arXiv subjects
Publications and source records attributed to Roderick R. Letchford.
Separation ($ρ$) and Position Angle (PA) measurements are reported of 10 pairs which measures where last reported in the WDS +20 years from epoch of observation 2021.066. Measurements were obtained by direct imaging and are presented with associated measurement uncertainties, as well as, comparisons to measurements determined from Gaia DR2 & EDR3 and historic data extrapolation at epoch of J2000.0.
Presented here is list of 50 pairs quasi-evenly spaced over the northern sky, and that have Separations and Position Angles accurate at the milli-arcsec, and milli-degree level. These pairs are suggested as calibration pairs for lucky imaging observations. This paper is a follow-up to our previous paper regarding southern sky calibration pairs.
Accurate measures of double stars require accurate calibration of the instrument. Here we present a list of 50 pairs, that are quasi-evenly spaced over the southern sky, and that have Separations and Position Angles accurate at the milli-arcsec, and milli-degree level. These wide angle pairs are suggested as calibration pairs for lucky imaging observations.