SIESTA, a time domain, general purpose simulation program for the VIRGO experiment

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.     

Estimation of Light Time Effects for Close Binaries in Triple Systems

We discuss implementation of light time effects in a general binary star program that solves for third body orbit parameters and binary star parameters together. The program combines radial velocities and light curves within a coherent analysis and can use data that are very unevenly distributed over time. By analyzing whole curves, the program has access to more information than only from eclipse timings. Results for λ Tau and VV Ori are shown.     

The Meteors, Meteoroids and Interplanetary Dust Program of the International Heliophysical Year 2007/9

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.     

Equinox and equator determinations from hypothetical minor planet observations

Hypothetical observations of minor planets 1, 2, 3, 4, 6, 7, 8, 9, and 15 were computed for a ten year observing period commencing 2 Jan. 1980. The mean errors of the equinox and equator corrections were determined versus: the distribution of clear nights during the year; the length of the observing program; the number of minor planets included in the program; and the elongation from the Sun. It is concluded that the equinox and equator are best determined by: choice of a site with a minimum of 60% clear nights well distributed throughout the year; an observing program that lasts a minimum of four years, but that little is gained by extension of the program to more than ten years; inclusion of a minimum of four or five minor planets in the program, but that more than nine is not necessary; that the best four minor planets to use are numbers 1, 4, 7, and 15; and that observations should be made as far from opposition as possible, but that it is not essential to observe beyond quadrature.Presented at the Symposium Star Catalogues, Positional Astronomy and Celestial Mechanics, held in honor of Paul Herget at the U.S. Naval Observatory, Washington, November 30, 1978.     

The Liège Oscillation code

The Liège Oscillation code can be used as a stand-alone program or as a library of subroutines that the user calls from a Fortran main program of his own to compute radial and nonradial adiabatic oscillations of stellar models. We describe the variables and the equations used by the program and the methods used to solve them. A brief account is given of the use and the output of the program.     

A Modified Gooding Method to Calculate Inclination Functions

In this paper, the expression of V k_lm(I) in the Gooding method is rewritten to be the form convenient for calculation, and a standard recursive lm procedure is used to calculate Ak_lm(I). We have rewritten the Gooding's program under the assumption that l and k have the same odd-even parity, this makes the program be shorten for one half, the computational effciency and readability of the program be raised, the computing time be shortened for 41%, and the computational accuracy and stability are also slightly improved.     

Recent observations of high-degree solar p-mode oscillations at the Kitt Peak National Observatory

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.

     

Using the quasar VLBI network for the fundamental time—positioning service of the GLONASS space system

Regular high-precision determinations of the Earth’s orientation parameters (EOPs) on the Quasar VLBI Network were begun in August 2006. The observations are performed within the framework of two national programs: daily sessions at three observatories of the Network to determine all five EOPs (the RU-E program) and 8-h sessions on the Zelenchukskaya-Badary and Svetloe-Badary baselines to determine the Universal Time (the RU-U program). The observations from August 2006 through May 2007 are analyzed. The rms deviations of the EOP values obtained in the RU-E program from the IERS C04 series are 1.1 mas for X _p and Y _p, 37 μs for UT1-UTC, and 0.7 and 0.6 mas for X _c and Y _c, respectively. These results closely match the prospective requirements of GLONASS. The rms deviations of the Universal Times obtained in the RU-U program from the IERS C04 series are 146 μs. We consider the immediate prospects for improving the accuracy of EOP determinations in daily sessions and for implementing the e-VLBI mode for an online determination of the Universal Time. Original Russian Text ? A.M. Finkelstein, E.A. Skurikhina, I.F. Surkis, A.V. Ipatov, I.A. Rakhimov, S.G. Smolentsev, 2008, published in Pis’ma v Astronomicheskiĭ Zhurnal, 2008, Vol. 34, No. 1, pp. 66–76.     

Detecting neutrino transients with optical follow-up observations

A novel method is presented which will enhance the sensitivity of neutrino telescopes to identify transient sources such as Gamma-Ray Bursts (GRBs) and core-collapse Supernovae (SNe). Triggered by the detection of high energy neutrino events from IceCube or other large scale neutrino telescopes, an optical follow-up program will allow the identification of the transient neutrino source. We show that once the follow-up program is implemented, the achievable sensitivity of IceCube to neutrinos from SNe and GRBs would increase by a factor of 2–3. The program can be realized with a small network of automated 1–2 m telescopes and has rather modest observing time requirements.     

Spectral studies of YSO envelopes and collimated outflows

A short review of the studies of young nebulous objects in the dark clouds at the Byurakan Observatory is presented. The results of the prolonged observational program, carried out mainly on the 6-meter telescope of SAO RAS, are described, and the relation of this program with the methodology of study of nonstable phenomena, traditional for Byurakan, is pointed out.Published in Astrofizika, Vol. 38, No. 4, pp. 519–527, October–December, 1995.     

NASA's Initiative to Develop Education through Astronomy (IDEA)

We describe a progressive program in science education called the Initiative to Develop Education through Astronomy (IDEA). IDEA represents a commitrnent by the Astrophysics Division of NASA Headquarters to pre-collegiate and public learning. The program enlists the full participation of research astronomers in taking advantage of the natural appeal of astronomy and the unique features of space astrophysics missions to generate valuable learning experiences and scientifically accurate and educationally effective products for students, teachers and citizens. One of the premier projects is called Flight Opportunities for Science Teacher EnRichment (FOSTER) — a program to fly teachers aboard the Kuiper Airborne Observatory during actual research missions. IDEA is managed by a visiting scientist with extensive educational background (each of the authors have served in this role), and the program is unique within NASA science divisions for having a full time scientist devoted to education. IDEA recognizes that the rapidly shifting social and political landscape has caused a fundamental change in how science is expected to contribute to society. It is in the enlightened self-interest of all research scientists to respond to the challenge of connecting forefront research to basic educational needs. IDEA is exploring the avenues needed to facilitate these connections, including supplementing research grants for educational purposes.Presented at the 2nd UN/ESA Workshop, held in Bogotá, Colombia, 9–13 November, 1992.     

Optimal low-thrust takeoff from an orbit about an oblate planet

Future space missions to the outer planets may depend upon the use of low-thrust propulsion systems. As these planets are decidedly oblate, the question of the effect of that oblateness on a low-thrust trajectory is of some interest. In this paper the problem of optimal energy increase is attacked under the assumption that the coefficients for the second zonal harmonic, i.e.,J ₂, and the nondimensional thrust acceleration are the same order of magnitude. Using a two variable asymptotic expansion technique, a near optimal control program is generated and the first order uniformly valid approximation for the corresponding trajectory is obtained. Tangential thrust is shown to be a good near-optimal thrust program even in the presence of oblateness effects. The optimal control program is found to be oscillatory and quite similar to the optimal control for energy increase in an inverse square gravitational field.This research was supported by the National Aeronautics and Space Administration under Grant NGR-23-005-329.     

Recent results on X-ray novae and microquasars at radio and infrared wavelengths

The Spanish MINISAT program has been structured in three main stagesplus several associated developments, achieving a modular family of lowcost platforms in the small satellite segment, designed to use mainly in lowearth orbit (LEO) applications. The first stage of the MINISAT programhave concluded with the complete development and orbit qualification ofthe platform MINISAT 0 together with the operational experiences is beingachieved to perform the scientific mission 01, launched on April 21^st 1997. The second stage of the MINISAT program consist of the modularupgrading of the platform 0 to reach the maximum performances orplatform MINISAT 1 to do earth observation missions. The first missionwith the platform 1 started the phase A of feasibility study in 1995. Thethird stage of the MINISAT program will consist of the development of theplatform MINISAT 2 that will be an adaptation of the platform MINISAT1 to be able to do communication missions even in the geostationary orbit.     

The interferometric mode of the European Very Large Telescope

The European Very Large Telescope program has been approved in 1987. It aims to consists of an array of four 8 m telescopes, plus two additional 2 m class auxiliary telescopes, the latter being fully dedicated to optical (infrared and visible) interferometry, with possible combination of some and, in the long term, all large telescopes. We discuss the implementation of this program in the next ten years.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Observational status of the USNO trigonometric parallax program

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.     

An implementation ofN-body chain regularization

The chain regularization method (Mikkola and Aarseth 1990) for high accuracy computation of particle motions in smallN-body systems has been reformulated. We discuss the transformation formulae, equations of motion and selection of a chain of interparticle vectors such that the critical interactions requiring regularization are included in the chain. The Kustaanheimo-Stiefel (KS) coordinate transformation and a time transformation is used to regularize the dominant terms of the equations of motion. The method has been implemented for an arbitrary number of bodies, with the option of external perturbations. This formulation has been succesfully tested in a generalN-body program for strongly interacting subsystems. An easy to use computer program, written inFortran, is available on request.     

Trigonometric parallaxes of 29 stars with large proper motions

While implementing the first stage of the Pulkovo program of research on stars with large proper motions, we determined the trigonometric parallaxes of 29 stars (12 ^m < V < 16 ^m ) based on CCD observations with a 26-inch refractor. The mean standard error was 3.7 mas. Comparison of the Pulkovo parallaxes with those obtained at the Observatory of the Yale University and the US Naval Observatory (USNO) has shown that the parallax differences (Pulkovo-Yale/USNO) lie within the limits of their measurement errors in an overwhelming majority of cases. On average, they are −0.6 ± 1.0 mas. No systematic dependences on stellar distance, magnitude, and color in this set of differences have been found. Our comparisons show that the observing and data reduction techniques used in the Pulkovo program of research on fast stars allow highly accurate trigonometric parallaxes of these objects to be obtained. All program stars are within 50 pc of the Sun; most of them belong to the immediate solar neighborhood (D < 25 pc). For two stars (J0522+3814 and J1202+3636), the trigonometric parallaxes have been determined for the first time.     

Classical Cepheids and the Distances of HST Program Galaxies

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 ±0^m.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.     

The DDO Short-Period Binary RV Program

The short-period binary radial velocity program at the David Dunlap Observatory is described in some detail, with a brief summary on its history. The program is now reaching its 100-th orbit, with about 40 more orbits remaining within our access to Northern ( δ < –15), bright <10 mag), short−period(< 1 day) binary systems. All data are processed uniformly using the Broadening Function (BF) formalism which offers best information extraction and permits analysis of heavily rotationally blended spectra. Many close binaries appear to have visual or spectroscopic companions.     

S/X波段致冷接收机状态控制与数据采集软件的研制

总结了S／X波段致冷接收机状态控制与数据采集软件的研制工作。介绍了安装调试情况以及按照任务书的技术指标进行检测的结果。经过在上海余山站及乌鲁木齐南山站的实地测试，结果表明该程序实现了与本地站程序stqkr的对接，主要技术指标均达到了原设计任务书的要求。