The CARMENES Search for Exoplanets Around M Dwarfs. Revisiting the GJ 581 Multi-planetary System with New Doppler Measurements from CARMENES, HARPS, and HIRES
GJ 581 is a nearby M dwarf known to host a packed multiple planet system with 2 super-Earths and a Neptune-mass planet. We present new orbital analyses of the system, utilizing recent RV data obtained from the CARMENES spectrograph combined with newly reprocessed archival data from the HARPS and HIRES spectrographs.
Our aim was to analyze the post-discovery spectroscopic data of GJ 581, which were obtained with CARMENES. In addition, we used publicly available HIRES and HARPS spectroscopic data to seek evidence of the known and disputed exoplanets in this system. We aimed to investigate the stellar activity of GJ 581 and update the planetary system’s orbital parameters using state-of-the-art numerical models and techniques. We performed a periodogram analysis of the available precise CARMENES, HIRES, and HARPS RVs and of stellar activity indicators.
We conducted detailed orbital analyses by testing various orbital configurations consistent with the RV data. We studied the posterior probability distribution of the parameters fit to the data and explored the long-term stability and overall orbital dynamics of the system. We refined the orbital parameters of the system using the most precise and complete set of Doppler data available. Consistent with the existing literature, we confirm that the system is unequivocally composed of only 3 planets detectable in the present data, dismissing the putative planet GJ 581 d as an artifact of stellar activity.
Our N-body fit reveals that the system’s inclination is i = 47.0 deg, which implies that the planets could be up to 30% more massive than their previously reported minimum masses. Furthermore, we report that the system exhibits long-term stability, as indicated by the posterior probability distribution, characterized by secular dynamical interactions without the involvement of mean motion resonances.
Injection-retrieval detection probability grids for CARMENES, HIRES, and HARPS, from left to right. Higher detection probabilities are marked with lighter colors. The location in the semi-amplitude-orbital period (K-P) diagram of the conjectural planet GJ 581 [d] is marked by a green dot. — astro-ph.EP
RVs, MLP periodogram, and best-fit model of GJ 581. Top panel: Precise Doppler measurements of GJ 581 from HIRES (purple circles), HARPS (orange diamonds), and CARMENES (pink triangles) modeled with a three-planet self-consistent N-body model simultaneously constructed with a GP component that fits the stellar activity periodicity in the RVs. The middle subpanel shows the residuals of the N-body model, where are effectively fit with the rotational kernel GP model. The bottom subpanel shows the data residuals to the total N-body+GP model. Middle panels: Phase folded data and N-body model for the three planetary signals as indicated in the subplots. Bottom panel: MLP periodogram of the RV model and GP residuals. No significant periodicity remains after the model is subtracted. — astro-ph.EP
A. von Stauffenberg, T. Trifonov, A. Quirrenbach, S. Reffert, A. Kaminski, S. Dreizler, I. Ribas, A. Reiners, M. KĂĽrster, J. D. Twicken, D. Rapetti, J. A. Caballero, P. J. Amado, V. J. S. BĂ©jar, C. Cifuentes, S. GĂłngora, A. P. Hatzes, Th. Henning, D. Montes, J. C. Morales, A. Schweitzer
Comments: 21 pages, 8 Figures, 5 Tables, 1 Appendix, Accepted for publication in A&A (20th March 2024), Data available at the CDS
Subjects: Earth and Planetary Astrophysics (astro-ph.EP)
Cite as: arXiv:2407.11520 [astro-ph.EP] (or arXiv:2407.11520v1 [astro-ph.EP] for this version)
https://doi.org/10.48550/arXiv.2407.11520
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Related DOI:
https://doi.org/10.1051/0004-6361/202449375
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Submission history
From: Antonia Von Stauffenberg
[v1] Tue, 16 Jul 2024 08:59:52 UTC (30,021 KB)
https://arxiv.org/abs/2407.11520
Astrobiology,
