Precision study of ground state capture in the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mrow><mml:msup><mml:mi /><mml:mrow><mml:mn>14</mml:mn></mml:mrow></mml:msup><mml:mi mathvariant="normal">N</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:mi>p</mml:mi><mml:mo>,</mml:mo><mml:mi>γ</mml:mi><mml:mo stretchy="false">)</mml:mo><mml:msup><mml:mi /><mml:mrow><mml:mn>15</mml:mn></mml:mrow></mml:msup><mml:mi mathvariant="normal">O</mml:mi></mml:mrow></mml:math>reaction

Marta, M.; Formicola, A.; Gyürky, Gy.; Bemmerer, D.; Broggini, C.; Caciolli, A.; Corvisiero, P.; Costantini, H.; Elekes, Z.; Fülöp, Zs.; Gervino, G.; Guglielmetti, A.; Gustavino, C.; Imbriani, G.; Junker, M.; Kunz, R.; Lemut, A.; Limata, B.; Mazzocchi, C.; Menegazzo, R.; Prati, P.; Roca, V.; Rolfs, C.; Romano, M.; Alvarez, C. Rossi; Somorjai, E.; Straniero, O.; Strieder, F.; Terrasi, F.; Trautvetter, H. P.; Vomiero, Alberto

doi:10.1103/physrevc.78.022802

Cited by 94 publications

(104 citation statements)

References 26 publications

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“…The main improvements that have been made to this code since the VandenBerg et al (2007) study of M67 are the following: (1) The gravitational settling of helium and turbulent mixing that occur below the envelope convection zones are now treated, using methods very similar to those employed by Proffitt & Michaud (1991) 1 , (2) the latest rates for H-burning reactions (see Weiss 2008;Marta et al 2008) and the improved conductive opacities given by Cassisi et al (2007) have been adopted and (3) the assumed solar abundances are those reported by Asplund et al (2009). To reproduce the properties of the Sun at its present age (4.57 Gyr; Bahcall et al 2005), it is necessary to adopt an initial helium content corresponding to Y = 0.2553, along with a value of α MLT = 2.007 for the usual mixing-length parameter.…”

Section: The Age Of M67mentioning

confidence: 99%

M67-1194, an unusually Sun-like solar twin in M67

Önehag

Korn

Gustafsson

et al. 2011

A&A

100

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Context. The rich open cluster M67 is known to have a chemical composition close to solar, and an age around 4 Gyr. It thus offers the opportunity to check our understanding of the physics and the evolution of solar-type stars in a cluster environment. Aims. We present the first spectroscopic study at high resolution, R ≈ 50 000, of the potentially best solar twin, M67-1194, identified among solar-like stars in M67. Methods. G dwarfs in M67 (d ≈ 900 pc) are relatively faint (V ≈ 15), which makes detailed spectroscopic studies time-consuming. Based on a pre-selection of solar-twin candidates performed at medium resolution by Pasquini et al. (2008, A&A, 489, 677), we explore the chemical-abundance similarities and differences between M67-1194 and the Sun, using VLT/FLAMES-UVES. Working with a solar twin in the framework of a differential analysis, we minimize systematic model errors in the abundance analysis compared to previous studies which utilized more evolved stars to determine the metallicity of M67. The differential approach yields precise and accurate chemical abundances for M67, which enhances the possibility to use this object in studies of the potential peculiarity, or normality, of the Sun. Results. We find M67-1194 to have stellar parameters indistinguishable from the solar values, with the exception of the overall metallicity which is slightly super-solar ([Fe/H] = 0.023 ± 0.015). An age determination based on evolutionary tracks yields 4.2 ± 1.6 Gyr. Most surprisingly, we find the chemical abundance pattern to closely resemble the solar one, in contrast to most known solar twins in the solar neighbourhood. Conclusions. We confirm the solar-twin nature of M67-1194, the first solar twin known to belong to a stellar association. This fact allows us to put some constraints on the physical reasons for the seemingly systematic departure of M67-1194 and the Sun from most known solar twins regarding chemical composition. We find that radiative dust cleansing by nearby luminous stars may be the explanation for the peculiar composition of both the Sun and M67-1194, but alternative explanations are also possible. The chemical similarity between the Sun and M67-1194 also suggests that the Sun once formed in a cluster like M67.

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Section: The Age Of M67mentioning

confidence: 99%

M67-1194, an unusually Sun-like solar twin in M67

Önehag

Korn

Gustafsson

et al. 2011

A&A

100

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“…value S 1,14 (0)=1.57±0.13 keV barn [31,32]. Another recent measurements has been performed at the Notre Dame University [33] at higher energies obtaining an extrapolated value higher than the one reported by LUNA.…”

Section: Epj Web Of Conferencesmentioning

confidence: 81%

Nuclear Astrophysics in underground laboratories: the LUNA experiment

Simpson¹,

Simenel²,

Cook³

et al. 2017

EPJ Web Conf.

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Abstract. One of the main ingredients of nuclear astrophysics is the knowledge of the thermonuclear reactions responsible for powering the stellar engine and for the synthesis of the chemical elements. At astrophysical energies the cross section of nuclear processes is extremely reduced by the effect of the Coulomb barrier. The low value of cross sections prevents their measurement at stellar energies on Earth surface and often extrapolations are needed. The Laboratory for Underground Nuclear Astrophysics (LUNA) is placed under the Gran Sasso mountain and thanks to the cosmic-ray background reduction provided by its position can investigate cross sections at energies close to the Gamow peak in stellar scenarios. Many crucial reactions involved in hydrogen burning has been measured directly at astrophysical energies with both the LUNA-50kV and the LUNA-400kV accelerators, and this intense work will continue with the installation of a MV machine able to explore helium and carbon burnings. Based on this progress, currently there are efforts in several countries to construct new underground accelerators. In this talk, the typical techniques adopted in underground nuclear astrophysics will be described and the most relevant results achieved by LUNA will be reviewed. The exciting science that can be probed with the new facilities will be highlighted.

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“…We note in passing that the cross sections of two important astrophysical factors (S 34 and S 1,14 ) have been updated by [41,42], and is highly recommended that the chosen set of thermonuclear reactions includes these latest values. Energy losses via neutrino emission (Eq.…”

Section: Choosing the Ingredientsmentioning

confidence: 99%

Stellar Evolution and Modelling Stars

Aguirre

2017

Astrophysics and Space Science Proceedings

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In this chapter I give an overall description of the structure and evolution of stars of different masses, and review the main ingredients included in state-ofthe-art calculations aiming at reproducing observational features. I give particular emphasis to processes where large uncertainties still exist as they have strong impact on stellar properties derived from large compilations of tracks and isochrones, and are therefore of fundamental importance in many fields of astrophysics.

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Precision study of ground state capture in the14N(p,γ)15Oreaction

Cited by 94 publications

References 26 publications

M67-1194, an unusually Sun-like solar twin in M67

M67-1194, an unusually Sun-like solar twin in M67

Nuclear Astrophysics in underground laboratories: the LUNA experiment

Stellar Evolution and Modelling Stars

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