scholarly journals Physical and dynamical characteristics of icy “dwarf planets” (plutoids)

2009 ◽  
Vol 5 (S263) ◽  
pp. 173-185 ◽  
Author(s):  
Gonzalo Tancredi
Keyword(s):  
Solar System ◽  
Classification Scheme ◽  
Reliable Estimate ◽  
Size Distributions ◽  
International Astronomical Union ◽  
Dynamical Characteristics ◽  
Dwarf Planets ◽  
International Astronomical ◽  
Solar System Bodies ◽  
Definition Of

AbstractThe geophysical and dynamical criteria introduced in the “Definition of a Planet in the Solar System” adopted by the International Astronomical Union are reviewed. The classification scheme approved by the IAU reflects dynamical and geophysical differences among planets, “dwarf planets” and “small Solar System bodies”. We present, in the form of a decision tree, the set of questions to be considered in order to classify an object as an icy “dwarf planet” (a plutoid). We find that there are 15 very probable plutoids; plus possibly 9 more, which require a reliable estimate of their sizes. Finally, the most relevant physical and dynamical characteristics of the set of icy “dwarf planets” have been reviewed; e.g. the albedo, the lightcurve amplitude, the location in the different dynamical populations, the size distributions, and the discovery rate.

Probing the New Solar System

2009 ◽  
Author(s):  
John Wilkinson
Keyword(s):  
Solar System ◽  
Planetary Systems ◽  
Planetary Exploration ◽  
Space Probe ◽  
International Astronomical Union ◽  
Historical Information ◽  
Dwarf Planets ◽  
International Astronomical ◽  
The Many ◽  
Definition Of

Exploration by space probes has revealed many fascinating details about Earth’s planetary neighbours. Today we stand on the threshold of the next phase of planetary exploration and knowledge, with several space probe missions currently underway and others being planned. Probing the New Solar System discusses the latest findings that have contributed to a changed understanding of the solar system – and how the revised definition of a planet in 2006 by the International Astronomical Union affected this understanding. Each chapter includes some historical information, ‘Did you know?’ items of particular interest to readers, and photographs of objects in the solar system showing newly discovered features of the planets, their moons and of dwarf planets. This is an up-to-date record of the many recent discoveries made about our solar system and other planetary systems using ground-based and space probe technology. It has been written for people interested in astronomy, both professional and amateur, as well as for students and educators.

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.

scholarly journals 14. Commission des Étalons de Longueur D’Onde et des Tables de Spectres Solaires

1939 ◽  
Vol 6 ◽  
pp. 79-102
Author(s):  
M. W. F. Meggers ◽  
MM. Babcock ◽  
Buisson ◽  
Burns ◽  
Ch. Fabry ◽  
...  
Keyword(s):  
Wave Length ◽  
Primary Standard ◽  
International Committee ◽  
International Astronomical Union ◽  
International Union ◽  
Weights And Measures ◽  
International Astronomical ◽  
Solar Research ◽  
Definition Of ◽  
Red Radiation

The red radiation, 6438.4696 A., emitted by a cadmium lamp of Michelson type was first chosen in 1907 by the International Union for Co-operation in Solar Research (Trans. I.U.S.R. 2, 109, 1907) as a definition of the unit of wave-length. This primary standard was subsequently adopted by the International Astronomical Union (Trans. I.A.U. 1, 35, 1922) and by the International Committee on Weights and Measures (Procès-Verbaux Comité Int. Poids et Mesures (2), 12,67,1927). Specifications for the production of this primary standard were adopted provisionally by the I.A.U. in 1925 (Trans. I.A.U. 2, 47, 232, 1925), and by the I.C.W.M. in 1927 (Procès-Verbaux Comité Int. Poids et Mesures (2), 12, 67, 1927). Three reports of this Commission (Trans. I.A.U. 3, 77, 236, 1928; ibid. 4, 58, 233,1932; ibid. 5, 81, 299, 1935) have discussed the divergences in these specifications and pointed out the unsatisfactory features of each. This discussion culminated in a revised specification (Trans. I.A.U. 5, 303, 1935) which was adopted unanimously by the I.C.W.M. in 1935 (Procès-Verbaux Comité Int. (2), 17, 91,1935).

scholarly journals Issues of Time for Reference Systems

1993 ◽  
Vol 156 ◽  
pp. 357-362
Author(s):  
P. K. Seidelmann
Keyword(s):  
General Assembly ◽  
Coordinate Systems ◽  
International Astronomical Union ◽  
Sidereal Time ◽  
Coordinate Time ◽  
International Astronomical ◽  
Definition Of ◽  
T Values ◽  
Barycentric Coordinate ◽  
Astronomical Constants

At the International Astronomical Union General Assembly in 1991 the terminologies Geocentric Coordinate Time (TCG) and Barycentric Coordinate Time (TCB) were introduced as the time coordinates of four dimensional geocentric and barycentric coordinate systems, respectively. The reasons for these time-like arguments and their applications will be discussed. The relationships between the different time-like arguments will be discussed along with their applications and relationships to the astronomical constants.Since these time-like arguments have secular differences, there are new issues to be resolved. These new issues include the definition of the epoch J2000.0, relationship between mean and apparent sidereal time, the time-like argument for specifying constants, the definition and future use of ephemeris time, delta T values and the transition to, or future use of, TCG, TCB and TDB.

scholarly journals The red line of cadmium as a standard of wave-length

1936 ◽  
Vol 155 (885) ◽  
pp. 407-419 ◽  
Keyword(s):  
Wave Length ◽  
Point Of View ◽  
International Astronomical Union ◽  
Length Standard ◽  
Interference Fringes ◽  
High Tension ◽  
International Astronomical ◽  
Definition Of ◽  
Good Agreement ◽  
Red Line

The line 6438 of the first spectrum of cadmium was chosen by Michelson as the standard against which to measure the metre, because it was the best line he had discovered both from the point of view of its simplicity of structure and its capability of giving measurable interference fringes over very long paths. It has been used for comparison with the metre in four subsequent investigations and the wave-length 6438·4696 was adopted by the international Astronomical Union as the primary wave-length standard (or indeed the definition of the International Angstrom) in 1907. The line was produced by Michelson by exciting an H-shaped discharge tube with high tension alternating current, the lamp at the same time being raised to a temperature of 320° C with the aid of a furnace. Similar sources were used in six subsequent comparisons of the metre and the red line of cadmium. The results of these comparisons are in very good agreement, the accuracy appearing to be of the order of one part in five million, as can be seen from Table I.

Mathematical cartography today

2019 ◽  
Vol 943 (1) ◽  
pp. 52-57
Author(s):  
M.V. Nyrtsov
Keyword(s):  
Solar System ◽  
Initial Data ◽  
Additional Research ◽  
Triaxial Ellipsoid ◽  
International Astronomical Union ◽  
Small Bodies ◽  
Map Projections ◽  
International Astronomical ◽  
A Cell ◽  
Almost All

For most small bodies of the Solar System shapes the International Astronomical Union recommends to use a triaxial ellipsoid. Today almost all major classes of cartographic projections for the triaxial ellipsoid have been developed. They require systematization, classification and additional research. The archives of libraries accumulated a significant list of paper maps of the Soviet times which are compiled in projections developed in our country. It is necessary to implement those projections in the PROJ.4 library used by GIS. Distortions in map projections can be defined as deformation of a cell. If we imagine that the sphere is covered with a net of regular hexagons then it is possible to estimate distortions in the projection by their deformation on the plane. Now the majority of cartographers use online calculators to define the values required for mathematical cartography. Programs are usually written in JavaScript and require the user to only enter the initial data. These are only some of the problems facing modern mathematical cartography.

scholarly journals Távoli csillagok és bolygóik új elnevezései

2020 ◽  
Vol 42 ◽  
pp. 213-220
Author(s):  
Judit Kozma
Keyword(s):  
Solar System ◽  
100Th Anniversary ◽  
Press Conference ◽  
International Astronomical Union ◽  
International Astronomical ◽  
Autonomous Regions

The International Astronomical Union (IAU) celebrated its 100th anniversary in 2019. To celebrate the occasion, the organisation announced a campaign for countries to name exoplanets, that is planets outside of our solar system and their stars. A total of 113 countries and autonomous regions took part in the campaign, choosing names by way of public votes. The IAU announced the 225 names chosen at a press conference on 17 December 2019 and accepted these as official (alongside the scientific names already in use). Following a brief description of exoplanets, the study categorises the planet names according to onomastic aspects and offers an overview of the names submitted to the Hungarian committee.

scholarly journals The Definition of UTC

2000 ◽  
Vol 180 ◽  
pp. 363-371
Author(s):  
Dennis D. McCarthy
Keyword(s):  
Time Scale ◽  
Rotation Rate ◽  
Working Group ◽  
Universal Time ◽  
International Astronomical Union ◽  
Current Definition ◽  
The Earth ◽  
International Astronomical ◽  
Definition Of

AbstractThe current definition of Coordinated Universal Time (UTC) is related to the unpredictable, variable rotation rate of the Earth. This is accomplished by irregular insertions of leap seconds, creating unpredictable discontinuities in UTC. With the increasing importance of a continuous, uniform time scale for users, it is appropriate to re-examine the current definition of this time scale. There are several possibilities to address this problem, and it is appropriate that the International Astronomical Union establish a working group to investigate the continuing need for leap seconds and possible changes in the definition of UTC.

scholarly journals COMMISSION 22: METEORS, METEORITES AND INTERPLANETARY DUST

2008 ◽  
Vol 4 (T27A) ◽  
pp. 174-178
Author(s):  
Pavel Spurný ◽  
Jun-ichi Watanabe ◽  
Ingrid Mann ◽  
Jiří Borovička ◽  
William J. Baggaley ◽  
...  
Keyword(s):  
Solar System ◽  
Planetary System ◽  
Interplanetary Dust ◽  
Dust Particles ◽  
International Astronomical Union ◽  
Division Iii ◽  
Interplanetary Dust Particles ◽  
Meteoroid Streams ◽  
Zodiacal Cloud ◽  
International Astronomical

Commission 22 is part of Division III on Planetary System Sciences of the International Astronomical Union. Members of Commission 22 are professional scientists studying bodies in the Solar System smaller than asteroids and comets, and their interactions with planets. The main subjects of interest are meteors, meteoroids, meteoroid streams, interplanetary dust particles, and also zodiacal cloud, meteor trains, meteorites, tektites, etc.

scholarly journals Comet composition and Lab

2015 ◽  
Vol 11 (A29A) ◽  
pp. 227-227
Author(s):  
Dominique Bockelée-Morvan
Keyword(s):  
Solar System ◽  
Small Worlds ◽  
Icy Satellites ◽  
Small Bodies ◽  
New Horizons ◽  
Dwarf Planets ◽  
Cassini Mission ◽  
Solar System Bodies ◽  
Geochemical Analyses ◽  
Comet 67P

The XXIX IAU General Assembly took place during the golden year of the exploration of small solar system bodies. With the Rosetta ESA mission around comet 67P, NASA Dawn and New Horizons missions nearby dwarf planets Ceres and Pluto, respectively, and the NASA/Cassini mission in Saturn neighborhood, year 2015 marked an important step towards further understanding of small solar system bodies. On August 11-13, Focus meeting 9 "Highlights in the exploration of small worlds" gathered scientists of all over the world to present and discuss the spectacular results obtained from these missions, as well as recent achievements obtained from past missions, comprehensive spectroscopic surveys from space (e.g., Herschel, NEOWISE, Gaia), ground-based observations, and geochemical analyses. This meeting was also the opportunity to discuss the state of our understanding of the nature of the various populations of small bodies in the Solar System, including icy satellites, in a cosmo-chemistry perspective.

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