Engineering topics

Pope, T.

Publications and source records attributed to Pope, T..

5 records

NASA NTRS1975

Evidence for non-radial fields in the sun's photosphere and a possible explanation of the polar magnetic signal

The appearance of H-alpha fibrils suggests the presence of magnetic fields inclined at noticeably nonradial angles in the sun's chromosphere. Evidence is presented to suggest that these angles continue into the photosphere. The presence even of small nonradial inclinations can significantly affect the appearance of regions observed by a longitudinal magnetograph. In particular, a simple bipolar loop can appear unbalanced when viewed near the limb. It is suggested that the observed polar signal may be nothing more than a geometric effect arising when a balanced but systematically aligned array of bipolar pairs is viewed at an angle.

Pope, T.↗

NASA NTRS1975

Height of helium emission in the chromosphere

Filtergrams of the limb show the He I D3 chromosphere as a shell which is separated from the limb by a gap. The height of maximum D3 contribution occurs at about 1350 km above the limb and is independent of the intensity of the D3 emission. We interpret this effect as the height to which coronal EUV radiation is capable of penetrating the atmosphere.

Pope, T.↗

NASA NTRS1972

Solar bright points in 3840 A and H-alpha.

Analysis of bright features in 3840 A and H-alpha shows that for every Ellerman bomb there is a cospatial brightening in the 3840 A network. We give properties of these bright points in both wavelengths as well as describe: (1) the appearance, and subsequent separation, of new elements in the 3840 A network and (2) the direct transition from a 3840 A bright point to a new sunspot.

Vorpahl, J.↗

NASA NTRS1971

Coronagraphic observations of an enhanced coronal region. I - Fe XIII and Ni XV emission line data.

Observation of nine coronal emission lines representing five stages of Fe ionization and one stage of Ni in an enhanced coronal region. The data from these observations are presented along with a density model of the enhanced region obtained from the Fe XIII and Ni XV emission line ratios as a function of position angle. The electron densities obtained from Fe XIII lines range from 10 to the 8th to 10 to the 9th per cu cm, and are slightly lower for Ni XV line data. Estimates of the variation of temperature over the enhanced region are inferred from the observed line intensities.

Fisher, R.↗

NASA NTRS1970

Coronagraphic solar limb data, 7 March 1970

Solar limb photographic, isodensity and isophotal data for eclipse of 7 March 1970 from coronagraph observations, noting coronal green line and prominence activity

Cain, S. D.↗