The Japanese National Large Telescope (JNLT) project

The astronomical community in Japan is promoting a national project to construct a large optical infrared telescope on Mauna Kea in Hawaii. The scientific objectives and the basic concept of the project are briefly presented, as they stand in September 1984.Paper presented at the IAU Third Asian-Pacific Regional Meeting, held in Kyoto, Japan, between 30 September–6 October, 1984.     

Evaluation of the JNLT site

Two steps have been taken to decide at what place and altitude to set up the JNLT on Mauna Kea. First, the wind tunnel experiment has been made in collaboration with the Institute of Meteorology using the two models of summit area with the reduced scales of 1/1000 and 1/5000. This study tells us that the north-west cone is suitable for JNLT. Secondly, we have done the measurement of the microthermal activities in this area with a 30 m tower, which was continued for about 4 months in collaboration with the University of Hawaii. This experiment has given the mean vertical profile ofC _T ² over 4 months and its scale height in the boundayr layer on our site. By use of these measurements, the contribution of the boundary layer to seeing is estimated. The behaviour ofC _T ² under strong winds can be explained very well by topographic effects, which is in fairly good agreement with the results of our wind tunnel experiment.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Optical instruments for JNLT

The plan for optical instruments for the Japanese National Large Telescope is described. Performance of the first-generation instruments is computed on the basis of tentative designs, and the capability of the telescope is demonstrated.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Mechanical structure of JNLT

The Japanese National Large Telescope (JNLT) requires mechanical performance of high tracking accuracy to achieve good image quality and a mechanical configuration to provide several kinds of focus modes. Under these requirements, a conceptual design for the JNLT mechanical structure has been performed. This paper presents the results of the conceptual design currently under consideration.Paper presented at the symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Infrared instruments for JNLT

The principal features of the JNLT as an infrared telescope are presented along with its ultimate performance of detectivity in typical methods of imagery and spectroscopy. Some infrared instruments: infrared camera, grating spectrometer, and Fabry-Pérot-based imager, currently proposed as the first generation instruments are also discussed in relation to the scientific objectives of the JNLT.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Can the optical very large array be coupled with the JNLT?

Coupling the JNLT with the Keck telescope is of considerable interest. Further enhancement may be possible with auxiliary small telescopes, as planned for ESO's VLT. Current plans for installing the optical very large array at Mauna Kea provide opportunities for extra OVLA telescopes near the JNLT.A coudé field slicer is proposed for interferometric observing of a reference star together with the main object. Additions to the JNLT coudé spectrograph are also suggested for use as a speckle camera with multiple spectral channels.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Outline of a theory of solar wind interaction with the magnetosphere

Some new ideas on the interaction of the solar wind with the magnetosphere are brought forward. The mechanism of reflection of charged particles at the magnetopause is examined. It is shown that in general the reflection is not specular but that a component of momentum of the particle parallel to the magnetopause changes. A critical angle is derived such that particles whose trajectories make an angle less than it with the magnetopause enter the magnetosphere freely, so transferring their forward momentum to it. Spatially or temporally non-uniform entry of charged particles into the magnetosphere causes electric fields parallel to the magnetopause which either allow the free passage of solar wind across it or vacuum reconnection to the interplanetary magnetic field depending on the direction of the latter. These electric fields can be discharged in the ionosphere and so account qualitatively for the dayside agitation of the geomagnetic field observed on the polar caps. The solar wind wind plasma which enters the magnetosphere creates (1) a dawn-dusk electric field across the tail (2) enough force to account for the geomagnetic tail and (3) enough current during disturbed times to account for the auroral electrojets. The entry of solar wind plasma across the magnetosphere and connection of the geomagnetic to interplanetary field can be assisted by wind generated electric field in the ionosphere transferred by the good conductivity along the geomagnetic field to the magnetopause. This may account for some of the observed correlations between phenomena in the lower atmosphere and a component of magnetic disturbance.     

Overview of the LAMOST-Kepler project

The NASA Kepler mission obtained long-term high-quality photometric observations for a large number of stars in its original field of view from 2009 to 2013. To provide reliable stellar parameters in a homogeneous way, the LAMOST telescope began to carry out low-resolution spectroscopic observations for as many stars as possible in the Kepler field in 2012. By June 2018, 238 386 low-resolution spectra with SNRg ≥ 6 had been collected for 155 623 stars in the Kepler field, enabling the determination of atmospheric parameters and radial velocities, as well as spectral classification of the target stars.This information has been used by astronomers to carry out research in various fields, including stellar pulsations and asteroseismology, exoplanets, stellar magnetic activity and flares, peculiar stars and the Milky Way, binary stars, etc. We summarize the research progress in these fields where the usage of data from the LAMOST-Kepler(LK) project has played a role. In addition, time-domain medium-resolution spectroscopic observations have been carried out for about 12 000 stars in four central plates of the Kepler field since 2018. The currently available results show that the LAMOST-Kepler medium resolution(LKMRS) observations provide qualified data suitable for research in additional science projects including binaries, high-amplitude pulsating stars, etc. As LAMOST is continuing to collect both low-and mediumresolution spectra of stars in the Kepler field, we expect more data to be released continuously and new scientific results to appear based on the LK project data.     

天文文献情报工程概述

本文主要介绍中国科学院天文系统文献情报自动化建设、文献工程建设、数据工程建设、资源共享与计算机共享网建设。由于其牵涉到1984年以来的一系列工程建设呐容繁多,所以仅从文献情报现代化建设、资源共享建设出发,从整体上对各有关内容作一概述。     

Progress of the Ubaye hypertelescope project

In this paper we present the principle of the prototype hypertelescope built in the valley of Ubaye in the Southern Alps. We detail the most representative results obtained during the last campaign of tests in August and September 2017. We conclude the paper by summarizing some of the other activities that we are developing toward the future implementation of an ambitious astronomical hypertelescope.     

Concept and status of the VLT project

The ESO Very Large Telescope project consists of an array of four 8-m telescopes. This concept presents a very great flexibility and covers a broad range of scientific applications. The most far reaching one is the co-phasing of the four telescopes which will open the way to very high resolution imaging.The funding has been granted in December 1987. The first telescope is scheduled for 1995. The whole array is expected to be completed by the 2000.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

Outline of a theory of planet formation in binary systems

A theory is presented for determining regions where planets may form in binary star systems. Planet formation by accretion is assumed possible if mean planetesimal collision velocities do not exceed a critical value. Collision velocities are increased by perturbations due to the companion star, treated by secular perturbation theory. Collision velocities are damped by aerodynamic drag within the solar nebula, taken as the linear case of Cameron and Pine.A general feature of planetary systems in binary stars is the existence of two zones. The inner zone has enough damping to permit unimpeded growth by accretion; in the outer zone, growth proceeds to a limited diameter, beyond which damping is insufficient. It is shown that the asteroids could not have failed to coalesce due to Jupiter perturbations in the primitive solar nebula. Binary star systems with semimajor axis < 30AU are not likely to have planets; these include Alpha Centauri and 70 Ophiuchi. Systems possibly possessing planets include Eta Cassiopeiae, 40 Eridani, and Σ 2398. Epsilon Eridani is a marginal case.     

Status of the physics of substellar objects project

A full understanding of the properties of substellar objects is one of the major challenges facing astrophysics. Since their discovery in 1995, hundreds of brown dwarfs and extrasolar planets have been discovered. While these discoveries have enabled important comparisons with theory, observational progress has been much more rapid than the theoretical understanding of cool atmospheres. The reliable determination of mass, abundances, gravities and temperatures is not yet possible. The key problem is that substellar objects emit their observable radiation in the infrared region of the spectrum where our knowledge of atomic, molecular and line broadening data is poor. Here we report on the status of our PoSSO (Physics of SubStellar Objects) project. In order to understand brown dwarfs and extrasolar planets increasing more like those in our solar system, we are studying a wide range of processes. Here we give an update on the project and sketch an outline of atoms, molecules and processes requiring study. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

The Galileo project

The Galileo project comprises the design, building, and operation of a 3.5 m Italian telescope the main elements (diameter, mechanical structure, active optics, etc.) of which consist of a duplication of the ESO New Technology Telescope (NTT). Modifications have been introduced in order to allow, beyond thef/11 Nasmyth foci, a prime focusf/2.2 station, a trappedf/6 focus, and a small Cassegrainf/20 facility. Other changes with respect to the NTT have been made to the control and data acquisition system, and to the service building. The telescope could be operational at the end of 1992.Paper presented at the Symposium on the JNLT and Related Engineering Developments, Tokyo, November 29–December 2, 1988.     

The DARWIN project

Angel and co-workers have proposed to detect exoplanets around nearby stars in the infrared (6–17 m) and to analyze their spectra, searching for H₂O, CO₂, CH₄, NH₃, and O₃ spectral features. The presence or absence of CO₂ would indicate either a strong similarity or difference with Solar telluric planet atmospheres. Water would indicate a habitable planet, and O₃ would reveal significant photosynthesis activity, due to the presence of carbon chemistry based life. Like these authors, we suggest an infrared nulling interferometer pointing to the star and working as a coronograph. Our main contribution is to propose an observatory made of four to five 1-meter class telescopes observing from about 4 to 5 AU to avoid the Solar Zodiacal Light (ZL) background at 10m instead of four 8-meter ones observing from the Earth vicinity. This allows the mission to be feasible in thenear future. The concept, named DARWIN, is under consideration by the European Space Agency for its Horizon 2000 Plus program.     

DI-aries panoramic energy-mass spectrometer of ions for the Phobos-Grunt project

One of the main goals of the Phobos-Grunt project is to analyze the surface composition of Phobos. Plasma methods of the studies make it possible to complete direct surface studies with measurements of the minor components of the solar wind, which are produced when a material sputtered from the surface of Phobos is ionized. The surface of Phobos is sputtered under the action of solar wind protons, energetic ions, hard solar radiation, and meteorites. In addition to the studies of Phobos, the experiment also includes the study of the interaction between the solar wind and Mars. An energy-mass spectrometer, which makes it possible to measure instantaneously complete unobscured distribution of the flux of different ions in the hemisphere, has been designed based on the new CAMERA analyzer of charged particles proposed previously (Vaisberg et al., 2001, 2005; Vaisberg, 2003). The instrument’s electro-optics model and the results of the numerical and laboratory tests are described in this paper. Such an instrument can be used in magnetospheric studies and to study different objects of the Solar System.