POLAR investigation of the Sun—POLARIS

Appourchaux, T.; Liewer, Paulett C.; Watt, Mark; Alexander, David; Andretta, V.; Auchère, F.; D'Arrigo, Paolo; Ayon, Juan A.; Corbard, T.; Fineschi, Silvano; Finsterle, W.; Floyd, L.; Garbe, Gregory; Gizon, Laurent; Hassler, Donald M.; Harra, L. K.; Kosovichev, A. G.; Leibacher, J. W.; Leipold, M.; Murphy, Neil; Maksimović, M.; Pillet, V. Martínez; Matthews, B. S. A.; Mewaldt, R. A.; Moses, D.; Newmark, Jeffrey; Régnier, Stéphane; Schmutz, W.; Socker, D. G.; Spadaro, D.; Stuttard, M.; Trosseille, C.; Ulrich, R. K.; Velli, Marco; Vourlidas, A.; Wimmer-Schweingruber, C. R.; Zurbuchen, T. H.

doi:10.1007/s10686-008-9107-8

Cited by 28 publications

(20 citation statements)

References 24 publications

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“…This limit would be low enough to detect g modes if they had amplitudes as high as those predicted by Belkacem et al (2009). The variations in the potential can be also detected by using laser ranging, e.g., the ASTROD mission (Ni 2007;Appourchaux et al 2009). As shown by Burston et al (2008), the capability of ASTROD would be sufficient to allow the detection of g modes even if their amplitudes were to be as low as those predicted by Kumar et al (1996).…”

Section: Discussionmentioning

confidence: 99%

The quest for the solar g modes

Appourchaux

Belkacem

Broomhall

et al. 2010

Astron Astrophys Rev

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127

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A ce compte, toutes les sciences ne seraient que des applications inconscientes du calcul des probabilités ; condamner ce calcul, ce serait condamner la science tout entière." "From this point of view all the sciences would only be unconscious applications of the calculus of probabilities. And if this calculus be condemned, then the whole of the sciences must also be condemned."Henri Poincaré, 1914, La Science et l'hypothèseAbstract Solar gravity modes (or g modes) -oscillations of the solar interior for which buoyancy acts as the restoring force -have the potential to provide unprecedented inference on the structure and dynamics of the solar core, inference that is not possible with the well observed acoustic modes (or p modes). The high amplitude of the g-mode eigenfunctions in the core and the evanesence of the modes in the convection zone make the modes particularly sensitive to the physical and dynamical conditions in the core.Owing to the existence of the convection zone, the g modes have very low amplitudes at photospheric levels, which makes the modes extremely hard to detect. In this paper, we review the current state of play regarding attempts to detect g modes. We review the theory of g modes, including theoretical estimation of the g-mode frequencies, amplitudes and damping rates. Then we go on to discuss the techniques that have been used to try to detect g modes. We review results in the literature, and finish by looking to the future, and the potential advances that can be made -from both data and data-analysis perspectives -to give unambiguous detections of individual g modes. The review ends by concluding that, at the time of writing, there is indeed a consensus amongst the authors that there is currently no undisputed detection of solar g modes.

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Section: Discussionmentioning

confidence: 99%

The quest for the solar g modes

Appourchaux

Belkacem

Broomhall

et al. 2010

Astron Astrophys Rev

Self Cite

127

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“…Note also that conventional intuition from Newton's second law can be misleading because the effective inertial masses depend on the coefficients (c w ) µν , as discussed following Eq. (134).…”

Section: Force-comparison Gravimeter Testsmentioning

confidence: 99%

“…High-quality data for the time delay and the gravitational Doppler shift have been obtained by tracking the Cassini spacecraft [133] in the gravitational field of the Sun. Proposed missions such as the Astrodynamical Space Test of Relativity using Optical Devices (AS-TROD) [134], the Mercury Orbiter Radio-science Experiment (MORE) [135], the Search for Anomalous Gravitation using Atomic Sensors (SAGAS) [136], and the Solar System Odyssey (SSO) [137] have the potential to improve these measurements using the Sun as the gravitational source, while the Beyond Einstein Advanced Coherent Optical Network (BEACON) [138] could sharpen results using the Earth as the gravitational source. Another relevant recent proposal involves the use of verylong-baseline interferometry (VLBI) [139] to measure the deflection of radio waves from distant sources by solarsystem objects.…”

Section: E Experimentsmentioning

confidence: 99%

Matter-gravity couplings and Lorentz violation

2011

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The gravitational couplings of matter are studied in the presence of Lorentz and CPT violation. At leading order in the coefficients for Lorentz violation, the relativistic quantum hamiltonian is derived from the gravitationally coupled minimal Standard-Model Extension. For spin-independent effects, the nonrelativistic quantum hamiltonian and the classical dynamics for test and source bodies are obtained. A systematic perturbative method is developed to treat small metric and coefficient fluctuations about a Lorentz-violating and Minkowski background. The post-newtonian metric and the trajectory of a test body freely falling under gravity in the presence of Lorentz violation are established. An illustrative example is presented for a bumblebee model. The general methodology is used to identify observable signals of Lorentz and CPT violation in a variety of gravitational experiments and observations, including gravimeter measurements, laboratory and satellite tests of the weak equivalence principle, antimatter studies, solar-system observations, and investigations of the gravitational properties of light. Numerous sensitivities to coefficients for Lorentz violation can be achieved in existing or near-future experiments at the level of parts in 10 3 down to parts in 10 15 . Certain coefficients are uniquely detectable in gravitational searches and remain unmeasured to date.

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“…This would be extremely important for practical space weather forecasting as well as CME Sun-to-Earth research. This work also provides scientific guidance for spacecraft missions that intend to look at CME propagation in the ecliptic plane from high latitude, e.g., the POLAR Investigation of the Sun (POLARIS; Appourchaux et al 2009) and the Solar Polar ORbit Telescope (SPORT; Wu et al 2011 The trajectories of the CMEs of interest, which are obtained from triangulation with the Fβ approximation (black) and triangulation with the HM approximation (red), respectively, are marked by crosses for CME1 and CME3 and diamonds for CME2. The estimated CME peak speed and launch time on the Sun are also given.…”

Section: Implications For Cme Observations and Interpretationsmentioning

confidence: 99%

On Sun-to-Earth Propagation of Coronal Mass Ejections

Liu

Luhmann

Lugaz

et al. 2013

ApJ

148

221

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We investigate how coronal mass ejections (CMEs) propagate through, and interact with, the inner heliosphere between the Sun and Earth, a key question in CME research and space weather forecasting. CME Sun-to-Earth kinematics are constrained by combining wide-angle heliospheric imaging observations, interplanetary radio type II bursts and in situ measurements from multiple vantage points. We select three events for this study, the 2012 January 19, 23, and March 7 CMEs. Different from previous event studies, this work attempts to create a general picture for CME Sun-to-Earth propagation and compare different techniques for determining CME interplanetary kinematics. Key results are obtained concerning CME Sun-to-Earth propagation: (1) the Sun-to-Earth propagation of fast CMEs can be approximately formulated into three phases: an impulsive acceleration, then a rapid deceleration, and finally a nearly constant speed propagation (or gradual deceleration); (2) the CMEs studied here are still accelerating even after the flare maximum, so energy must be continuously fed into the CME even after the time of the maximum heating and radiation has elapsed in the corona; (3) the rapid deceleration, presumably due to interactions with the ambient medium, mainly occurs over a relatively short time scale following the acceleration phase; (4) CME-CME interactions seem a common phenomenon close to solar maximum. Our comparison between different techniques (and data sets) has important implications for CME observations and their interpretations: (1) for the current cases, triangulation assuming a compact CME -2geometry is more reliable than triangulation assuming a spherical front attached to the Sun for distances below 50-70 solar radii from the Sun, but beyond about 100 solar radii we would trust the latter more; (2) a proper treatment of CME geometry must be performed in determining CME Sun-to-Earth kinematics, especially when the CME propagation direction is far away from the observer; (3) our approach to comparing wide-angle heliospheric imaging observations with interplanetary radio type II bursts provides a novel tool in investigating CME propagation characteristics. Future CME observations and space weather forecasting are discussed based on these results.

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POLAR investigation of the Sun—POLARIS

Cited by 28 publications

References 24 publications

The quest for the solar g modes

The quest for the solar g modes

Matter-gravity couplings and Lorentz violation

On Sun-to-Earth Propagation of Coronal Mass Ejections

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