Engineering topics

Koch, Robert H.

Publications and source records attributed to Koch, Robert H..

2 records

NASA NTRS1989

Old and new observations of V523 Saggitarii

The history of V523 Sgr is reviewed. New photoelectric timings of minimum light are used to improve the period of apsidal rotation and the orbital eccentricity. UBV photometry indicates that the mean spectral type is F0, and not A5. Blue and yellow light curves described here are the first photelectric ones ever obtained. Within satisfactory limits, the light curves have been solved for consistent stellar parameters with the code EBOP. With significant qualifications, a mean value of the stellar structural constant is given.

Koch, Robert H.↗

NASA NTRS1987

Apsidal rotation in the eclipsing binary AG Persei

New three-filter light curves of AG Per are given. These yield times of minimum light in accord with the known rate of apsidal rotation but do not improve that rate. These light curves and all other published historical ones have been treated with the code EBOP and are shown to give largely consistent geometric and photometric parameters no matter which orientation of the orbit is displayed to the observer.

Koch, Robert H.↗