Signatures of planets and Galactic subpopulations in solar analogs: Precise chemical abundances with neural networks
Methods. We developed a neural network (NN) algorithm using Python to derive atmospheric parameters and chemical abundances for a sample of 99 solar twins and solar analogs previously studied in the literature from normalized high-quality spectra from HARPS, with a resolving power of R ∼ 115 000 and...
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| Main Authors: | , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
1 July 2025
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| In: |
Astronomy and astrophysics
Year: 2025, Volume: 699, Pages: 1-14 |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/202554675 |
| Online Access: | Verlag, kostenfrei, Volltext: https://doi.org/10.1051/0004-6361/202554675 Verlag, kostenfrei, Volltext: https://www.aanda.org/10.1051/0004-6361/202554675 
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| Author Notes: | Giulia Martos, Jorge Meléndez, Lorenzo Spina, and Sara Lucatello |
| Summary: | Methods. We developed a neural network (NN) algorithm using Python to derive atmospheric parameters and chemical abundances for a sample of 99 solar twins and solar analogs previously studied in the literature from normalized high-quality spectra from HARPS, with a resolving power of R ∼ 115 000 and a signal-to-noise ratio of S/N > 400. - Results. We obtained precise atmospheric parameters and abundance ratios [X/Fe] of 20 chemical elements (Li, C, O, Na, Mg, Al, Si, S, Ca, Sc, Ti, V, Cr, Mn, Co, Ni, Cu, Zn, Y, and Ba). The results we obtained are in line with the literature, with average differences and standard deviations of (2 ± 27) K for Teff, (0.00 ± 0.06) dex for log g, (0.00 ± 0.02) dex for [Fe/H], (−0.01 ± 0.05) km s−1 for microturbulence velocity (vt), (0.02 ± 0.08) km s−1 for the macro turbulence velocity (vmacro), and (−0.12 ± 0.26) km s−1 for the projected rotational velocity (vsini). Regarding the chemical abundances, most of the elements agree with the literature within 0.01 -0.02 dex. The abundances were corrected from the effects of the Galactic chemical evolution through a fitting versus the age of the stars and analyzed with the condensation temperature (Tcond) to verify whether the stars presented depletion of refractories compared to volatiles. - Conclusions. We found that the Sun is more depleted in refractory elements compared to volatiles than 89% of the studied solar analogs, with a significance of 9.5σ when compared to the stars without detected exoplanets. We also found the possible presence of three subpopulations in the solar analogs: one Cu-rich, one Cu-poor, and the last one being slightly older and poor in Na. |
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| Item Description: | Gesehen am 22.12.2025 |
| Physical Description: | Online Resource |
| ISSN: | 1432-0746 |
| DOI: | 10.1051/0004-6361/202554675 |