共查询到10条相似文献，搜索用时 62 毫秒
1.
Yu. A. Chernetenko 《Solar System Research》2008,42(2):144-153
In 2000, the last international program of photographic observations of selected asteroids aimed at the determination of the mutual orientation of the dynamic and stellar coordinate systems came to an end. The Institute of Applied Astronomy of the Russian Academy of Sciences collected more than 25 000 observations for 15 asteroids spanning from 1949 through 1995. These observations were reduced to the reference frame of the Hipparcos catalog using dependencies published along with observations. The accuracy of observations of selected asteroids was 0.30 arcsec, which is comparable to that of modern CCD observations of minor planets. The observations are available at ftp://quasar.ipa.nw.ru/pub/SMP. An important advantage of these observations is that they are already reduced to the reference frame of a single catalog. Our criteria for the quality of the reduction methods and the accuracy of the observations are based on estimating the parameters of the orientation of the reference frames of the PPM and Hipparcos catalogs with respect to DE200/LE200. The most reliable results are those obtained when reducing old optical observations along with modern ground-based and space-borne observations. 相似文献
2.
A. V. Devyatkin D. L. Gorshanov V. N. L’vov S. D. Tsekmeister M. S. Chubey 《Kinematics and Physics of Celestial Bodies》2016,32(5):241-244
The use of ground-based and space baseline observations of Solar System bodies is considered. Baseline observations allow one to determine the distance to observed objects and (in some cases) the parameters of their orbital motion. Certain results of baseline observations of near-Earth asteroids and the results of model analysis of spacecraft observations are presented. 相似文献
3.
Ryszard Gabryszewski 《Planetary and Space Science》1997,45(12):1653-1655
An adaptation of Bielicki's method of reduction of old cometary micrometer observations of the comet-minus-star type to the PPM star catalogue is presented. A fully automatic utility is described which reduces old positions of stars to the coordinates in the PPM star catalogue for comet-minus-star astrometric observations. The reduction clears observations from systematic errors in old catalogues and decreases the mean error of observations. That may have implications for orbit improvement. The utility predicts new positions of stars in the PPM catalogue as needed and can also restore observations which have been previously rejected due to a selection criterion. It helps to get all data in one, coherent reference frame with maximum possible precision when there are lots of old and new observations of the same object. As an illustration, results of application of the utility to observations of comets 122P/de Vico and 109P/Swift-Tuttle are presented. 相似文献
4.
M. C. Weisskopf M. Karovska G. G. Pavlov V. E. Zavlin T. Clarke 《Astrophysics and Space Science》2007,308(1-4):151-160
We present an overview of Chandra X-ray Observatory observations of neutron stars. The outstanding spatial and spectral resolution of this great observatory
have allowed for observations of unprecedented clarity and accuracy. Many of these observations have provided new insights
into neutron star physics. We present an admittedly biased and overly brief review of these observations, highlighting some
new discoveries made possible by the Observatory’s unique capabilities. This includes our analysis of recent multiwavelength
observations of the putative pulsar and its pulsar-wind nebula in the IC443 SNR.
相似文献
5.
Yulia A. Chernetenko 《Celestial Mechanics and Dynamical Astronomy》2001,80(3-4):185-194
International programs of observations of selected minor planets have lasted about 50 years and the last one comes to the end in 2000. The main aim of these observational programs consists in obtaining the orientation of the stellar reference frame with respect to the dynamical one using observations of the bright minor planets. The observations are also useful for the orbital improvements of the asteroids themselves. They are available from the author via e-mail at the address .During the above mentioned period more than 23 000 observations of minor planets, referred to different reference star catalogues, have been obtained. The reduction procedure of observations to the PPM star catalogue is described. The orientation parameters are given and discussed. 相似文献
6.
The global signature of granulation, meso- and supergranulation is calculated using values for intensities and lifetimes from spatially resolved observations. These simulations are compared with observations from ACRIM, IPHIR and the SOVA-1 photometers. The results indicate that the overall shape of the background signal in the simulations reproduce the observations at low frequency. However when the granulation lifetimes are about 500 seconds the simulated data do not correspond to the observations between 1 and 2 mHz. 相似文献
7.
O. S. Shalygina V. V. Korokhin E. V. Shalygin Yu. I. Velikodskii 《Kinematics and Physics of Celestial Bodies》2008,24(4):201-208
Peculiarities in the use of CCD matrices for photopolarimetric observations are considered. Algorithms for processing the CCD photopolarimetric and polarimetric observations of Jupiter and other bright extended objects are described with an emphasis on the specifics of these photodetectors. We present new estimates of the north-south asymmetry parameter of polarization of Jupiter obtained from the observations in 2006 and 2007. The new data are in good agreement with the previous observations. 相似文献
8.
Summary Astrometric measurements of 18 visual double stars carried out with a CCD are given.
The present observations are a test of the propriety of the CCD technique for astrometric observations of visual double stars.
The duration of the observations was 75 minutes. The precision of the CCD measures corresponds the precision of the photographic
method, so the advantages of CCD's are the great loss of reduction work and the corresponding time saving, inclusive shortering
the observing time.
Based on observations made at E.S.O., La Silla, Chile. 相似文献
9.
Takashi Sakurai 《Journal of Astrophysics and Astronomy》2000,21(3-4):389-395
Recent advances in the understanding of the quiet corona and coronal holes are reviewed. The review is based on long-term
accumulation of data from eclipse observations, coronagraph observations, helium 10830 å spectroheliograms, and
X-ray observations. 相似文献
10.
T. P. Kiseleva I. S. Izmailov O. A. Kalinichenko T. A. Vasilieva 《Solar System Research》2010,44(1):60-67
The results of the reduction, investigation, and comparison of the photographic observations of the major Saturnian satellites
and CCD observations with an ST6 CCD camera obtained at the 264nch Pulkovo refractor in 1995–2007 are presented. A comparison
of the observational results with the TASS 1.7 theory of motion of the Saturnian satellites has served as the basis for investigating
and comparing the series of observations. The period-averaged (O-C) residuals and observational errors have been calculated.
A comparison of the series of CCD and photographic observations has shown the same external accuracy of the observations at
a higher internal accuracy of the CCD observations than that of the photographic ones. A comparison of the Pulkovo results
with those of other authors has shown them to be close in accuracy. The accuracy of the theory has been estimated by comparing
simultaneous (on the same night) CCD and photographic observations. The errors of the observations and the theory have been
found from this comparison to be the following: 0.081“ and 0.067” for the observations and 0.077“ and 0.115” for the theory
(inxandy, respectively). An analysis of the dependence of (O-C)x,y for three satellites (the sixth, seventh, and eighth) on the satellite positions in Saturn-centered orbits has revealed systemat
ic deviations for the seventh satellite in both coordinates. The positions of Saturn have been determined from satellite observations
without measuring its images on photographic plates with accuracies of 0.121“ and 0.105” in right ascension and declination,
respectively. 相似文献