Ophiuchus is a vast constellation found in the Milky Way. It is located just above Scorpius. For binoculars two of the many Messier deep sky objects here are large and bright enough to enjoy, and a non-Messier cluster as well. Ophiuchus, the Serpent Holder, grasps the serpent in his hands. Thus a simultaneous study of Serpens is suggested.
Alpha Ophiuchi is known as Ras Alhague, The Head of the Serpent Holder. With a visual magnitude of 2.1 this white star is the brightest in this part of the heavens, while not competing with Vega and Altair. Finding Ras Alhague should be quite easy. The star forms the southwestern tip of an equilateral triangle with Altair and Vega. There are a number of other relationships which you may find more convenient, such as approximiately midway between a line drawn from Arcturus to Altair. Ras Alhague is the northern-most star in this asterism. As Ophiuchus is quite large, its principal stars are generally separated by several FOV. Beta, a yellow giant nearly as bright at 2.8, is to the south-southeast of Ras Alhague, about nine degrees, just out of one FOV.
Beta Ophiuchi is a yellow giant, the second brightest star, ten degrees south of alpha. It takes a telescope to pick out the star with the largest known proper motion, known as Barnard's Star, and found due east of beta about one full FOV.
Delta Ophiuchi is known as ‘Yed Prior’ (The Preceding Star of the Hand). The neighbouring star, epsilon Oph, is ‘Yed Posterior’ (Following Star of the Hand). Both stars are 3rd-mag orange giants and represent the left hand of Ophiuchus, which is holding the serpent. These two stars are easily found three and a half binocular fields to the southwest of alpha Oph, or just above the Scorpion's stinger (if you've studied Scorpius) You can also find them from Serpens. Following Serpens Caput down to its most southerly star, mu, we find the two Ophiuchi stars in the same field. East of delta and epsilon are the two finest Messier objects in Ophiuchus, M10 and M12.
Eta Ophiuchi is a white star which forms the southern-most point of the body of Ophiuchus. The star is convenient for locating the tail of the serpent (Serpens Cauda), as this constellation resumes (nu Serpentis) at a point just northeast of eta Ophiuchi. To find eta drop southwest about ten degrees from delta Ophiuchi. You'll come across zeta Oph; (considered Ophiuchus' left knee). Another ten degrees southwest brings you to eta. The star cluster in the same field (M9) is quite faint and unspectacular.
Nu Ophiuchi is Ophiuchus' right hand, as it too grasps the serpent. The star is a 3.3 magnitude, making it brighter than the serpent's nearby stars. With the naked eye draw a line from alpha Oph to beta Oph (southeast). Now extend that line twice the distance and you'll come to nu Oph. Nu Oph is also found by following the stars of Serpens, as it's in the same FOV as omicron Serpentis.
Theta Ophiuchi is Ophiuchus' right foot, as well as being a blue-white subgiant. Theta is very far to the south, and three binocular fields east of Antares.
