Arthur R. Upgren - Böcker

The stars that form a halo around our Galaxy are intriguing; they have abundances of elements that suggest they are old. The properties of these 'hot stars' and similar stars in other galaxies challenge the well-established theory of stellar evolution in many ways. Studying the collective properties of these stars provides important input to many areas of astrophysics - including the formation of our Galaxy, stellar evolution and the stellar populations of other galaxies. The study of hot stars in the halo of our Galaxy is undergoing an exciting renaissance owing to important new observations with the Hubble Space Telescope and ASTRO1 and to techniques recently developed for ground-based observations. Advances in computers have also recently led to a far more detailed and complete theoretical understanding of stellar evolution. This volume, first published in 1994, draws together the proceedings of a conference held in Union College, New York, which gathered experts in the field in question.

The stars that form a halo around our Galaxy are intriguing; they have abundances of elements that suggest they are old. The properties of these 'hot stars' and similar stars in other galaxies challenge the well-established theory of stellar evolution in many ways. Studying the collective properties of these stars provides important input to many areas of astrophysics - including the formation of our Galaxy, stellar evolution and the stellar populations of other galaxies. The study of hot stars in the halo of our Galaxy is undergoing an exciting renaissance owing to important new observations with the Hubble Space Telescope and ASTRO1 and to techniques recently developed for ground-based observations. Advances in computers have also recently led to a far more detailed and complete theoretical understanding of stellar evolution. This volume, first published in 1994, draws together the proceedings of a conference held in Union College, New York, which gathered experts in the field in question.

This IAU Symposium brought together researchers who use CCDs and arrays, designers and manufacturers of CCDs and array mosaics, and those who write the software to control these devices and to reduce the large amounts of data contained in each frame. At the meeting such topics as plans for applying the new technology to the new large telescopes that have been built recently and those planned in the near future, new developments in infra-red arrays, advances and concerns with the use of CCDs in photometry and spectroscopy and the creation of large mosaics in photometry and spectroscopy, and the creation of large mosaics of chips which allow larger areas of the sky to be covered in a single frame were discussed. There were sessions devoted to the following topics: new developments in CCD technology; new developments in IR detector arrays; direct imaging with CCDs and other arrays; spectroscopy with CCDs and other arrays; and large field imaging with array mosaics. Scientific results of studies made with this technology were covered in the poster sessions. CCD and array detectors have become the detectors of choice at all the world's optical observatories.Such instruments on small university and college telescopes have turned these telescopes into instruments that can now do observations which in the past were done only on the largest telescopes. CCDs and arrays are known as "the people's detector" because of their ability to turn small telescopes into true research instruments. On large telescopes observations can be made of extremely faint and crowded objects that were impossible to observe before the advent of CCD and Array technology. The proceedings of this meeting should be useful to all those who are interested in the design, manufacture and use of CCDs and arrays for astronomical observations.

This IAU Symposium brought together researchers who use CCDs and arrays, designers and manufacturers of CCDs and array mosaics, and those who write the software to control these devices and to reduce the large amounts of data contained in each frame. At the meeting such topics as plans for applying the new technology to the new large telescopes that have been built recently and those planned in the near future, new developments in infra-red arrays, advances and concerns with the use of CCDs in photometry and spectroscopy and the creation of large mosaics in photometry and spectroscopy, and the creation of large mosaics of chips which allow larger areas of the sky to be covered in a single frame were discussed. There were sessions devoted to the following topics: new developments in CCD technology; new developments in IR detector arrays; direct imaging with CCDs and other arrays; spectroscopy with CCDs and other arrays; and large field imaging with array mosaics. Scientific results of studies made with this technology were covered in the poster sessions. CCD and array detectors have become the detectors of choice at all the world's optical observatories.Such instruments on small university and college telescopes have turned these telescopes into instruments that can now do observations which in the past were done only on the largest telescopes. CCDs and arrays are known as "the people's detector" because of their ability to turn small telescopes into true research instruments. On large telescopes observations can be made of extremely faint and crowded objects that were impossible to observe before the advent of CCD and Array technology. The proceedings of this meeting should be useful to all those who are interested in the design, manufacture and use of CCDs and arrays for astronomical observations.