Jacques Cassini also proved that Arcturus had even since the time of Tycho Brahe shifted five minutes in latitude; for r l Bootis, which would have shared in the change, if it had been due to a motion of the ecliptic, had not moved appreciably.
Probably the velocity of Arcturus is also over 100 m.
Arcturus has been supposed to be referred to in various passages of the Hebrew Bible; the Vulgate reads Arcturus for stars mentioned in Job ix.
Of the first magnitude red stars Antares is the most deeply coloured, Betelgeux,.Aldebaran and Arcturus being successively less conspicuously red.
This constellation has been known by many other names - Arcas, Arctophylax, Arcturus minor, Bubuleus, Bubulus, Canis latrans, Clamator, Icarus, Lycaon, Philometus, Plaustri custos, Plorans, Thegnis, Vociferator; the Arabs termed it Aramech or Archamech; Hesychius named it Orion; Jules Schiller, St Sylvester; Schickard, Nimrod; and Weigelius, the Three Swedish Crowns.
Then follows a gradual absorption of first the helium and then the hydrogen, the photosphere grows continually cooler, and the star passes successively through the stages exemplified by Sirius, Procyon, the Sun, Arcturus and Antares.