Abbreviation:  Oph
English Name:  The Serpent Holder
Genitive: Rasalhague
Hemisphere:  Northern Hemisphere
Location: Between the constellations of Hercules and Scorpius.
Visible between latitudes:  
+80 and -80 degrees
Best season: Summer
Seen in three seasons: Spring, Summer, and Autumn.
Best seen in:  July
Seen between: June and August.
Right Ascension (RA):  17 hour
Declination (DEC):  +00 degrees
Area (square degrees):  948 (11th)

Ophiuchus  (The Serpent Holder)

  • Ophiuchus is a very large but not particularly classifiable constellation; the southern portion of which extends to the galactic plane.
  • The whole of the southern area is filled with gas and dust, giving rise to all three types of diffuse nebulae – there are some Open Clusters and about 25 Globular Clusters.

Messier Objects

  • M9  –  Globular Cluster; Medium concentration of stars – bright, large and round. (Magnitude: +7.9)
  • M10  –  Globular Cluster; Very well resolved in apertures greater than 10-inch. (Magnitude: +6.6)
  • M12  –  Globular Cluster; low power (telescope’s eyepiece) there is a rocket-shaped. (Magnitude: +6.7)
  • M14  –  Globular Cluster; Remarkable object – extremely rich. (Magnitude: +7.6)
  • M19  –  Globular Cluster; appearing elongated/oval-shaped, even in binoculars – it begins to be resolved with 6-inch telescopes. (Magnitude: +7.2)
  • M62  –  Globular Cluster; High concentrated of stars, large and bright. (Magnitude: +6.6)
  • M107  –  Globular Cluster; faintest as suffering from concentration, being so close to the galactic centre.

Features of Interest

  • NGC 6572  –  Planetary Nebula; bright and is visible with 3-inch small telescopes. (Magnitude: +9.1)
  • NGC 6633  –  Open Cluster; bright, intergrated magnitude +4.6 – visible with naked-eye. Worth examining with binoculars.
  • IC 4665  –  Open Cluster; large and scattered – no concentration of stars, moderate range in brightness.  It is readily seen in binoculars and small telescopes. (Magnitude: +4.2)

Named Stars

  • Rasalhague (Alpha Oph)
  • Cebalrai (Beta Oph)
  • Yed Prior (Delta Oph)
  • Yed Posterior (Epsilon Oph)
  • Sabik (Eta Oph)
  • Marfic (Lambda Oph)


  • Photo of the constellation; Ophiuchus, as it appears to the naked eye. (Lines have been added for clarity.)
  • Sky Chart  –  Ophiuchus
  • List of stars in Ophiuchus.


Back to The 88 Constellations Lists  page.

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