Sagittarius (constellation)

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Sagittarius
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Abbreviation	Sgr
Genitive	Sagittarii
Symbology	the Archer
Right ascension	19 h
Declination	−25°
Area	867 sq. deg. Ranked 15th
Number of stars (Bayer-Flamsteed)	67
Number of bright stars (magnitude < 3)	7
Number of nearby stars (Distance < 100 ly)	3
Brightest star	ε Sgr (Kaus Australis) (App. magnitude 1.9)
Nearest Star	λ Sag (Kaus Borealis) (Distance: 77 ly)
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

For the astrological sign, see Sagittarius (astrology).

Sagittarius (IPA: /ˌsædʒiˈteɪriəs/, Latin: archer, symbol Image:Sagittarius.svg, Unicode ♐) is a constellation of the zodiac, commonly depicted as a centaur drawing a bow. Sagittarius lies between Ophiuchus to the west and Capricornus to the east.

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

[edit] 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. [1] [2]

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).

[edit] 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.

[edit] 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]. Sometimes it is called the 'Teapot' as it looks like that. 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.

[edit] 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).

[edit] 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 (or "the City")
γ²	10	Gamma-2 Sagittarii, Alnasl, Nasl, El Nasl, Nash, Alwazl, Nushaba, Zujj al Nushshaba	2.98	96	النصل an-naşl the Arrowhead
η		Eta Sagittarii, Sephdar, Ira Furoris	3.10	149	< الصفدر al-safdar the Violent Warrior < Latin for "Fierce Wrath" or "Raging Anger" (of the Archer) Irregular variable
φ	27	Phi Sagittarii, Nanto	3.17	231	< 斗 näntō South Dipper
τ	40	Tau Sagittarii, Hecatebolus, Hekatebolos	3.32	120	< Εκατηβολος Hekatebolos alternate name for the god Apollo, meaning "Far Darter" or "Sudden Death"
ξ²	37	Xi-2 Sagittarii	3.52	372
ο	39	Omicron Sagittarii, Manubrij, Manubrium	3.76	139	< Latin for "handle" or "haft"
μ	13	Mu Sagittarii, Polis	3.84	8150	five star system
ρ¹	44	Rho-1 Sagittarii, Cappa	3.92	122	< Latin for "cape" (worn by Sagittarius)
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	189
β²		Beta-2 Sagittarii, Arkab Posterior	4.27	378	عرقوب ^{c^arqūb} hamstring + posterior
θ¹		Theta-1 Sagittarii	4.37	618
c	62	Terebellum, 62 Sagittarii, HR 7650, HD 189763	4.43	448	Irregular variable
υ	46	Upsilon Sagittarii	4.52	1673	the prototypical hydrogen-deficient binary
b¹	59	Terebellum, 59 Sagittarii, HR 7604, HD 188603	4.52	1200
	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	77.6
	4	4 Sagittarii	4.74
γ¹		Gamma-1 Sagittarii, W Sagittarii	4.79	340	A Cepheid variable
	21	21 Sagittarii	4.81
A	60	Terebellum, 60 Sagittarii, HR 7618, HD 189005	4.84	1850
ν¹	32	Nu-1 Sagittarii, Ain al Rami, Facies	4.86	330	عين الرامي ^{c^{ain ar-rāmī}} eye of the archer
ψ	42	Psi Sagittarii	4.86	270
f	56	56 Sagittarii	4.87
d	43	43 Sagittarii	4.88
	11	11 Sagittarii	4.96
ν²	35	Nu-2 Sagittarii	5.00	>2300
g	61	61 Sagittarii	5.01
ξ¹	36	Xi-1 Sagittarii	5.02	221
χ¹	47	Chi-1 Sagittarii	5.02	618
e²	55	55 Sagittarii	5.06
	29	29 Sagittarii	5.22
	15	15 Sagittarii	5.29
θ²		Theta-2 Sagittarii	5.30	506
e¹	54	54 Sagittarii	5.30
	7	7 Sagittarii	5.37
	28	28 Sagittarii	5.37
χ³	49	Chi-3 Sagittarii	5.45	244
		HD 183275	5.52
	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	371
κ²		Kappa-2 Sagittarii	5.64	359
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[4]	has 2 planets
	16	16 Sagittarii	5.96
	26	26 Sagittarii	6.22
		HD 179949	6.25	88[5]	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	1200
		Ross 154	10.46	9.56	nearby
		Gliese 783	5.31	19.7	nearby
		OGLE-TR-10	14.93	5000[6]	has a planet
		S2			orbits Sgr A* black hole
		Pistol Star			hypergiant