共查询到20条相似文献，搜索用时 750 毫秒
1.
C. R. O’Dell 《Experimental Astronomy》2009,25(1-3):261-272
The Hubble Space Telescope has been the most successful space astronomy project to date, producing images that put the public in awe and images and spectra that have produced many scientific discoveries. It is the natural culmination of a dream envisioned when rocket flight into space was first projected and a goal set for the US space program soon after NASA was created. The design and construction period lasted almost two decades and its operations have already lasted almost as long. The capabilities of the observatory have evolved and expanded with periodic upgrading of its instrumentation, thus realizing the advantages of its unique design. The success of this long-lived observatory is closely tied to the availability of the Space Shuttle and the end of the Shuttle program means that the end of the Hubble program will follow before long. 相似文献
2.
B. Caron L. Derome R. Flaminio X. Grave F. Marion B. Mours D. Verkindt F. Cavalier A. Vicer 《Astroparticle Physics》1999,10(4):2650-386
In this paper we present the simulation program that has been developed for the VIRGO gravitational wave detection experiment. Although this program — SIESTA — is still evolving, it has reached a stage where the design requirements have been largely fulfilled. We first remind the needs and the choices which have steered the program design and led to the present structure. The contents of the program is then reviewed, the performances are discussed, and some typical applications are briefly described. 相似文献
3.
William H. Jefferys 《Celestial Mechanics and Dynamical Astronomy》1972,6(1):117-124
A translator has been written which simplifies the programming of problems with the formula manipulation system TRIGMAN. It allows for the introduction of a new data type, SERIES, into a FORTRAN program, and translates the user's program into legal FORTRAN. It should not be difficult to adapt it for other formula manipulation systems now being used in Celestial Mechanics. 相似文献
4.
本文将1983年版的Wilson-Devinney方法程序,扩展到包含黑子参数的微分改正解,并提出黑子纬度的网络测定方法,由此,对RS CVn型食双星RT CrB的食外测光扰动波,进行了黑子模拟解,得出其次子星上两个黑子的位置,大小和温度,其理论光变曲线能较好地重现畸变波的观测特征。作者对黑子模型参数微分改正解的收敛性问题和不定性问题进行了初步讨论。 相似文献
5.
G. I. Pinigin 《Astrophysics and Space Science》1991,177(1-2):225-227
Observing programs are discussed for the Pulkovo automatic horizontal meridian circle. The instrument is highly efficient and yields precise and accurate positions. We prepare an observing program of faint FK5 stars with the aim of improving on the system of this catalogue and also prepare a program of observations of IRS reference catalogue stars. 相似文献
6.
An international program of cooperation linked Astrophysics Department of the University of Nice and the Astronomical and Geophysical Laboratory of Rabat. This program has permitted the installation of an observational instrument for the study of solar seismological phenomena in the framework of the IRIS programme, on the mountain site of Oukaïmeden, in Morocco. 相似文献
7.
Since 1983, a TI 800×800 CCD has been routinely used on the 1.5-m astrometric reflector during dark time to measure parallaxes of faint (V16.0) stars. The rest of the time remains devoted to the fine grain (Kodak type IIIa emulsions) photographic parallax program, which now uses magnitude compensating filters to extend the range of the program to V=0. Sufficient data are now available to evaluate the precisions of these programs. For CCD fields, the mean error for the relative parallax ranges from ±0".0025 for fields with relatively few observations to ±0".0005 for intensively observed fields such as vB10. The photographic program is now producing relative parallaxes with average mean errors of ±0".0026 compared to ±0".0038 previously obtained with coarse grain emulsions. 相似文献
8.
Solar System Research - Finding and studying possible collisions of asteroids approaching the Earth requires a significant amount of computation. This paper describes the R0 program created to... 相似文献
9.
Current-sheet creation in three dimensions above an active region is shown in a numerical experiment. The calculations are
performed for the complex magnetic field of an active region. The PERESVET program solves the 3D resistive compressible MHD
equations. 相似文献
10.
Gareth S. COLLINS H. Jay MELOSH Robert A. MARCUS 《Meteoritics & planetary science》2005,40(6):817-840
Abstract— We have developed a Web‐based program for quickly estimating the regional environmental consequences of a comet or asteroid impact on Earth ( http:www.lpl.arizona.eduimpacteffects ). This paper details the observations, assumptions and equations upon which the program is based. It describes our approach to quantifying the principal impact processes that might affect the people, buildings, and landscape in the vicinity of an impact event and discusses the uncertainty in our predictions. The program requires six inputs: impactor diameter, impactor density, impact velocity before atmospheric entry, impact angle, the distance from the impact at which the environmental effects are to be calculated, and the target type (sedimentary rock, crystalline rock, or a water layer above rock). The program includes novel algorithms for estimating the fate of the impactor during atmospheric traverse, the thermal radiation emitted by the impact‐generated vapor plume (fireball), and the intensity of seismic shaking. The program also approximates various dimensions of the impact crater and ejecta deposit, as well as estimating the severity of the air blast in both crater‐forming and airburst impacts. We illustrate the utility of our program by examining the predicted environmental consequences across the United States of hypothetical impact scenarios occurring in Los Angeles. We find that the most wide‐reaching environmental consequence is seismic shaking: both ejecta deposit thickness and air‐blast pressure decay much more rapidly with distance than with seismic ground motion. Close to the impact site the most devastating effect is from thermal radiation; however, the curvature of the Earth implies that distant localities are shielded from direct thermal radiation because the fireball is below the horizon. 相似文献
11.
R. Gil Hutton 《Earth, Moon, and Planets》1995,71(3):207-210
Using a Super-Schmidt camera installed at the Cesco Observatory we are developing a program conducted to detect asteroids (especially members of the Aten Group) and comets approaching the Earth. The search strategy is based on simulations of the population of objects in this kind of orbits. 相似文献
12.
A brief summary is given of a program which is currently being carried out with the McMath telescope of the Kitt Peak National Observatory in order to study high-degree (l ≳ 150) solar p-mode oscillations. This program uses a 244 × 248 pixel CID camera and the main spectrograph of the McMath telescope to obtain velocity-time maps of the oscillations which can be converted into two-dimensional (k h - ω) power spectra of the oscillations. Several different regions of the solar spectrum have been used in order to study the oscillations at different elevations in the solar atmosphere. The program concentrates on eastward- and westward-propagating sectoral harmonic waves so that measurements can be made of the absolute rotational velocities of the solar photospheric and shallow sub-photospheric layers. Some preliminary results from this program are now available. First, we have been unable to confirm the existence of a radial gradient in the equatorial rotational velocity as was previously suggested. Second, we have indeed been able to confirm the presence of p-mode waves in the solar chromosphere as was first suggested by Rhodes et al. (1977). Third, we have been able to demonstrate differences in photospheric and chromospheric power spectra.
相似文献13.
14.
H. V. Abrahamyan 《Astrophysics》2004,47(3):389-403
The distances of HST program galaxies are revised using the PL-relations we have obtained previously along with a different method from that employed by Freedman et al. On the average, the resulting distances to these galaxies have higher internal accuracies than those obtained before by others. In addition, we have used no corrections for metallicity or for the incompleteness of the samples of classical cepheids in deriving these distances. Despite this, our distance moduli, with a dispersion of ±0m.395, agree with those of Freedman et al. This indicates that these two effects have little or even no effect for the samples of classical cepheids in the HST program galaxies. 相似文献
15.
Solar System Research - Ultraviolet space telescope Т-170М is a base element of the space observatory of the Spektr-UF program. Acquisition of high-resolution UV-range spectra and... 相似文献
16.
Under the title ‘Meteors, Meteoroids and Interplanetary Dust’, meteor research is included in the program of the International
Heliophysical Year 2007/9.We list issues for coordinated meteor research within the framework of this global international
program. 相似文献
17.
A program is developed for determining the history of star-forming galaxies based on the use of two- or multicolor photometry of the resolved stars in a given galaxy. We create a library of synthetic color-magnitude diagrams from theoretical stellar isochrones, taking the initial mass function, distance to the galaxy, internal and external absorption, and photometric errors into account. The resulting synthetic diagrams are combined linearly and compared quantitatively with photometric data for stars in a galaxy in order to determine star formation rates as a function of age and metallicity. This program is tested in detail under different conditions using artificial color-magnitude diagrams. Special attention is given to the limiting case when only the brightest stars of a galaxy can be seen in the color-magnitude diagram and the number of resolved stars is at most a few hundred. This limiting case corresponds to a large fraction of the nearby galaxies at distances of 3-5 Mpc observed by large ground based telescopes and the Hubble Space Telescope. 相似文献
18.
《New Astronomy Reviews》1999,43(2-4):263-269
We describe a Two Channel Correlation Polarimeter built by the Milan Radio Group for searching polarization of the Cosmic Microwave Background. The system sensitivity is sufficient to detect linearly polarized signals or set firm upper limits at levels of few μK. The program of observations and some preliminary results are presented. 相似文献
19.
Gabdeev M. M. Fatkhullin T. A. Borisov N. V. Shimansky V. V. Kolbin A. I. Moskvitin A. S. Aitov V. N. Mitiani G. Sh. 《Astronomy Letters》2020,46(7):482-487
Astronomy Letters - We present the results of the first year of searching for polar candidates within the 3BS (3-Band Survey) program using medium-band filters. Observational data for 84 selected... 相似文献
20.
We developed a code for the reconstruction of nonlinear force-free and non-force-free coronal magnetic fields. The 3D magnetic
field is computed numerically with the help of an optimization principle. The force-free and non-force-free codes are compiled
in one program. The force-free approach needs photospheric vector magnetograms as input. The non-force-free code additionally
requires the line-of-sight integrated coronal density distribution in combination with a tomographic inversion code. Previously
the optimization approach has been used to compute magnetic fields using all six boundaries of a computational box. Here we
extend this method and show how the coronal magnetic field can be reconstructed only from the bottom boundary, where the boundary
conditions are measured with vector magnetographs. The program is planed for use within the Stereo mission. 相似文献