Photoelectric Measurements of Lunar Occultations. V. Observational Results
Abstract
Observational timings of 254 lunar occultations, almost all disappearances, made between December 1968 and April 1971 with the McDonald 364nch reflector, using equipment and techniques previously described, are reported. A number of observers have participated in this, now semiroutine, program, and their contributions are acknowledged with gratitude. For some 40% of the observations (a total of 98 cases) in which the observational noise was sufficiently small and the diffraction pattern well enough defined, a lunar limb slope has been derived. An ambiguity in this has been noted and discussed, and is considered likely to be of minor importance, pending further observations. For the tabulated determinations of slope, 70% are numerically below t0 and only three in excess of 300. The determination of limb slopes is closely bound up with the use of occultation observations for astrometry of double stars. Seven cases of discovery of double stars are included in notes to the main table of results. Six other cases of possible duplicity requiring confirmatory observations are noted. One certain case of a perceptible angular diameter, that of X Aqr, has been discussed in detail in a separate publication. Three other cases marginally capable of yielding diameters are noted, and will be examined more closely later. The main table of results forms the basis of the file of traces which we intend to establish-to which other observers are invited to contribute, so that the advantages of duplicate observations may be made available to those interested. The present listing is by SAO numbers, possessed by all the occulted stars, but other designations are more useful for astro- physical purposes. To facilitate reference crossAndices in terms of SAO, HD, DM, and HR, Bayer and Flamsteed designations have been prepared and are available on application to the author.
- Publication:
-
The Astronomical Journal
- Pub Date:
- December 1971
- DOI:
- 10.1086/111227
- Bibcode:
- 1971AJ.....76.1107E