The first and second left-hand column of the following Table are easily understood, from the title. The third column shews the difference of right ascension, in mean time, between the star and its satellite: The attendant, preceding the fixed star, is set down in the first place, in the table; the attendant, following, is placed after its fixed star. The fourth column notes the difference between the fixed star and its attendant, as I have observed it at Manheim. The letter A denotes, that the attendant is to the southward; letter B more northward. The following columns contain the observations of the same star, made by Flamstead.
It appears from the whole of the observations, that, of all the stars, Arcturus is carried with the greatest celerity, by his own motion, westward; since the same attendant, which in Flamstead’s time, on the 14th of February, 1690, preceded Arcturus 5″ in time, now enters the meridian 6″ after him. From the diminished difference also, of declination between Arcturus and his attendant, it is evident, that Arcturus progresses annually, by his own appropriate motion, nearly 2″ in a circular course, towards the south. From this it clearly results, that the declination of the attendant, as observed by me, reduced to the parallel of Greenwich, produces the same altitude of the Greenwich pole, as that deduced from Flamstead’s observation; but not so, the declination of Arcturus, observed at the present day, even with the aberration and nutation corrected.
A similar investigation may be made, with respect to the other fixed stars and their attendants; and, from the comparison already begun with other fixed stars, it may be ascertained whether an appropriate motion is to be attributed to the fixed star or its attendant, or to both.
All my observations are made in a meridienal plane with a mural quadrant, at Manheim, in his Serene Highness the Elector Palatine’s new Observatory, erected for me: its longitude, East from Greenwich, is nearly 34′ 6″, in time; its latitude, nearly 49° 27′ 50″.
It will give me very great pleasure, if I shall learn that these observations of mine do not prove unacceptable to your illustrious society: to whose goodness I most respectfully commend myself; being ever the very devoted admirer and humble servant of your illustrious and celebrated Society.
Christian Mayer,
Astronomer to his Serene Highness the Elector
Palatine and Duke of Bavaria.
Manheim, in Germany, April 24, 1778.
