Tracking Advanced Planetary Systems (TAPAS) with HARPS-N

Niedzielski, A.; Villaver, E.; Wolszczan, A.; Adamów, M.; Kowalik, Kacper; Maciejewski, G.; Nowak, G.; García-Hernández, D. A.; Deka, B.; Adamczyk, M.

doi:10.1051/0004-6361/201424399

Cited by 35 publications

(31 citation statements)

References 119 publications

(113 reference statements)

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“…Although their initial conditions are different from ours, the fraction of migrating planets obtained in these studies and their orbital distribution are comparable to what is obtained in our study. For example, the fraction (∼1%) and orbits of migrating planets displayed in Figure 10 of Petrovich (2015a) are clearly similar to those shown in our Figure 5. This suggests that while the perturber plays the fundamental role in inducing the planetary LK oscillations, the perturber properties are likely to not impact our general results.…”

Section: Discussionsupporting

confidence: 85%

Dynamical Constraints on the Origin of Hot and Warm Jupiters With Close Friends

Antonini

Hamers

Lithwick

2016

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Gas giants orbiting their host star within the ice line are thought to have migrated to their current locations from farther out. Here we consider the origin and dynamical evolution of observed Jupiters, focusing on hot and warm Jupiters with outer friends. We show that the majority of the observed Jupiter pairs (20 out of 24) are dynamically unstable if the inner planet is placed at 1 au distance from the stellar host. This finding is at odds with formation theories that invoke the migration of such planets from semimajor axes 1 au due to secular dynamical processes (e.g., secular chaos, Lidov-Kozai [LK] oscillations) coupled with tidal dissipation. In fact, the results of N-body integrations show that the evolution of dynamically unstable systems does not lead to tidal migration but rather to planet ejections and collisions with the host star. This and other arguments lead us to suggest that most of the observed planets with a companion could not have been transported from farther out through secular migration processes. More generally, by using a combination of numerical and analytic techniques, we show that the high-e LK migration scenario can only account for less than 10% of all gas giants observed between 0.1 and 1 au. Simulations of multiplanet systems support this result. Our study indicates that rather than starting on highly eccentric orbits with orbital periods above 1 yr, these "warm" Jupiters are more likely to have reached the region where they are observed today without having experienced significant tidal dissipation.

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Section: Discussionsupporting

confidence: 85%

Dynamical Constraints on the Origin of Hot and Warm Jupiters With Close Friends

Antonini

Hamers

Lithwick

2016

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“…We also observed HD 107028 with the 3.58 m Telescopio Nazionale Galileo (TNG) and its High Accuracy Radial Velocity Planet Searcher for the Northern hemisphere (HARPS-N, Cosentino et al 2012) and with the 1.2 m Mercator telescope and Hermes spectrograph (Raskin et al 2011). The instrumental setups, reduction, and radial velocity measurements for HET/HRS and TNG/HARPS-N were described in detail in Niedzielski et al (2015;hereafter Paper I). We obtained a total of sixteen HET/HRS spectra with a typical signal-to-noise ratio (S/N) of 150−200 and 22 TNG/HARPS-N spectra with S/N of 30−100.…”

Section: Observations and Data Reductionmentioning

confidence: 99%

Tracking Advanced Planetary Systems (TAPAS) with HARPS-N

Adamów

Niedzielski

Villaver

et al. 2015

A&A

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Context. Lithium-rich giant stars are rare objects. For some of them, Li enrichment exceeds the abundance of this element found in solar system meteorites, suggesting that these stars have gone through a Li enhancement process. Aims. We identified a Li-rich giant HD 107028 with A(Li) > 3.3 in a sample of evolved stars observed within the PennState Toruń Planet Search. In this work we study different enhancement scenarios and we try to identify the one responsible for Li enrichment in HD 107028. Methods. We collected high-resolution spectra with three different instruments, covering different spectral ranges. We determined stellar parameters and abundances of selected elements with both equivalent width measurements and analysis, and spectral synthesis. We also collected multi-epoch high-precision radial velocities in an attempt to detect a companion. Results. Collected data show that HD 107028 is a star at the base of the red giant branch (RGB). Except for high Li abundance, we have not identified any other anomalies in its chemical composition, and there is no indication of a low-mass or stellar companion. We exclude Li production at the luminosity function bump on the RGB as the effective temperature and luminosity suggest that the evolutionary state is much earlier than the RGB bump. We also cannot confirm the Li enhancement by contamination as we do not observe any anomalies that are associated with this scenario. Conclusions. After evaluating various scenarios of Li enhancement we conclude that the Li-overabundance of HD 107028 originates from main-sequence evolution, and may be caused by diffusion processes.

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“…Thus, the preferred option to solve this issue has been to apply the RV method on K giants, the evolved counterparts of those massive stars, with generally low rotation rates and a larger number of spectral lines in their much cooler spectra when compared with their unevolved MS counterparts (e.g. Frink et al 2002;Sato et al 2003;Lovis & Mayor 2007;Niedzielski et al 2015). This allows to probe a different stellar mass range.…”

Section: Introductionmentioning

confidence: 99%

Planets around evolved intermediate-mass stars

Mena

Santos

Silva

et al. 2018

A&A

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Aims. The aim of this work is to search for planets around intermediate-mass stars in open clusters by using data from an extensive survey with more than 15 years of observations. Methods. We obtain high-precision radial velocities (RV) with the HARPS spectrograph for a sample of 142 giant stars in 17 open clusters. We fit Keplerian orbits when a significant periodic signal is detected. We also study the variation of stellar activity indicators and line-profile variations to discard stellar-induced signals.Results. We present the discovery of a periodic RV signal compatible with the presence of a planet candidate in the 1.15 Gyr open cluster IC4651 orbiting the 2.06 M star No. 9122. If confirmed, the planet candidate would have a minimum mass of 7.2M J and a period of 747 days. However, we also find that the FWHM of the CCF varies with a period close to the RV, casting doubts on the planetary nature of the signal. We also provide refined parameters for the previously discovered planet around NGC2423 No. 3 but show evidence that the BIS of the CCF is correlated with the RV during some of the observing periods. This fact advises us that this might not be a real planet and that the RV variations could be caused by stellar activity and/or pulsations. Finally, we show that the previously reported signal by a brown dwarf around NGC4349 No. 127 is presumably produced by stellar activity modulation. Conclusions. The long-term monitoring of several red giants in open clusters has allowed us to find periodic RV variations in several stars. However, we also show that the follow-up of this kind of stars should last more than one orbital period to detect long-term signals of stellar origin. This work warns that although it is possible to detect planets around red giants, large-amplitude, long-period RV modulations do exist in such stars that can mimic the presence of an orbiting planetary body. Therefore, we need to better understand how such RV modulations behave as stars evolve along the Red Giant Branch and perform a detailed study of all the possible stellar-induced signals (e.g. spots, pulsations, granulation) to comprehend the origin of RV variations.

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Tracking Advanced Planetary Systems (TAPAS) with HARPS-N

Cited by 35 publications

References 119 publications

Dynamical Constraints on the Origin of Hot and Warm Jupiters With Close Friends

Dynamical Constraints on the Origin of Hot and Warm Jupiters With Close Friends

Tracking Advanced Planetary Systems (TAPAS) with HARPS-N

Planets around evolved intermediate-mass stars

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