A plan for a new generation 2M-class telescope in Indonesia

One of the prime astrophysical interests of the Observatorium Bosscha is, and has always been, double star research: visual double star research with the double-60 cm Zeiss telescope (dedicated in 1928), and theoretical research of evolved massive spectroscopic binaries (since 1972). For one thing, this is the very reason that this IAU Colloquium No. 80, celebrating the 60th anniversary of the Observatorium Bosscha in Lembang, is devoted to binary astrophysics.Up to now, visual, photographic, and photometric tools have been used for binary research at the Observatorium Bosscha. An important, essential additional tool for binary research is spectrographic equipment, in order to measure radial velocities of binary components.Therefore, we suggest to make a plan for a new modern telescope, a reflector with a primary mirror of about 2 m in diameter and with a modern spectrograph/detector combination for radial velocity measurements.At a number of major astronomical observatories scientists have been considerating to erect new telescopes devoted primarily to radial velocity measurements. The reason for this is that at the end of this decade the parallax and proper motion measurements to be made by the ESA astrometric satellite Hipparcos will become available of more than 100 000 single stars and double stars. At that time there will be a compelling need for radial velocity measurements of all these stars to complement the parallax and proper motion measurements. With the combination of this data enormous progress will be made in double star research, and in the study of galactic dynamics, another topic of interest of the Observatorium Bosscha. If it could be realized to build such a dedicated radial velocity telescope in Indonesia, Indonesian astronomers could take a leading role in this field of research.Without going into technical details, we would like to emphasize here that such a new instrument should be a trueNew Generation Telescope, and that the Institut Teknologi Bandung should participate from the very beginning in its design, construction and assembling, and the subsequent servicing; ITB could participate in the field of optics, mechanics, and electronics. Modern astronomy offers tremendous challenges to technology, which are of great interest to technological institutes. The new telescope should be computer controlled, and the spectrograph should have a modern digital read-out (Reticon, IPCS, or CCD). The telescope should have one of those recently becoming availablethin mirrors, allowing more mechanical freedom. It could be a telescope with a siderostat which feeds the light into a fixed telescope, thus improving both the stability of the telescope and that of the spectrograph. In this way the staff and students of ITB, as well as the technical staff of the Observatorium Bosscha will be drawn into modern techniques of many varieties. And for ITB such an enterprise may even have a spin-off into other fields than astronomy.One aspect which is of great importance for the new telescope is the selection of its site. The present site of the Observatorium Bosscha in Lembang is a good one, but for a new modern telescope one wants to make sure that it is going to be located at the most ideal site.Therefore an Indonesian site-survey should be initiated promptly. Site survey equipment is available at many big observatories and could be borrowed. The site survey should extend over at least 4–5 years to monitor the meteorological and environmental situation at many sites.In the meantime the design and fund rainsing can be considered. Modern day astronomy depends on financial support from governments and inter-governmental organizations. Therefore it is urged that a proposal for a new telescope as indicated above clearly describes the advantages of such a new telescope both for astrophysical research in Indonesia, and for the introduction of new technologies in Indonesian technological institutes.The recently formed Steering Committee for Indonesian-Netherlands Astrophysics (INA) is willing to explore the possibilities for this plan. We hope that after investigating the interest of ITB in this matter, a proposal could be made before the end of this year.Paper presented at the Lembang-Bamberg IAU Colloquium No. 80 on Double Stars: Physical Properties and Generic Relations, held at Bandung, Indonesia 3–7 June, 1983.     

Remote comets and related bodies: VJHK colorimetry and surface materials

Spectrophotometric data show that major compositional groups among outer solar system (OSS) surfaces include bright ices and at least two distinct classes of blackish carbonaceous-like materials, called C-type and RD-type. VJHK colorimetry of asteroids, satellites, and laboratory samples shows that these three classes can be distinguished by VJHK colors. We define an “α index” that denotes the position of objects in VJHK color - color diagrams; it empirically increases with albedo and ice/dirt ratio. We use the above data to define color fields that may be useful in interpreting our observations of eight comets (1980–1981). All eight comets have colors generally resembling RD asteroids and are inconsistent with reflection off clean ice surfaces. The observations suggest that these comets' halos contain RD dirt or dirty ice grains colored by RD dirt, supporting J. Gradie and J. Veverka's [Nature283, 840–842 (1980)] prediction of RD, rather than C, material in comets. Remote Comet P/Schwassmann-Wachmann 1 was observed both during outburst and quiescence and had the highest α index of any observed comet. Comet α indices appear to be correlated with solar distance. Further work will be needed to clarify possible coloring effects due to particle size, dispersal, and composition. We suggest a number of physical interpretations based on a single two-component mixing model, which assumes that all OSS planetesimals formed primarily from bright ices and dark carboneceous-like dirt, consistent with condensation theory. We discuss differentiation processes that concentrated one component or the other at the surface. All measured OSS interplanetary bodies have surfaces of dark dirt or dark dirty ice colored by the dirt component. Comets, consistent with the Whipple dirty iceberg model, are such objects close enough to the Sun for volatilization to throw dirty ice grains into the coma. In remote comets, the ice component of the grains remains stable, and we see dirty ice grains; in near comets, the ice component vaporizes, and we see dirt grains. A volatile-depleted dusty regolith on P/Schwassmann-Wachmann 1 and other remote comets could explain their eruptive behavior by means of gas pressure buildup in the porous, weakly bonded dust.     

High-density CO2−N2 inclusions in eclogite-facies metasediments of the Münchberg gneiss complex,SE Germany

The eclogite-facies metasedimentary rocks in the Münchberg gneiss complex (T=630±30° C/P17–24 kbar) locally contain CO₂–N₂-rich fluid inclusions of extremely low molar volumes (32 cm³/mol) in quartz. These fluid compositions are mainly found in rocks intercalated with calcsilicate bands. Densities were determined from low-temperature phase transitions like stable or metastable homogenization (L+VL), partial homogenization (S+L+VS+L) and the transition S+LL (L = liquid, V = vapour, S = solid). The high fluid densities are in agreement with eclogite-facies pressure and temperature and subsequent amphibolite facies. CO₂–N₂ inclusions were not observed in adjacent eclogites nor in non-calcareous metasediments. These rock types contain predominantly H₂O-rich inclusions correlating with amphibolite-facies conditions. The variation of fluid composition with lithological differences indicates local fluid gradients and speaks against a pervasive fluid flow during eclogite-facies metamorphism.     

The chemistry of orthophosphate uptake from seawater on to calcite and aragonite

The chemistry of orthophosphate uptake from synthetic seawater onto the surfaces of synthetic calcite, aragonite and low-magnesium biogenic calcite has been studied, in order to elucidate the kinetics of the process (generally believed to be the major control of dissolved reactive phosphate in carbonate-rich marine sediments). Our results differ from those obtained by others, who have studied orthophosphate uptake in low ionic strength solutions and at much higher supersaturations relative to apatite.In both ‘free drift’ and chemostat experiments, Mg and F have only a minor effect on the reaction rate. Even at constant solution composition the rate of orthophosphate uptake was found to decrease by 10⁶ over a two week period. The data from the ‘free drift’ experiments can be fitted to the Elovich equation. This indicates that the kinetics observed for this reaction can be explained by an exponential decrease in available surface reaction sites and/or a linear increase in the activation energy associated with chemisorption as the reaction proceeds.     

The appearance of Mars from 1907 to 1971: Graphic synthesis of photographs from the I.A.U. center at Meudon

Using selected high quality plates collected at the I.A.U. Planetary Data Center in Meudon (Paris), the author has drawn 32 Mercator charts of the planet Mars for every opposition from 1907 to 1971. This graphic synthesis of albedo distribution may be used in the study of major surface changes over the years.     

Elucidation of different forms of organic carbon in marine sediments from the Atlantic coast of Spain using thermal analysis coupled to isotope ratio and quadrupole mass spectrometry

Analysis of river, estuary and marine sediments from the Atlantic coast of Spain using thermogravimetry–differential scanning calorimetry–quadrupole mass spectrometry–isotope ratio mass spectrometry (TG–DSC–QMS–IRMS) was used to (a) distinguish bulk chemical hosts for C within a sediment and humic acid fraction, (b) track C pools with differing natural C isotope ratios and (c) observe variation with distance from the coast. This is the first application of such a novel method to the characterisation of organic matter from marine sediments and their corresponding humic acid fractions. Using thermal analysis, a labile, a recalcitrant and a refractory carbon pool can be distinguished. Extracted humic fractions are mainly of recalcitrant nature. The proportion of refractory carbon is greatest in marine sediments and humic acid fractions. Quadrupole mass spectrometry confirmed that the greatest proportion of m/z 44 (CO₂) and m/z 18 (H₂O) were detected at temperatures associated with recalcitrant carbon (510–540 °C). Isotope analysis detected progressive enrichment in δ¹³C for the sediment samples with an increase in marine influence. Isotopic heterogeneity in the refractory organic matter in marine sediments could be due to products of anthropogenic origin or natural combustion products. Isotope homogeneity of humic acids confirms the presence of terrigenous C in marine sediments, allowing the terrestrial input to be characterised.     

An electrochemical study of pyrite oxidation in the presence of carbon coatings in cyanide medium

The anodic and cathodic behaviour of pyrite with clay and different carbon coatings of activated carbon, graphite and carbonaceous matter in cyanide medium was investigated using the potentiodynamic method. The presence of clay coating did not change the polarisation curve appearance for either the anodic oxidation of pyrite or the cathodic reduction of oxygen or the potential of the current plateau, but only decreased the plateau current especially at a higher coating thickness. The presence of the carbon coatings marginally shifted the rest potential for pyrite to a more anodic position and slightly changed the polarisation curve appearance for pyrite oxidation. The current density for pyrite oxidation largely increased in the presence of the carbon coatings, the potential at the plateau shifted to more cathodic positions, and the plateau width became smaller. These effects became more noticeable at a higher coating thickness. The activated carbon, graphite and carbonaceous matter coatings performed similarly in affecting pyrite oxidation at a similar thickness. The carbon coatings significantly increased the limiting current densities for oxygen reduction on pyrite, and the limiting current plateau became steeper at a higher coating thickness. The carbon coatings increased the limiting current density for oxygen reduction to a similar extent at a low coating thickness, but increased to varied extents at a higher coating thickness. The carbon coatings also greatly increased the cathodic current density for gold reduction on pyrite. The enhancement of pyrite oxidation and oxygen or gold reduction on pyrite by the carbon coatings was likely attributed to the electrochemical interaction between pyrite and the carbon materials with electron-rich surfaces and high conductivity. The presence of the carbon coatings significantly increased the oxidation of pyrite in aerated cyanide solutions and the preg-robbing of pyrite especially at a higher coating thickness.     

Visualization experiments of iron precipitates: Application for in-situ arsenic remediation

Laboratory experiments were carried out to acquire more insight and understanding of the phenomena associated with the in-situ arsenic remediation. Visualization techniques are the most informative for the detection of Fe(II) while flowing in soils. Green Rust (GR) was considered as representative of in-situ iron precipitates. In a visualization flat cell, the change in color of GR to orange, due to oxidation, was monitored by a digital camera and the images were analyzed giving the spatial and temporal distribution of Fe(II). Moreover, both oxygen and pH changes in time were recorded in two sections along the flow direction in the cell. The measured and calculated concentration profiles were compared and the actual reaction rates were predicted. The reaction rate constants measured in this study, under flowing conditions, are in a good agreement with the values obtained from batch experiments reported in the literature.     

Developments in the characterisation of waste materials for environmental impact assessment purposes

The characterisation of waste is entering a new phase with the latest developments of characterisation leaching tests and associated modelling capabilities. The currently applied too simple testing approaches lead to poor choices in waste management. With the increased insight in release controlling processes chemical speciation aspects can be addressed even in the most complex and heterogeneous waste materials. From a composition perspective materials may be highly variable, but often materials are far more consistent in their leaching behaviour. This aspect should be exploited more extensively as it holds the key to treat waste materials in such a way that long term solutions are achieved rather than reaching temporary gains.