scholarly journals Carlsberg Positions of Planets Compared with JPL DE403

1997 ◽  
Vol 165 ◽  
pp. 541-546
Author(s):  
L.V. Morrison ◽  
M.E. Buontempo
Keyword(s):  
Solar System ◽  
Reference Frame ◽  
Systematic Difference ◽  
Outer Solar System ◽  
Vlbi Observations ◽  
Solar System Objects ◽  
Hipparcos Catalogue ◽  
Preliminary Version ◽  
Celestial Reference Frame

AbstractThe Carlsberg meridian telescope has made nearly 20 000 observations of outer Solar System objects since it began operation in 1984. A preliminary version of the Hipparcos catalogue has been used to refer the positions to the International Celestial Reference Frame (ICRF). The observed positions of the major planets are compared with JPL DE403 which is also referred to the ICRF. The agreement with DE403 is good, except for the declination of Jupiter where there is a systematic difference reaching 015 in 1995. The cause of this discrepancy is being investigated at JPL with recent VLBI observations of Galileo.

scholarly journals Relativistic Effects in the Rotation of Jupiter’s Inner Satellites

2020 ◽  
Vol 55 (3) ◽  
pp. 118-129
Author(s):  
Vladimir V. Pashkevich ◽  
Andrey N. Vershkov
Keyword(s):  
Solar System ◽  
Reference Frame ◽  
Central Body ◽  
Relativistic Effects ◽  
Euler Angles ◽  
Coordinate Systems ◽  
Geodetic Precession ◽  
Long Time ◽  
Celestial Reference Frame ◽  
Jupiter’S Satellites

AbstractThe most significant relativistic effects (the geodetic precession and the geodetic nutation, which consist of the effect of the geodetic rotation) in the rotation of Jupiter’s inner satellites were investigated in this research. The calculations of the most essential secular and periodic terms of the geodetic rotation were carried out by the method for studying any bodies of the solar system with long-time ephemeris. As a result, for these Jupiter’s satellites, these terms of their geodetic rotation were first determined in the rotational elements with respect to the International Celestial Reference Frame (ICRF) equator and the equinox of the J2000.0 and in the Euler angles relative to their proper coordinate systems. The study shows that in the solar system there are objects with significant geodetic rotation, due primarily to their proximity to the central body, and not to its mass.

scholarly journals Evaluating the Dynamical Stability of Outer Solar System Objects in the Presence of Planet Nine

2017 ◽  
Vol 154 (2) ◽  
pp. 61 ◽  
Author(s):  
Juliette C. Becker ◽  
Fred C. Adams ◽  
Tali Khain ◽  
Stephanie J. Hamilton ◽  
David Gerdes
Keyword(s):  
Solar System ◽  
Dynamical Stability ◽  
Outer Solar System ◽  
Solar System Objects

scholarly journals DYNAMICALLY EXCITED OUTER SOLAR SYSTEM OBJECTS IN THEHUBBLE SPACE TELESCOPEARCHIVE

2011 ◽  
Vol 742 (2) ◽  
pp. 118 ◽  
Author(s):  
Cesar I. Fuentes ◽  
David E. Trilling ◽  
Matthew J. Holman
Keyword(s):  
Solar System ◽  
Outer Solar System ◽  
Solar System Objects

scholarly journals Astrometry and Geodesy from VLBI

1993 ◽  
Vol 156 ◽  
pp. 159-171
Author(s):  
C. Ma ◽  
J. L. Russell
Keyword(s):  
Reference Frame ◽  
Reference Frames ◽  
Radio Sources ◽  
Dual Frequency ◽  
Terrestrial Reference Frames ◽  
Vlbi Observations ◽  
Using Data ◽  
Celestial Reference Frame ◽  
Right Ascension ◽  
Better Than

Dual frequency Mark III VLBI observations acquired since 1979 by several geodetic and astrometric observing programs have been used to establish precise celestial and terrestrial reference frames. The program to establish a uniformly distributed celestial reference frame of ∼400 compact radio sources with optical counterparts was begun in 1987. Some 700 sources have been considered as part of this effort and a preliminary list of ∼400 has been observed. At present, 308 sources have formal 1σ errors less than 1 mas in right ascension and 308 have similar precision in declination. The astrometric results include some data acquired for geodetic purposes. The geodetic results using data to September, 1992 include the positions of 105 sites with formal 1σ horizontal errors generally less than 1 cm at 1992.6 and the velocities of 64 sites with formal 1σ horizontal errors generally better than 2 mm/yr.

scholarly journals Near-infrared Methanol Bands Probe Energetic Processing of Icy Outer Solar System Objects

2020 ◽  
Vol 894 (1) ◽  
pp. L3 ◽  
Author(s):  
Riccardo Giovanni Urso ◽  
Donia Baklouti ◽  
Zahia Djouadi ◽  
Noemí Pinilla-Alonso ◽  
Rosario Brunetto
Keyword(s):  
Solar System ◽  
Near Infrared ◽  
Outer Solar System ◽  
Solar System Objects

scholarly journals Models for Source Structure Corrections

2000 ◽  
Vol 180 ◽  
pp. 29-39
Author(s):  
P. Charlot
Keyword(s):  
Reference Frame ◽  
Very Long Baseline Interferometry ◽  
Radio Sources ◽  
Time Varying ◽  
Long Baseline ◽  
Vlbi Observations ◽  
Spatially Extended ◽  
Astrometric Data ◽  
Celestial Reference Frame ◽  
Source Structure

AbstractAt the milliarcsecond scale, most of the extragalactic radio sources exhibit spatially-extended intrinsic structures which are variable in both time and frequency. Such radio structures set limits on the accuracy of source positions determined with the Very Long Baseline Interferometry (VLBI) technique unless their effects in the astrometric data can be accounted for. We review the modeling scheme for calculating source structure corrections and discuss the magnitude and impact of these effects for the sources that are part of the International Celestial Reference Frame (ICRF). Results obtained by applying source structure corrections to actual VLBI observations on the time-varying source 4C39.25 (0923 + 392) are also presented.

scholarly journals New accuracy levels for solar system ephemerides

1996 ◽  
Vol 172 ◽  
pp. 29-36 ◽  
Author(s):  
E. M. Standish ◽  
X X Newhall
Keyword(s):  
Solar System ◽  
Reference Frame ◽  
Data Reduction ◽  
Equations Of Motion ◽  
Adjustment Process ◽  
Dynamical Modeling ◽  
Reduction Techniques ◽  
Condensed Representation ◽  
Lunar Ephemeris ◽  
Hipparcos Catalogue

DE403/LE403 is the latest JPL Planetary and Lunar Ephemeris. It represents a number of changes and improvements to previous JPL ephemerides: the reference frame is now that of the IERS, newer and more accurate observations are used in the adjustment process, some of the data reduction techniques have been refined, and improved dynamical modeling has been incorporated into the equations of motion. As a result, the internal accuracy of the inner four planets has been improved. Further, various measurements accurately tie Jupiter onto the IERS Reference Frame. In the future, use of CCD measurements and the Hipparcos Catalogue should improve the ephemerides of the outermost four planets.DE403/LE403 has been integrated over 6000 years, from 3000 BC to 3000 AD. A more condensed representation has been made from this, named DE404/LE404. It replaces DE102 as the new JPL “Long Ephemeris”.

scholarly journals Extension of the Optical Reference Frame:Space Based

1998 ◽  
Vol 11 (1) ◽  
pp. 304-306
Author(s):  
S. Röser
Keyword(s):  
Reference Frame ◽  
General Assembly ◽  
Radio Sources ◽  
Practical Realization ◽  
The Earth ◽  
Optical Reference ◽  
Hipparcos Catalogue ◽  
Optical Wavelengths ◽  
Celestial Reference Frame ◽  
23Rd General

At its 23rd General Assembly, Kyoto 1997, the IAU decided that the International Celestial Reference Frame (ICRF) should be defined by the positions of 608 compact extragalactic radio sources (Ma & Feissel 1997), with the Hipparcos Catalogue (ESA 1997) being its practical realization at optical wavelengths. Although the Hipparcos instrument was unable to observe the defining sources of the ICRF directly in the optical regime, it is linked to the ICRF via a number of auxiliary observations (Kovalevsky et al. 1997). The Hipparcos Catalogue is the first celestial reference frame which is constructed from observations not made from the surface of the Earth.

scholarly journals Formation of The International Celestial Reference Frame

1998 ◽  
Vol 11 (1) ◽  
pp. 281-286
Author(s):  
C. Ma ◽  
E.F. Arias ◽  
T.M. Eubanks ◽  
A.L. Fey ◽  
A.-M. Gontier ◽  
...  
Keyword(s):  
Reference Frame ◽  
Reference Frames ◽  
Terrestrial Reference Frame ◽  
Naval Research ◽  
Dual Frequency ◽  
Cooperative Effort ◽  
Space Navigation ◽  
Vlbi Observations ◽  
Crustal Dynamics ◽  
Celestial Reference Frame

The goal of the work described here is to create the definitive catalogue for the new International Celestial Reference Frame (ICRF) using the best data and methods available at the time the work was done. This work is the joint cooperative effort of a subgroup of the IAU Working Group on Reference Frames which was formed expressly for this purpose in February 1995. The authors of this report constituted the subgroup. A fuller account of this report can be found in the introduction to the ICRF catalog (IERS 1997). The ICRF of 608 sources presented here is based on essentially all the VLBI observations accu-mulated over about 15 years in several worldwide programs. Dual frequency Mark III data have both geodetic and astrometric applications. Most of the data (95% of nearly 2 million observations) were acquired primarily for geodetic purposes. The major geodetic programs include: NASA’s Crustal Dynamics Project/Space Geodesy Program and USNO’s NAVEX sessions for the terrestrial reference frame, as well as IRIS, NAVNET and NEOS sessions for monitoring Earth rotation. The geodetic programs have used the brightest radio sources, gradually concentrating on the most com-pact as sensitivity improved. These geodetic sources were also the foundation of astrometric work because of the large number of observations for the ~150 most commonly used. The astrometric programs which densify the sky include the Radio-Optical Reference Frame sessions done by US Naval Research Laboratory (NRL) and USNO and the space navigation efforts of Jet Propulsion Laboratory (JPL).

scholarly journals Extension of The Optical Reference Frame: Ground Based

1998 ◽  
Vol 11 (1) ◽  
pp. 300-303
Author(s):  
N. Zacharias
Keyword(s):  
Reference Frame ◽  
Radio Sources ◽  
Proper Motions ◽  
Magnitude Range ◽  
Optical Reference ◽  
Hipparcos Catalogue ◽  
Optical Wavelengths ◽  
The Mean ◽  
Celestial Reference System ◽  
Celestial Reference Frame

The International Celestial Reference Frame (ICRF) is realized by the positions of 608 compact extragalactic radio sources (Ma & Feissel 1997) with milliarcsecond (mas) and sub-mas accuracy, all being on the same system, the International Celestial Reference System (ICRS). The Hipparcos Catalogue (ESA 1997) is the practical realization of the ICRF at optical wavelengths, giving accurate positions (≈ 1 mas) at the mean epoch of 1991.25 and proper motions (≈ 1 mas/yr) for 117995 stars. This is about 2.5 stars per square degree, most being in the 7 to 9 magnitude range and a few as faint as 12. However, for many astronomical applications the Hipparcos Catalogue is not dense enough and does not reach faint enough magnitudes. The Tycho Catalogue (ESA 1997) provides accurate positions (≈ 25 mas) for about one million stars to magnitude 11, but lacks precise proper motions. Ground-based observations are an efficient way to complement the Hipparcos mission and to extend the optical reference frame to fainter magnitudes and yield a denser grid of astrometric standard stars. New reductions of early epoch photographic data will be used to provide highly accurate proper motions for stars to about magnitude 12. Current and new observational projects will extend the optical reference frame to even fainter magnitudes.

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