Bungula

Bungula, more usually called Rigil Kentaurus or Toliman, is Alpha Centauri, and it is the nearest star system to our own, at about 4.4 light years. What appears as a single brilliant star is a close pair, a star very like the Sun together with a cooler orange companion, accompanied at a great distance by the faint red dwarf Proxima Centauri, which is the very nearest individual star to the Sun and the likely host of at least one planet. It marks the foot of the Centaur, which its Arabic name Rigil Kentaurus records; the odd name Bungula, used in the old astrological lists, is of uncertain and probably corrupt origin.

Proxima Centauri's planet, Proxima b, orbits well within the star's habitable zone by insolation, but Proxima is a flare star prone to sudden, violent outbursts of radiation, which has made the genuine habitability of any planet there a live and unresolved question in current astrophysics rather than a settled fact. Alpha Centauri's binary pair completes an orbit around their common centre of mass in about eighty years, close enough to a human lifetime that dedicated observers have followed a substantial fraction of a single orbit within living memory. That eighty-year orbit has been tracked closely enough that its predicted closest and widest separations are known with real confidence decades in advance.

Sources AstronomyAndrew Fraknoi, David Morrison, and Sidney C. Wolff (OpenStax) with Almagest (Mathematike Syntaxis)Claudius Ptolemy

The tradition gives Bungula the nature of Venus with Jupiter, the same benefic pairing as its neighbour Agena, and Robson reads it for beneficence, honour, friends and a refined, self-reflective nature. As with Agena the delineation is a product of the modern compiling tradition, since Alpha Centauri lies too far south to have entered the reckoning of the ancient Mediterranean astrologers. The star's true and extraordinary distinction is astronomical rather than astrological: of all the stars in the sky it is the closest to the Sun, the nearest neighbour of our own system and the first target imagined for any future journey beyond it.

The corrupted name Bungula appears to be a garbled Latin rendering, of uncertain derivation, that entered specifically the astrological star lists rather than the astronomical literature, which has always used Rigil Kentaurus or the bare Bayer designation Alpha Centauri; Bungula is accordingly a name one finds in Robson and his sources but essentially nowhere else. The star's true distinction, nearest system to the Sun, was established only once reliable stellar parallax measurement became possible in the nineteenth century, centuries after Bungula had already acquired its name in the older astrological lists.