Sentence examples for seconds of arc from inspiring English sources
noun
Plural of second of arc
It is usually measured in seconds of arc per year.
The excess was tiny, about 38 seconds of arc per century, compared with the 527 seconds of arc per century that Leverrier attributed to known planetary perturbations.
Barnard's star has the largest proper motion of any known star 10.25 seconds of arc annually.
Seeing is expressed in units of seconds of arc, or 1/3,600 of a degree.
(Some GRBs that were detected with X-rays could have their locations determined to within 10 seconds of arc).
Einstein's theory predicts that the orbit of Mercury precesses an extra 43 seconds of arc each century, compared with Newton's laws, in exact agreement with observations.
Angular motions were about 0.02 second of arc per year.
The best observatory sites have seeing between 0.5 and 1 second of arc.
Photographic resolution of about one second of arc is achievable today.
Thus, a 25-cm-diameter objective has a theoretical resolution of 0.45 second of arc and a 250-cm (100-inch) telescope has one of 0.045 second of arc.
The accuracy in modern first-order or geodetic instruments, with five-inch glass circles, is approximately one second of arc, or 1/3,600 of a degree.
