Serpens

Serpens

Constellation
List of stars in Serpens
Abbreviation	Ser
Genitive	Serpentis
Pronunciation	/ˈsɜrpɨnz/, genitive /sərˈpɛntɨs/
Symbolism	the Snake
Right ascension	Serpens Caput: 16 h Serpens Cauda: 18
Declination	Serpens Caput: +10° Serpens Cauda: −5
Area	637 sq. deg. (23rd)
Main stars	9
Bayer/Flamsteed stars	57
Stars with known planets	5
Bright stars	1
Nearby stars	3
Brightest star	α Ser (Unukalhai) (2.63m)
Nearest star	γ Ser (36.3 ly)
Messier objects	2
Bordering constellations	Serpens Caput: Corona Borealis Boötes Virgo Libra Ophiuchus Hercules Serpens Cauda: Aquila Ophiuchus Sagittarius Scutum
Visible at latitudes between +80° and −80°. Best visible at 21:00 (9 p.m.) during the month of July.

Serpens is a constellation. Its name is Latin for snake, and it is unique among the modern constellations in being split into two separate sections, Serpens Caput (the snake's head) to the west and Serpens Cauda (the tail) to the east. Between these two halves lies the constellation of Ophiuchus, the serpent holder. Serpens was one of the 48 constellations listed by the 2nd century astronomer Ptolemy and it remains one of the 88 modern constellations.

Notable features

Serpens held by Ophiuchus, as depicted in Urania's Mirror, a set of constellation cards published in London c.1825. Above the tail of the serpent is the now-obsolete constellation Taurus Poniatovii while below it is Scutum.

Stars

Since Serpens is regarded as one constellation despite being split into two halves, the ordering of Bayer designations goes in order of brightness among both halves.

Only one of the stars in Serpens is brighter than third magnitude, so the constellation is not easy to perceive. α Serpentis, named Unukalhai, is in the head part. δ Serpentis, also in the head, is a double star 210 light-years from Earth. θ Serpentis. also named Alya ("the snake" in Arabic), in the tail, is also double.

Stars in the head include α, β, γ, δ, ε, ι, κ, λ, μ, π, ρ, σ, τ, χ and ω Serpentis. Stars in the tail include ζ, η, θ, ν, ξ, and ο Serpentis.

Deep-sky objects

Messier 5, a globular cluster located approximately 8° southwest of α Serpentis in the head.

Messier 16 is a young open cluster associated with the Eagle Nebula, a diffuse nebula which is a region of current star formation in the tail.

MWC 922, a nebula in the Mount Wilson Catalog, is a Symmetric Bipolar Nebula notable for its appearance as a perfectly symmetrical square or rectangle. It is also known as IRAS 18184-1302, and located at RA: 18:21:16 DEC: -13:01:27, near M16 in Serpens Cauda. The MWC is from Mount Wilson Observatory.

Part of the Milky Way passes through the tail, as illustrated by the shaded regions of the star map.

The Serpens South star cluster was uncovered by NASA's Spitzer Space Telescope in the southern portion of the Serpens cloud. The discovery was possible due to the infrared observation capabilities of the SST because at visible wavelengths the stars are completely obscured by interstellar dust in the Serpens cloud.

History

Originally, Serpens and Ophiuchus were considered a single constellation, the snake-holder, out of which developed an associated myth of the founding of medicine.^{[citation needed]}

References

• Ian Ridpath and Wil Tirion (2007). Stars and Planets Guide, Collins, London. ISBN 978-0007251209. Princeton University Press, Princeton. ISBN 978-0691135564.

External links

Wikimedia Commons has media related to: Serpens

• The Deep Photographic Guide to the Constellations: Serpens
• Star Tales – Serpens
• Stellar Siblings in Serpens South

Coordinates: 17^h 00^m 00^s, +03° 00′ 00″