Sagittarius

For the astrological sign, see Sagittarius.

, Unicode ♐) is a constellation of the zodiac, commonly depicted as a centaur drawing a bow. Sagittarius lies between Scorpius to the west and Capricornus to the east.

Notable features

The constellation's brighter stars (from left to right on the map: τ, ζ, σ, φ, λ, ε, δ, η and γ² Sagittarii) form an easily recognizable asterism called the Teapot. The Milk Dipper is part of the Teapot. The stars δ Sgr (Kaus Media), ε Sgr (Kaus Australis), ζ Sgr (Ascella), and φ Sgr form the body of the pot; λ Sgr (Kaus Borealis) is the point of the lid; γ² (Alnasl) is the tip of the spout; and σ Sgr (Nunki) and τ Sgr the handle. [http://www.flandrau.org/astronomy/skywatchers/picupclose.php?picid=89

α Sgr (Rukbat) isn't the brightest star of the constellation, having a magnitude of only 3.96 (not shown on the map as it is located below the map's southwestern corner, north is up).

Notable deep-sky objects

The Milky Way as seen from the earth is at its densest as it passes through Sagittarius, as this is where the galactic center lies. Consequently, Sagittarius contains many star clusters and nebulae. One of the brightest of the star clusters is M55, about 7.5° west of δ Sgr.

The constellation contains nebulae such as the Lagoon Nebula (M8), near λ Sagittarii, beautiful in telescopes; the Omega, Swan, or Horseshoe Nebula (M17), near the border with Scutum; and the Trifid Nebula (M20), a large nebula containing some very young, hot stars.

The complex radio source Sagittarius A is also here. Astronomers believe that one of its components, known as Sagittarius A*, is associated with a supermassive black hole at the center of the galaxy.

The Sagittarius Dwarf Elliptical Galaxy is located just outside the Milky Way.

Mythology

Sagittarius has the rough appearance of a stick-figure archer drawing its bow, and when including the fainter stars, appears to have a horse-like body ^*. The Greeks identified such a figure as a centaur, whereas earlier cultures, such as the Babylonians, identified it as the god Pabilsag (which also had wings and a lion's head).

In Greek mythology, Sagittarius was sometimes identified as Chiron, aiming his bow at the Scorpion, although the more usual identification of Chiron was with the constellation Centaurus. The constellation Sagitta was sometimes considered to be an arrow fired by Sagittarius.

Other early identifications include that of a rattle, which the constellation's brightest stars considered together vaguely resemble. As such, together with other constellations in the Zodiac sign of Sagittarius (specifically, Cygnus, Lyra, and Aquila), may be a significant part of the origin of the myth of the Stymphalian Birds, one of The Twelve Labours of Herakles.

Astrology

Main article: Sagittarius (astrology)

The Western astrological sign Sagittarius of the tropical zodiac (November 22 - December 21) differs from the astronomical constellation and the Hindu astrological sign of the sidereal zodiac (December 18 - January 18).

Notable and named stars

قوس qaws bow + austrālis southern

ascella armpit

قوس qaws bow + media middle

قوس qaws bow + boreālis northern

البلطة al-balţah the axe

النصل an-naşl the arrowhead

Irregular variable

five star system

عرقوب ^{c^arqūb} hamstring + prior

ركبة الرامي rukbat^* ar-rāmī knee of the archer/bowman

عرقوب ^{c^arqūb} hamstring + posterior

Irregular variable

the prototypical hydrogen-deficient binary

A Cepheid variable

A Cepheid variable

عين الرامي ^{c^{ain ar-rāmī}} eye of the archer

has 2 planets

has a planet

nearby

nearby

has a planet

orbits Sgr A* black hole

hypergiant

BD	F	Star Names and other designations	Mag.	Ly away
ε	20	Epsilon Sagittarii, Kaus Australis	1.79	145
σ	34	Sigma Sagittarii, Nunki, Sadira, Pelag	2.05	224
ζ	38	Zeta Sagittarii, Ascella	2.60	89
δ	19	Delta Sagittarii, Kaus Media, Kaus Meridionalis, Kaus Medius, Media	2.72	306
λ	22	Lambda Sagittarii, Kaus Borealis	2.82	77
π	41	Pi Sagittarii, Albaldah, Al Baldah	2.88	440
γ²	10	Gamma-2 Sagittarii, Alnasl, Nasl, El Nasl, Nash, Alwazl, Nushaba, Zujj al Nushshaba	2.98	96
η		Eta Sagittarii	3.10	149
φ	27	Phi Sagittarii	3.17	231
τ	40	Tau Sagittarii	3.32	120
ξ²	37	Xi-2 Sagittarii	3.52	372
ο	39	Omicron Sagittarii, Manubrij	3.76	139
μ	13	Mu Sagittarii, Polis	3.84	8150
ρ¹	44	Rho-1 Sagittarii	3.92	122
β¹		Beta-1 Sagittarii, Arkab Prior	3.96	378
α		Alpha Sagittarii, Rukbat, Rucba, Rukbat al Rami, Alrami	3.96	170
ι		Iota Sagittarii	4.12
β²		Beta-2 Sagittarii, Arkab Posterior	4.27
θ¹		Theta-1 Sagittarii	4.37
c	62	Terebellum, 62 Sagittarii, HR 7650, HD 189763	4.43
υ	46	Upsilon Sagittarii	4.52
b¹	59	Terebellum, 59 Sagittarii, HR 7604, HD 188603	4.52
	3	X Sagittarii	4.53
h²	52	52 Sagittarii	4.59
ω	58	Terebellum, Omega Sagittarii, HR 7597, HD 188376	4.74
	4	4 Sagittarii	4.74
γ¹		Gamma-1 Sagittarii, W Sagittarii	4.79	1500
	21	21 Sagittarii	4.81
A	60	Terebellum, 60 Sagittarii, HR 7618, HD 189005	4.84
ν¹	32	Nu-1 Sagittarii, Ain al Rami, Facies	4.86
ψ	42	Psi Sagittarii	4.86
f	56	56 Sagittarii	4.87
d	43	43 Sagittarii	4.88
	11	11 Sagittarii	4.96
ν²	35	Nu-2 Sagittarii	5.00
g	61	61 Sagittarii	5.01
ξ¹	36	Xi-1 Sagittarii	5.02
χ¹	47	Chi-1 Sagittarii	5.02
e²	55	55 Sagittarii	5.06
	29	29 Sagittarii	5.22
	15	15 Sagittarii	5.29
θ²		Theta-2 Sagittarii	5.30
e¹	54	54 Sagittarii	5.30
	7	7 Sagittarii	5.37
	28	28 Sagittarii	5.37
χ³	49	Chi-3 Sagittarii	5.45
	14	14 Sagittarii	5.49
	24	24 Sagittarii	5.49
	50	50 Sagittarii	5.57
	18	18 Sagittarii	5.58
κ¹		Kappa-1 Sagittarii	5.60
κ²		Kappa-2 Sagittarii	5.64
h¹	51	51 Sagittarii	5.64
	33	33 Sagittarii	5.68
	63	63 Sagittarii	5.69
ρ²	45	Rho-2 Sagittarii	5.84
	57	57 Sagittarii	5.88
	9	9 Sagittarii	5.89
		HD 169830	5.91	118.5^*
	16	16 Sagittarii	5.96
	26	26 Sagittarii	6.22
		HD 179949	6.25	88^*
	6	6 Sagittarii	6.27
	30	30 Sagittarii	6.29
	53	53 Sagittarii	6.33
	25	25 Sagittarii	6.53
	65	65 Sagittarii	6.53
	17	17 Sagittarii	6.89
χ²	48	Chi-2 Sagittarii	7.26
		Ross 154	10.46	9.56
		Gliese 783	5.31	19.7
		OGLE-TR-10	14.93	5000^*
		S2
		Pistol Star

Source: The Bright Star Catalogue, 5th Revised Ed., The Hipparcos Catalogue, ESA SP-1200

External links

The Deep Photographic Guide to the Constellations: Sagittarius