The fast rotation of Orcus obtained from TESS measurements

2020 ◽  
Author(s):  
Csaba Kiss ◽  
András Pál ◽  
Róbert Szakáts ◽  
Gábor Marton ◽  
Thomas Müller
Keyword(s):  
Kuiper Belt ◽  
Large Body ◽  
Satellite Orbits ◽  
Triaxial Ellipsoid ◽  
Kuiper Belt Objects ◽  
Considerable Uncertainty ◽  
Fast Rotation ◽  
Rotation Periods ◽  
History Of ◽  
Large Satellite

<p>(90482) Orcus is one of the largest Kuiper belt objects, with one known, relatively large satellite, Vanth. There have been several ~10-20h rotation periods reported in the literature for Orcus, with considerable uncertainty. Here we report on recent measurements of Orcus with the TESS Space Telescope providing a light curve period of 7 h, the fastest rotation among those large trans-Neptunian objects for which the rotation is not expected to cause a distorted, triaxial ellipsoid shape, like in the case of Haumea. While moons of large Kuiper belt objects are usually assumed to be formed from an original large body via collisions, the fast rotation may point to a scenario in which Vanth was captured from a nearby heliocentric orbit early in the history of the Solar system, and subsequent tidal evolution led to the present, nearly circular orbit. In this sense the Orcus-Vanth system is peculiar, as the present rotational characteristics and satellite orbits of all other large Kuiper belt objects are consistent with a collisional origin. </p>

scholarly journals Resonant Kuiper belt objects: a review

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Renu Malhotra
Keyword(s):  
Solar System ◽  
System Architecture ◽  
Kuiper Belt ◽  
Dynamical Structure ◽  
Kuiper Belt Objects ◽  
History Of ◽  
Orbital Migration ◽  
New View

Abstract Our understanding of the history of the solar system has undergone a revolution in recent years, owing to new theoretical insights into the origin of Pluto and the discovery of the Kuiper belt and its rich dynamical structure. The emerging picture of dramatic orbital migration of the planets driven by interaction with the primordial Kuiper belt is thought to have produced the final solar system architecture that we live in today. This paper gives a brief summary of this new view of our solar system’s history and reviews the astronomical evidence in the resonant populations of the Kuiper belt.

MINING THE ARCHIVES: A POTTERY SEQUENCE FOR BORNO, NIGERIA

2003 ◽  
Vol 1 (1) ◽  
pp. 39-76 ◽  
Author(s):  
Graham Connah ◽  
S.G.H. Daniels
Keyword(s):  
Large Body ◽  
Archaeological Research ◽  
Independent Data ◽  
Frankfurt Am Main ◽  
Archaeological Pottery ◽  
New Findings ◽  
History Of ◽  
1960S And 1970S ◽  
The 1960S ◽  
Johann Wolfgang Goethe

New archaeological research in Borno by the Johann-Wolfgang-Goethe-Universität, Frankfurt am Main, Germany, has included the analysis of pottery excavated from several sites during the 1990s. This important investigation made us search through our old files for a statistical analysis of pottery from the same region, which although completed in 1981 was never published. The material came from approximately one hundred surface collections and seven excavated sites, spread over a wide area, and resulted from fieldwork in the 1960s and 1970s. Although old, the analysis remains relevant because it provides a broad geographical context for the more recent work, as well as a large body of independent data with which the new findings can be compared. It also indicates variations in both time and space that have implications for the human history of the area, hinting at the ongoing potential of broadscale pottery analysis in this part of West Africa and having wider implications of relevance to the study of archaeological pottery elsewhere.

U-Band Photometry of Kuiper Belt Objects

2007 ◽  
Vol 134 (5) ◽  
pp. 2046-2053 ◽  
Author(s):  
David Jewitt ◽  
Nuno Peixinho ◽  
Henry H. Hsieh
Keyword(s):  
Kuiper Belt ◽  
Kuiper Belt Objects

scholarly journals Analysis of the Rotational Properties of Kuiper Belt Objects

2006 ◽  
Vol 131 (4) ◽  
pp. 2314-2326 ◽  
Author(s):  
Pedro Lacerda ◽  
Jane Luu
Keyword(s):  
Kuiper Belt ◽  
Kuiper Belt Objects

scholarly journals JUDICIAL UNCERTAINTIES CONCERNING TERRITORIAL SEA DELIMITATION UNDER ARTICLE 15 OF THE UNITED NATIONS CONVENTION ON THE LAW OF THE SEA

2017 ◽  
Vol 66 (3) ◽  
pp. 589-623 ◽  
Author(s):  
Massimo Lando
Keyword(s):  
United Nations ◽  
Law Of The Sea ◽  
Practical Implementation ◽  
Two Stage ◽  
Considerable Uncertainty ◽  
History Of ◽  
United Nations Convention ◽  
International Tribunals ◽  
The Law ◽  
Special Circumstances

AbstractRecent international jurisprudence has shown considerable uncertainty with regard to the delimitation of the territorial sea. While international tribunals endorse a two-stage approach to territorial sea delimitation, there is a lack of judicial consensus on the practical implementation of such an approach. This article argues that the rule-exception relationship between equidistance and special circumstances, as reflected in the drafting history of LOSC Article 15 and in jurisprudence prior to 2007, should inform the delimitation of the territorial sea. Cases since 2007 which have strayed from the earlier jurisprudence on LOSC Article 15, should be seen as a misconstruction of the law applicable to territorial sea delimitation.

scholarly journals Reconstruction of asteroid spin states from Gaia DR2 photometry

2018 ◽  
Vol 620 ◽  
pp. A91 ◽  
Author(s):  
J. Ďurech ◽  
J. Hanuš
Keyword(s):  
Rotation Period ◽  
Inversion Method ◽  
Triaxial Ellipsoid ◽  
Independent Data ◽  
Rotation Periods ◽  
Shape Models ◽  
Pole Parameter ◽  
Data Points ◽  
Sidereal Rotation ◽  
Gaia Dr2

Context. In addition to stellar data, Gaia Data Release 2 (DR2) also contains accurate astrometry and photometry of about 14 000 asteroids covering 22 months of observations. Aims. We used Gaia asteroid photometry to reconstruct rotation periods, spin axis directions, and the coarse shapes of a subset of asteroids with enough observations. One of our aims was to test the reliability of the models with respect to the number of data points and to check the consistency of these models with independent data. Another aim was to produce new asteroid models to enlarge the sample of asteroids with known spin and shape. Methods. We used the lightcurve inversion method to scan the period and pole parameter space to create final shape models that best reproduce the observed data. To search for the sidereal rotation period, we also used a simpler model of a geometrically scattering triaxial ellipsoid. Results. By processing about 5400 asteroids with at least 10 observations in DR2, we derived models for 173 asteroids, 129 of which are new. Models of the remaining asteroids were already known from the inversion of independent data, and we used them for verification and error estimation. We also compared the formally best rotation periods based on Gaia data with those derived from dense lightcurves. Conclusions. We show that a correct rotation period can be determined even when the number of observations N is less than 20, but the rate of false solutions is high. For N > 30, the solution of the inverse problem is often successful and the parameters are likely to be correct in most cases. These results are very promising because the final Gaia catalogue should contain photometry for hundreds of thousands of asteroids, typically with several tens of data points per object, which should be sufficient for reliable spin reconstruction.

scholarly journals Comets (Existing Populations)

1994 ◽  
Vol 160 ◽  
pp. 77-94
Author(s):  
Ľ. Kresák
Keyword(s):  
Kuiper Belt ◽  
Dynamical Evolution ◽  
Oort Cloud ◽  
Survival Times ◽  
Evolutionary Time ◽  
Origin And Evolution ◽  
History Of ◽  
The Individual ◽  
Evolutionary Paths

The definition, population, extent, origin and evolution of the individual subsystems of comets and transitions between them are discussed, together with presentation of the relevant statistical data and their changes with time. The largest outer subsystems are unobservable, but their existence is documented by the necessity of progressive replenishment of the observable populations, with limited survival times. There is persuasive evidence for two different evolutionary paths, one from the Oort cloud and another from the Kuiper belt. While the extent and accuracy of the data available is increasing rapidly, the Jupiter family of comets is the only one for which the evolutionary time scales do not exceed by many orders of magnitude the history of astronomical observations. The individual comet populations differ from one another not only by the distribution of orbits, but also by the size distribution and aging rate of their members. Their dynamical evolution is coupled with disintegration processes, which make it questionable whether the present state can be interpreted as a long-term average.

scholarly journals Statistical Methods for Detecting Stellar Occultations by Kuiper Belt Objects: The Taiwanese?American Occultation Survey

2004 ◽  
Vol 19 (2) ◽  
pp. 265-274 ◽  
Author(s):  
Chyng-Lan Liang ◽  
John A. Rice ◽  
Imke de Pater ◽  
Charles Alcock ◽  
Tim Axelrod ◽  
...  
Keyword(s):  
Statistical Methods ◽  
Kuiper Belt ◽  
Kuiper Belt Objects ◽  
Stellar Occultations ◽  
Taiwanese American

scholarly journals Census of the Kuiper-Belt Objects - The Taiwan-America Occultation Survey (TAOS)

2002 ◽  
Vol 12 ◽  
pp. 245-246 ◽  
Author(s):  
W.P. Chen
Keyword(s):  
Kuiper Belt ◽  
Brightness Variation ◽  
False Detection ◽  
Kuiper Belt Objects ◽  
Lawrence Livermore Laboratory ◽  
Robotic Telescopes ◽  
Coincidence Mode ◽  
Set Up ◽  
Central Taiwan ◽  
Large Telescopes

AbstractMore than two hundred transneptunian Kuiper-Belt Objects (KBOs) have so far been identified. Because of their large distances from the Sun, and their intrinsically small sizes, only the largest members (diameters more than 100 km) can be observed by direct imaging with large telescopes. Even smaller KBOs, though expected to be more numerous on theoretical grounds, cannot be seen directly unless they happen to block out the light from background stars. The Taiwan-America Occultation Survey (TAOS) project is a collaboration among the Lawrence Livermore Laboratory (USA), Academia Sinica, National Central University (both of Taiwan), and other institutes, that aims to measure the frequency of such chance stellar occultations, and thereby conduct the census of the Kuiper-Belt population down to a few kilometer sizes. An array of robotic telescopes are being set up in central Taiwan to monitor the brightness variation of several thousand stars at a rate of a few Hz. Observations will be operated in a synchronized and coincidence mode, so the sequence and timing of any candidate occultation event can be recorded and distinguished against a false detection. The full survey is expected to start in the fall of 2000.

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