发布求助
文献互助 智能选刊 最新文献

Bulletin of the American Astronomical Society最新文献

筛选
英文 中文
On the mass of nova DQ Hercules (1934) 关于新星DQ大力神的质量(1934)
Bulletin of the American Astronomical Society Pub Date : 1993-06-10 DOI: 10.1086/172752
K. Horne, W. Welsh, R. Wade
{"title":"On the mass of nova DQ Hercules (1934)","authors":"K. Horne, W. Welsh, R. Wade","doi":"10.1086/172752","DOIUrl":"https://doi.org/10.1086/172752","url":null,"abstract":"Time-resolved high-resolution CCD spectroscopy covering two 4.6-hr orbits of DQ Her are presented. Analysis of the Na I 8183,8195 A absorption doublet yields estimates of the secondary star's projected orbital velocity and rotational broadening. The estimate of the projected orbital velocity is refined using models of the effects of irradiation on the secondary star, producing a final value of 227 +/- 10 km/s. The stellar masses are estimated at M1 = 0.60 +/- 0.07 and M2 = 0.40 +/- 0.05 solar mass.","PeriodicalId":9423,"journal":{"name":"Bulletin of the American Astronomical Society","volume":"23 12 1","pages":"738"},"PeriodicalIF":0.0,"publicationDate":"1993-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85019342","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}
引用次数: 46
The FK5 Extension on the FK4 system FK4系统上的FK5扩展
Bulletin of the American Astronomical Society Pub Date : 1993-06-01 DOI: 10.1086/116613
M. Lattanzi, L. Taff
{"title":"The FK5 Extension on the FK4 system","authors":"M. Lattanzi, L. Taff","doi":"10.1086/116613","DOIUrl":"https://doi.org/10.1086/116613","url":null,"abstract":"This paper reports on the computations necessary to place the FK5 Extension (epoch of place B1950.0) on the B1950.0/FK4 system from its published form and the availability of this version of the catalog. An application of the utility of the new version of the FK5 Extension, to the AGK3U, is given too. This confirms both the system of the AGK3U and the estimated values of its equatorial coordinate and proper motion mean errors. In addition, we have fully exploited the flexibility of the method of infinitely overlapping circles to compute a mean epoch of place/FK4 version of the FK5 Extension which we also make available. These modifications include taking into account the changes induced by the new system of general precession constants, adjusting for the e-terms of aberration, correcting for both the FK5/FK4 equinox offset and motion, and the FK5/FK4 positional and the proper motion systematic differences.","PeriodicalId":9423,"journal":{"name":"Bulletin of the American Astronomical Society","volume":"68 1","pages":"1231"},"PeriodicalIF":0.0,"publicationDate":"1993-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77154406","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}
引用次数: 1
Invited Talk: (The NASA High Energy Solar Physics (HESP) Mission for the Next Solar Maximum) 特邀演讲:(NASA高能太阳物理(HESP)下一个太阳极大期任务)
Bulletin of the American Astronomical Society Pub Date : 1993-06-01 DOI: 10.1016/0273-1177(93)90512-A
R. Lin, B. Dennis, R. Ramaty, A. Emslie, R. Canfield, G. Doschek
{"title":"Invited Talk: (The NASA High Energy Solar Physics (HESP) Mission for the Next Solar Maximum)","authors":"R. Lin, B. Dennis, R. Ramaty, A. Emslie, R. Canfield, G. Doschek","doi":"10.1016/0273-1177(93)90512-A","DOIUrl":"https://doi.org/10.1016/0273-1177(93)90512-A","url":null,"abstract":"","PeriodicalId":9423,"journal":{"name":"Bulletin of the American Astronomical Society","volume":"84 1","pages":"1180"},"PeriodicalIF":0.0,"publicationDate":"1993-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78461008","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}
引用次数: 3
On the origin of the Z-shaped narrow-line region in the Seyfert galaxy NGC 3516 关于塞弗特星系NGC 3516 z形窄线区域的起源
Bulletin of the American Astronomical Society Pub Date : 1993-04-01 DOI: 10.1086/116512
S. Veilleux, R. Tully, J. Bland-Hawthorn
{"title":"On the origin of the Z-shaped narrow-line region in the Seyfert galaxy NGC 3516","authors":"S. Veilleux, R. Tully, J. Bland-Hawthorn","doi":"10.1086/116512","DOIUrl":"https://doi.org/10.1086/116512","url":null,"abstract":"A kinematic study has been carried out of the line-emitting gas in the Seyfert galaxy NGC 3516. The existence of two curved filaments in the central 2.5 kpc of this galaxy, which give Z-shaped appearance to its NLR. A precessing twin-jet model in which the line-emitting material is entrained by a precessing radio jet and kept ionized by the nuclear ionization field can explain the kinematic data of the brightest emission rather well. If this model is valid, this would make NGC 3516 the least luminous known active galaxy with a precessing jet. An alternative scenario assumes that the curved inner filaments represent gas entrained by a radio jet which is deflected by ram pressure from the rotation interstellar medium of the galaxy.","PeriodicalId":9423,"journal":{"name":"Bulletin of the American Astronomical Society","volume":"3 1","pages":"1428"},"PeriodicalIF":0.0,"publicationDate":"1993-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79374976","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}
引用次数: 30
Calibrated Solar EUV Spectrum from Serts 来自Serts的校准太阳EUV光谱
Bulletin of the American Astronomical Society Pub Date : 1993-01-01 DOI: 10.1007/978-94-011-1964-1_23
R. Thomas, W. Neupert, W. Thompson
{"title":"Calibrated Solar EUV Spectrum from Serts","authors":"R. Thomas, W. Neupert, W. Thompson","doi":"10.1007/978-94-011-1964-1_23","DOIUrl":"https://doi.org/10.1007/978-94-011-1964-1_23","url":null,"abstract":"","PeriodicalId":9423,"journal":{"name":"Bulletin of the American Astronomical Society","volume":"11 1","pages":"195-198"},"PeriodicalIF":0.0,"publicationDate":"1993-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72965014","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}
引用次数: 1
Infrared photometry and spectroscopy of the brown dwarf candidate PC0025+0447 棕矮星候选者PC0025+0447的红外光度测定和光谱分析
Bulletin of the American Astronomical Society Pub Date : 1992-11-01 DOI: 10.1086/116377
J. Graham, K. Matthews, J. Greenstein, G. Neugebauer, C. Tinney, S. E. Persson
{"title":"Infrared photometry and spectroscopy of the brown dwarf candidate PC0025+0447","authors":"J. Graham, K. Matthews, J. Greenstein, G. Neugebauer, C. Tinney, S. E. Persson","doi":"10.1086/116377","DOIUrl":"https://doi.org/10.1086/116377","url":null,"abstract":"We have obtained I, J, H, Kf and L' photometry and infrared spectroscopy (λ/Δλ ≃ 100) from 1.2-2.4 µm of the unusual emission line M star PC0025+0447. The near infrared photometry shows that this star has infrared colors which are comparable to the latest M dwarf stars such as LHS 2924 and LHS 2065. The infrared colors of PC0025+0447 establish that this star is a dwarf and not a distant giant. The infrared spectrum is dominated by strong H_2O absorption bands, and these bands are the \u0000strongest measured in any dwarf. Since H_2O band strength increases with decreasing temperature it is very likely that PC0025-f 0447 is substantially cooler than any of the stars calibrated by Berriman & Reid [MNRAS, 227, 315 (1987)], i.e. T_(eff) 10^9 yr) H burning star, with M ≃ 0.08 M_☉, or a younger brown dwarf.","PeriodicalId":9423,"journal":{"name":"Bulletin of the American Astronomical Society","volume":"2010 1","pages":"1416"},"PeriodicalIF":0.0,"publicationDate":"1992-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86311271","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}
引用次数: 8
The star formation history of the Large Magellanic Cloud 大麦哲伦星云的恒星形成历史
Bulletin of the American Astronomical Society Pub Date : 1992-04-01 DOI: 10.1086/171163
G. Bertelli, M. Mateo, C. Chiosi, A. Bressan
{"title":"The star formation history of the Large Magellanic Cloud","authors":"G. Bertelli, M. Mateo, C. Chiosi, A. Bressan","doi":"10.1086/171163","DOIUrl":"https://doi.org/10.1086/171163","url":null,"abstract":"Deep photometric observations of stars in three fields of the LMC are presented, and these data are interpreted using synthetic CMDs and LFs generated from overshoot models. The field CMDs and LFs with a star formation rate that experienced a large increase (4 +/- 0.5) x 10 exp 9 yr ago is successfully modeled. The precise age of this 'burst' depends sensitively on the characteristics of the models. Classical (i.e., nonovershoot) models yield a burst age about 2 x 10 exp 9 yr younger than the value obtained. An initial mass function with slope of 2.35 (the Salpeter value) and a mean field star metallicity of Fe/H of about -0.7 are consistent with the photometric data and LFs. It is suggested that the star formation rate in the LMC was globally quite low during at least the first half of its lifetime, and that a major event triggered a substantial and relatively sudden increase in the star formation rate throughout the entire LMC which persisted for several 10 exp 9 yr and even up to the present epoch in some parts of that galaxy.","PeriodicalId":9423,"journal":{"name":"Bulletin of the American Astronomical Society","volume":"2 1","pages":"949"},"PeriodicalIF":0.0,"publicationDate":"1992-04-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85473875","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}
引用次数: 59
The Optically Thick C III Spectrum: I. Term Populations and Multiplet Intensities at Lower Optical Depths 光学厚度的C III光谱:1 .低光深度下的项族和多路强度
Bulletin of the American Astronomical Society Pub Date : 1992-03-01 DOI: 10.1086/191648
A. Bhatia, S. O. Kastner
{"title":"The Optically Thick C III Spectrum: I. Term Populations and Multiplet Intensities at Lower Optical Depths","authors":"A. Bhatia, S. O. Kastner","doi":"10.1086/191648","DOIUrl":"https://doi.org/10.1086/191648","url":null,"abstract":"The C III spectrum is studied quantitatively under both optically thin and optically thick conditions, yielding term populations and line/multiplet intensities for column lengths from zero to 10 exp 18/sq cm. The roles of escape probabilities and line profiles in the calculation are discussed in some detail. It is shown that use of the fully integrated escape factor, rather than the more appropriate monodirectional escape probability, can lead to appreciable errors in calculated intensities. The results for populations and intensities make it possible to identify two unassigned features in the solar EUV spectrum of Vernazza and Reeves (1978) as C III multiplets, and to establish that an unidentified infrared solar feature at 8500.32 A, seen in both absorption (Fraunhofer) and emission (chromospheric) spectra, is the C III transition 2s3s(1S)-2s3p(1P). Voigt parameters for the C III lines and multiplets, obtained by a modified semiclassical method are tabulated. A new, unambiguous notation for the numerous line ratios present in a typical spectrum, which is argued to be an improvement over present arbitrary notations, is proposed and used.","PeriodicalId":9423,"journal":{"name":"Bulletin of the American Astronomical Society","volume":"74 1","pages":"1203"},"PeriodicalIF":0.0,"publicationDate":"1992-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83975222","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}
引用次数: 6
Massive star formation in galactic disks. 星系盘中大质量恒星的形成。
Bulletin of the American Astronomical Society Pub Date : 1992-01-01 DOI: 10.25911/5D6E501F72B69
S. Ryder
{"title":"Massive star formation in galactic disks.","authors":"S. Ryder","doi":"10.25911/5D6E501F72B69","DOIUrl":"https://doi.org/10.25911/5D6E501F72B69","url":null,"abstract":"","PeriodicalId":9423,"journal":{"name":"Bulletin of the American Astronomical Society","volume":"37 1","pages":"1210"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73812631","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}
引用次数: 2
Variable Hα emission in the helium-strong star δ orionis C 氦强恒星δ猎户座C的可变Hα发射
Bulletin of the American Astronomical Society Pub Date : 1992-01-01 DOI: 10.1007/3-540-55256-1_309
D. Bohlender, C. T. Bolton, G. Walker
{"title":"Variable Hα emission in the helium-strong star δ orionis C","authors":"D. Bohlender, C. T. Bolton, G. Walker","doi":"10.1007/3-540-55256-1_309","DOIUrl":"https://doi.org/10.1007/3-540-55256-1_309","url":null,"abstract":"","PeriodicalId":9423,"journal":{"name":"Bulletin of the American Astronomical Society","volume":"9 1","pages":"221-223"},"PeriodicalIF":0.0,"publicationDate":"1992-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82014566","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}
引用次数: 1
首页 上一页 下一页 尾页
0
×
引用
GB/T 7714-2015
复制
MLA
复制
APA
复制
导出至
BibTeX EndNote RefMan NoteFirst NoteExpress
×
提示
您的信息不完整，为了账户安全，请先补充。
现在去补充
×
提示
您因"违规操作"
具体请查看互助需知
我知道了
×
提示
现在去查看 取消
×
提示
确定
请完成安全验证×
相关产品
×
本文献相关产品
联系我们：info@booksci.cn Book学术提供免费学术资源搜索服务，方便国内外学者检索中英文文献。致力于提供最便捷和优质的服务体验。 Copyright © 2023 布克学术 All rights reserved.
京ICP备2023020795号-1
ghs 京公网安备 11010802042870号
Book学术文献互助
Book学术文献互助群
群 号：481959085
Book学术官方微信