再发新星天箭WZ(WZSge)1978年的爆发

本文给出了再发新星天箭WZ1978年爆发期间,应用北京天文台兴隆站的40/200厘米双筒天体照相仪于1978年12月6日到25日对其所做的照相观测结果。同时对再发新星WZ Sge爆发期间的光度变化情况进行了讨论。并计算了其在1978年爆发时所释放出的总辐射能量约为1.07×10~(40)尔格。估计了WZ Sge下次可能爆发的时间以及它在爆发时的极大光度情况。     

NGC 4321中超新星1979_c的照相研究

1979年4月23日—12月27日,我们用北京天文台40/200cm双筒天体照相仪对旋涡星系M100(NGC 4321)中的亮超新星SN1979c进行了照相观测.本文简述了观测情况,并结合前人的观测,分析讨论了我们的结果. 它的光变曲线可以`划分为四个阶段.5月8日—6月5日间光变曲线有驼峰状突起.其光度变化既不同于Ⅰ型超新星,也与典型的Ⅱ型超新星不完全吻合. 计算得到超新星亮度极大时的绝对照相星等为M_(pg)(max)=-19~(m)78;极大光度L_SN(max)=1.076×10~(10)L⊙. 我们利用Balinskaya和Carney等人1980年发表的三色测光资料计算了这颗超新星在不同时刻的色温度变化,推算出它极大时刻的色温度约为T_c(max)≈9.0×10~3K. 爆发期间超新星辐射的总能量E_t=4.2×10~(16)L⊙. 根据这颗超新星的光变曲线、在星系中的位置及爆发期间辐射的总能量等主要特征,我们认为SN1979c是某些性质比较特殊的II型超新星.     

1975年8月16日天鹅座新星N Cyg 1975的星等

我们和北京天文台恒星室的同志于1975年8月16日(离新星爆发极大前15天左右)使用北京天文台40/200 cm双筒天体照相仪拍摄了NGC 7000区域.由于视场为8°×8°,正巧把新星拍在象场边缘附近.观测时左右筒同时露光,使用柯达103a-0底片,未加滤光片.为了定出新星在这一时刻的星等,     

哈雷彗星与彗星研究

彗星是太阳系的一种奇特天体。在太阳辐射和太阳风作用下,彗星发生一系列物理过程和化学过程,表现为外貌形态(彗发、彗尾)、亮度、光谱及运动特性等多种变化。彗星研究是天文学和空间科学的重要课题,对于了解太阳系起源、有机分子仍至生命起源、太阳风及等离子体过程都有重要意义。 著名的哈雷彗星将在1985—86年再次回归到内太阳系。它有多种彗星现象,从地面到近地空间及空间会合的各种观测及样品分析,预料会取得彗星研究的新进展。本文先概述国际哈雷彗星联测(IHW)的计划;然后,评述彗星研究的一些进展,包括:(1)彗星的化学组成和化学过程;(2)尘埃彗尾和颗粒;(3)等离子体彗尾;(4)彗发;(5)彗星的亮度、爆发和分裂;(6)彗核的蒸发、寿命及非引力效应;(7)彗核,其中也包括我国的彗星研究情况。     

海豚座新星(N Del 1967)1967年12月极大前的光谱变化

本文对1967年海豚座新星12月极大前光谱作了分光光度测量,测定了壳层膨胀速度.分析测量结果,提出如下看法:一、归纳出新星极大前光谱变化有三个共同的特征.这些特征是:1.壳层膨胀速度逐步减小,并渐趋稳定;2.色温度总的趋势是下降;3.某些电离电位或激发电位相对较高的元素的发射线,其相对于连续谱的强度也有下降的趋势.二、海豚座新星特征有利于把其平坦极大阶段看成是极大前休止的假设.三、用连续物质流的假设可以满意地解释我们所观测到的新星极大前光谱变化的特征.     

重要测距结果一览

天体距离的多途径测定 从前面对天体距离测定一些主要方法的简要介绍,细心的读者不难看出,就某一类天体来说,可以通过不同的途径来确定它们的距离。例如,对于像仙女星系M31这样的近距离河外星系,能利用的标距天体（或标距关系）有天琴RR型变星、造父变星、新星、球状星团光度函数以及行星状星云光度函数,等等。这就为比较各种方法的测距结果,并进而为论证这些结果以及方法的可靠性提供了观测依据。     

奇妙的变星世界

在浩瀚的恒星世界中,有一类有亮度变化的星,叫变星,其中包括那些由于星体的膨胀、收缩或爆发活动引起光度变化的物理变星和那些由于两个子星互相掩食使之观测到亮度变化的食变星。这里我们只谈谈奇妙的物理变星。     

对新星宽波段测光的意见

①在新星的早期阶段,仅研究新星的大体光变时,用通常的测光归化技术是可以的.②新星进入星云阶段之后,不能使用常规的恒星观测的化归公式.无论是化归与不化归都不能自称为 U、B、V.③我们使用本台自己的光谱观测资料进行了定量计算.证明:(a)如果光电观测仪器系统反应函数的边缘部分有小的差别,就可能会导致观测结果有意外大的差别.(b)较差消光改正也不能用常法进行处理.④对如何更好地进行新星的光度工作提出了一些意见.     

1975年天鹅座新星(V1500 Cyg)的照相分光光度研究

本文给出新星V1500 Cyg根据1975年8月至1976年1月观测资料得出的距离、星际消光星等、某些发射带的相对强度比、温度、壳层的电子密度和电子温度等物理量。中心星的温度和壳层的电子温度都随新星亮度的下降而逐渐升高。同一时期的中心星温度和壳层的电子温度有某些相似的起伏和变化。     

1971年1—4月太阳H_α谱斑亮度、面积的极大同耀斑的相关性

本文对1971年1月至4月期间,日面各活动区每天的H。谱斑最大亮度、谱斑面积等参数同耀斑爆发进行统计。统计表明:谱斑各参数(特别是亮度)极大同耀斑爆发有一定的相关性。对所统计的耀斑,在其爆发前五天内,对应的谱斑亮度都呈现过极大。就耀斑爆发前三天而言,也有92.8％的耀斑对应的谱斑亮度呈现过极大。此外,统计还显示出许多耀斑爆发前谱斑亮度可能有着1—2天的周期性变化。这可能意味着活动区磁场也有类似的变化,它可能反映了谱斑亮度极大-磁场-耀斑之间存在着本质的物理联系。     

Spectroscopic study of Be-shell stars: 4 Her and 88 Her

We present an optical spectroscopic study based on 41 spectra of 4 Her and 32 spectra of 88 Her,obtained over a period of 6 months.We estimate the rotational velocity of these stars from Hel lines in the blue spectral region(4000-4500 ?).We find that these stars are likely to be rotating at a fractional critical rotation of~0.80.We measure the average I_p/I_c ratio to quantify the strength of the Hα line and obtain1.63 for 4 Her and 2.06 for 88 Her.The radius of the Ha emission region is estimated to be R_d/R_*~5.0,assuming a Keplerian disk.These stars are thus found to be fast rotators with a relatively small Ha emission region.We detect V/R variation of the Ha spectral line during the observed period.We re-estimate the periods for both stars and obtain a period of ~46 d and its harmonic of 23.095 d for 4 Her,and a period of~86 d for 88 Her.As these two cases are shell stars with binaries and have low Ha EW with the emission region closer to the central star,the V/R variation and a change in period may be an effect of the binary on the circumstellar disk.     

The accretion matter at the disk rim in Her X-1/HZ Her

The Crosa and Boynton (1980) empirical model for discrete mass transfer in Her X-1 is further developed. The photometric features of the light curve (peaks of an hour duration and 0.3–0.7 ^m amplitude, steps near orbital phase =0); and the linear polarization bursts are assumed to be due to the formation and eclipses of the plasma blobs produced by discrete transfer of matter from optical star surface and its interaction with the accretion disc rim. The long lifetime (20^h) of the cold (3×10⁴ K) blob extending up to 10¹¹ cm above the disc plane, as well as the deep X-ray flickerings (300 s) during the X-ray absorption dips are assumed to arise from a dispersal of accreting matter by the Rayleigh-Taylor instability in a blob moving through a hot corona of the disk atT _c =3×10⁶ K andn _c =3×10¹¹ cm^–3. Thermal equilibrium in the corona and in the blobs are supported by X-ray flux. Within the first few hours after its formation a blob disintegrates into drops withr=5×10⁹ cm,T=3×10⁴ K, andn=3×10¹³ cm^–3 which move then along Keplerian orbits. Frictional interactions of the drops with the corona destroy them on a 20^h time-scale. The proposed model makes it possible to interpret the diverse observational facts and to predict numerous observational displays in the optical, UV, and X-ray bands. The first results of our optical-spectrum observations of blobs are briefly described.     

Dust and Molecules in Nova Environments

The current status of our knowledge about the formation and evolution of dust and molecules in the environments of classical novae is reviewed. We discuss the chemistry that leads to the formation of diatomic molecules and nucleation sites, dust formation in nova winds, the properties and the processing of dust in nova environments, and the eventual fate of the dust. We also discuss the environment of nova progenitors, and what this can tell us about the pre-nova evolution of close binary systems. This revised version was published online in September 2006 with corrections to the Cover Date.     

Spectral models of AM Her stars

Most of the optical light from AM Her systems is cyclotron radiation. Simple models for the spectrum and polarization are successful for some systems, but in others the spectrum rolls over more gently at high frequencies and is polarized over a wider range of frequencies than the models predict. This paper considers the emission from both the sides and top of the accretion column and the effects of oscillations in the shock height. These features lead to a slower roll over at high frequencies than is found in the simple models, but it is still not as flat as in some of the AM Her systems.Paper presented at the IAU Colloquium No. 93 on Cataclysmic Variables. Recent Multi-Frequency Observations and Theoretical Developments, held at Dr. Remeis-Sternwarte Bamberg, F.R.G., 16–19 June, 1986.     

Observations and analysis of MT Her

Previously reportedBV photometry of MT Her is analysed with the aid of efficient curve-fitting techniques. There is insufficient overall data to allow a definitive parametrization of the binary, but we can confidently rule out the possibility of a classical Algol.A provisional model is advanced which consists of two close unevolved dwarfs: the primary a late F-type and the secondary a mid K-type. The system is located at a distance of about 250 pc in a region of fairly heavy interstellar extinction near the galactic disk. It may be a short-period RS CVn-type binary, but this possibility, as the provisional model itself, requires spectrographic confirmation.     

La distance de la Nova Delphini 1967

The good agreement found between the observed flux of radio emission of the Nova Delphini 1967 and that calculated theoretically enables us to deduce the angular diameter of the Nova's envelope. This result, when combined with the known linear diameter of the envelope, gives a distance of the order of 885 pc for Nova Delphini.     

Nova Oph 1994光谱观测研究

用２．１６ｍ望远镜及其卡焦光谱仪对ＮｏｖａＯｐｈ１９９４进行了一系列的光谱观测，其早期光谱中出现的大量ＦｅＩＩ线表明它是一颗ＦｅＩ型新星，而它的发射线的多峰结构在其他ＦｅＩＩ型新星中是不多见的．我们根据得到的光谱和从国际互联网络（Ｉｎｔｅｒｎｅｔ）得到的测光资料，讨论了它的光谱特征和演化．     

Spectrophotometry of Nova Coronae Austrinae, 1981

Spectrophotometric observations of Nova Coronae Austrinae 1981, during its nebular phase are reported. The various emission lines are identified. The electron densities and the mass of the ionized hydrogen in the shell have been calculated. The excess flux in the red continuum probably indicates the appearance of the dust component.