scholarly journals The solar gravitational redshift from HARPS-LFC Moon spectra

2020 ◽  
Vol 643 ◽  
pp. A146
Author(s):  
J. I. González Hernández ◽  
R. Rebolo ◽  
L. Pasquini ◽  
G. Lo Curto ◽  
P. Molaro ◽  
...  
Keyword(s):  
Solar System ◽  
Spectral Range ◽  
Frequency Comb ◽  
Line Shift ◽  
Spectral Lines ◽  
Gravitational Redshift ◽  
Solar Photosphere ◽  
The Sun ◽  
The Moon ◽  
Solar System Bodies

Context. The general theory of relativity predicts the redshift of spectral lines in the solar photosphere as a consequence of the gravitational potential of the Sun. This effect can be measured from a solar disk-integrated flux spectrum of the Sun’s reflected light on Solar System bodies. Aims. The laser frequency comb (LFC) calibration system attached to the HARPS spectrograph offers the possibility of performing an accurate measurement of the solar gravitational redshift (GRS) by observing the Moon or other Solar System bodies. Here, we analyse the line shift observed in Fe absorption lines from five high-quality HARPS-LFC spectra of the Moon. Methods. We selected an initial sample of 326 photospheric Fe lines in the spectral range between 476–585 nm and measured their line positions and equivalent widths (EWs). Accurate line shifts were derived from the wavelength position of the core of the lines compared with the laboratory wavelengths of Fe lines. We also used a CO5BOLD 3D hydrodynamical model atmosphere of the Sun to compute 3D synthetic line profiles of a subsample of about 200 spectral Fe lines centred at their laboratory wavelengths. We fit the observed relatively weak spectral Fe lines (with EW< 180 mÅ) with the 3D synthetic profiles. Results. Convective motions in the solar photosphere do not affect the line cores of Fe lines stronger than about ∼150 mÅ. In our sample, only 15 Fe I lines have EWs in the range 150< EW(mÅ) < 550, providing a measurement of the solar GRS at 639 ± 14 m s−1, which is consistent with the expected theoretical value on Earth of ∼633.1 m s−1. A final sample of about 97 weak Fe lines with EW < 180 mÅ allows us to derive a mean global line shift of 638 ± 6 m s−1, which is in agreement with the theoretical solar GRS. Conclusions. These are the most accurate measurements of the solar GRS obtained thus far. Ultrastable spectrographs calibrated with the LFC over a larger spectral range, such as HARPS or ESPRESSO, together with a further improvement on the laboratory wavelengths, could provide a more robust measurement of the solar GRS and further testing of 3D hydrodynamical models.

scholarly journals Geodetic Rotation of the Solar System Bodies

2007 ◽  
Vol 42 (1) ◽  
pp. 59-70 ◽  
Author(s):  
G. Eroshkin ◽  
V. Pashkevich
Keyword(s):  
Spectral Analysis ◽  
Solar System ◽  
Angular Velocity ◽  
Least Squares ◽  
Least Squares Method ◽  
Time Span ◽  
The Sun ◽  
The Moon ◽  
Analysis Methods ◽  
Solar System Bodies

Geodetic Rotation of the Solar System Bodies The problem of the geodetic (relativistic) rotation of the major planets, the Moon, and the Sun is studied by using DE404/LE404 ephemeris. For each body the files of the ecliptical components of the vectors of the angular velocity of the geodetic rotation are determined over the time span from AD1000 to AD3000 with one day spacing. The most essential terms of the geodetic rotation are found by means of the least squares method and spectral analysis methods.

scholarly journals New High-Precision Values of the Geodetic Rotation of the Major Planets, Pluto, the Moon and the Sun

2016 ◽  
Vol 51 (2) ◽  
pp. 61-73
Author(s):  
V.V. Pashkevich
Keyword(s):  
Spectral Analysis ◽  
Solar System ◽  
Least Squares Method ◽  
Time Span ◽  
Euler Angles ◽  
The Sun ◽  
The Moon ◽  
Coordinate Systems ◽  
Solar System Bodies ◽  
First Time

Abstract This investigation is continuation of our studies of the geodetic (relativistic) rotation of the Solar system bodies (Eroshkin and Pashkevich, 2007) and (Eroshkin and Pashkevich, 2009). For each body (the Moon, the Sun, the major planets and Pluto) the files of the values of the components of the angular velocity of the geodetic rotation are constructed over the time span from AD1000 to AD3000 with one day spacing, by using DE422/LE422 ephemeris (Folkner, 2011), with respect to the proper coordinate systems of the bodies (Seidelmann et al., 2005). For the first time in the perturbing terms of the physical librations for the Moon and in Euler angles for other bodies of the Solar system the most essential terms of the geodetic rotation are found by means of the least squares method and spectral analysis methods.

scholarly journals New High-Precision Values of the Geodetic Rotation of the Mars Satellites System, Major Planets, Pluto, the Moon and the Sun

2019 ◽  
Vol 54 (2) ◽  
pp. 31-42
Author(s):  
V.V. Pashkevich ◽  
A.N. Vershkov
Keyword(s):  
Solar System ◽  
Relativistic Effects ◽  
Euler Angles ◽  
The Sun ◽  
The Moon ◽  
Geodetic Precession ◽  
Long Time ◽  
Solar System Bodies ◽  
First Time ◽  
Mars Satellites

Abstract In this study the relativistic effects (the geodetic precession and the geodetic nutation, which consist of the effect of the geodetic rotation) in the rotation of Mars satellites system for the first time were computed and the improved geodetic rotation of the Solar system bodies were investigated. The most essential terms of the geodetic rotation were computed by the algorithm of Pashkevich (2016), which is applicable to the study of any bodies of the Solar system that have long-time ephemeris. As a result, in the perturbing terms of the physical librations and Euler angles for Mars satellites (Phobos and Deimos) as well as in the perturbing terms of the physical librations for the Moon and Euler angles for major planets, Pluto and the Sun the most significant systematic and periodic terms of the geodetic rotation were calculated. In this research the additional periodic terms of the geodetic rotation for major planets, Pluto and the Moon were calculated.

scholarly journals Inter-Commission Working Group on the Prevention of Interplanetary Pollution

1997 ◽  
Vol 23 (1) ◽  
pp. 263-274
Keyword(s):  
Solar System ◽  
Interplanetary Space ◽  
Planetary Science ◽  
General Assembly ◽  
Space Vehicles ◽  
The Moon ◽  
International Astronomical Union ◽  
International Astronomical ◽  
Solar System Bodies ◽  
Interplanetary Mission

At the 1988 Baltimore General Assembly of the International Astronomical Union, members of several Commissions dealing with planetary science expressed deep concern that no work was being undertaken to identify and avoid pollution problems in interplanetary space beyond the Moon. At that time NASA had convened a conference on problems in cislunar space due to the large and growing numbers of orbiting fragments hazardous to space vehicles. In translunar space this is hardly a problem. However an alarming number of future interplanetary mission proposals were considered for other reasons to be potentially harmful to various solar system bodies and interplanetary space itself.

The Effects of Hyperbolic Meteoroids from Parker Solar Probe to the Moon

2020 ◽  
Author(s):  
Jamey Szalay ◽  
Petr Pokorny ◽  
Mihaly Horanyi ◽  
Stuart Bale ◽  
Eric Christian ◽  
...  
Keyword(s):  
Solar System ◽  
Solar Radiation ◽  
Radiation Pressure ◽  
Solar Radiation Pressure ◽  
The Sun ◽  
The Moon ◽  
Zodiacal Cloud ◽  
Impact Ejecta ◽  
Density Enhancement ◽  
Small Grains

&lt;p&gt;The zodiacal cloud in the inner solar system undergoes continual evolution, as its dust grains are collisionally ground and sublimated into smaller and smaller sizes. Sufficiently small (~&lt;500 nm) grains known as beta-meteoroids are ejected from the inner solar system on hyperbolic orbits under the influence of solar radiation pressure. These small grains can reach significantly larger speeds than those in the nominal zodiacal cloud and impact the surfaces of airless bodies. Since the discovery of the Moon's asymmetric ejecta cloud, the origin of its sunward-canted density enhancement has not been well understood. We propose impact ejecta from beta-meteoroids that hit the Moon's sunward side could explain this unresolved asymmetry. The proposed hypothesis rests on the fact that beta-meteoroids are one of the few truly asymmetric meteoroid sources in the solar system, as unbound grains always travel away from the Sun and lack a symmetric inbound counterpart. This finding suggests beta-meteoroids may also contribute to the evolution of other airless surfaces in the inner solar system as well as within other exo-zodiacal disks. We will also highlight recent observations from the Parker Solar Probe (PSP) spacecraft, which suggest it is being bombarded by the very same beta-meteoroids. We discuss how observations by PSP, which lacks a dedicated dust detector, can be used to inform the structure and variability of beta-meteoroids in the inner solar system closer to the Sun than ever before.&lt;/p&gt;

scholarly journals Some Aspects of Constructing Long Ephemerides of the Sun, Major Planets and the Moon: Ephemeris AE95

1997 ◽  
Vol 165 ◽  
pp. 245-250
Author(s):  
G.I. Eroshkin ◽  
N.I. Glebova ◽  
M.A. Fursenko ◽  
A. A. Trubitsina
Keyword(s):  
Mathematical Model ◽  
Solar System ◽  
Numerical Integration ◽  
High Precision ◽  
The Sun ◽  
Specific Character ◽  
The Moon ◽  
Special Edition ◽  
Polynomial Representation

The construction of long-term numerical ephemerides of the Sun, major planets and the Moon is based essentially on the high-precision numerical solution of the problem of the motion of these bodies and polynomial representation of the data. The basis of each ephemeris is a mathematical model describing all the main features of the motions of the Sun, major planets, and Moon. Such mathematical model was first formulated for the ephemerides DE/LE and was widely applied with some variations for several national ephemeris construction. The model of the AE95 ephemeris is based on the DE200/LE200 ephemeris mathematical model. Being an ephemeris of a specific character, the AE95 ephemeris is a basis for a special edition “Supplement to the Astronomical Yearbook for 1996–2000”, issued by the Institute of the Theoretical Astronomy (ITA) (Glebova et al., 1995). This ephemeris covering the years 1960–2010 is not a long ephemeris in itself but the main principles of its construction allow one to elaborate the long-term ephemeris on an IBM PC-compatible computer. A high-precision long-term numerical integration of the motion of major bodies of the Solar System demands a choice of convenient variables and a high-precision method of the numerical integration, taking into consideration the specific features of both the problem to be solved and the computer to be utilized.

scholarly journals Volatiles and Refractories in Surface-Bounded Exospheres in the Inner Solar System

2021 ◽  
Vol 217 (5) ◽  
Author(s):  
Cesare Grava ◽  
Rosemary M. Killen ◽  
Mehdi Benna ◽  
Alexey A. Berezhnoy ◽  
Jasper S. Halekas ◽  
...  
Keyword(s):  
Solar System ◽  
Lunar Surface ◽  
Noble Gas ◽  
The Moon ◽  
Solar System Bodies ◽  
Calcium Magnesium ◽  
End Members

AbstractVolatiles and refractories represent the two end-members in the volatility range of species in any surface-bounded exosphere. Volatiles include elements that do not interact strongly with the surface, such as neon (detected on the Moon) and helium (detected both on the Moon and at Mercury), but also argon, a noble gas (detected on the Moon) that surprisingly adsorbs at the cold lunar nighttime surface. Refractories include species such as calcium, magnesium, iron, and aluminum, all of which have very strong bonds with the lunar surface and thus need energetic processes to be ejected into the exosphere. Here we focus on the properties of species that have been detected in the exospheres of inner Solar System bodies, specifically the Moon and Mercury, and how they provide important information to understand source and loss processes of these exospheres, as well as their dependence on variations in external drivers.

scholarly journals Spectroscopic Radial Velocities: Photospheric Lineshifts Calibrated By Hipparcos

1998 ◽  
Vol 11 (1) ◽  
pp. 564-564
Author(s):  
D. Gullberg ◽  
D. Dravins
Keyword(s):  
Radial Velocity ◽  
High Precision ◽  
Open Clusters ◽  
Radial Velocities ◽  
Radial Motion ◽  
Spectral Lines ◽  
Gravitational Redshift ◽  
The Sun

Wavelengths of stellar spectral lines depend not only on the star’s motion. Until recently, accurate studies of shifts not caused by radial motion were feasible only for the Sun. Solar lineshifts are interpreted as gravitational redshift (636 m/s) and convective blueshifts (~ 400 m/s; caused by velocity-brightness correlations). In other stars, such effects may be greater (Dravins & Nordlund 1990). Accurate astrometric radial velocities are now available from Hipparcos (Dravins et al. 1997a; 1997b), permitting studies of such shifts also in some other stars. For such stars in the open clusters of Hyades, Ursa Major and Coma Berenices, a spectroscopic program is in progress, analyzing wavelength shifts in groups of lines with different strengths, excitation potentials, etc., using the ELODIE high-precision radial-velocity instrument (Baranne et al. 1996) at Haute-Provence Observatory.

scholarly journals Everything Is A Circle: A New Universal Orbital Model

2021 ◽  
Author(s):  
AslıPınar Tan
Keyword(s):  
Solar System ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Ecliptic Plane ◽  
The Sun ◽  
The Moon ◽  
Circular Orbits ◽  
Orbital Parameters ◽  
The Earth ◽  
Angular Velocities

Based on measured astronomical position data of heavenly objects in the Solar System and other planetary systems, all bodies in space seem to move in some kind of elliptical motion with respect to each other. According to Kepler&rsquo;s 1st Law, &ldquo;orbit of a planet with respect to the Sun is an ellipse, with the Sun at one of the two foci.&rdquo; Orbit of the Moon with respect to Earth is also distinctly elliptical, but this ellipse has a varying eccentricity as the Moon comes closer to and goes farther away from the Earth in a harmonic style along a full cycle of this ellipse. In this paper, our research results are summarized, where it is first mathematically shown that the &ldquo;distance between points around any two different circles in three dimensional space&rdquo; is equivalent to the &ldquo;distance of points around a vector ellipse to another fixed or moving point, as in two dimensional space&rdquo;. What is done is equivalent to showing that bodies moving on two different circular orbits in space vector wise behave as if moving on an elliptical path with respect to each other, and virtually seeing each other as positioned at an instantaneously stationary point in space on their relative ecliptic plane, whether they are moving with the same angular velocity, or different but fixed angular velocities, or even with different and changing angular velocities with respect to their own centers of revolution. This mathematical revelation has the potential to lead to far reaching discoveries in physics, enabling more insight into forces of nature, with a formulation of a new fundamental model regarding the motions of bodies in the Universe, including the Sun, Planets, and Satellites in the Solar System and elsewhere, as well as at particle and subatomic level. Based on the demonstrated mathematical analysis, as they exhibit almost fixed elliptic orbits relative to one another over time, the assertion is made that the Sun, the Earth, and the Moon must each be revolving in their individual circular orbits of revolution in space. With this expectation, individual orbital parameters of the Sun, the Earth, and the Moon are calculated based on observed Earth to Sun and Earth to Moon distance data, also using analytical methods developed as part of this research to an approximation. This calculation and analysis process have revealed additional results aligned with observation, and this also supports our assertion that the Sun, the Earth, and the Moon must actually be revolving in individual circular orbits.

A New Scientist

2018 ◽  
Author(s):  
David D. Nolte
Keyword(s):  
Solar System ◽  
Scientific Method ◽  
Free Time ◽  
The Sun ◽  
The Moon ◽  
Galileo Galilei ◽  
House Arrest ◽  
University Of Padua ◽  
The University

Galileo Galilei was the first modern scientist, launching a new scientific method that superseded, after one and a half millennia, Aristotle’s physics. This chapter describes the trajectory of Galileo’s career, beginning with his studies of motion at the University of Pisa that were interrupted after his move to the University of Padua by his telescopic discoveries of mountains on the Moon and the moons of Jupiter. Galileo became the first rock star of science, and he used his fame to promote the ideas of Copernicus and the Sun-centered model of the solar system. But he pushed too far when he lampooned the Pope. Ironically, Galileo’s conviction for heresy and his sentence to house arrest for the remainder of his life gave him the free time to finally finish his work on the physics of motion, which he published in Two New Sciences in 1638.

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