Location.—A line drawn from ε Delphini to γ Aquilæ, prolonged about 30°, strikes the star Ras Alhague, the brightest star in the constellation and the head of Ophiuchus. It is at one angle of an isosceles triangle, of which Altair is at the apex, and Vega the third angle.
Two constellations are here combined. Ophiuchus is represented as an old man, holding in his hands a writhing serpent.
Ras Algethi, marking the head
Equally distant southeast and southwest of Ras Alhague are to be seen two stars close together, representing the shoulders of Ophiuchus. His foot rests on the Scorpion just above Antares.
The head of Serpens is the star group in the form of an "X" just below the Crown.
1604 indicates the spot where in that year a famous temporary star appeared, called Kepler's star.
Note the asterism the "Bull of Poniatowski" just east of γ. The star marked 70 is one of the most distant stars for which a parallax has been obtained. Its distance from the earth = 1,300,000 radii of the earth's orbit, or 120 quadrillion miles.
There is something remarkable in the central position of this gigantic figure. It is situated almost exactly in the mid-heavens, being nearly equidistant from the poles, and midway between the vernal and autumnal equinoxes.