OPHIUCHUS AND SERPENS

Ophiuchus, the Serpent Bearer, sprawls his way across the center of the picture (north up and to the right), his brightest star, Rasalhague (Alpha), at top center. (The reddish glow is coming from reflection by light clouds.) Just down and to the right of Rasalhague is Rasalgethi in Hercules, a bit down and to the left Cebalrai (Beta), and down and to left of Cebalrai is Muliphen (Gamma). Ophiuchus is a distorted pentagon-shaped figure, its bottom starting with two stars close together toward lower center (Yed Prior, at right, and Yed Posterior) and running to the left through Zeta Ophiuchi and ending in bright Sabik. Marfik, Lambda Oph, is up and just to the right of Yed Prior. Theta Oph (seen in the context of the Milky Way west of Sagittarius) is the brightest of the string of four stars near the lower left corner; Xi is about mid-way between it and Sabik. Rho Oph, the brighter of the two stars near the left lower edge, is better seen in the context of Scorpius whose bright star Antares is near the bottom left. 67 and 70 Oph are in v-shaped "Poniatowski's Bull" up and to the left of Cebalrai (as is invisible Barnard's Star). Kappa Oph is the brighter of the pair down and to the left of Rasalhague, while Chi is the middle star of the near-vertical trio below Zeta. Mu Oph, to the left of center, is the second star directly above Sabik, while Nu Oph is up and to the left of Mu. Sigma Oph lies down and to the right of Beta.

Coming off the bottom and swinging up to both the right and left are two streams of stars that make the divided figure of Serpens, the Serpent. The stream to the left is Serpens Cauda, the Serpent's Tail, that to the right Serpens Caput, the Serpent's Head. Unukalhai, the brightest star in Serpens Caput, is the bright star toward the lower right. Delta Ser is to the right and just up from it, while Beta Ser and Gamma Ser are progressively upward from Delta. Epsilon Ser is immediately to the left of Unukalhai, while Lambda is just above it. Kappa Ser lies in the middle of the Serpent's head immediately to the right of Gamma Ser. In Serpens Cauda, Xi Ser is up and to the left of Sabik. Far above it, towards the top, is Eta Ser. Serpens Cauda continues upward off the picture and ends in Alya (Theta Ser), near Aquila.

As noted above, the Milky Way in Scutum and Sagittarius runs downward at left; the red glow is the diffuse nebula Messier 8. Antares in Scorpius is at the lower left. Southern Hercules is at the upper right, the curve of Corona Borealis below. Omega Herculis is the more distant of the two stars well to the right of and a bit down from Kappa Oph.

The bright golobular clusters Messier 10 and Messier 12 lie within the pentagon and are identified in the labelled image. The curved smudge up and to the left of center is an image flaw.

To see a labelled image, push the star:

See full resolution.

See Ophiuchus in context with Hercules, Lyra, and Draco.

See Ophiuchus and Serpens from Bayer's Uranometria of 1603.

See Serpens Cauda within the wide field around Sagittarius.

By Jim Kaler. Return to STARS.