Optical fibres are used to convey light from star images to the entrance slit of a spectrograph. Using an arrangement, the position of the fibre ends are monitored. The spectral transmission factor of the system and modification in the beam divergence have been measured.

The use of optical fibres has recently allowed the full field of some Schmidt telescopes to be accessed for multi-object spectroscopy. The new device: the MOS (multi-object spectrograph) is to revolutionize the field of astronomical spectroscopy. Cosmic objects grouped into aggregates having apparent angular diameters of 1 to 6 degrees and similar apparent brightness in the visual or near infrared spectral range are to be the most probable future targets of MOSs. Flare stars — as it has been demonstrated convincingly by various authors (see Szecsenyi-Nagy 1986, and references therein) — are the most abundant type of variable stars but because of their low luminosity and relatively late discovery we have only very limited amount of spectroscopic data about most of these objects. It is a real bonanza that most of the catalogued flare stars are associated with young open clusters and this fact of course suggests them as really promising targets for wide-field Schmidt cameras equipped with MOSs. In an average open cluster scrutinized for its flare star members some dozen or some hundred representatives of this species are known which are distributed over a sky field of 10–20 square degrees. Fortunately, they are never packed into unresolvable concentrations and even short focal length cameras are able to produce separate images of all cluster member flare stars for an accurate photographic photometry of the objects. The apparent visual brightness of these stars most often fits a 5–7 magnitude range. This seems to be profitable also for the effectiveness of using fibre-fed MOSs in flare star spectroscopy. The first steps of such a program should be the study of radial velocities and the comparison of the measured values with the accepted radial velocity of the cluster. These measurements could provide new and independent arguments for (or against?) the cluster membership of the flare stars observed in the fields of catalogued open clusters. Later, more detailed spectral studies should collect information about the time dependent features of the spectra of flare stars.

The large field of Schmidt plates allows monitoring of hundreds of thousands or even millions of stars, either for magnitude variations or for proper motions. CCD cameras benefit from the sensitivity, linearity, and easy interface to computers of detectors of increasing dimensions. However, especially for proper motion studies, there is no substitute to plates of first or intermediate epochs. In addition, the photographic plates, with their large sky coverage free of gaps, are irreplaceable for the accurate astrometry of optical counterparts of sources detected at other wavelengths.

We first introduce the subject by mentioning a few problems concerning the replacement of Schmidt plates by CCD detectors. After a brief survey of astronomical applications requiring accurate astrometry or massive processing in large fields, we develop in more detail the results obtained in proper motion studies by several groups using the MAMA system (Berger et al. 1991). The last part of this paper is devoted to the studies of stellar variability and to the EROS and DUO microlensing programmes. Our conclusion (not a surprise, we think), is that Schmidt telescopes with photographic facilities should remain available to the general astronomical community for at least a decade and probably more.

The introduction of film-based Kodak Technical Pan emulsion at the UKST has led to a new lease of life for deep, wide-field astrophotography. This is because the excellent imaging, resolution and low noise characteristics of Tech Pan typically yield a one magnitude depth gain over equivalent IIIa-F plates. Many new projects are underway to take advantage of the significant information gains. The cheap cost of film and ease of transportation gives direct economic benefits too. Tech Pan could also offer a medium term, competitive alternative to CCD mosaics for providing new, deep, wide-field surveys via stacking of several digitised exposures of the same field. A one magnitude gain could result from the stacking of just 6 Tech Pan films to yield an R ∼ 23.5–24. Even without digital co-addition the largest current CCDs cannot hope to match Tech Pan’s inherent ∼ 3 µm resolution and the 40 square degree area coverage of the UKST.

Results of a spectroscopic search for M32-like compact elliptical galaxies in the Fornax cluster are presented. None were found, which suggests that these objects represent the low luminosity end of the giant elliptical luminosity function, rather than being formed by tidal stripping. The sample is used to investigate the large-scale distribution of bright ellipticals.

We present the preliminary results of a search for new blue compact dwarf (BCD) galaxies in the Virgo cluster. Our search is based on the automated selection of compact galaxies from digitised scans of UK Schmidt plates and is designed to put quantitative limits on the luminosity function of compact galaxies in Virgo.

We have selected a sample of 310 candidate BCD galaxies and have obtained radial velocities for 177 of them using the UK Schmidt FLAIR-II multi-object fibre spectrograph. We have confirmed two new members of the cluster. One is classified as a member (but without velocity) in the Binggeli, Sandage and Tammann (1985) catalogue (VCC) and the other does not appear in the VCC and is therefore probably a new BCD. The other 175 galaxies are background objects at higher redshift, including one classified as ”BCD or background“ in the VCC which we now confirm to be a background object.

We report on a redshift survey of ∼ 4000 galaxies of B ≲ covering a 1500 square degree area of sky around the SGP region. This 1-in-3 sampled survey probes a contiguous volume of 4 × 106 Mpc3 to a depth of 300 h−1 Mpc. The survey has been compiled using the fibrelinked spectroscopy system, FLAIR, on the UK Schmidt Telescope and has produced high quality redshift maps giving a clear visual picture of structure in the universe as well as providing an excellent data base for a statistical analysis of galaxy clustering. Filamentary and sheet-like features are clearly discernible to the eye in the completed sections of the survey although the redshift two-point correlation function is consistent with zero on scales of r ≳ 10h−1 Mpc. The survey, which is now substantially complete, demonstrates the potential of the FLAIR spectroscopy system for extending this project to a medium-deep galaxy redshift survey of the whole of the southern sky on timescales which would remain competitive with other surveys under construction.

We describe an instrumental configuration for detecting large gas-giant planets orbiting main sequence stars via the small drop in stellar brightness that occurs when the planet transits the stellar disk. Our proposed scheme involves the long-term monitoring of the light-curves of tens of thousands of stars using a Schmidt telescope coupled to a CCD via a bundle of 10,000 optical fibres. Using an existing theoretical model of planetary system formation we calculate a detection rate of 14 transits per year for our proposed system.

A description of a magnitude limited redshift survey covering 9 adjacent UKST fields is presented together with some initial results. The survey is currently ∼ 90% complete to bj ≤ 17.1. The compilation of ∼ 1700 redshifts will form one of the largest, independent, contiguous, well sampled and most homogeneous redshift catalogues currently available. The special features of this catalogue are its coverage (∼ 330deg2), mean sampling depth (∼ 125h–1 Mpc) and field to field photometric accuracy (bj ± 0.05). Morphological classifications have also been determined for all galaxies in the survey fields down to bj ≤ 17.1 and COSMOS image parameters are also available. This extensive catalogue should prove a valuable database for many projects but particularly in delineating the detailed structure in the large scale galaxy distribution.

This paper describes the major sky surveys carried out with the large Schmidt telescopes and the sky atlases made from them. It also describes some of the science which has come from them and notes the importance of this work in almost every branch of astronomy.

The contemporary state of the Schmidt/Maksutov telescope plate archives and their unification in an Index Plate Catalogue as part of the Wide Field Plate Database is presented.

Two CCD detector systems for the U. K. Schmidt Telescope that would allow a southern digital sky sulvey of faint objects to be carried out are described.

Since 1990 we have operated a program in which all plates and films exposed at the 1.2 m U.K. Schmidt Telescope (UKST) are searched for suspicious trails that may represent fast-moving (Earth-approaching) objects. When a possible near-Earth asteroid is discovered, we obtain follow-up astrometric positions using photography on either the UKST (if the object is faint) or the 0.5 m Uppsala Southern Schmidt at the same site. Further astrometric positions, once a reasonable ephemeris is available, are obtained with a large-format CCD on the 40 inch telescope of the Siding Spring Observatory (SSO).

In the near term we plan to extend our use of the UKST making use of time near bright-of-moon when the telescope is currently underused. We will conduct photographic searching by taking dedicated films in pairs of 5-10 minutes exposure, with 30-60 minutes gaps between. These will then be inspected using electronically blinked video cameras to scan the films and look for objects that have moved between the exposures. We believe that we can better than triple our current discovery rate (which is about 8-10 near-Earth asteroids per year) in this way.

In the longer term clearly the installation of a mosaic of CCDs covering some reasonable fraction of the UKST focal surface is a desideratum, and this is under consideration.

We describe our routine identification of images of asteroids and comets on plates and films in the U.K. Schmidt Telescope archive. The asteroids of most interest to us are those which approach the Earth, and whenever such an object is found (by anyone) we perform backintegrations in order to determine whether the object may have been recorded on any UKST plate taken since 1973. In many cases the object is found (‘precovered’) and measured, allowing an accurate orbit to be determined soon after its discovery; other studies such as long-term dynamical investigations, or predictions of future close approaches to the Earth, are then possible. Similar programs using other wide-field plate archives are to be encouraged, since valuable scientific results may be derived.

The limititations to the use of data from the major Schmidt surveys, i.e. grain noise as well as practical considerations of image processing and astrometry, are discussed, together with the question of mounting films on microdensitometer platens. Next, the major scanning systems dedicated to Schmidt surveys, their accomplishments, and their future programs are considered. Finally, the archiving and distribution of the scan data is discussed, and some suggestions regarding future directions are made.

A method for a fully automatic reduction of digitised objective prism spectra is developed. It leads to positions and radial velocities, magnitudes and intensities of spectral lines. The latter then can be used for classification purposes. The system is tested with plates taken with a specific telescope-prism-filter combination.

A large set of exposures of a single UK Schmidt Telescope field has been obtained, covering five colour bands over 18 years. Techniques have been developed for combining digitised data from many plates. The results of adding 64 exposures in Bj and R are demonstrated showing that the expected gain of ~ 2.5 magnitudes in limiting magnitude are achieved. By combining various subsets of the data, proper motions and variability can be determined. Two examples of the many possible uses of the dataset are given: the discovery of low mass brown dwarf candidates using colours and proper motions, and of quasars using variability and colours.

We have digitally co-added eight IIIa-J/GG395 UKST plates centred on the IC 4296 cluster of galaxies. The factor of increase in S/N in the co-added array enables galaxy profiles to be followed, and filamentary and diffuse features to be detected, down to bj surface brightnesses of 28 mag arcsec−2. Examples of warped disks, shells, trails, diffuse IGM and extended haloes revealed by this technique are discussed and illustrated.

Photographic plates are well established as stable detectors, well suited for positional astronomy. The completion of the current second epoch 48 inch Schmidt surveys in both hemispheres will provide material spanning baselines of 20–45 years, allowing proper motions to be determined to an accuracy of 4–7 mas yr−1. This paper discusses some of the Galactic structure problems that these data, combined with accurate photometry, can be used to address.

We are compiling a catalogue of positions and proper motions of 4 million stars, based on the Guide Star Catalogue (GSC) and the Astrographic Catalogue (AC). The GSC is re-reduced by a method described in this paper. The AC has been newly reduced recently by us for the determination of positions and proper motions of the PPM catalogue.

The expected accuracy of the proper motions of the GSC-AC catalogue ranges between 5 and 6 mas/year. Having an average star density of 100 per square degree, this catalogue will be a useful tool for the reduction of CCD frames.