WY Cnc的四色uvby测光和食外畸变波的黑子模拟

作者于1986年3月间,对短周期RS CVn型双星WY Cnc进行了uvby四色光电观测。采用改进了的包含黑子微分改正的W-D程序,对b和y光变曲线,以及Chambliss 1965年发表的B和V两色曲线,分别进行了食外测光畸变波的黑子模拟分析,得出WY Cnc在两个时期中,其主子星均存在两个黑子活动区,并给出它们的大小、位置和活动区平均温度结果。新的测光质比为q=m_2/m_1=0.454±0.005。WY Cnc属主序不接双星。     

恒星黑子的观测

本文对恒星黑子的观测方法和结果作了综合评述。介绍了恒星黑子温度的多色测光测定方法；黑子大小，温度和分布情况的测光畸变波黑子模型解，和高信噪比谱线轮廓多普勒成像方法；以及黑子寿命观测统计方法等的基本原理和研究进展。对已取得的有关恒星黑子的观测分析结果作了概括，与太阳典型黑子情况作了对比，并对恒星黑子的巨黑子，极区黑子以及长寿命黑子特殊性作了讨论，对需要进一步观测研究的问题作了总结。     

磁场中p模／s模的转换及黑子对声波的吸收

在柱坐标下将黑子周围的不形区域（黑子除外）内的振荡分解为朝向黑子传播的（入射的）波和离开黑子传播的（出射的）波。对无黑子的环形区域内的振荡也进行了同样的分解。将黑子周转的入射波看成是被黑子磁流管磁化了介质（介质内的磁场基本是水平的）中的波。而无黑子区的放射波看成是非磁化介质中的波。比较这两种波在固定波数下功率随的分布发现，在磁化介质中不同径向除ｎ的声波（Ｐ模）频率系统降低，同时功率也降低，降低的功     

磁场中p模/s模的转换及黑子对声波的吸收

在柱坐标下将黑子周围的环形区域（黑子除外）内的振荡分解为朝向黑子传播的（入射的）波和离开黑子传播的（出射的）波。对无黑子的环形区域内的振荡也进行了同样的分解。将黑子周围的入射波看成是被黑子磁流管磁化了的介质（介质内的磁场基本是水平的）中的波。而无黑子区的入射波看成是非磁化介质中的波。比较这两种波在固定波数下功率随频率的分布发现，在磁化介质中不同径向除ｎ的声波（ｐ模）频率系统降低，同时功率也降低，降低的功率最高达非磁化介质中波的功率的３０％。而比较在固定频率下功率随波数的分布发现，磁场中ｆ模及ｎ＝１，２，３的ｐ模的脊向高波数方向位移，功率的降低受频率调制，即声波在某些有限的频带中被吸收。这些观测表明，在磁场中ｐ模与磁声重力波（ＭＡＧ）产生了模式混合或耦合。模式混合的存在支持了模式转换作为ｐ模式被黑子吸收的机制的解释。此外，本文还分析了转换的ＭＡＧ波进入黑子磁流管（其中的磁场基本上是垂直的）后进一步被吸收，吸收的功率最高达ＭＡＧ波的２０％。在磁流管内没有进一步观测到模式的转换     

黑子面积随黑子数变化的统计研究

对1874年5月-2015年3月期间每月黑子数和黑子面积数进行数据分析,统计研究黑子数与黑子面积比例的变化。结果表明:黑子数与黑子面积非线性变化,在活动周极大时期更明显。二者的分布概率整体相似,都随数值增大而降低,但黑子面积下降得更明显,表明二者存在非线性关系。黑子数与黑子面积的比例在活动周极小时期约为10.2,在极大时期约为21.8,长期约为16.8。每个周的上升期和下降期确定的比例有微小差别,不同活动周确定的比例有小的差别,二者间的比例有减小的趋势。     

太阳活动区δ黑子的研究进展

对太阳活动区δ黑子的研究有着非常重要的意义。因为几乎所有大耀斑都产生在δ黑子中，近３０多年来对δ黑子的观测和研究，取得了长足的进步但仍有许多问题需要我们作进一步的研究和观测证实。在本文中总结了３０多年来对δ黑子的研究进展，着重讨论了δ黑子的形成，发展和衰亡，以及与耀斑的关系等方面取得的最新成果。     

旋转黑子的太阳周时间延迟研究

统计结果显示23周旋转黑子的纬度随时间的变化呈蝴蝶图分布.对23周旋转黑子蝴蝶图和黑子蝴蝶图两翼的4条拟合曲线间的均方差随相位变化进行研究的结果表明:黑子蝴蝶图南北半球之间、旋转黑子蝴蝶图南北半球之间以及在同一半球旋转黑子蝴蝶图和黑子蝴蝶图之间存在着系统的时间延迟.这说明:23周南北半球太阳黑子活动不是同时发生的,南半球和北半球之间存在着系统的时间延迟或提前(相位差),且是南半球滞后于北半球;23周旋转黑子蝴蝶图和黑子蝴蝶图之间存在着相位差,且是旋转黑子蝴蝶图滞后于黑子蝴蝶图,观测滞后值略小于发电机模型预言的理论值.     

无黑子区的耀斑

本文分析了廿一周峰年期间云南天文台观测到的廿个无黑子区耀斑,得到如下结果: 1.无黑子区耀斑的一般特征是:1) 无黑子区耀斑的自然产率约3％,2) 其卡林顿经度分布有向东飘移的趋势,3) 无黑子区的耀斑多为低能耀斑,4) 无黑子区耀斑产生的背景条件和黑子区耀斑一样,必须在耀斑区的太阳大气中存在异极性磁场结构。无黑子区耀斑都发生在沿大尺度磁场中性线(H_=0)延伸的暗条两侧或其附近。 2.在耀斑前,由于磁场的扰动,使被浮托在H_=0线上的宁静暗条在耀斑前几小时到一两天激活,临近耀斑位置的一段暗条先是发展增大,同时伴随着谱斑增亮,在耀斑爆发前几分钟或与耀斑发展的同时,该暗条迅速衰减乃至完全消失。与此同时,有的无黑子活动区的可见纤维与暗条的交角由大变小,表明活动区所受的力由挤压力逐渐转化为剪切力。本文还粗略地估计了无黑子区耀斑的能量。     

旋涡黑子在1972年10月太阳活动中的作用

本文收集了云南天文台和北京天文台观测的1972年10月太阳活动区(McMath 12094)的68个耀斑192个节点的照相资料和一些黑子日珥形态,对它们进行了相关分折,得到如下主要结果:1.本区最初的耀斑活动开始于全群诸黑子中具有扭结磁场最高能态的前导黑子A(N)的上空,它迅速发展到后随S极黑子上空,然后发展到黑子面积以外.这一演变过程与全群黑子的形态变化和旋转运动同步.2.A黑子附近的耀斑活动最初开始于扭结磁力管的内部,与扭结磁形态的松解过程同步,耀斑节点的分布由黑子本影附近移向半影的外面.当扭结完全松开,该处耀斑活动全面减少.3.发现了一个巨大的黑子冕珥下面的强烈的吸引中心是旋涡黑子,从而证实了冕珥是强大电流在日冕中收缩形成的.4.对于A黑子的扭转磁结构提供了本区耀斑活动的主要能量来源和导致不稳定性的问题进行了讨论.     

黑子磁流体静力学模型的研究进展

太阳黑子是太阳活动最明显的标志之一,近一个世纪来对太阳黑子的观测,积累了大量的黑子磁场和热力学量的资料,提出了许多黑子的模型。本文介绍了黑子的观测经验模型以及三种有用的磁流体静力学理论模型,即无力场模型、ST模型和RF模型,用静力学理论去解释黑子的一些现象,如黑子本影和半影界面及半景和光球分界面,而不讨论它的动力学模型,着重探讨了这些模型的定量性质,总结了它们的发展历史和研究进展。最后简要地指出了今后的一些研究设想。     

Radial velocity observations and physical activities of the contact binary system SW lacertae

We present our 1984 radial velocity observations of the W UNa system SW Lac. These give a new spectroscopic mass ratio q_sp = 1.255 ±0.011. A joint solution of the velocity and light curves give the following revised absolute parameters: M₁ = 0.78 M, M₂ = 0.96M, R₁ = 0.91R, and R₂ = 1.00 R. Based on our new results, together with a detailed review of the period changes, probable mass transfer, mass loss, spot activity and other physical properties of SW Lac are discussed.     

Time‐series photometric spot modelling – VI. A new computer code and its application to 23 years of photometry of the active giant IM Pegasi

We present and apply a new computer program named SpotModeL to analyze single and multiple bandpass photometric data of spotted stars. It is based on the standard analytical formulae from Budding and Dorren. The program determines the position, size, and temperature of up to three spots by minimizing the fit residuals with the help of the Marquardt‐Levenberg non‐linear least‐squares algorithm. We also expand this procedure to full time‐series analysis of differential data, just as real observations would deliver. If multi‐bandpass data are available, all bandpasses can be treated simultaneously and thus the spot temperature is solved for implicitly. The program may be downloaded and used by anyone. In this paper, we apply our code to an ≈23 year long photometric dataset of the spotted RS CVn giant IM Peg. We extracted and modelled 33 individual light curves, additionally, we fitted the entire V dataset in one run. The resulting spot parameters reflect the long term light variability and reveal two active longitudes on the substellar point and on the antipode. The radius and longitude of the dominant spot show variations with 29.8 and 10.4 years period, respectively. Our multicolour data suggests that the spot temperature is increasing with the brightening of the star. The average spot temperature from V, I_C is 3550 ± 150 K or approximately 900 K below the effective temperature of the star.     

The relationship between lunar hot spots and the geomorphic index

The previously developed geomorphic index of lunar surfaces is applied to the surface distribution of the lunar hot spots. It was found that the hot spot number density is the highest in areas of intermediate geomorphic index, corresponding to mature maria. Young and old maria and the terrae have fewer hot spots per unit area. An hypothesis is presented relating the probability of formation of a hot spot by impact with the evolutionary stage of the regolith of the target surface. The older is the surface, the deeper is the regolith and also the smaller is the average boulder size. For these reasons hot spots will be less probable. The paucity of hot spots in young maria could also be related with the evolution of the regolith, but fundamental changes in the petro-physics of the mare effusions cannot be ruled out.This paper constitutes contribution no. 04 of the Lunar Science Institute and was performed under NASA Contract No. NSR 09-051-001.     

Period changes and photometric solution of AP Leonis

The results of BV photometry of AP Leonis are presented. Photometric analysis is carried out by using the Wilson-Devinney program. The solution shows that the system is an over-contact binary with an over-contact degree of 23.5% and its mass ratio q equal to 0.301. A starspot group is found in the low latitude region on the secondary component. The average temperature of the spot is about 1220 K lower than that of surrounding photosphere.

The light minimum times observed over ninety years are collected. The O-C curve of minima reveals that the period of AP Leo changes with the time in a pseudo-sinusoidal pattern and there is probably a third body in the system.     

Phase Space Analysis: The Equilibrium of the Solar Magnetic Cycle

We present the results of a statistical study of the solar cycle based on the analysis of the superficial toroidal magnetic field component phase space. The magnetic field component used to create the embedded phase space was constructed from monthly sunspot number observations since 1750. The phase space was split into 32 sections (or time instants) and the average values of the orbits on this phase space were calculated (giving the most probable cycle). In this phase space it is shown that the magnetic field on the Sun’s surface evolves through a set of orbits that go around a mean orbit (i.e., the most probable magnetic cycle that we interpret as the equilibrium solution). It follows that the most probable cycle is well represented by a van der Pol oscillator limit curve (equilibrium solution), as can be derived from mean-field dynamo theory. This analysis also retrieves the empirical Gnevyshev – Ohl’s rule between the first and second parts of the solar magnetic cycle. The sunspot number evolution corresponding to the most probable cycle (in phase space) is presented.     

Photometry of stars with nonhomogeneous temperature spots

In the framework of the direct photometric problem for spotted stars we obtained an analytic solution adopting gradually changing of the spot temperature from the center to the outskirts of the spots. The results are intended for the solution of the corresponding inverse problem that could give information for the mechanisms leading to spot creating.     

超新星爆发的前身星模型研究

本文利用Woosley提供的4个不同的前身星模型数据作为计算的前超新星分布，并利用自己独立编制的程序和改进的状态方程进行数值模拟．对其结果进行分析比较，考察前身星对超新星的坍缩、激波传输和爆发等过程的影响．     

Temporal fluctuations of the magnetic field in sunspots

The magnetic field strength in sunspots was derived from time series of two-dimensional spectra taken with the Göttingen 2D-spectrometer at the Vacuum Tower Telescope on Tenerife in August 1997. For the present measurements the magnetically sensitive line Fe?i 684.3 nm was selected. The main spot of the investigated sunspot group has a maximum magnetic field strength of 2270 G. Enhanced power of the magnetic field variations was found at the boundary between umbra and penumbra for all frequency ranges. These fluctuations are not well correlated with those of intensity variations or line shifts. Other spatial power peaks occur in a dark patch inside the centreside penumbra and at the centres of some accompanying small spots. Since no clear peaks at certain frequencies are found, the variations are not harmonic oscillations. A possible relation to Hα flares is investigated. There are several cases of published observations of magnetic field variations where flares occurred soon after the measurements, but very little before. Therefore it is not very probable that flares act as exciters of magnetic field variations.

     

An optimization technique for the fourier analysis of the light curves of totally-eclipsing systems of algol-type

A fully automatized technique for the evaluation of geometric and photometric elements of Algol-type systems exhibiting total eclipses is presented. The method requires observations in at least two wavelengths and enables us to choose the most probable solution from a grid of solutions performed with various possible phase angles of the first contact of the eclipse.     

New analysis of II Peg 1977 light curve

The solution of the inverse photometric problem for spotted stars obtained on the basis of the analytical solution of the direct problem is applied to II Peg 1977 light curve. The geometric parameters of the spot configuration so obtained are unambigously determined in contrast to the cases when analysis of the light curve is done on the basis of numerical modelling. A comparison between both methods has been carried out.