上海天文台25 m射电望远镜首次单天线脉冲星观测

介绍上海天文台25 m射电望远镜首次单天线脉冲星观测。2010年4月23日,使用上海天文台位于佘山观测基地的25 m射电望远镜对脉冲星J0332+5434在L波段进行了观测,此次观测使用VLBI终端进行数据采集记录,通过对观测数据进行非相干消色散和周期折叠,成功获得目标源的平均轮廓。此次观测的成功,表明该天线具备开展单天线脉冲星观测的条件,并为上海天文台建设中的65 m天线的天文观测提供了参考,为将来自主研发脉冲星终端进行了技术储备。     

日全食观测之行

8月1日,在天津科技馆领导的大力支持下,我们有幸随北京天文馆日食观测队前往甘肃酒泉进行了观测。天公作美,当日天气竟然超越新疆伊吾观测区,日食全过程丝毫未受干扰,观测非常成功．全食时刻壮观程度无法言表。只有震撼挥之不去。     

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。     

ALMA——世界最大的射电望远镜阵列

目前正在南美智利安第斯山北部建设的世界最大规模天文射电望远镜阵——ALHA毫米波／亚毫米波射电望远镜阵,在今年1月进行了初次测试,成功启用已建成的直径12米的三架抛物面天线望远镜对同一天体,即一个遥远的河外星系进行了观测,并成功合成了信号。ALMA最近这次试验性观测被认为是ALMA完成建设之前最重要的一次测试。     

LAMOST观测控制系统用户界面设计

位于国家天文台兴隆观测基地的大天区面积多目标光纤光谱天文望远镜(LAMOST)是世界上最大的、可操控的反射施密特望远镜。为了便于控制望远镜,提高观测效率,设计了观测控制系统图形用户界面。首先分析了LAMOST望远镜的控制软件体系结构,采用基于场景的以用户为中心的设计方法,对界面进行了分析和设计。使用Qt、CORBA、多线程技术和MVC模式,实现了用户界面,并对界面进行了测试。最后,用户界面得到了用户的认可,成功应用于LAMOST观测。     

甘肃金塔地区大气对太阳射电辐射吸收的测量研究

2008年8月1日,在我国西北的新疆、内蒙、甘肃等地区可以观测到一次日全食的天象,紫金山天文台太阳射电团组在甘肃省金塔用两架太阳射电望远镜对这次日全食进行了观测,并成功地取得了观测资料.为了科学分析观测资料,在日全食的前两天,实测了当地的大气吸收.着重分析这些观测数据,结合太阳射电方法,测得在λ=2.4 cm和λ=8....     

利用IRC进行国际天文遥在观测

１９９７年３月６日至３月７日,我们利用ＩＮＴＥＲＮＥＴＲＥＬＡＹＣＨＡＴ（ＩＲＣ）进行了首次国际天文联合遥在观测试验,并获得了成功。本次试验由分布在全球７个不同地点的工作组联合进行,包括中国、美国、加拿大和英国。这一试验的成功为天文观测开创了一个新型的途径,也是对通过Ｉｎｔｅｒ－ｎｅｔ进行更紧密的国际合作的一种尝试。     

新疆天文台南山站DBBC2数字终端系统的建立

随着计算机数字技术的高速发展,甚长基线干涉仪测量(Very Long Baseline Interferometry,VLBI)所需的关键观测终端设备基带转换器(Base Band Converter,BBC)已从模拟系统(Analog BBC,ABBC)发展为数字系统(Digital BBC,DBBC)。相对于模拟系统,数字系统具有很高的灵活性,并能成倍提高VLBI观测带宽,进而能满足各种高灵敏度的观测需求。考虑到这些技术优势,以及新疆天文台南山站在国内和国际VLBI网中的重要作用,南山站2016年对VLBI终端系统进行了升级,引进了一套意大利Hat-Lab公司研发的DBBC2终端。介绍了DBBC2系统的主要构成模块和工作原理以及系统的组装、连接、配置、校准和调试方法。在对系统硬件和软件进行全面的检测和测试后,与国内和国际的主要台站开展了联合观测,并多次成功获得相关干涉条纹。这一系列的成功观测表明,南山DBBC2系统已成功安装,并具有很高的可靠性。应用新的DBBC2系统,南山站可参与2/4 Gbps的记录速率的宽带VLBI观测,极其有助于天文学家对宇宙中更暗弱的射电源开展毫角秒分辨率的成图观测。     

天府之国追日食——我的2009日全食观测全记录

2008年8月1日,我成功观测了人生中的第一次日全食,然后就马不停蹄地投入到了今年日全食观测的前期工作……     

1983年6月11日日全食光学观测

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全食观测队天文组在1983年6月11日的日全食中成功地进行了下述几种项目的光学观测:(1)色球和日冕的光谱观测——拍摄波区为3600埃到6600埃,平均色散度约6.4埃/毫米,高度分辨率约110公里。(2)宽带日冕的光度及偏振观测。(3)日食全过程的彩色摄影。 本文对仪器结构、观测方法和获得的资料作了简要介绍。     

Submillimeter observations of the asteroid 10 hygiea

We report the first successful ground-based observations of any asteroid at submillimeter wave-lengths. Observations of the asteroid 10 Hygiea at 370 and 770 μm are combined with observations in the near and thermal infrared (2.2, 10.6, and 21 μm) to study the thermal properties of Hygiea's regolith. The “standard” (nonrotating) thermal model is consistent with the entire data set, although a rotating thermophysical model with a “lunarlike” thermal inertia cannot be ruled out.     

Radio counterparts to GRANAT sources

We summarize the main results of a long-term VLA monitoring of several hard X-ray emitters in the Galactic Bulge. Most of the observed targets correspond to sources detected by the GRANAT satellite. Our main findings include the discovery of new radio counterparts to some of them. The sources identified at radio wavelengths are: GRS 1734−292, GX 354−0 and Terzan 1. The VLA positions obtained are accurate at the arcsec level and represent an excellent starting point to search for optical and near infrared counterparts. Imaging observations at these wavelengths have been conducted using different ESO telescopes. As a result, we were so far successful in identifying the optical/infrared counterpart to GRS 1734−292, as well as a likely infrared candidate for GX 354−0.     

Simultaneous infrared and H-alpha measurements of Be stars

The observed infrared excess in Be stars is usually interpreted as free-free and free-bound emission from a hot gas envelope around the Be star. This hot gas should also emit H-alpha line radiation. Earlier observations had suggested that the infrared excess and Hα radiation were not consistent with models in which they arise from the same ionized region; however the observations were made at different times. We have made simultaneous observation of infrared and H-alpha line radiation. Our observations imply that either both these radiations cannot arise from the same hot gas or additional processes have to be invoked to account for the observed excess infrared radiation.     

Circumstellar disks and planets

We present a review of the interplay between the evolution of circumstellar disks and the formation of planets, both from the perspective of theoretical models and dedicated observations. Based on this, we identify and discuss fundamental questions concerning the formation and evolution of circumstellar disks and planets which can be addressed in the near future with optical and infrared long-baseline interferometers. Furthermore, the importance of complementary observations with long-baseline (sub)millimeter interferometers and high-sensitivity infrared observations is outlined.     

Infrared observations of symbiotic stars

Near infrared measurements in the J, H and K bands have been carried out for a number of symbiotic stars with the 1.5 m telescope at the Rothney Astrophysical Observatory (RAO). A comparison with the earlier observations shows that the S-type symbiotic stars do not have any significant variation in the infrared flux over the past five years. However a small variation ∼ 0.3 magnitude in the infrared flux has been detected for CH Cygni. The observations of HM Sagittae show large decreases in the infrared flux compared to the previous measurements. The variability in the infrared fluxes of both these objects could be attributed to a variation in the temperature due to the cooling of the dust shell. The variability observed for V1016 Cygni is found consistent with the previous measurements.     

Large beam radio observations of M87

Results of our wide beam radio observations of M87 are given here. Combined with the infrared observations of Virgo (Ceccarelli et al. 1982), we show that in order to explain both the radio and infrared observations, it is convenient to postulate an extended tepid (∼(+5)K) halo, in addition to a hot (∼(+8)K) halo surrounding M87. This tepid halo would be able to close the system gravitationally.     

Ultraviolet observations of comet Hale-Bopp

Ultraviolet spectroscopy and imaging of comet Hale-Bopp (C/1995 O1) were obtained from a variety of space platforms from shortly after the discovery of the comet through perihelion passage. Observations with the International Ultraviolet Explorer (IUE) and the Hubble Space Telescope (HST) spanned the range of 6.8 to 2.7 AU pre-perihelion, but IUE was decommissioned in September 1996 and HST was precluded from near-perihelion observations because of its solar avoidance constraint. In September 1996, observations were made by the Extreme Ultraviolet Explorer (EUVE) that showed the presence of soft X-rays offset from the optical center of the coma and provided a sensitive spectroscopic upper limit to the Ne/O abundance ratio. During the perihelion period NASA mounted a successful campaign of four sounding rockets that were launched at the White Sands Missile Range, New Mexico, between March 25 and April 8, 1997. The payloads included long-slit spectroscopy and ultraviolet imaging polarimetry. In addition, Hale-Bopp was observed near perihelion by ultraviolet instruments on orbiting spacecraft that were designed for solar or terrestrial observations. Observations with HST, using the Space Telescope Imaging Spectrograph (STIS), installed during the February 1997 servicing mission, resumed in August 1997. Intercomparison of the ultraviolet observations and comparison with the results on gas composition and activity from ground-based visible, infrared and radio observations may permit the resolution of many discrepant results present in the literature. This revised version was published online in July 2006 with corrections to the Cover Date.     

Observations of the infrared source in s 140 and the heating of the associated gas

Near infrared observation of the infrared source in S140 was made using the 1.26 m infrared telescope of Beijing Observatory, yielding fluxes in the J, H and K bands. Combining with data from satellite and ground-based IR and submillimetre observations, we found the spectral gradient, IR luminosity and the shell structure of the IR source.

We also combined observations of CO and NH₃ in an analysis of the heating of the gas associated with the source. Besides through dust, the central source may also input energy into the gas through shock waves. External sources of heat and heating by photoelectric process and cosmic rays are also discussed.     

Anomalous X-ray pulsars: persistent states with fallback disks

The anomalous X-ray pulsar 4U 0142+61 was recently detected in the mid infrared bands with the SPITZER Observatory (Wang, Chakrabarty and Kaplan: Nature 440, 772 (2006)). This observation is the first instance for a disk around an AXP. From a reanalysis of optical and infrared data, we show that the observations indicate that the disk is likely to be an active disk rather than a passive dust disk beyond the light cylinder, as proposed in the discovering paper. Furthermore, we show that the irradiated accretion disk model can also account for all the optical and infrared observations of the anomalous X-ray pulsars in the persistent state.