The Chemical Signatures of Planetary Engulfment Events in Binary Systems

Nagar, Tushar; Spina, L.; Karakas, Amanda I.

doi:10.3847/2041-8213/ab5dc6

Cited by 38 publications

(27 citation statements)

References 52 publications

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“…We also include two pairs (HD 98744/45 and HIP 70386A/B) from Nagar, Spina & Karakas (2020) for examination, because both pairs show overall abundance offsets but no T cond trends. We found that the observed differences in [Fe/H] agree with the theoretical models for four of our pairs (HD 108574/75, HD 146368A/B, HD216122A/B and HIP 92961/62) and one pair (HD 98744/45) from Nagar, Spina & Karakas (2020), all with log g differences exceeding 0.05 dex.…”

Section: Effects Of Atomic Diffusionsupporting

confidence: 83%

“…These studies favour the M09 scenario, where they found the planet-hosting stars are depleted in refractory elements. Meanwhile, Saffe et al (2017); Oh et al (2018); Ramírez et al (2019) and Nagar, Spina & Karakas (2020) have studied several binary systems and found that one of the binary components exhibits a significant increase in elemental abundances (0.1 -0.2 dex) of e.g., HAT-P-4 system, HD 240430/29 and HIP 34407/26. They tentatively attributed the large abundance differences to the effects of planet engulfment.…”

Section: Introductionmentioning

confidence: 99%

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Detailed elemental abundances of binary stars: Searching for signatures of planet formation and atomic diffusion

Liu,

Bitsch,

Asplund

et al. 2021

Preprint

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Binary star systems are assumed to be co-natal and coeval, thus to have identical chemical composition. In this work we aim to test the hypothesis that there is a connection between observed element abundance patterns and the formation of planets using binary stars. Moreover, we also want to test how atomic diffusion might influence the observed abundance patterns. We conduct a strictly line-by-line differential chemical abundance analysis of 7 binary systems. Stellar atmospheric parameters and elemental abundances are obtained with extremely high precision (< 3.5%) using the high quality spectra from VLT/UVES and Keck/HIRES. We find that 4 of 7 binary systems show subtle abundance differences (0.01 -0.03 dex) without clear correlations with the condensation temperature, including two planet-hosting pairs. The other 3 binary systems exhibit similar degree of abundance differences correlating with the condensation temperature. We do not find any clear relation between the abundance differences and the occurrence of known planets in our systems. Instead, the overall abundance offsets observed in the binary systems (4 of 7) could be due to the effects of atomic diffusion. Although giant planet formation does not necessarily imprint chemical signatures onto the host star, the differences in the observed abundance trends with condensation temperature, on the other hand, are likely associated with diverse histories of planet formation (e.g., formation location). Furthermore, we find a weak correlation between abundance differences and binary separation, which may provide a new constraint on the formation of binary systems.

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Section: Effects Of Atomic Diffusionsupporting

confidence: 83%

Section: Introductionmentioning

confidence: 99%

Detailed elemental abundances of binary stars: Searching for signatures of planet formation and atomic diffusion

Liu,

Bitsch,

Asplund

et al. 2021

Preprint

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“…The code delivers the EW of each line of interest along with its uncertainty. The same method for the EW measurement was employed in the high-precision spectroscopic analysis of twin stars by Nagar et al (2020).…”

Section: Stellar Parameters and Chemical Abundancesmentioning

confidence: 99%

The Gaia-ESO survey: the non-universality of the age–chemical-clocks–metallicity relations in the Galactic disc

Casali

Spina

Magrini

et al. 2020

A&A

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Context. In the era of large spectroscopic surveys, massive databases of high-quality spectra coupled with the products of the Gaia satellite provide tools to outline a new picture of our Galaxy. In this framework, an important piece of information is provided by our ability to infer stellar ages, and consequently to sketch a Galactic timeline. Aims. We aim to provide empirical relations between stellar ages and abundance ratios for a sample of stars with very similar stellar parameters to those of the Sun, namely the so-called solar-like stars. We investigate the dependence on metallicity, and we apply our relations to independent samples, that is, the Gaia-ESO samples of open clusters and of field stars. Methods. We analyse high-resolution and high-signal-to-noise-ratio HARPS spectra of a sample of solar-like stars to obtain precise determinations of their atmospheric parameters and abundances for 25 elements and/or ions belonging to the main nucleosynthesis channels through differential spectral analysis, and of their ages through isochrone fitting. Results. We investigate the relations between stellar ages and several abundance ratios. For the abundance ratios with a steeper dependence on age, we perform multivariate linear regressions, in which we include the dependence on metallicity, [Fe/H]. We apply our best relations to a sample of open clusters located from the inner to the outer regions of the Galactic disc. Using our relations, we are able to recover the literature ages only for clusters located at RGC > 7 kpc. The values that we obtain for the ages of the inner-disc clusters are much greater than the literature ones. In these clusters, the content of neutron capture elements, such as Y and Zr, is indeed lower than expected from chemical evolution models, and consequently their [Y/Mg] and [Y/Al] are lower than in clusters of the same age located in the solar neighbourhood. With our chemical evolution model and a set of empirical yields, we suggest that a strong dependence on the star formation history and metallicity-dependent stellar yields of s-process elements can substantially modify the slope of the [s/α]–[Fe/H]–age relation in different regions of the Galaxy. Conclusions. Our results point towards a non-universal relation [s/α]–[Fe/H]–age, indicating the existence of relations with different slopes and intercepts at different Galactocentric distances or for different star formation histories. Therefore, relations between ages and abundance ratios obtained from samples of stars located in a limited region of the Galaxy cannot be translated into general relations valid for the whole disc. A better understanding of the s-process at high metallicity is necessary to fully understand the origin of these variations.

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“…Under the reasonable and common assumption that the components of binary systems share their initial composition (e.g., Desidera et al 2006;Andrews et al 2019;Hawkins et al 2020;Nelson et al 2021), since they form coevally from the same molecular cloud, it is unlikely that their dissimilar abundances are caused by different Galactic chemical evolution (e.g., Adibekyan et al 2014;Nissen 2015) or different stellar environment effects (e.g., Önehag et al 2014). Alternatively, as discussed in several previous studies of binary stars with similar components, the elemental abundance differences might be connected to processes of planetary formation and evolution (e.g., Ramírez et al 2011Ramírez et al , 2015Teske et al 2016a,b;Saffe et al 2015Saffe et al , 2017Oh et al 2018;Nagar et al 2020).…”

Section: Refined Planet Properties Of Wasp-160b Bmentioning

confidence: 89%

The peculiar chemical pattern of the WASP-160 binary system: signatures of planetary formation and evolution?

Jofré,

Petrucci,

Chew

et al. 2021

Preprint

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Wide binary stars with similar components hosting planets provide a favorable opportunity for exploring the star-planet chemical connection. We perform a detailed characterization of the solartype stars in the WASP-160 binary system. No planet has been reported yet around WASP-160A while WASP-160B is known to host a transiting Saturn-mass planet, WASP-160B b. For this planet, we also derive updated properties from both literature and new observations. Furthermore, using TESS photometry, we constrain the presence of transiting planets around WASP-160A and additional ones around WASP-160B. The stellar characterization includes, for the first time, the computation of high-precision differential atmospheric and chemical abundances of 25 elements based on high-quality Gemini-GRACES spectra. Our analysis reveals evidence of a correlation between the differential abundances and the condensation temperatures of the elements. In particular, we find both a small but significant deficit of volatiles and an enhancement of refractory elements in WASP-160B relative to WASP-160A. After WASP-94, this is the second stellar pair among the shortlist of planet-hosting binaries showing this kind of peculiar chemical pattern. Although we discuss several plausible planet formation and evolution scenarios for WASP-160A and B that could explain the observed chemical pattern, none of them can be conclusively accepted or rejected. Future high-precision photometric and spectroscopic follow-up, as well as high-contrast imaging observations, of WASP-160A and B, might provide further constraints on the real origin of the detected chemical differences.

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The Chemical Signatures of Planetary Engulfment Events in Binary Systems

Cited by 38 publications

References 52 publications

Detailed elemental abundances of binary stars: Searching for signatures of planet formation and atomic diffusion

Detailed elemental abundances of binary stars: Searching for signatures of planet formation and atomic diffusion

The Gaia-ESO survey: the non-universality of the age–chemical-clocks–metallicity relations in the Galactic disc

The peculiar chemical pattern of the WASP-160 binary system: signatures of planetary formation and evolution?

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