Icarus and the Determination of Astronomical Constants

Lieske, J. H.; Null, G. W.

doi:10.1086/110810

Cited by 23 publications

(11 citation statements)

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“…This space measurement leads to an equator-to-pole radius difference of 13.72 ± 0.44 mas, i.e., of the same order of magnitude as the mean value found at the Pic du Midi for the years 1993-1996: 11.5 ± 3.4 mas, as seen in Table 1 given by Rozelot & Bois (1997) In spite of the (apparent) dispersion, mainly due to the different techniques used, the observed oblateness seems to be in phase with the solar activity index. For the sake of clarity, the quoted authors are as follows: LN: Lieske & Null (1969); HS: Hill & Stebbins (1975a, 1975b; VI: reported estimate as deduced from the Viking Probe in 1975 (CNES Report 1976); DU: Duvall et al (1984); MA: Maier et al (1992); LA: Landgraf (1992). (A color version of this figure is available in the online journal.)…”

Section: The Oblateness (ε)mentioning

confidence: 99%

Probing the Solar Surface: The Oblateness and Astrophysical Consequences

Rozelot

Damiani

Pireaux

2009

ApJ

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Based on historical records, the Sun's dimensions are temporally dependent. Until the recent past, varying dimensions were keenly disputed. Recent accurate observations have removed the doubt, whether from direct limb observations or from helioseismology f-modes analysis. A shrinking or an expanding shape is ultimately linked to solar activity, as even a small variation in the solar radius causes variations in gravitational energy. Based on accurate space-and ground-based observations, we will argue that the oblateness of the Sun is time dependent. Indeed, considering the first two shape coefficients, we can interpret such a temporal variation as a change in the relative importance of the hexadecapolar term, i.e., at the time of high activity, only the dipolar moment c 2 has a significant effect, but at the time of low activity, c 4 is predominant; this results in a decrease of the total value of the oblateness. The combination of the two terms leads to a solar oblateness varying along with solar activity. More studies are needed to get accurate measurements from space, which will provide us with the unique opportunity to study detailed changes of global solar properties.

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Section: The Oblateness (ε)mentioning

confidence: 99%

Probing the Solar Surface: The Oblateness and Astrophysical Consequences

Rozelot

Damiani

Pireaux

2009

ApJ

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“…This idea was concretized several times [4][5][6][7] by estimating a relativity parameter that takes the value one in GR. The best measurements were achieved to a precision of a few percent.…”

Section: Introductionmentioning

confidence: 99%

Tests of fundamental physics with the Gaia mission through the dynamics of minor planets

Mouret

2011

Phys. Rev. D

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With a launch planned in March 2013, the ESA Gaia mission will scan the whole sky several times during its operational five years. It will provide highly accurate astrometric observations of celestial bodies (at the sub-milli-arcsecond level) not exclusively beyond the Solar System, since about 250 000 asteroids will be observed. Gaia will thus give us the opportunity of performing various valuable tests of fundamental physics by assessing global parameters from the dynamics of minor planets; in this paper, we evaluated its performance from realistic simulated data and a variance analysis carried out from the observation residuals on a data model linearized with respect to the initial position and velocity of each asteroid and the set of global parameters. Currently, the most relevant fits turn out to be for the PPN parameter ( $ 1:4 Â 10 À3 ), the temporal variation of the gravitational constant _ G=G ( _ G=G $ 3:2 Â 10 À12 yr À1 ), the Nordtvedt parameter ( $ 2:4 Â 10 À3 ) and the Gm of Jupiter ( Gm j $ 2:9 Â 10 À15 au 3 d À2 ), which show a low level of correlation. The underestimated astrometric precision used in the simulations and the possibility to combine Gaia data with future accurate ground-based observations foreshadow more accurate determinations.

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“…28 This result is consistent with an earlier analysis of Lieske and Null. 29 The GR prediction for the perihelion precession of Icarus, including the J 2 of Hill et al f is AM R = 10".18±0.04 per century.…”

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confidence: 95%

Consequences of a New Experimental Determination of the Quadrupole Moment of the Sun for Gravitation Theory

Moffat

1983

Phys. Rev. Lett.

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Ontario M5S1A7, CanadaA preliminary experimental determination by Hill, Bos, and Goode of the interior rotation of the sun leads to a nonzero value for the quadrupole moment coefficient J 2 -This produces a deviation of 1.6% from Einstein's prediction of the precession of the perihelion of Mercury. A nonsymmetric gravitational theory can fit the measured precession with this J 2 and all other solar-system relativity experiments for one value of a post-Newtonian parameter in the theory. A prediction is made for the perihelion precession of Icarus.

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Icarus and the Determination of Astronomical Constants

Cited by 23 publications

References 0 publications

Probing the Solar Surface: The Oblateness and Astrophysical Consequences

Probing the Solar Surface: The Oblateness and Astrophysical Consequences

Tests of fundamental physics with the Gaia mission through the dynamics of minor planets

Consequences of a New Experimental Determination of the Quadrupole Moment of the Sun for Gravitation Theory

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