共查询到20条相似文献，搜索用时 324 毫秒
1.
Mikhail Sachkov 《Astrophysics and Space Science》2010,329(1-2):261-266
The hot subdwarf B (sdB) stars are considered to be core He-burning stars with surface temperatures T eff up to 40?000 K and log?g≥5. They are UV bright and ultraviolet observatories have a significant impact on studies of these objects. Using the technical characteristics of the instruments of the World Space Observatory–Ultraviolet (WSO–UV) mission and data from previous UV studies of sdBs we estimate the limiting apparent magnitudes for these stars that can be observed with the signal-to-noise ratio required in fine spectroscopic analysis. WSO–UV is an international space observatory for observation in UV spectral range 100–350 nm, that is beyond the reach of ground-based instruments but where most of astrophysical processes can be efficiently studied with unprecedented capability. The WSO–UV project is currently funded by national space agencies of Russia and Spain with participation of Germany, Ukraine and China. The WSO–UV consists of a 1.7 m aperture telescope (under responsibility of Russia) with instrumentation designed to carry out high resolution spectroscopy, long-slit low resolution spectroscopy and direct sky imaging. The WSO–UV Ground Segment is under development by Spain and Russia. They will coordinate the Mission and Science Operations and provide the satellite tracking stations for the project. The WSO–UV will work as a targeted scientific observatory. The scientific program of the observatory is open to excellent scientific projects from the world-wide community and occupies up to 40% of total observational time. 相似文献
2.
A half-century of terrestrial analog studies: From craters on the Moon to searching for life on Mars
Richard Léveillé 《Planetary and Space Science》2010,58(4):631-638
Terrestrial analogs to the Moon and Mars have been used to advance knowledge in planetary science for over a half-century. They are useful in studies of comparative geology of the terrestrial planets and rocky moons, in astronaut training and testing of exploration technologies, and in developing hypotheses and exploration strategies in astrobiology. In fact, the use of terrestrial analogs can be traced back to the origins of comparative geology and astrobiology, and to the early phases of the Apollo astronaut program. Terrestrial analog studies feature prominently throughout the history of both NASA and the USGS’ Astrogeology Research Program. In light of current international plans for a return missions to the Moon, and eventually to send sample return and manned missions to Mars, as well as the recent creation of various analog research and development programs, this historical perspective is timely. 相似文献
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Low-frequency radio observations offer unique diagnostics of the solar corona and solar wind. After a prolongued hiatus, there is renewed interest in this important frequency regime. Two new ground-based instruments will provide critical new low-frequency observations: the low-frequency array (LOFAR) and the frequency agile solar radiotelescope (FASR). This brief topical review summarizes low-frequency radio phenomena that will be accessible to detailed study by LOFAR and FASR in the coming decade. Energy release, drivers of space weather, and studies of the solar wind are emphasized. Both instruments are expected to play important roles in both basic research problems and national and international space weather capabilities. While FASR is a solar-dedicated instrument, LOFAR is not. Solar observing requirements for LOFAR are briefly discussed. 相似文献
5.
Oleg Malkov Mikhail Sachkov Boris Shustov Pavel Kaigorodov Francisco Javier Yáñez Ana Ines Gómez de Castro 《Astrophysics and Space Science》2011,335(1):323-327
We present scientific program construction principles and a time allocation scheme developed for the World Space Observatory—Ultraviolet
(WSO-UV) mission, which is an international space observatory for observation in UV spectral range 100–300 nm. The WSO-UV
consists of a 1.7 m aperture telescope with instrumentation designed to carry out high resolution spectroscopy, long-slit
low resolution spectroscopy and direct sky imaging. The WSO-UV Ground Segment is under development by Spain and Russia. They
will coordinate the Mission and Science Operations and provide the satellite tracking stations for the project. 相似文献
6.
David L. Crawford 《Experimental Astronomy》1994,5(1-2):187-188
Astronomy is faced with environmental threats to observational research, such as light pollution and space junk. Space billboards are the latest of these potential serious impacts. There are solutions to most of these issues, but we all have to work together to ensure a positive approach. The International Dark-Sky Association, a membership based non-profit organization offers a route for us all to participate. 1 Operated by AURA, Inc. under cooperative agreement with the National Science Foundation. 相似文献
7.
R. M. Bonnet 《Solar physics》1996,169(2):233-243
The paper presents an overview of C. de Jager's career and his achievements in space science and solar physics. His role as a European space leader and as one of the founders of ESRO and ESA is outlined. The international dimension of this outstanding scientist is illustrated through personal memories and a long-lasting friendship.Dedicated to Cornelis de Jager 相似文献
8.
Jeffrey O. Bennett 《Astrophysics and Space Science》1994,214(1-2):225-235
This paper represents a commentary on the importance of communicating science to the general public, and offers specific suggestions on how best to gain public support for space astronomy. The presentation of space astronomy makes use of the contextual framework called Mission to the Universe, as developed by an international working group of astrophysicists and by the author.Presented at the 2nd UN/ESA Workshop, held in Bogotá, Colombia, 9–13 November, 1992.Humanity has embarked on a great voyage of discovery, with a mission to understand the origin, nature, and fate of our universe. Our ships are an international fleet of space observatories. Our captains are scientists from nearly every country of the world. All of us can be the explorers. Come share in our adventure... 相似文献
9.
V. Bumba 《Solar physics》1967,1(3-4):371-376
Preliminary results of magnetic field measurements in small sunspots from spectrograms obtained with the aid of the McMath Solar Telescope at the Kitt Peak National Observatory are presented. The measured intensities are greater than or equal to about 1200 Gauss. Furthermore, a broadening of the Fei line 6302.508 Å was found in some places of intergranular space. The importance of intergranular space as a possible potential earliest stage of sunspot development is mentioned.Kitt Peak National Observatory, Contribution No. 222.Visiting Astronomer, 1964, Kitt Peak National Observatory.Operated by the Association of Universities for Research in Astronomy, Inc., under contract with the Nat. Science Foundation. 相似文献
10.
We investigated the archival ground-based VLBI images of the extragalactic radio sources included in both the Wilkinson Microwave Anisotropy Probe (WMAP) and the Planck catalogues, and selected 49 bright and compact sources as potential targets for space Very Long Baseline Interferometry (VLBI) observations at mm wavelengths. These sources have a flat radio continuum spectrum between 33 and 94 GHz. They are identified as core-dominated active galactic nuclei (AGN), located at declinations above ?40°, and have never been observed with ground-based VLBI at 86 GHz. The radio properties of the 49 new sources are presented. We compare this new sample with similar samples of compact AGN available from earlier studies. The new candidates, together with the existing bright compact AGN sample identified from 86-GHz ground-based VLBI imaging surveys, form a catalogue of more than 160 AGN. These could be primary targets for mm-VLBI observations on the ground, as well as for future mm-wavelength space VLBI missions such as the project with two satellites currently under study in China. 相似文献
11.
The article discusses the progress made in studying space radiation in the heliosphere using SINP MSU instruments on board a spacecraft built by the Lavochkin Association, in predicting flight radiation conditions, and in studying the radiation resistance of spacecraft components. 相似文献
12.
P. Martinez 《Astrophysics and Space Science》1997,258(1-2):367-382
The UN/ESA workshops aim to foster the development of basic space science in developing countries. It is argued that the involvement
of these countries in international collaborations in ground-based astronomy is an effective method of achieving this aim.
A brief analysis of patterns of international cooperation in ground-based astronomy is presented. Where possible, the discussion
is illustrated with examples chosen to highlight contributions by developing countries. Mechanisms to support international
cooperation are discussed, along with some problems and possible solutions.
This revised version was published online in July 2006 with corrections to the Cover Date. 相似文献
13.
O. M. Alifanov A. L. Medvedskiy V. V. Terentyev D. V. Lyskov 《Solar System Research》2018,52(7):590-596
The development project of a prototype demonstrator for a descent vehicle and the possibilities of descent from orbit using aero-elastic braking devices deployable in space and in the atmosphere is considered. The project was carried out jointly by the Lavochkin Scientific Production Association and the Moscow Aviation Institute teams in 2013–2015. The results are evaluated for both the project itself and the cooperation of the two organizations. 相似文献
14.
Walter Flury 《Earth, Moon, and Planets》1995,70(1-3):79-91
37 years of space activities have led to a large number of anthropogenic objects orbiting the Earth. Ground-based observations with radar and optical facilities reveal the existence of about 7500 objects in space, which do not represent an immediate excessive danger. However, adequate actions are required to keep the long-term debris hazard for manned and unmanned missions within acceptable tolerances. In this paper the space debris environment of the Earth and its future evolution are described. New developments which could have a major impact on the space environment, are the the planned multi-satellite constellations for communications purposes or solar power stations in Earth orbit. Finally, methods for debris reduction are outlined. Space debris is a global problem which can only be effectively solved by international cooperation. 相似文献
15.
We present a detailed survey of the dynamical structure of the phase space around the new moons of the Pluto–Charon system. The spatial elliptic restricted three-body problem was used as model and stability maps were created by chaos indicators. The orbital elements of the moons are in the stable domain on the semimajor axis, eccentricity and inclination spaces. The structures related to the 4:1 and 6:1 mean motion resonances are clearly visible on the maps. They do not contain the positions of the moons, confirming previous studies. We showed the possibility that Nix might be in the 4:1 resonance if its argument of pericentre or longitude of node falls in a certain range. The results strongly suggest that Hydra is not in the 6:1 resonance for arbitrary values of the argument of pericentre or longitude of node. 相似文献
16.
A. A. Kotomin S. A. Dushenok D. B. Demyanenko V. V. Efanov V. V. Gorovtsov 《Solar System Research》2016,50(7):546-551
A new generation of spacecraft pyroautomatic systems is developed as a result of a long-term cooperation of NPO Lavochkin, St. Petersburg State Technological Institute (Technical University), and the Special Design and Technological Bureau (Technolog). Separation systems based on elastic explosives have proven their high efficiency and reliability in a number of Russian and international interplanetary and astrophysical space projects. Advanced devices based on new pyrotechnic compositions are developed. 相似文献
17.
Claude Catala 《Astrophysics and Space Science》2003,284(1):53-60
Intermediate mass pre-main sequence stars (1.5 to 5 M
)cross the instability strip on their way to the main sequence.They are therefore expected to be pulsating in a similar way as the Scuti stars. In this review, I present the status of observational studies ofpulsations in these stars, and comment on prospects for futureinvestigations of these pulsations from the ground and from space. 相似文献
18.
Studying space weather is an excellent subject for getting people interested in space science in general; therefore, it is being included as part of the education and public outreach activities being organized during the International Heliophysical Year (IHY). The general public find the subject interesting because variation in the space environment, i.e., space weather, can be related to their daily lives. The international organization concerned with space weather is called the International Space Environment Service (ISES). This organization is composed of the World Warning Agency (WWA) and 11 Regional Warning Centers (RWCs). The WWA and RWCs collect, collate, and disseminate space weather information on a regular basis. This report contains history and activities of the ISES. 相似文献
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着重评述了含激波吸积理论的发展历史和研究现状, 介绍了在伪牛顿势以及严格广义相对论框架下, 对等温和绝热两种不同的流体模型中可能发生的Ｒ－ Ｈ 激波、等温激波等各种不同激波的解析和数值模拟研究, 包括激波发生的参数空间、不同流体参数（ 比能量和比角动量） 下激波发生的位置、强度以及耗散的能量。这些研究结果表明, 在理想流体近似下, 黑洞吸积流中必定会产生激波。此外, 还介绍了含激波吸积理论在活动星系核方面的应用。对黑洞吸积理论简单讨论, 评述了含激波吸积理论与ＡＤＡＦ 吸积理论的关系, 着重评述了目前对于ＡＤＡＦ 中是否会发生激波这一存在很大争议的问题。 相似文献