric signals and also find spectroscopic evidence for stellar activity. We used a posterior sampling algorithm that includes the number of Keplerian signals, Np, as a free parameter to test and compare (1) purely Keplerian models (2) a Keplerian model with linear activity correlation and (3) Keplerian models with Gaussian processes. A preferred model, with one Keplerian and quasi-periodic Gaussian process indicates a planet with a period of Pb = 3.4982+0.0015 −0.0027 d and corresponding minimum mass of mb sin i = 12.2+1.8 −1.9 M⊕. Without further high-time resolution observations over a longer time-scale, we cannot definitively rule out the purely Keplerian model with two candidates planets with Pb = 2.4570+0.0026 −0.0462 d, minimum mass mb sin i = 8.0+1.1 −1.5 M⊕ and Pc = 5.4196+0.6766 −0.0030 d and corresponding minimum mass of mb sin i = 12.2+1.4 −1.6 M⊕. The candidate planets lie in the region below the lower-envelope of the Neptune Desert. Continued mass-loss may originate from the highly irradiated planets or from an as yet undetected body in the system. |
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