As snakes shed their skin every year, they were known as the symbol of rebirth in ancient Greek society, and legend says Asclepius would revive dead humans using the same technique he witnessed.

However, this posed the problem of how to disentangle the two constellations, with Deporte deciding to split Serpens into two areas—the head and the tail—separated by the continuous Ophiuchus.

[1] Serpens Caput is bordered by Libra to the south, Virgo and Boötes to the west, Corona Borealis to the north, and Ophiuchus and Hercules to the east; Serpens Cauda is bordered by Sagittarius to the south, Scutum and Aquila to the east, and Ophiuchus to the north and west.

Traditionally called Unukalhai,[7] is a red giant of spectral type K2III located approximately 23 parsecs distant with a visual magnitude of 2.630 ± 0.009,[8] meaning it can easily be seen with the naked eye even in areas with substantial light pollution.

[12] Another solar analog in Serpens is the primary of Psi Serpentis, a binary star[13] located slightly further away at approximately 14 parsecs.

[22] Delta Serpentis, forming part of the body of the snake between the heart and the head, is a multiple star system[23] positioned around 70 parsecs from Earth.

[26] Positioned very near Delta, both in the night sky and likely in actual space at an estimated distance of around 70 parsecs,[27] is the barium star 16 Serpentis.

Xi, where the asterism crosses over to Mu Serpentis in the head, is a triple star system[9] located approximately 105 parsecs away.

[51][52] Two of the stars, with a combined apparent magnitude of around 3.5, form a spectroscopic binary with an angular separation of only 2.2 milliarcseconds,[53] and thus cannot be resolved with modern equipment.

[51] Theta, forming the tip of the tail, is also a multiple system, consisting of two A-type main-sequence stars with a combined apparent magnitude of around 4.1 separated by almost half an arcminute.

[68] Another Orion variable in the region is VV Serpentis, a Herbig Ae star that has been found to exhibit Delta Scuti pulsations.

[69] VV Serpentis has also, like MWC 297, been found to have a dusty disk surrounding it,[70] and is also a UX Orionis star,[71] meaning that it shows irregular variations in its brightness.

[74] Barely visible to the naked eye is HD 172365,[75] a likely post-blue straggler in the open cluster IC 4756 that contains a large excess of lithium.

[79] Although not visible to the naked eye, HD 167971 (MY Serpentis) is a Beta Lyrae variable triple system consisting of three very hot O-type stars.

[84] South of the Eagle Nebula on the border with Sagittarius is the eclipsing binary W Serpentis, whose primary is a white giant that is interacting with the secondary.

The system has been found to contain an accretion disk, and was one of the first discovered Serpentids, which are eclipsing binaries containing exceptionally strong far-ultraviolet spectral lines.

[89] The system has also been found to approximately every 3 days brighten by around 3.5 K-band magnitudes, possibly due to the presence of a synchrotron jet.

Many stars are leaving this globular cluster due to the Milky Way's gravity, forming a tidal tail over 30000 light-years long.

[118] Slightly fainter is NGC 5921, a barred spiral galaxy with a LINER-type active galactic nucleus situated somewhat closer at a distance of 21 megaparsecs.

It consists of two large spiral galaxies in the process of colliding with their nuclei orbiting at a distance of 1,200 light-years, causing extensive star formation throughout both components.

It possesses a large cluster of more than a billion stars, partially covered by thick dust clouds near one of the galaxies' core.

[133] The foreground member of the pair (4C 11.50 A) does not have enough mass to refract light from the background component (4C 11.50 B) enough to produce a lensed image, although it does have a true companion of its own.

[143] Part of the galactic plane passes through the tail, and thus Serpens Cauda is rich in deep-sky objects within the Milky Way galaxy.

The Eagle Nebula and its associated star cluster, Messier 16 lie around 5,700[144] light-years from Earth in the direction of the Galactic Center.

The stars being born in the Eagle Nebula, added to those with an approximate age of 5 million years have an average temperature of 45,000 kelvins and produce prodigious amounts of radiation that will eventually destroy the dust pillars.

[151] Despite the presence of the Milky Way in Serpens Cauda, one globular cluster can be found: NGC 6535, although invisible to the naked eye, can be made out in small telescopes just north of Zeta Serpentis.

[163] The Serpens South protocluster was uncovered by NASA's Spitzer Space Telescope in the southern portion of the cloud,[164] and it appears that star formation is still continuing in the region.

[165] Another site of star formation is the Westerhout 40 complex, consisting of a prominent HII region adjacent to a molecular cloud.

[167] Despite the presence of the Milky Way, several active galaxies are visible in Serpens Cauda as well, such as PDS 456, found near Xi Serpentis.

The most intrinsically luminous nearby active galaxy,[170] this AGN has been found to be extremely variable in the X-ray spectrum.