A CCD-based spectrophotometer for a new automated 0.5-m telescope at the
\nFairborn Observatory, Washington Camp, AZ, USA, altitude 1800 m should begin
\noperations by Spring 2004. The Citadel ASTRA (Automated Spectrophotometric
\nTelescope Research Associates) Telescope will permit observations of Vega the
\nprimary spectrophotometric standard, rapid measurements of the naked-eye stars,
\nsufficient observing time to obtain photometric measurements of the nightly
\nextinction, and still obtain high quality observations of stars of about 10.5
\nmagnitude in an hour. This multiplexed cross-dispersed instrument should
\nproduce high-quality fluxes at least of 3300-9000 A with a
\nresolution of 14 A in first and 7 A in second order and full wavelength
\ncoverage except for regions badly affected by telluric lines.<\/p>\n
The telescope and spectrophotometer are optimally designed for efficient
\noperations using input from astronomers and the experience of the design team.
\nThe CCD frames will be reduced to one-dimensional spectra using program CCDSPEC
\nby Austin F. Gulliver & Graham Hill and photometrically calibrated using
\nprogram SPECPHOTOCAL by Barry Smalley that should correct for the effects of
\nmost telluric lines at airmasses < 4.\n\nModel atmospheres are the analytical link between the physical properties of\nstars (M, R, L, and composition) and the observed flux distributions and\nspectral line profiles. By comparing predictions of model atmospheres with\nspectrophotometric fluxes (and Balmer line profiles) effective temperatures,\nsurface gravities, and metallicities can be found for a wide variety of stars.\nComparisons for the same star between the best-fitting model atmospheres\ncalculated from different codes will provide insight into how well each code\nreproduces these observations. High-quality elemental abundance studies will\npermit consistency checks. As the efficiency of convection can produce\nobservable results in the energy distributions, it should be possible to check\nthe results of different convection theories. Investigators will be able to\nsynthesize a variety of indices which could be obtained by filter photometry.\n\nThe first major observing project will be the revision and extension of the\nbright secondary standards. The existing grid of good secondary standards will\nbe increased several-fold and include those selected to be near variables of\nparticular interest. Over the lifetime of the instrument, measurements of\nsecondary stars for calibration and extinction will be used to improve the\nquality of the secondary standard fluxes. In less than a year of normal\nobserving, all isolated stars with V < 7.5 mag. and declinations between\n+76 and -35 degrees can have their fluxes well measured.\n\nAdelman, Gulliver, and Smalley in planning to deal with this potential flood\nof ASTRA data, realize that they will need help to make the best scientific\nuses of it. Thus they are interested in discussing possible collaborations.\nAs many studies of variable stars will utilize local spectrophotometric\nstandards, they plan to calibrate such stars as part of the initial effort. \n<\/p>\n","protected":false},"excerpt":{"rendered":"
A CCD-based spectrophotometer for a new automated 0.5-m telescope at the Fairborn Observatory, Washington Camp, AZ, USA, altitude 1800 m should begin operations by Spring 2004. The Citadel ASTRA (Automated Spectrophotometric Telescope Research Associates) Telescope will permit observations of Vega the primary spectrophotometric standard, rapid measurements of the naked-eye stars, sufficient observing time to obtain […]<\/p>\n","protected":false},"author":3,"featured_media":0,"parent":8,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-123","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/people.brandonu.ca\/gulliver\/wp-json\/wp\/v2\/pages\/123","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/people.brandonu.ca\/gulliver\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/people.brandonu.ca\/gulliver\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/people.brandonu.ca\/gulliver\/wp-json\/wp\/v2\/users\/3"}],"replies":[{"embeddable":true,"href":"https:\/\/people.brandonu.ca\/gulliver\/wp-json\/wp\/v2\/comments?post=123"}],"version-history":[{"count":3,"href":"https:\/\/people.brandonu.ca\/gulliver\/wp-json\/wp\/v2\/pages\/123\/revisions"}],"predecessor-version":[{"id":186,"href":"https:\/\/people.brandonu.ca\/gulliver\/wp-json\/wp\/v2\/pages\/123\/revisions\/186"}],"up":[{"embeddable":true,"href":"https:\/\/people.brandonu.ca\/gulliver\/wp-json\/wp\/v2\/pages\/8"}],"wp:attachment":[{"href":"https:\/\/people.brandonu.ca\/gulliver\/wp-json\/wp\/v2\/media?parent=123"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}