朱文鑫《历代日食考》研究

用现代天文计算结果来全面研究整理中国古代日食记录,首推朱文鑫先生的<历代日食考>.他开拓的利用现代天文计算方法系统考察中国古代天象记录的研究,成为中国天文学史研究中的显学.介绍了<历代日食考>一书的内容和学术价值,比较了各个研究者对中国各代日食记录的统计,并对错误较多的西汉日食记录做了进一步的考证,以续朱先生言.分析指出,西汉日食记录的错误,许多是由另一条正确记录衍生出的.其错误的形态显示,原始记录只有年月,而日干支和所在宿度,是衍生错误已经发生之后加注的.     

日食的射电观测(英)

日食为射电天文提供了一维高空间分辨率太阳射电观测机会．日食射电观测在太阳射电物理的发展上起过重要的作用．文中对日食射电观测的若干重要因素作了介绍和分析．日食射电观测在我国太阳射电天文发展上也起了重要作用．文中简要介绍了在我国组织观测的1958年、1968年、1980年及1987年的太阳射电日食观测及其主要结果．     

中国早期日食记录研究进展

中国古代系统的日食记录始自春秋。自汉以至清代,整齐而完备。此前的夏、商、西周三代,日食记录零散而模糊。历来研究者众而难得定论。近年来由于天文计算方法和历史年代学的进展,早期日食记录的研究也获得新的成就。     

中国早期的日食记录和公元前十四至公元前十一世纪日食表

迄今所知,中国和西亚地区有几条可能的日食记录发生在 B.C.1400至 B.C.1000,其中主要被保存在出土的中国殷商时期的卜辞中。但它们都没有完整的年月日纪日。其中有一些需要进一步证实它们是不是日食。有些明确的日食纪事需要考订它们发生的时日。这些研究对历史学、天文学都是有意义的。文中对先秦时期的日食记录进行了讨论。本文依据 P.V.Neugebauer 的方法计算给出了 B.C.1399至 B.C.1000四百年间的日食表。为了研究殷墟出土卜辞中的日食记录,本文并计算列出了殷商时期安阳—殷商首都全部可见的日食。此外,介绍了 Dr.R.R.Newton 在这方面做的工作。     

1983年6月11日日全食的光学观测

1983年6月11日,由北京天文台、紫金山天文台和南京天文仪器厂组成的中国日食观测队天文组在巴布亚—新几内亚成功地作了一次日全食观测。 这次日食的最佳观测地点是印尼爪哇岛,所以大部分国家的观测队都集中于日惹,但由于种种原     

日食的射电观测

日食为射电天文提供了一维高空间分辨率太阳射电观测机会,日食射电观测在太阳射电物理的发展上起过重要的作用,文中对日食射电观测的若干重要因素作了介绍和分析,日食射电观测在我国太阳射电天文台发展上也起了重要作用,文中简要介绍了在我国组织观测的１９５８年,１９６８年,１９８０年及１９８７年太阳射电日食观测及其主要结果。     

清代正史日食记录初探

通过对清代正史日食记录的全面复算,对清代正史日食记录作了分析和讨论。根据前人和我们的分析,《清史稿》、《清实录》、《清朝文献通考》等正史里的日食史料来自日食预报,清朝正史中的日食记录包括了清代发生的日食的绝大多数;从1735年开始至清末,清代日食预报的时刻精度比之前提高了5分钟左右,得益于《历象考成后编》的编纂;《历象考成》、《历象考成后编》、《仪象考成》的编纂是清代日食预报中太阳所在宿度精度提高的主要原因;《西洋新法历书》的计算方法中日食方位是按太阳的地平方位来定位的,而《历象考成》和《历象考成后编》则自日面顶点计算日食方位。《历象考成后编》中日食方位的计算方法比《西洋新法历书》的方法有了极大改进。     

用中国古代的日食观测记载研究地球自转变化

用中国古代的日食观测记载研究地球自转变化中国科学院北京天文台韩延本３月９日日全食的壮观景象，一定还深深地留在许多天文爱好者的记忆中。古人同样也对日食非常感兴趣，因而在古书中留下了许多观测日食的记载，这些记载不仅是人类古代文明和古代天文学发达的象征，对...     

博山“摄”日

7月22日上午,山东淄博一中高二天文小组的同学在淄博博山公园首次观测日食,成功拍摄了日偏食照片,并进行了小孔成像实验。同学们一边观测,一边给周围群众讲解日食的基本原理及观测注意事项,在公园里掀起了一股观测日食的热潮。     

几次成功观测日食的体会

本文作者是参加过5次日食观测的天文科普工作者,曾多次带领青少年天文爱好者进行观测。具有丰富的实际观测经验,作者根据多次观测的经验体会及青少年天文爱好者进行观测时容易出现的问题进行了几个方面的提示,相信定会对首次进行日食观测的老师和同学有所帮助。     

Instructions for authors

正Research in Astronomy and Astrophysics publishes original research papers and reviews on all branches of astronomy and astrophysics.Reviews are by invitation only.Important new results that require rapid publication can be submitted as a Letter(Letters must be restricted in length to 6 printed pages).Authors who submit a paper are expected to be able to certify that the paper is original work,     

Alkali and halogen chemistry in volcanic gases on Io

We use chemical equilibrium calculations to model the speciation of alkalis and halogens in volcanic gases emitted on Io. The calculations cover wide temperature (500-2000 K) and pressure (10⁻⁶ to 10⁺¹ bars) ranges, which overlap the nominal conditions at Pele (T=1760 K, P=0.01 bars). About 230 compounds of 11 elements (O, S, Li, Na, K, Rb, Cs, F, Cl, Br, I) are considered. The elemental abundances for O, S, Na, K, and Cl are based upon observations. CI chondritic elemental abundances relative to sulfur are used for the other alkalis and halogens (as yet unobserved on Io). We predict the major alkali species in Pele-like volcanic gases and the percentage distribution of each alkali are LiCl (73%), LiF (27%); NaCl (81%), Na (16%), NaF (3%); KCl (91%), K (5%), KF (4%); RbCl (93%), Rb (4%), RbF (3%); CsCl (92%), CsF (6%), Cs (2%). Likewise the major halogen species and the percentage distribution of each halogen are NaF (88%), KF (10%), LiF (2%); NaCl (89%), KCl (11%); NaBr (89%), KBr (10%), Br (1%); NaI (61%), I (30%), KI (9%). We predict the major halogen condensates and their condensation temperatures at P=0.01 bar are NaF (1115 K), LiF (970 K); NaCl (1050 K), KCl (950 K); KBr (750 K), RbBr (730 K), CsBr (645 K); and solid I₂ (200 K). We also model disequilibrium chemistry of the alkalis and halogens in the volcanic plume. Based on this work and our prior modeling for Na, K, and Cl in a volcanic plume, we predict the major loss processes for the alkali halide gases are photolysis and/or condensation onto grains. Their estimated photochemical lifetimes range from a few minutes for alkali iodides to a few hours for alkali fluorides. Condensation is apparently the only loss process for elemental iodine. On the basis of elemental abundances and photochemical lifetimes, we recommend searching for gaseous KCl, NaF, LiF, LiCl, RbF, RbCl, CsF, and CsCl around volcanic vents during eruptions. Based on abundance considerations and observations of brown dwarfs we also recommend a search of Io's extended atmosphere and the Io plasma torus for neutral and ionized Li, Cs, Rb, and F.     

Instructions for authors

正Research in Astronomy and Astrophysics publishes original research papers and reviews 011 all liranchcs of astronoiriy and astrophysics.Reviews arc by invitation only.Important new results that require rapid publication can be submitted as a Letter(Letters must be restricted in length     

The climatic and physiographic controls of the eastern Mediterranean over the late Pleistocene climates in the southern Levant and its neighboring deserts

Modern-day synoptic-scale eastern Mediterranean climatology provides a useful context to synthesize the diverse late Pleistocene (60–12 ka) paleohydrologic and paleoenvironmental indicators of past climatic conditions in the Levant and the deserts to its south and east. We first critically evaluate, extract, and summarize paleoenvironmental and paleohydrologic records. Then, we propose a framework of eastern Mediterranean atmospheric circulation features interacting with the morphology and location of the southeast Mediterranean coast. Together they strongly control the spatial distribution of rainfall and wind pattern. This cyclone–physiography interaction enforces the observed rainfall patterns by hampering rainfall generation south and southeast of the latitude of the north Sinai coast, currently at 31°15′.The proposed framework explains the much-increased rains in Lebanon and northern Israel and Jordan as deduced from pollen, rise and maintenance of Lake Lisan, and speleothem formation in areas currently arid and semiarid. The proposed framework also accounts for the southward and eastward transition into semiarid, arid, and hyperarid deserts as expressed in thick loess accumulation at the deserts' margins, dune migration from west to east in the Sinai and the western Negev, and the formation of hyperarid (< 80 mm yr^− 1) gypsic–salic soils in the southern Negev and Sinai. Our climatic synthesis explains the hyperarid condition in the southern Negev, located only 200–250 km south of the much-increased rains in the north, probably reflecting a steeper rainfall gradient than the present-day gradient from the wetter Levant into its bordering southern and eastern deserts.At present, the rainiest winter seasons in Lebanon and northern and central Israel are associated with more frequent (+ 20%), deeper Cyprus Lows traversing the eastern Mediterranean at approximately the latitude of southern Turkey. Even these wettest years in northern Israel do not yield above average annual rainfall amounts in the hyperarid southern Negev. This region is mainly influenced by the Active Red Sea Troughs that produce only localized rains. The eastern Mediterranean Cyprus Lows also produce more dust storms and transport higher amounts of suspended dust to the loess area than any other atmospheric pattern. Concurrent rainfall and dust are essential to the late Pleistocene formation of the elongated thick loess zone along the desert northern margin. Even with existing dust storms, the lack of rain and very sparse vegetation account for the absence of late Pleistocene loess sequences from the southern Negev and the formation of hyperarid soils.When the north Sinai coast shifted 30–70 km northwest due to last glacial global sea level lowering, the newly exposed coastal areas supplied the sand and dust to these active eastern Mediterranean cyclones. This enforced the latitude of the northern boundary of the loess zone to be directly due east of the LGM shoreline. This shift of coast to the northwest inhibited rainfall in the southern Levant deserts and maintained their hyperaridity. Concurrently, frequent deep eastern Mediterranean Cyprus Lows were funneled along the northern Mediterranean increasing (probably doubling) the rains in central and northern Israel, Lebanon, southwestern Syria and northern Jordan. These storms and rains formed lakes, forests, and speleothems only a short distance north of the deserts in the southern Levant.     

Active hot star shells

Interferometry in the visible provides milliarcsecond spatial resolution and thus has been used for studying the circumstellar environment of active hot stars. In this paper I will illustrate how the visibility modulus and phase can be used to better constrain the physics of Be disks through results from the VLA, the MkII and the GI2T interferometers. I will insist on the importance and the potential of coupling high angular resolution with high spectral resolution to the study of Be shells. Finally I will present a possible study of the circumstellar disk of Be stars using the VLTI. This revised version was published online in July 2006 with corrections to the Cover Date.     

Fitting X-ray Afterglow Light curves of Gamma-ray Bursts by Using the Magnetar Energy Injection Model

The central compact object for some gamma-ray bursts (GRBs) may be a strongly magnetized millisecond pulsar. It can inject energy to the outer shock of the GRB by through the magnetic dipole radiation, and therefore causes the shallow decay of the early afterglow. Recently, from a large number of GRB X-ray afterglows observed by Swift/XRT(X-ray telescope), it is revealed that many of them exhibit the shallow decay about 10²∼10⁴ s after the burst prompt emission. We have fitted the X-ray afterglow light curves of 11 GRBs by using the energy injection model of a magnetar with the rotation period in the millisecond order of magnitude. The obtained result shows the validity and universality of the magnetar energy injection model in explaining the shallow decay of afterglows, and simultaneously provides some constraints on the magnetic field strength and rotation period of the central magnetar.     

Dynamical study of wide pairs of stars based on data from the WDS catalog

Using the method of apparent motion parameters, we have studied the relative motion of the components in 561 pairs of wide (ρ > 2″) and relatively nearby (Hipparcos parallaxes > 0.01″) visual double stars based on data from the WDS catalog. The minimum masses of the double stars have been calculated at given parallaxes. We have identified 358 optical pairs. For 11 stellar pairs, we have found the minimum mass to exceed the estimate corresponding to their spectral types and luminosities. This excess is 5–7 M _⊙ for two stars, ADS 7446 and 9701.     

Microscopic black hole detection in UHECR: the double bang signature

According to recent conjectures on the existence of large extra dimensions in our universe, black holes could be produced during the interaction of Ultra High Energy Cosmic Rays with the atmosphere. However, and so far, the proposed signatures are based on statistical effects, not allowing identification on an event by event basis, and may lead to large uncertainties. In this note, events with a double bang topology, where the production and instantaneous decay of a microscopic black hole (first bang) is followed, at a measurable distance, by the decay of an energetic tau lepton (second bang) are proposed as an almost background free signature. The characteristics of these events and the capability of large cosmic ray experiments to detect them are discussed.