Sagittarius

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Sagittarius
Image:Sagittarius constellation map.png click for larger image
Abbreviation	Sgr
Genitive	Sagittarii
Symbology	the Archer
Right ascension	19 h
Declination	−25°
Area	867 sq. deg. Ranked 15th
Number of stars (magnitude < 3)	7
Brightest star	ε Sgr (Kaus Australis) (App. magnitude 1.9)
Meteor showers
Bordering constellations	Aquila Scutum Serpens Cauda Ophiuchus Scorpius Corona Australis Telescopium Indus (corner) Microscopium Capricornus
Visible at latitudes between +55° and −90° Best visible at 21:00 (9 p.m.) during the month of August

Sagittarius (Image:Saggitarius symbol.png, and Latin for Archer) 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.

The name Sagittarius has also been given to a recently discovered galaxy, the Sagittarius Dwarf Elliptical Galaxy, located just outside the Milky Way.

1 Notable features
2 Notable deep-sky objects
3 Mythology
- 3.1 Astrology
4 Notable and named stars
5 See also
6 External links

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 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. [1] [2]

α Sgr (Rukbat) isn't the brightest star of the constellation, having a magnitude of only 3.96. (It is 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 associated with the galactic centre is also here. Astronomers believe that Sagittarius A may contain a supermassive black hole.

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 [3]. 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

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).

In some cosmologies, Sagittarius is associated with the classical element Fire, and thus called a Fire Sign (with Aries and Leo). It is also one of the four Mutable signs (along with Gemini, Virgo, and Pisces). Its polar opposite is Gemini. Each astrological sign is assigned a part of the body, viewed as the seat of its power, Sagittarius assigned with the hips and thighs. It is the domicile of Jupiter. The symbol for Sagittarius is the centaur or archer.

Notable and named stars

BD	F	Star Names and other designations	Mag.	Ly away	Comments
ε	20	Epsilon Sagittarii, Kaus Australis	1.79	145	قوس qaws bow + austrālis southern
σ	34	Sigma Sagittarii, Nunki, Sadira, Pelag	2.05	224
ζ	38	Zeta Sagittarii, Ascella	2.60	89	ascella armpit
δ	19	Delta Sagittarii, Kaus Media, Kaus Meridionalis, Kaus Medius, Media	2.72	306	قوس qaws bow + media middle
λ	22	Lambda Sagittarii, Kaus Borealis	2.82	77	قوس qaws bow + boreālis northern
π	41	Pi Sagittarii, Albaldah, Al Baldah	2.88	440	البلطة al-balţah the axe
γ²	10	Gamma-2 Sagittarii, Alnasl, Nasl, El Nasl, Alwazl, Nushaba, Zujj al Nushshaba	2.98	96	النصل an-naşl the arrowhead
η		Eta Sagittarii	3.10	149	Irregular variable
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	five star system
ρ¹	44	Rho-1 Sagittarii	3.92	122
β¹		Beta-1 Sagittarii, Arkab Prior	3.96	378	عرقوب ^{c^arqūb} hamstring + prior
α		Alpha Sagittarii, Rukbat, Rucba, Rukbat al Rami, Alrami	3.96	170	ركبة الرامي rukbat[u] ar-rāmī knee of the archer/bowman
ι		Iota Sagittarii	4.12
β²		Beta-2 Sagittarii, Arkab Posterior	4.27		عرقوب ^{c^arqūb} hamstring + posterior
θ¹		Theta-1 Sagittarii	4.37
c	62	Terebellum, 62 Sagittarii, HR 7650, HD 189763	4.43		Irregular variable
υ	46	Upsilon Sagittarii	4.52		the prototypical hydrogen-deficient binary
b¹	59	Terebellum, 59 Sagittarii, HR 7604, HD 188603	4.52
	3	X Sagittarii	4.53		A Cepheid variable
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	A Cepheid variable
	21	21 Sagittarii	4.81
A	60	Terebellum, 60 Sagittarii, HR 7618, HD 189005	4.84
ν¹	32	Nu-1 Sagittarii, Ain al Rami	4.86		عين الرامي ^{c^{ain ar-rāmī}} eye of the archer
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		has 2 planets
	16	16 Sagittarii	5.96
	26	26 Sagittarii	6.22
		HD 179949	6.25		has a planet
	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	nearby
		OGLE-TR-10	14.93		has a planet
		S2			orbits Sgr A* black hole
		Pistol Star			hypergiant