Engineering topics

Warren, W. H., Jr.

Publications and source records attributed to Warren, W. H., Jr..

78 records · Page 5

NASA NTRS1976

A photometric study of the Orion OB 1 association. 1: Observational data

An extensive catalog of observational data is presented for stars in the region of the young stellar association Orion OB 1. In addition to new photoelectric observations obtained on the uvbyB and UBV systems, photoelectric and spectroscopic data were compiled for the stars observed and for several bright members of the association having available photometric indices. Mean weighted values were computed for the uvbyB and UBV data and are tabulated in summary tables which include all references for individual values. These tables are expected to be reasonably complete for association members earlier than spectral type A0. From an analysis of currently available proper motion, radial velocity, and photometric data, membership criteria were derived and qualitative membership probabilities for 526 stars were summarized. A set of charts is included for assistance in identification of the program stars in all regions of the association.

Warren, W. H., Jr.↗

NASA NTRS1974

Scanner observations of selected cool stars

Photoelectric spectral scans at 30 A resolution of nine dwarfs, ten giants, and six supergiants with spectral types G0 to M5 are presented. (All stars were observed every 4 A from 3300 to 7000 A.) Absorption features observed at this resolution coincide with: strong atomic lines of Fe I, Fe II, Ca I, Ca II, Mg I, and Na I; vibrational bands of the electronic transitions of TiO, MgH, CaH, SiH, AlH, CN, CH, C2, OH, and NH. The dependences of the 3740-A Fe I blend and the 3440-A depression on temperature are discussed.

Fay, T. D., Jr.↗

NASA NTRS1974

On the relation between carbon star spectral types and colors

Observations of 32 carbon stars are listed in a table, taking into account the spectral classes given by Yamashita (1966) and Richer (1971). The relations between spectral type and color for carbon stars appear consistent with the differences between Yamashita's and Richer's types if carbon star groups I-III lie on a decreasing boundary temperature sequence.

Honeycutt, R. K.↗

NASA NTRS1974

Scanner observations of carbon stars from 5000 to 7000 A

New photoelectric spectral scans of 26 N-type and 11 R-type carbon stars are presented. The spectral energy distributions were also measured to gain new insight into the composition, chemistry, and structure of carbon star atmospheres. Using the best continuum points in the wavelength region from 5000 to 7000 A a color index is defined, taking into account fluxes at 0.57 and 0.68 microns. The new color index correlates well with the widely used (V-R) broad-band color index.-

Fay, T. D., Jr.↗

NASA NTRS1974

Scanner observations of selected cool stars

Photoelectric spectral scans at 30-A resolution of 9 dwarfs, 10 giants and 6 supergiants with spectral types GO to M5 were presented. All stars were observed every 4 A from wavelength 3300 to wavelength 7000. Absorption features at this resolution coincide with: strong atomic lines of Fe 1,11, Ca 1,11, Mg 1, and Na 1; vibrational bands of the electronic transitions of TiO, MgH, CaH, SiH, AlH, Cn, Ch, C2, OH, and NH. The dependence of the wavelength 3740 Fe 1 blend and the wavelength 3440 depression on temperature is discussed.

Fay, T. D., Jr.↗

NASA NTRS1973

Scanner observations of hot helium-carbon stars.

Photoelectric spectral scans at 20 A resolution of four hot helium-carbon-rich stars have been reduced to fluxes and are presented in graphical form. Similar flux curves for several normal (hydrogen-rich) stars in the same temperature range are presented for comparison.

Fay, T.↗