Ninth Satellite Of Saturn Research Articles

Precise CCD positions of Phoebe in 2011–2014

346 new CCD observations during the years 2011–2014 have been reduced to derive the precise positions of Phoebe, the ninth satellite of Saturn. The observations were made by the 2.4 m telescope at Yunnan Observatory over nine nights. Due to the use of a focal-reducer on the telescope, its significant geometric distortion is solved for and removed for each CCD field of view. The positions of Phoebe are measured with respect to the stars in UCAC2 catalogue. The theoretical position of Phoebe was retrieved from the Institute de Mechanique Celeste et de Calcul des Ephemerides ephemeris which includes the latest theory PH12 by Desmars et al., while the position of Saturn was obtained from the Jet Propulsion Laboratory ephemeris DE431. Our results show that the mean O−Cs (observed minus computed) are −0.02 and −0.07 arcsec in right ascension and declination, respectively. The dispersions of our observations are estimated at about 0.04 arcsec in each direction.

Phoebe’s orbit from ground-based and space-based observations

The ephemeris of Phoebe, the ninth satellite of Saturn, is not very accurate. Previous dynamical models were usually too simplified, the astrometry is heterogeneous and, the Saturn's ephemeris itself is an additionnal source of error. The aim is to improve Phoebe's ephemeris by using a large set of observations, correcting some systematic errors and updating the dynamical model. The dynamical model makes use of the most recent ephemeris of planets and Saturnian satellites. The astrometry of Phoebe is improved by using a compilation of ground-based and space-based observations and by correcting the bias in stellar catalogues used for the reduction. We present an accurate ephemeris of Phoebe with residuals of 0.45 arcsec and with an estimated accuracy of Phoebe's position of less that 100 km on 1990-2020 period.

A CONVENIENT SOLUTION TO GEOMETRIC DISTORTION AND ITS APPLICATION TO PHOEBE'S OBSERVATIONS

A simple but effective approach is proposed for measuring the geometric distortion of a CCD field of view of a ground-based telescope. For three open clusters (M35, M67, and NGC 2324), 425 CCD frames taken by a 1 m telescope at the Yunnan Observatory are used to test this approach. It is found that the geometric distortion pattern depends strongly on the corresponding filter used. The geometric distortion is then used to correct the pixel positions for Phoebe, the ninth satellite of Saturn, and its reference stars imaged in 220 CCD frames taken by the same telescope. The standard deviation of the (O - C; observed minus computed) residuals of Phoebe is significantly improved after correcting the geometric distortions.

Updated ephemeris of Phoebe, ninth satellite of Saturn

Context. The theoretical model of natural satellite motion may need improvement each time new observations of a considerable amount are accumulated over a significant time interval. Aims. The goal of our work is to elaborate the ephemeris of Phoebe based on all ground-based observations available to date and readily accessible for any user via the Internet. Methods. Our model for the orbit of Phoebe is based on numerical integration of the equations of motion. In the theory of satellite motion, all necessary perturbations were taken into account. To produce the ephemeris of Phoebe, we used a database that contains all published ground-based observations and expands constantly as new observations appear. Results. The new ephemeris of Phoebe, based on 1606 ground-based observations made at 39 observatories in the 103 year time interval, was elaborated. The real precision of the ephemeris is limited by the observational precision and is not worse than 0.15 �� . The ephemeris is available at: http://www.imcce.fr/sat and http://www.sai.msu.ru/neb/nss/index.htm. The ephemeris of Phoebe will be updated as new observations become available.

Precise positions of Phoebe determined with CCD image-overlapping calibration

This paper presents 210 positions of Phoebe, the ninth satellite of Saturn, observed with the 1-m telescope at the Yunnan Observatory during the years 2003–2005, using a CCD image-overlapping calibration method proposed recently by Peng et al. After the observed positions of Phoebe are compared with its theoretical positions computed by the new JPL ephemerides DE405 and SAT199, the mean residuals (observed minus computed) are 0.21 and −0.05 arcsec in right ascension and declination, respectively, with a standard deviation of 0.06 arcsec.

Analytical theory of motion of phoebe, the ninth satellite of saturn

The literal solution of the restricted three body problem obtained by the authors up to the eleventh order with respect to the minor parameter is applied to the investigation of the motion of Phoebe, the ninth satellite of Saturn. As distinct from the existing analytical theories of the motion of the satellite, in the present paper the planetary perturbations are taken into account. A comparison with the modern numerical theory of the motion of Phoebe has shown that the new analytical theory of the satellite motion represents observations with the same degree of accuracy.

Theorie litterale du neuvieme satellite de Saturne, Phoebe

We study a theory for the ninth satellite of Saturn, Phoebe, based on the literal solution we have obtained in the main problem of the lunar theory.

FRANK ELMORE ROSS, 1874-1960

Frank Ross was born in San Francisco on April 2, 1874, and received his early education in the schools of that city. He graduated from the University of California with a B.S. degree in 1896. After graduation, he taught mathematics and physics for one year in the Mount Tamalpais Military Academy and then returned to the University of California for graduate work. In his first year as a graduate student he had a fellowship at Berkeley and in his second year was a fellow at the Lick Observatory. Before receiving his Ph.D. degree from the University of California in 1901, he spent one year at the University of Nevada where he was an assistant professor of mathematics. After graduation Dr. Ross computed perturbations of the Watson Asteroids for one year and then went to Washington, D.C., where for a year he was an assistant in the Nautical Almanac Office and for two years served as a Research Assistant of the Carnegie Institution of Washington. In that capacity he worked under Simon Newcomb on planetary and lunar problems and, at Newcomb's suggestion, computed a definitive orbit of Phoebe, the ninth satellite of Saturn. This orbit, which was published in the Annals of the Harvard College Observatory in 1905, was his first major independent publication in astronomy. In 1904, Dr. Ross married Margaret Benton and in 1905 they went to Gaithersburg, Maryland, where Dr. Ross became director of the International Latitude Observatory. There he completed the computations of the orbits of the sixth and seventh satellites of Jupiter that he had begun in Washington, and published them in the Lick Observatory Bulletin and the Astronomische Nachrichten, respectively. For the next ten years Dr. Ross continued

Micrometer observations of Phoebe, the ninth satellite of Saturn.

Astronomische NachrichtenVolume 194, Issue 19 p. 333-335 Article Micrometer observations of Phoebe, the ninth satellite of Saturn. E. E. Barnard, E. E. Barnard Yerkes Observatory, Williams Bay, WisconsinSearch for more papers by this author E. E. Barnard, E. E. Barnard Yerkes Observatory, Williams Bay, WisconsinSearch for more papers by this author First published: 1913 https://doi.org/10.1002/asna.19131941904Citations: 1AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article.Citing Literature Volume194, Issue191913Pages 333-335 RelatedInformation

Observations of Phoebe, the ninth satellite of Saturn

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