
Abbreviation: Â Oph
English Name: Â The Serpent Holder
Genitive:Â Rasalhague
Hemisphere:Â Â Northern Hemisphere
Location:Â Between the constellations of Hercules and Scorpius.
Visible between latitudes: Â +80 and -80 degrees
Best season: Summer
Seen in three seasons:Â Spring, Summer, and Autumn.
Best seen in:Â July
Seen between:Â June and August.
Right Ascension (RA):Â 17 hour
Declination (DEC):Â Â +00 degrees
Area (square degrees): Â 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 Â – Â Globular Cluster; Medium concentration of stars – bright, large and round. (Magnitude: +7.9)
- M10 Â – Â Globular Cluster; Very well resolved in apertures greater than 10-inch. (Magnitude: +6.6)
- M12 Â – Â Globular Cluster; low power (telescope’s eyepiece) there is a rocket-shaped. (Magnitude: +6.7)
- M14 Â – Â Globular Cluster; Remarkable object – extremely rich. (Magnitude: +7.6)
- M19 Â – Â Globular Cluster; appearing elongated/oval-shaped, even in binoculars – it begins to be resolved with 6-inch telescopes. (Magnitude: +7.2)
- M62 Â – Â Globular Cluster; High concentrated of stars, large and bright. (Magnitude: +6.6)
- M107 Â – Â Globular Cluster; faintest as suffering from concentration, being so close to the galactic centre.
Features of Interest
- NGC 6572 Â – Â Planetary Nebula; bright and is visible with 3-inch small telescopes. (Magnitude: +9.1)
- NGC 6633 Â – Â Open Cluster; bright, intergrated magnitude +4.6 – visible with naked-eye. Worth examining with binoculars.
- IC 4665 Â – Â Open Cluster; large and scattered – no concentration of stars, moderate range in brightness. Â 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)
Others
- Photo of the constellation;Â 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.