Engineering topics

Boyden, J. E.

Publications and source records attributed to Boyden, J. E..

3 records

NASA NTRS1983

The Mount Wilson magnetograph

In the summer of 1957, an instrument quite similar to the prototype solar magnetograph described by Babcock (1953) was installed at the 150-foot tower telescope at the Mount Wilson Observatory, and daily magnetograph observations of the full disk of the sun were started. During the following years, the instrument was modified and improved on several occasions. The present investigation is concerned with the present state of the magnetograph, which was largely rebuilt during 1981. Attention is given to the spectrograph entrance slit, the diffraction grating, the exit slit, the employed microprocessor, the setup procedure, the magnetic signal, the Doppler signal, and a solar magnetogram.

Howard, R.↗

NASA NTRS1983

Solar rotation results at Mount Wilson

Solar rotation results from Doppler velocity measurements made at Mount Wilson over a period of more than 14 years are presented based on a single reduction procedure. The observations were made with the wavelength 5250.2 A line of Fe I, and wavelength shifts of the line were simultaneously recorded. Data from 188 rotations are presented. Measurements of scattered light along with its effect on the measured rotation rate are given.

Howard, R.↗

NASA NTRS1980

Solar rotation measurements at Mount Wilson. I - Analysis and instrumental effects

We examine the background velocity fields of the sun as observed at Mount Wilson. The method of velocity reduction of the full-disk Mount Wilson data is outlined. We describe a number of tests that have been carried out in order to find an instrumental origin for short-term rotation variations and a large-scale background line-shift - the ears. No instrumental cause can be found for this ear effect, although such a cause cannot yet be ruled out.

Howard, R.↗