Marvin E Germain

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We have measured the diameters of the Cepheid variables δ Cephei (18 nights) and η Aquilae (11 nights) with the Navy Prototype Optical Interferometer. The primary results of these observations are the mean angular diameters 〈θLD〉 of these Cepheids: 1.520 ± 0.014 milliseconds of arc (mas) for δ Cep and 1.69 ± 0.04 mas for η Aql. We also report limb-darkened(More)
We present mean angular diameters for two cepheid variables, α Ursae Minoris and ζ Geminorum, determined with the Navy Prototype Optical Interferometer (NPOI). We present linear radii for these cepheids and two additional cepheids, δ Cephei and η Aquilae, previously observed at the NPOI. We find the limb-darkened angular diameter of α Ursae Minoris and of ζ(More)
We present mean angular diameters for two Cepheid variables, a UMi and f Gem, determined with the Navy Prototype Optical Interferometer (NPOI). We present linear radii for these Cepheids and two additional Cepheids, d Cep and g Aql, previously observed at the NPOI. We Ðnd the limb-darkened angular diameters of a UMi and of f Gem to be 3.28 ^ 0.02 and 1.55^(More)
We have measured the angular diameters of 50 F, G, K, and M giant and supergiant stars using the Navy Prototype Optical Interferometer at wavelengths between 649 and 850 nm and using three baselines with lengths up to 37.5 m. Uniform-disk diameters, obtained from Ðts to the visibility amplitude, were transformed to limb-darkened diameters through the use of(More)
The problem of aligning an optical delay line for use in long-baseline stellar interferometry is discussed. particular, the development of the Navy Prototype Optical Interferometer alignment system is described. Rapid mirror alignment must be performed with sufficient precision that beam shear is limited to a few millimeters over an optical path length that(More)
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