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Tifft, W. G.

Publications and source records attributed to Tifft, W. G..

14 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS1979

The Hercules supercluster. I - Basic data

A sample of more than 150 redshifts, the majority new, is presented for galaxies brighter than an apparent photographic magnitude of 15.8 in a 28-square-deg field in Hercules containing the clusters A2151, A2152, and A2147. This sample populates a 60,000 cu Mpc conical volume. It contains a super-cluster centered near a radial velocity of 11,000 km/sec a large void of depth approximately 100 Mpc in front of the supercluster, and foreground structure at 4700 and 2300 km/sec the former associated with Seyfert's sextet.

Tarenghi, M.↗
NASA NTRS1974

Digicon photometry of an intergalactic bridge

Surface brightness and color data are derived for two points in the bridge and tail structure of Arp 295. The best observed point has a surface brightness in V of 25.9 magnitudes per square arc second and (B-V) = +1.00 m. A point on the tail is brighter with the same color.

Beaver, E. A.↗
NASA NTRS1974

Results from computer program for analyzing scattered light suppression systems for large space telescope

A computer program was developed which has the ability to analyze the performance of most light suppression systems so as to predict the amount of scattered light which will reach the image plane for various conditions of unwanted light input from the sun, earth, or moon. This program was used to analyze three different configurations of the large space telescope (LST): an LST with a truncated sunshield, an LST with an extended cylindrical sunshield, and an LST with a conical sunshield which is tilted upwards. The computer program gives the user detailed information as to the paths taken by the unwanted stray light to reach the image plane, and pinpoints those portions of the light suppression system which contribute most of the stray light, so that areas requiring improvements are evident. Certain design guide lines were formulated for any light suppression system selected for the LST, and one which meets these requirements (the tilted sunshade) is described in detail.

Tifft, W. G.↗
NASA NTRS1973

Literature survey for suppression of scattered light in large space telescopes

A literature survey is presented of articles dealing with all aspects of predicting, measuring, and controlling unwanted scattered (stray) light. The survey is divided into four broad classifications: (1) existing baffle/telescope designs; (2) computer programs for the analysis/design of light suppression systems; (3) the mechanism, measurement, and control of light scattering; and (4) the advantages and problems introduced by the space environment for the operation of diffraction-limited optical systems.

Tifft, W. G.↗
NASA NTRS1972

Two-dimensional area scanning with image dissectors.

An image dissector system for direct two-dimensional area scanning has been fabricated and is briefly described. Examples of application to direct scanning and digitization of photographic images are given.

Tifft, W. G.↗
NASA NTRS1972

Rapid evolution of galactic nuclei.

An evolutionary sequence is suggested for Virgo cluster galaxies, in a radial velocity-nuclear magnitude diagram. This evolution, on a time scale of about 100 m.y., is discussed in terms of the morphology and radial color variations of the galaxies, nuclear size and radio emission. An area scan and profiles of nuclei, obtained with image dissector equipment, are presented.

Tifft, W. G.↗
NASA NTRS1971

A 1:1 apochromat transfer lens system

A prototype system for remote control was constructed for the University of Arizona 90-inch telescope on Kitt Peak. The system uses image dissector tubes, a conventional photocell, and photographic plates as detectors for images formed at the Cassegrain focus of the 90-inch telescope. It was decided to use an image relay system to transfer selected portions of the image plane to image dissectors and the photographic plate. The design of a 1:1 relay system is described. Design considerations are discussed and alternate designs are outlined.

Tifft, W. G.↗