Observational constraints on the origin of the elements. IV: The standard composition of the Sun
Ekaterina Magg, Maria Bergemann, Aldo Serenelli, Manuel Bautista, Bertrand Plez, Ulrike Heiter, Jeffrey M. Gerber, Hans-Günter Ludwig, Sarbani Basu, Jason W. Fe… 展开作者
Ekaterina Magg, Maria Bergemann, Aldo Serenelli, Manuel Bautista, Bertrand Plez, Ulrike Heiter, Jeffrey M. Gerber, Hans-Günter Ludwig, Sarbani Basu, Jason W. Ferguson, Helena Carvajal Gallego, Sébastien Gamrath, Patrick Palmeri, Pascal Quinet
The chemical composition of the Sun is requested in the context of various studies in astrophysics, among them in the calculation of the standard solar models (SSMs), which describe the evolution of the Sun from the pre-main-sequence to its present age. In this work, we provide a critical re-analysis of the solar chemical abundances and corresponding SSMs. For the photospheric values, we employ new high-quality solar observational data collected with the IAG facility, state-of-the art non-equilibrium modelling, new oscillator strengths, and different atmospheric models, including the MARCS model, but also averages based on Stagger and CO5BOLD 3D radiation-hydrodynamics simulations of stellar convection. We perform new calculations of oscillator strengths for transitions in O I and N I. For O I - the critical element for the interior models - calculations are carried out using several independent methods. We find unprecedented agreement between the new estimates of transition probabilities, thus supporting our revised solar oxygen abundance. We also provide new estimates of the noble gas Ne abundance. We investigate our results in comparison with the previous estimates. We discuss the consistency of our photospheric measurements with meteoritic values taking into account systematic and correlated errors. Finally, we provide revised chemical abundances, leading to a new value of the solar photospheric present-day metallicity $Z/X = 0.0225$, and employ them in the calculations of the SSM. We find that the puzzling mismatch between the helioseismic constraints on the solar interior structure and the model is resolved with the new chemical composition.
The composition, including the ionic charge states and elemental abundances of heavy elements, within interplanetary coronal mass ejections (ICMEs) has tight correlations with their source regions and eruption processes. This can help analyze the eruption mechanisms and plasma origins of CMEs, and deepen our understanding of energetic solar activities. The active regions and quiet-Sun regions have different physical properties, thus from a statistical point of view, ICMEs originating from the two types of regions should exhibit different compositional characteristics. To demonstrate the differ…
The Sun provides a standard reference against which we compare the chemical abundances found anywhere else in the Universe. Nevertheless, there is not a unique 'solar' composition, since the chemical abundances found in the solar interior, the photosphere, the upper atmosphere, or the solar wind, are not exactly the same. The composition of the solar photosphere, usually preferred as a reference, changes with time due to diffusion, convection, and probably accretion. In addition, we do not know the solar photospheric abundances, inferred from the analysis of the solar spectrum using model atmo…
High resolution UV spectra of stellar H I Lyman-alpha lines from the Hubble Space Telescope (HST) provide observational constraints on the winds of coronal main sequence stars, thanks to an astrospheric absorption signature created by the interaction between the stellar winds and the interstellar medium. We report the results of a new HST survey of M dwarf stars, yielding six new detections of astrospheric absorption. We estimate mass-loss rates for these detections, and upper limits for nondetections. These new constraints allow us to characterize the nature of M dwarf winds and their depende…
The origin of small-scale interplanetary magnetic flux-ropes (SIMFRs) and the relationship between SIMFRs and magnetic clouds (MCs) are still controversial. In this study, two populations of SMIFRs were collected, i.e., SIMFRs originating from the Sun (SIMFR-SUN) and those originating from the solar wind (SIMFR-SW). We defined the SIMFR-SUN (SIMFR-SW) as the SMIFRs that include (exclude) the counter-streaming suprathermal electrons and stay away from (close to) the heliospheric current sheet. After fitting with force-free flux-rope model, 52 SIMFR-SUN and 57 SIMFR-SW events observed by Advance…
The first ionization potential (FIP) bias is currently used to trace the propagation of solar features ejected by the wind and solar eruptions (coronal mass ejections). The FIP bias also helps us to understand the formation of prominences, as it is a tracer for the solar origin of prominence plasma. This work aims to provide elemental composition and FIP bias in quiescent solar prominences. This is key information to link these features to remnants of solar eruptions measured in-situ within the heliosphere and to constrain the coronal or photospheric origin of prominence plasma. We used the di…
Through meticulous daily observation of the Sun's large-scale magnetic field the Wilcox Solar Observatory (WSO) has catalogued two magnetic (Hale) cycles of solar activity. Those two (~22-year long) Hale cycles have yielded four ($\sim$11-year long) sunspot cycles (numbers 21 through 24). Recent research has highlighted the persistence of the "Extended Solar Cycle" (ESC) and its connection to the fundamental Hale Cycle - albeit through a host of proxies resulting from image analysis of the solar photosphere, chromosphere and corona. This short manuscript presents the correspondence of the ESC,…
In order to characterize giant exoplanets and better understand their origin, knowledge of how the planet's composition depends on its mass and stellar environment is required. In this work, we simulate the thermal evolution of gaseous planets and explore how various common model assumptions such as different equations of state, opacities, and heavy-element distributions affect the inferred radius and metallicity. We examine how the theoretical uncertainties translate into uncertainties in the inferred planetary radius and bulk metallicity. While we confirm the mass-metallicity trend previousl…
Building a reliable forecast of solar activity is a long-standing problem that requires to accurately describe past and current global dynamics. However, synoptic observations of magnetic fields and subsurface flows became available relatively recently. In this paper, we present an investigation of effects of short observational data series on accuracy of solar cycle prediction. This analysis is performed using the annual sunspot number time-series applied to the Parker-Kleeorin-Ruzmaikin dynamo model and employing the Ensemble Kalman Filter (EnKF) data assimilation method. The testing of the …
Coronal Mass Ejections from Young Suns: An Observational View through the Solar-Stellar Connection
The Hakubi Center for Advanced Research, Kyoto University（京都大学白兔高级研究中心）；Department of Physics, Kyoto University（京都大学物理系）；Heliophysics Science Division, NASA Goddard Space Flight Center（NASA戈达德太空飞行中心太阳物理学部）；Department of Physics, The Catholic University of America（美国天主教大学物理系）
Our understanding of the formation and evolution of the corona and the heliosphere is linked to our capability of properly interpreting the data from remote sensing and in-situ observations. In this respect, being able to correctly connect in-situ observations with their source regions on the Sun is the key for solving this problem. In this work we aim at testing a diagnostics method for this connectivity. This paper makes use of a coronal jet observed on 2010 August 2nd in active region 11092 as a test for our connectivity method. This combines solar EUV and in-situ data together with magneti…
