光学天文台址的高度探讨

本文对全球现有天文台址的海拔高度、大望远镜所在地的高度和近十年来的光学天文台的选址在海拔高度上的考虑进行了综述和分析,并对云南境内候选点的高度提出看法。     

北极星拖影仪的研制

北极星拖影仪是天文宁静度观测的专用仪器。按照里克天文台(Publ.Vol.7 7P246—252 By E.A.Harlan and Merle.F.Walker)文章所提供的技术要求和数据,云南天文台台属工厂于1978年10月——1979年8月间,研制成功四台供选址用的北极星拖影仪。1979年8—9月在台内试观测后,置于滇西候选点,至今已在云南宾川二个候选点山头上,进行了四个月的拖影照相观测。目前,使用情况良好,能在北极星周日运动的各方位上,拍到清晰的北极星拖影像。     

基于直接成像法的多星系统观测

系外行星直接成像探测能够获取系外行星更全面的物理信息,是未来搜寻系外生命的关键技术之一.针对近期地基望远镜高对比度成像观测数据,对新发现的多星候选体进行系统展示.前期,结合地基系外行星高对比度成像设备观测能力,从已发表文献整理的Gaia星表恒星数据中筛选,得到约1000个观测目标.这些目标分布于不同的年轻星团中.近期,使用Palomar天文台Hale望远镜对上述观测目标中的42个目标在K波段开展了高对比度成像观测.这些目标恒星在可见光波段为7.5-14.2019年经过两轮观测,发现了6个多星系统候选体,这些目标在Gaia Data Release 2星表和Gaia early Data Release 3星表中难以确认是单星还是多星系统.     

云南天文台丽江高美古和昆明的大气视宁度研究

研究云南天文台昆明凤凰山和丽江高美古两地点的大气视宁度。利用云南天文台于1994年建立的3孔较差视宁度监视仪（3孔DIMM），对这两个地点的视宁度对比观测。还利用云南天文台的1米望远镜所得到的视宁度与3孔DIMM所测的视宁度进行对比。1米望远镜和3孔DIMM同时观测了7个晚上，各取得308组数据，它们的视宁度平均分别为0．90〃和0．84〃。还讨论了3孔DIMM采用不同曝光时间对视宁度测量值的影响，从实验得出3孔DIMM采用20ms曝光比采用8ms曝光所测视宁度的值要好15％左右。从1995年5月－1996年12月，对丽江高美古和昆明凤凰山二地进行了视宁度的对比观测。在高美古和昆明分别观测了234夜和256夜，观测结果是两个点的视宁度平均；丽江为0．70〃，昆明为0．95〃，同时也统计了两个点的月平均视宁度和最好夜的视宁度，并讨论了两地视宁度随时间的变化规律。     

云南天文台大气视宁度观测和初步探讨

介绍了为云南丽江高美古选址点作对比的云南天文台点的大气视宁度观测统计和结果，对观测过程中的有关问题作了初步探讨。对高美古和云南天文台的１９９５年５月和１９９５年１２月２０日观测资料作了对比，结果表明：高美古选址点的视宁度明显优于云南天文台。     

白日视宁度监测仪和在抚仙湖的初步观测结果

报导了用南方基地云南天文台太阳差分像运动视宁度监测仪和美国国立太阳天文台的太阳闪烁仪 ,在云南省澄江县抚仙湖老鹰地红外太阳塔选址点进行的对比观测 ,简要地介绍了这两种视宁度测量方法的原理 ,对观测的初步结果进行了分析。     

卫星云图和云南天文观测台址的筛选

本文通过对ＮＯＡＡ－１０，１１两颗气象卫星１９８９年５月至１９９０年４月的云图资料，在作等经纬度投影处理和定标，定位订正的基础上，利用红外域值方法，对东经９９°—１０４°，北纬２３．５°—２８．５°云南区域内３１个天文台址侯选点的云量进行了统计和计算，得到几个云量最少的候选点。此外，我们还对卫星云图ＣＣ≤３的晴日晴夜和三十年地面气象观测资料中ＣＣ≤２的晴天数作了相关分析，发现它们之间具有很好的相关性。云图和地面资料综合分析表明：（１）永仁的俄尼刀博，姚安的老官山，元谋气象区的白露，祥云的大营后山，宾川的小鸡山，华坪的蘑菇山，宁蒗的他尔布子都是较理想的候选点。（２）俄尼刀博，老官山和白露可用夜（ＣＣ≤３）预计可超过２５０夜。因此应列为下一步选址的重点。     

白日视宁度监测仪和在抚仙湖的初步观测结果

报导了用南方基地云南天文台太阳差分像运动视宁度监测仪和美国国立太阳天文台的太阳闪烁仪,在云南省澄江县抚仙湖老鹰地红外太阳塔选址点进行的对比观测,简要地介绍了这两种视宁度测量方法的原理,对观测的初步结果进行了分析。     

滇西宾川选址总结报告(Ⅰ) 总述及气象条件

本文简述了确定滇西宾川为我国南方天文台候选区域的历史过程、具体定点观测山峰的一般条件、定点观测项目及总的时间安排,最后给出了一年(1979年3月——1980年2月)定点气象和天文可用时间的观测结果。     

“利用微型计算机实时采集和处理的积分光度计系统”鉴定会

1983年3月1日至3日,受中国科学院数理学部委托昆明分院主持召开鉴定会,对云南天文台和云南电子设备厂共同研制的“利用微型计算机实时采集和处理的积分光度计系统”进行鉴定。15个单位的38名代表出席了在云南天文台举行的这次会议。会议推选的由七个单位的七名专家组成的检测小组在对该系统的各项功能进行了检查、对主要技术指标作了测定后认为: 1.这套系统经过一年零五个月的试用已成为云南天文台一米望远镜的常规附属设     

Radii and albedos of asteroids 1, 2, 3, 4, 6, 15, 51, 433, and 511

We derive the following radii (in kilometers) and visual geometric albedos for nine asteroids from 10- and 20-μm radiometry: 1 Ceres (540, .16); 2 Pallas (275, .08); 3 Juno (125, .14); 4 Vesta (270, .21); 6 Hebe (110, .16); 15 Eunomia (135, .15); 51 Nemausa (80, .05); 433 Eros (12, .07); and 511 Davida (180, .04). Vesta has the highest albedo measured for an asteroid, while Davida, the lowest-albedo object in the sample, is one of the darkest known objects in the solar system. The median of all asteroid albedos measured to date is 0.1.     

Sun,Solar System,Stars, Interstellar Matter,Galaxy, Extragalactic Systems,Instruments, History of Astronomy

P01 Calibrations on DSS‐II Plates P02 High‐Resolution Near‐Infrared Speckle Interferometry and Radiative Transfer Modeling of the OH/IR star OH 26.5 + 0.6 P03 Mid‐infrared long‐baseline interferometry of the symbiotic Mira star RX Pup with the VLTI/MIDI instrument P04 N₂D⁺ abundance in high mass star forming regions P05Causal Viscosity in Accretion Disc Boundary layers P06 Planetesimals in protoplanetary disks P07 Star Clusters in the Large Magellanic Cloud P08 Is there a universal mass function? P09 On CO cooling in dense molecular clouds P10 An unbiased search for molecular clumpuscules P11 Vertical structure of accretion disks P12 A New Data Acquisition System and User Control Program for CCD Cameras at “Hoher List” Observatory P13 Tracing the Photon Dominated Region around DR21 with CO, CI, CII, and OI emission P14 Time resolved spectroscopy of CI Aql P15 Empirical Color Transformations between SDSS Photometry and Other Photometric Systems P16 V4332 Sgr P17 Low rotation velocities of white dwarfs from the CaII K line P18 E‐Learning in Astronomy P19 RR Lyrae stars: Kinematics, orbits and z‐distribution P20 New developments on the field of chemically peculiar stars in the milky way and the LMC P21 Large‐scale CO Mapping of the CEPHEUS Giant Molecular Cloud using KOSMA P22 HoLiCS II – The “Hoher List Control System” II P23 88 GHz “Holotransmitter” for the Nanten2 Telescope P24 Comet Astrometry – Tracing the last witnesses of the solar system's childhood P25 Considerations on the spectral appearance of M‐type brown dwarfs P26 Photon Dominated Region Modelling of Barnard 68 P27 A New Versatile Multichannel CCD‐Controller for BUSCA P28 High Precision “Bonn Shutters” for the largest CCD Mosaic Cameras P29 High‐Resolution Near‐Infrared Speckle Interferometry and Radiative Transfer Modeling of the OH/IR star OH 104.9 + 2.4 P30 A new Doppler image of the weak‐line T Tauri star V410 Tauri P31 Improving our knowledge on open cluster radial velocities P32 The Distribution of MSX Infrared Dark Clouds in the inner Milky Way P33 Was the Early Earth shielded from UV by Ozone produced from the Smog Mechanism? P34 Structure Analysis of the CO data in the Perseus clouds P35 Evidence for Turbulence in the Velocity Fields of Perseus Cores P36 Dust‐driven Winds and Their Resulting Mass Loss at Subsolar Metallicity P37 Two adjacent gigantic (∼9°) IRAS filaments of bipolar morphology: An almost invisible pair P38 A new optical filament of the Monogem Ring P39 The Far Ultraviolet Spectroscopic Explorer Survey of OVI Emission in the Milky Way     

Photoelectric photometry of asteroids 37, 80, 97, 216, 270, 313, and 471

Photoelectric observations of several minor planets were made from 1975 to 1977 at the Astronomical Observatory of Torino. Lightcurves and period information are given for 7 objects: 37 Fides, 80 Sappho, 97 Klotho, 216 Kleopatra, 270 Anahita, 313 Chaldaea, and 471 Papagena.     

Cassini RADAR observations of Enceladus, Tethys, Dione, Rhea, Iapetus, Hyperion, and Phoebe

Cassini 2.2-cm radar and radiometric observations of seven of Saturn's icy satellites yield properties that apparently are dominated by subsurface volume scattering and are similar to those of the icy Galilean satellites. Average radar albedos decrease in the order Enceladus/Tethys, Hyperion, Rhea, Dione, Iapetus, and Phoebe. This sequence most likely corresponds to increasing contamination of near-surface water ice, which is intrinsically very transparent at radio wavelengths. Plausible candidates for contaminants include ammonia, silicates, metallic oxides, and polar organics (ranging from nitriles like HCN to complex tholins). There is correlation of our targets' radar and optical albedos, probably due to variations in the concentration of optically dark contaminants in near-surface water ice and the resulting variable attenuation of the high-order multiple scattering responsible for high radar albedos. Our highest radar albedos, for Enceladus and Tethys, probably require that at least the uppermost one to several decimeters of the surface be extremely clean water ice regolith that is structurally complex (i.e., mature) enough for there to be high-order multiple scattering within it. At the other extreme, Phoebe has an asteroidal radar reflectivity that may be due to a combination of single and volume scattering. Iapetus' 2.2-cm radar albedo is dramatically higher on the optically bright trailing side than the optically dark leading side, whereas 13-cm results reported by Black et al. [Black, G.J., Campbell, D.B., Carter, L.M., Ostro, S.J., 2004. Science 304, 553] show hardly any hemispheric asymmetry and give a mean radar reflectivity several times lower than the reflectivity measured at 2.2 cm. These Iapetus results are understandable if ammonia is much less abundant on both sides within the upper one to several decimeters than at greater depths, and if the leading side's optically dark contaminant is present to depths of at least one to several decimeters. As argued by Lanzerotti et al. [Lanzerotti, L.J., Brown, W.L., Marcantonio, K.J., Johnson, R.E., 1984. Nature 312, 139-140], a combination of ion erosion and micrometeoroid gardening may have depleted ammonia from the surfaces of Saturn's icy satellites. Given the hypersensitivity of water ice's absorption length to ammonia concentration, an increase in ammonia with depth could allow efficient 2.2-cm scattering from within the top one to several decimeters while attenuating 13-cm echoes, which would require a six-fold thicker scattering layer. If so, we would expect each of the icy satellites' average radar albedos to be higher at 2.2 cm than at 13 cm, as is the case so far with Rhea [Black, G., Campbell, D., 2004. Bull. Am. Astron. Soc. 36, 1123] as well as Iapetus.     

MINERALOGY,PETROGRAPHY AND CHEMISTRY OF THE CHONDRITE,KAMIOMI, SASHIMA-GUN,IBARAKI-KEN,JAPAN

The Kamiomi, Sashima-gun (Iwai-shi), Ibaraki-ken, Japan, chondrite (observed to fall in spring, during the period 1913–6), consists of olivine, orthopyroxene, nickel-iron and troilite with minor amount of plagioclase, clinopyroxene, apatite and chromite. The average molar composition of olivine (Fa₁₉) and orthopyroxene (Fs₁₇) indicates that Kamiomi is a typical olivine bronzite chondrite. From the well-recrystallized texture, the presence of poorly-definable chondrules, homogeneous composition of olivine and absence of glass, this chondrite could be classified in petrologic type 5. The bulk chemical composition, especially, total Fe (27.33%) and metallic Fe (17.00%) as well as Fe_total/SiO₂(0.72), Fe_metal/Fe_total (0–633) and SiO₂/MgO (1.59) support the above conclusion. Coexistence of heavily-shocked olivine grains in the matrix composed of olivines and pyroxenes which suffered from light to moderate shock effect suggest that impacting phenomena, small-scaled but locally strong, occurred on the Kamiomi parent body.     

Photoelectric photometry of asteroids 45, 120, 776, 804, 814, and 1982DV

Photoelectric lightcurves of six asteroids, observed at the ESO 50-cm photometric telescope, are presented. 45 Eugenia, observed for pole determination program, showed a small amplitude of light variation, i.e., about 0.09÷0.10 mag. For 120 Lachesis, no period of rotation was deduced from three observing nights; it is probably longer than 20 hr. 776 Berbericia was observed again to eliminate the ambiguity between 23^h and 15^h.3 periods, as pointed out by Schober (1979). The longer period is ruled out, but we suggest a very plausible shorter period of 7^h.762, implying, at least at this opposition, one maximum and one minimum per cycle. A similar ambiguity is present for 804 Hispania also. The period could be either 14.^h.84 or 7^h.42. These two objects are typical of a class of asteroids whose periods are uncertain by a factor two. A short discussion on this problem is given. For 814 Tauris a long period of 35.8 hr is found, confirming the tendency of dark asteroids of intermediate size to rotate more slowly than larger ones. Finally a single-night lightcurve of the fast-moving object 1982DV is presented. Our observations agree very well with Harris' results (1982, private communication).     

Excitation equilibrium for low lying levels in Cii,Niii, Oiv,Nevi, Mgviii,Six, and Siii

The populations of the excited state ² P _3/2 relative to the ground state ² P _1/2 have been investigated in C ii, N iii, O iv, Ne vi, Mg viii, Si x, and Si ii by considering all the radiative and collisional processes including the collisional transitions to the higher states which cascade to the upper level. The relative populations are used for the calculation of the line emissivities. The intensities of 76 320, 30 258 and 14 302 lines of Nevi, Mgviii, and Six ions respectively in the chromosphere-corona transition region are also calculated.     

Narrow-band spectrophotometry of Ariel,Umbriel, Titania,Oberon, and Triton

The spectral reflectances of Ariel, Umbriel, Titania, Oberon, and Triton were measured in 28 bandpasses between λ326 and λ976 nm on the night of 28/29 June 1974. These observations were made with the 200-in. Hale telescope and multichannel spectrometer. Bandpasses of 8 nm from λ326 to λ566 nm and 16 nm from λ592 to λ976 nm were employed. The spectral reflectances of Ariel, Oberon, and Titania increase from λ342 to λ534 nm and are relatively flat from λ550 to λ976 nm. Umbriel's reflectance decreases monotonically with increasing wavelength through the entire range of measured wavelengths. Triton is found to have a constant spectral reflectance.     

Outflow channel sources, reactivation, and chaos formation, Xanthe Terra, Mars

The undulating, warped, and densely fractured surfaces of highland regions east of Valles Marineris (located north of the eastern Aureum Chaos, east of the Hydraotes Chaos, and south of the Hydaspis Chaos) resulted from extensional surface warping related to ground subsidence, caused when pressurized water confined in subterranean caverns was released to the surface. Water emanations formed crater lakes and resulted in channeling episodes involved in the excavation of Ares, Tiu, and Simud Valles of the eastern part of the circum-Chryse outflow channel system. Progressive surface subsidence and associated reduction of the subsurface cavernous volume, and/or episodes of magmatic-driven activity, led to increases of the hydrostatic pressure, resulting in reactivation of both catastrophic and non-catastrophic outflow activity. Ancient cratered highland and basin materials that underwent large-scale subsidence grade into densely fractured terrains. Collapse of rock materials in these regions resulted in the formation of chaotic terrains, which occur in and near the headwaters of the eastern circum-Chryse outflow channels. The deepest chaotic terrain in the Hydaspis Chaos region resulted from the collapse of pre-existing outflow channel floors. The release of volatiles and related collapse may have included water emanations not necessarily linked to catastrophic outflow. Basal warming related to dike intrusions, thermokarst activity involving wet sediments and/or dissected ice-enriched country rock, permafrost exposed to the atmosphere by extensional tectonism and channel incision, and/or the injection of water into porous floor material, may have enhanced outflow channel floor instability and subsequent collapse. In addition to the possible genetic linkage to outflow channel development dating back to at least the Late Noachian, clear disruption of impact craters with pristine ejecta blankets and rims, as well as preservation of fine tectonic fabrics, suggest that plateau subsidence and chaos formation may have continued well into the Amazonian Period. The geologic and paleohydrologic histories presented here have important implications, as new mechanisms for outflow channel formation and other fluvial activity are described, and new reactivation mechanisms are proposed for the origin of chaotic terrain as contributors to flooding. Detailed geomorphic analysis indicates that subterranean caverns may have been exposed during chaos formation, and thus chaotic terrains mark prime locations for future geologic, hydrologic, and possible astrobiologic exploration.