What is the Serpens constellation?
The Serpent (Snake) is one of the 88 modern constellations, and was also one of the 48 Ptolemaic constellations. Among the modern constellations it is the only one that is divided into two parts: Serpens Caput, which represents the head of the snake, towards the west and Serpens Cauda, which represents the tail, towards the east. Between these two parts is the constellation of Ophiuchus, the Serpentarium.
Main Stars Serpens
Since Snake is considered a single constellation although separated into two parts, the order of the Bayer designation is according to the luminosity between both constellations.
Only one of Serpens’ stars is brighter than the third magnitude, so the constellation is not easy to see. α Serpentis, called Unukalhai, is the head part. δ Serpentis, also overhead, is a double star just 27 light years from Earth. θ Serpentis, in the tail, is also double.
Eventually we can find the stars α, β, γ, δ, ε, ι, κ, λ, μ, π, ρ, σ, τ, χ and ω Serpentis. In the tail are the stars ζ, η, θ, ν, ξ, and ο Serpentis.
Unakalhai (α Serpentis)
The main star of Serpens, Unukalhai (α Serpentis), is located in the head. It is of apparent magnitude 2.60. It is an orange giant about 15 times larger than the Sun.
Its name derives from an Arabic phrase that means the neck of the snake.
Other stars
δ SerpentisAfter all, it is a double star that is 210 light years from Earth. These two components are very similar, two white subgiants. It seems that they would be more than 370 ua apart.
θ Serpentis, on the tail, is also double and is named after Alya.
R Serpentis is a Mira type variable, which evolves between magnitudes 5.16 and 14 in 357 days.
Serpens Deep Sky Objects
The Serpens constellation contains many celestial objects:
M5 It is a globular cluster, located 8° southwest of α Serpentis in the head. This is one of the most beautiful in heaven. Milky Way satellite has a diameter of 500 light years, making it almost a dwarf galaxy.
M16, the Eagle Nebula, is a diffuse nebula illuminated by fifteen young stars. This is a star formation zone.
We also find the diffuse nebula NGC 6611 and the open clusters NGC 6604 and IC 4756.
History and mythology of the Sculptor constellation
Snake It is an ancient constellation, although its original symbology remains unknown. Greek mythology is identified with the serpent that revealed the secrets of medicine to Asclepius. Consequently, it is always represented carried by Ophiuchus (the Serpentarian), this is the one who controls the power of the animal.