Pub Date : 1900-01-01DOI: 10.1017/S1539299600013952
A. Boesgaard
{"title":"Oxygen in Unevolved Starss","authors":"A. Boesgaard","doi":"10.1017/S1539299600013952","DOIUrl":"https://doi.org/10.1017/S1539299600013952","url":null,"abstract":"","PeriodicalId":422890,"journal":{"name":"Highlights of Astronomy","volume":" 11","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120830264","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1017/S1539299600012806
J. Lacy
Some recent observations of interstellar, circumstellar, and stellar atoms and molecules, with ground-based telescopes and ISO, are discussed. The advantages of observations with SIRTF and SOFIA, and needed laboratory work are mentioned more briefly.
{"title":"Observations of Gas-Phase Atoms and Molecules","authors":"J. Lacy","doi":"10.1017/S1539299600012806","DOIUrl":"https://doi.org/10.1017/S1539299600012806","url":null,"abstract":"Some recent observations of interstellar, circumstellar, and stellar atoms and molecules, with ground-based telescopes and ISO, are discussed. The advantages of observations with SIRTF and SOFIA, and needed laboratory work are mentioned more briefly.","PeriodicalId":422890,"journal":{"name":"Highlights of Astronomy","volume":"78 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120897569","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1017/S1539299600015288
Jingxiu Wang, Guiping Zhou, Jun Zhang
mass ejections are thought to originate from the over accumulation of magnetic helicity While recent studies revealed the incompetence of CME associated active regions in creating enough helicity for CMEs therein), we have tried to seek, on the other hand, if particular helicity patterns are retained by CME-associated active regions.
{"title":"Helicity pattern of CME source active regions","authors":"Jingxiu Wang, Guiping Zhou, Jun Zhang","doi":"10.1017/S1539299600015288","DOIUrl":"https://doi.org/10.1017/S1539299600015288","url":null,"abstract":"mass ejections are thought to originate from the over accumulation of magnetic helicity While recent studies revealed the incompetence of CME associated active regions in creating enough helicity for CMEs therein), we have tried to seek, on the other hand, if particular helicity patterns are retained by CME-associated active regions.","PeriodicalId":422890,"journal":{"name":"Highlights of Astronomy","volume":"51 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120942916","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1017/S1539299600011060
T. Herring
Abst.ra.ct! We discuss the formulation of a new nutation series to be used 'in the reduction of modern space geodetic data. The motivation for devel: oping such a series is to develop a nutation series that has smaller short . period errors than the IAU 1980 nutation series and to provide a series that can be used with techniques such as the Global Positioning System (GPS) eo • that have sensitivity to nutations but can directly separate the effects of o M ' nutations from errors in the dynamical force models that effect the satellite ^ to ,$• orbits. A modern nutation series should allow the errors in the force models ^ *o
Abst.ra.ct !我们讨论了一个新的章动级数的公式，用于现代空间大地测量数据的约简。开发这样一个系列的动机是开发一个短时间更小的章动系列。与IAU 1980章动序列相比，周期误差更大，并提供一个可以与全球定位系统(GPS) eo•等技术一起使用的系列，这些技术对章动具有敏感性，但可以直接将o M '章动的影响与影响卫星轨道的动力模型中的误差分开。现代章动序列应该允许力模型中的误差^ *o
{"title":"An a priori model for the reduction of nutation observations: KSV(1994.3) nutation series","authors":"T. Herring","doi":"10.1017/S1539299600011060","DOIUrl":"https://doi.org/10.1017/S1539299600011060","url":null,"abstract":"Abst.ra.ct! We discuss the formulation of a new nutation series to be used 'in the reduction of modern space geodetic data. The motivation for devel: oping such a series is to develop a nutation series that has smaller short . period errors than the IAU 1980 nutation series and to provide a series that can be used with techniques such as the Global Positioning System (GPS) eo • that have sensitivity to nutations but can directly separate the effects of o M ' nutations from errors in the dynamical force models that effect the satellite ^ to ,$• orbits. A modern nutation series should allow the errors in the force models ^ *o <? .for GPS to be better understood. The series is constructed by convolving 2 £ § the Kinoshita and Souchay rigid Earth nutation series with an Earth response function whose parameters are partly based on geophysical models ^ 't of the Earth and partly estimated from a long series (1979-1993) of very x. long baseline interferometry (VLBI) estimates of nutation angles. Secular 2 rates of change of the nutation angles to represent corrections to the precession constant and a secular change of the obliquity of the ecliptic are included in the theory. Time dependent amplitudes of the Free Core Nutation (FCN) that is most likely excited by variations in atmospheric pressure are included when the geophysical parameters are estimated. The complex components of the prograde annual nutation are estimated simultaneously with the geophysical parameters because of the large contribution to the nutation from the 5i atmospheric tide. The weighted root mean square (WRMS) scatter of the nutation angle estimates about this new model are 0.32 mas and the largest correction to the series when the amplitudes of the ten largest nutations are estimated is 0.17 ± 0.03 mas for the in phase component of the prograde 18.6 year nutation.","PeriodicalId":422890,"journal":{"name":"Highlights of Astronomy","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120946023","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1017/S1539299600022358
C. Turon
The Hipparcos data are providing a dramatic increase, qualitatively and quantitatively, of the basic available distance information. For example, the numbers of stars for which a relative accuracy better than 10 % is available from Hipparcos data and from ground-based data are respectively 22 396 and about 1000. Moreover, the range of spectral types and luminosity classes for which precise parallaxes are available is considerably enlarged, including many stars in open clusters and a small number of Cepheids and RR Lyrae. The bottom of the main sequence is populated down to absolute Hp magnitude 14, including a number of subdwarf stars essential to derive globular clusters distances and ages (Pont et al, 1997a).
喜巴可思的数据在质量和数量上都大大增加了现有的基本距离信息。例如，Hipparcos数据和地面数据的相对精度高于10%的恒星数量分别为22 396颗和1000颗左右。此外，光谱类型和光度等级的范围也大大扩大了，其中包括疏散星团中的许多恒星和少数造父变星和天琴座RR星。主序的底部被填充到绝对的Hp等14，包括一些亚矮星，这对于推断球状星团的距离和年龄至关重要(Pont et al, 1997a)。
{"title":"Hipparcos and Primary Distance Scale Indicators","authors":"C. Turon","doi":"10.1017/S1539299600022358","DOIUrl":"https://doi.org/10.1017/S1539299600022358","url":null,"abstract":"The Hipparcos data are providing a dramatic increase, qualitatively and quantitatively, of the basic available distance information. For example, the numbers of stars for which a relative accuracy better than 10 % is available from Hipparcos data and from ground-based data are respectively 22 396 and about 1000. Moreover, the range of spectral types and luminosity classes for which precise parallaxes are available is considerably enlarged, including many stars in open clusters and a small number of Cepheids and RR Lyrae. The bottom of the main sequence is populated down to absolute Hp magnitude 14, including a number of subdwarf stars essential to derive globular clusters distances and ages (Pont et al, 1997a).","PeriodicalId":422890,"journal":{"name":"Highlights of Astronomy","volume":"111 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120967586","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1017/S1539299600013733
V. Abalakin, A. Arkharov, Y. Gnedin, I. I. Kanayev, D. Polojentsev, H. Potter
{"title":"The Role of the Central (Pulkovo) Observatory in Southern Hemisphere Star Observations","authors":"V. Abalakin, A. Arkharov, Y. Gnedin, I. I. Kanayev, D. Polojentsev, H. Potter","doi":"10.1017/S1539299600013733","DOIUrl":"https://doi.org/10.1017/S1539299600013733","url":null,"abstract":"","PeriodicalId":422890,"journal":{"name":"Highlights of Astronomy","volume":"72 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120994258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1007/978-94-011-4778-1_20
J. Babel
{"title":"Diffusion, Winds and X-Rays from Magnetic Stars","authors":"J. Babel","doi":"10.1007/978-94-011-4778-1_20","DOIUrl":"https://doi.org/10.1007/978-94-011-4778-1_20","url":null,"abstract":"","PeriodicalId":422890,"journal":{"name":"Highlights of Astronomy","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121001684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1017/S1539299600022693
J. T. Lynch
Many people, including Wernher von Braun, have drawn an analogy between the manned exploration of the solar system and scientific stations in Antarctica. Some of the Space/Antarctic parallels are quite obvious, such as the necessity to select small groups of highly trained individuals who can work together in isolation for extended periods, or in the case of the Moon/Antarctic comparison, the long day/night cycle. However, the parallel can be carried considerably further to include the types of science to be done, and, in some cases, there is even a strong similarity in environmental conditions. It may be worth while to build a new Antarctic station just to learn more about how to do planetary exploration.
{"title":"An international research station in Antarctica","authors":"J. T. Lynch","doi":"10.1017/S1539299600022693","DOIUrl":"https://doi.org/10.1017/S1539299600022693","url":null,"abstract":"Many people, including Wernher von Braun, have drawn an analogy between the manned exploration of the solar system and scientific stations in Antarctica. Some of the Space/Antarctic parallels are quite obvious, such as the necessity to select small groups of highly trained individuals who can work together in isolation for extended periods, or in the case of the Moon/Antarctic comparison, the long day/night cycle. However, the parallel can be carried considerably further to include the types of science to be done, and, in some cases, there is even a strong similarity in environmental conditions. It may be worth while to build a new Antarctic station just to learn more about how to do planetary exploration.","PeriodicalId":422890,"journal":{"name":"Highlights of Astronomy","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121052197","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1017/S1539299600013356
C. Bergh, M. Barucci, A. L. Bras, J. Romón, B. Schmitt, J. Cuby
As part of an observing programme with the ISAAC infrared spectrometer at the 8-m Antu telescope of the ESO-Very Large Telescope (Chile) devoted to the study of the surface composition of Kuiper Belt Objects and Centaurs, we obtained, in May 1999, spectra of the red Centaur Asbolus in the J, H and K bands. The spectra appear featureless.
{"title":"Infrared spectroscopy of the Centaur Asbolus with the ESO-Very Large Telescope","authors":"C. Bergh, M. Barucci, A. L. Bras, J. Romón, B. Schmitt, J. Cuby","doi":"10.1017/S1539299600013356","DOIUrl":"https://doi.org/10.1017/S1539299600013356","url":null,"abstract":"As part of an observing programme with the ISAAC infrared spectrometer at the 8-m Antu telescope of the ESO-Very Large Telescope (Chile) devoted to the study of the surface composition of Kuiper Belt Objects and Centaurs, we obtained, in May 1999, spectra of the red Centaur Asbolus in the J, H and K bands. The spectra appear featureless.","PeriodicalId":422890,"journal":{"name":"Highlights of Astronomy","volume":"104 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121057977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 1900-01-01DOI: 10.1017/S1539299600010947
D. Mccarthy, B. Luzum
The observations of dip and de used in this analysis were taken from the combination solution of the IERS Sub-Bureau for Rapid Service and Precition (McCarthy and Luzum 1991a). Besides correc tions to the coefficients determined from VLBI, additional estimates can be derived from lunar laser ranging (LLR) observations (Williams et al. 1991; Whipple 1993). Table ?? shows a comparison of the estimates of the change in longitude and obliquity derived in this analysis with corresponding terms from analyses by other authors using different observations. The theoretical value of obliquity by Williams (1994) is also included for comparison. There are significant unexplained discrepancies among the rate estimates. Difference in the methods of the analyses such as the procesure for the estimation of the nutation coefficients and correlations within the solutions probably account for the greater part of these discrepancies. In considering the adoption of changes in the IAU model for nuta tion, it is important to recall that changes must also be made in the precession constant. Introduction of changes in nutation without corresponding changes in precession will not improve the agreement between observations and theory.
本分析中使用的倾角和de观测值来自IERS快速服务和精确分局的组合溶液(McCarthy and Luzum 1991a)。除了对VLBI确定的系数进行校正外，还可以从月球激光测距(LLR)观测中获得额外的估计值(Williams et al. 1991;惠普尔1993)。表? ?将本分析得出的经度和倾角变化估计值与其他作者使用不同观测所得的分析得出的相应项进行比较。Williams(1994)对倾角的理论价值也进行了比较。费率估计数之间存在无法解释的重大差异。分析方法的不同，例如对解中章动系数和相关性的估计程序的不同，可能是造成这些差异的主要原因。在考虑改变国际天文联合会的运动模式时，重要的是要记住，也必须改变岁差常数。引入章动变化而没有相应的进动变化不会改善观测和理论之间的一致性。
{"title":"Observations of Luni-solar precession","authors":"D. Mccarthy, B. Luzum","doi":"10.1017/S1539299600010947","DOIUrl":"https://doi.org/10.1017/S1539299600010947","url":null,"abstract":"The observations of dip and de used in this analysis were taken from the combination solution of the IERS Sub-Bureau for Rapid Service and Precition (McCarthy and Luzum 1991a). Besides correc tions to the coefficients determined from VLBI, additional estimates can be derived from lunar laser ranging (LLR) observations (Williams et al. 1991; Whipple 1993). Table ?? shows a comparison of the estimates of the change in longitude and obliquity derived in this analysis with corresponding terms from analyses by other authors using different observations. The theoretical value of obliquity by Williams (1994) is also included for comparison. There are significant unexplained discrepancies among the rate estimates. Difference in the methods of the analyses such as the procesure for the estimation of the nutation coefficients and correlations within the solutions probably account for the greater part of these discrepancies. In considering the adoption of changes in the IAU model for nuta tion, it is important to recall that changes must also be made in the precession constant. Introduction of changes in nutation without corresponding changes in precession will not improve the agreement between observations and theory.","PeriodicalId":422890,"journal":{"name":"Highlights of Astronomy","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127297429","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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