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List of stars in Sagittarius
List of stars in Sagittarius
List of stars in Sagittarius
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This is the list of notable stars in the constellation Sagittarius, sorted by decreasing brightness.

Name B F G. Var HD HIP RA Dec vis.
mag. 		abs.
mag. 		Dist. (ly) Sp. class Notes
ε Sgr ε 20 61 169022 90185 18h 24m 10.35s −34° 23′ 03.5″ 1.79 −1.44 145 B9.5III Kaus Australis, Thalith al Warida[1]
σ Sgr σ 34 112 175191 92855 18h 55m 15.92s −26° 17′ 47.7″ 2.05 −2.14 224 B2.5V Nunki, Thani al Sadira[1]
ζ Sgr ζ 38 130 176687 93506 19h 02m 36.72s −29° 52′ 48.4″ 2.60 0.42 89 A3IV Ascella, Thalith al Sadira[1]
δ Sgr δ 19 54 168454 89931 18h 20m 59.62s −29° 49′ 40.9″ 2.72 −2.14 306 K3III Kaus Media (Kaus Medius, Kaus Meridionalis, Thani al Warida[1])
λ Sgr λ 22 67 169916 90496 18h 27m 58.27s −25° 25′ 16.5″ 2.82 0.95 77 K1IIIb Kaus Borealis
π Sgr π 41 147 178524 94141 19h 09m 45.83s −21° 01′ 24.7″ 2.88 −2.77 440 F2II/III Al Baldah,[2] Nir al Beldat, Lucida Oppidi[1]
γ2 Sgr γ2 10 28 165135 88635 18h 05m 48.52s −30° 25′ 25.1″ 2.98 0.63 96 K0III Alnasl, Nash, Nushaba, Awal al Warida[1]
η Sgr η 46 167618 89642 18h 17m 37.73s −36° 45′ 40.6″ 3.10 −0.20 149 M2III Rabi al Warida[1]irregular variable
φ Sgr φ 27 95 173300 92041 18h 45m 39.35s −26° 59′ 26.8″ 3.17 −1.08 231 B8.5III Awal al Sadira[1]
τ Sgr τ 40 139 177716 93864 19h 06m 56.44s −27° 40′ 11.3″ 3.32 0.48 120 K1/K2III Rabi al Sadira[1]
ξ2 Sgr ξ2 37 120 175775 93085 18h 57m 43.78s −21° 06′ 23.8″ 3.52 −1.77 372 G8/K0II/III
ο Sgr ο 39 136 177241 93683 19h 04m 40.93s −21° 44′ 28.9″ 3.76 0.61 139 K0III
μ Sgr μ 13 41 166937 89341 18h 13m 45.81s −21° 03′ 31.8″ 3.84 >3000 B2III: Polis;[2] quintuple star; Algol variable
ρ1 Sgr ρ1 44 174 181577 95168 19h 21m 40.38s −17° 50′ 50.1″ 3.92 1.06 122 F0III/IV δ Sct variable
β1 Sgr β1 168 181454 95241 19h 22m 38.29s −44° 27′ 32.1″ 3.96 −1.36 378 B9V Arkab Prior
α Sgr α 177 181869 95347 19h 23m 53.15s −40° 36′ 56.3″ 3.96 0.38 170 B8V Rukbat, Alrami
ι Sgr ι 241 188114 98032 19h 55m 15.68s −41° 52′ 06.3″ 4.12 0.30 189 K0III
β2 Sgr β2 172 181623 95294 19h 23m 13.06s −44° 47′ 58.7″ 4.27 1.13 139 F2III Arkab Posterior
θ1 Sgr θ1 256 189103 98412 19h 59m 44.17s −35° 16′ 34.5″ 4.37 −2.02 617 B2.5IV
62 Sgr c 62 265 V3872 189763 98688 20h 02m 39.46s −27° 42′ 35.6″ 4.43 −1.26 448 M4III V3872 Sgr; part of the Terebellum; irregular variable
υ Sgr υ 46 176 181615 95176 19h 21m 43.62s −15° 57′ 18.0″ 4.52 −4.03 1672 B2Vpe+A2IaS the prototypical hydrogen-deficient binary; Be star
X Sgr 3 2 X 161592 87072 17h 47m 33.63s −27° 49′ 50.7″ 4.53 −3.06 1076 F7II Cepheid variable
59 Sgr b1 59 250 188603 98162 19h 56m 56.82s −27° 10′ 11.5″ 4.54 −3.30 1207 K3III part of the Terebellum
HD 165634 31 165634 88839 18h 08m 04.96s −28° 27′ 25.3″ 4.55 −0.59 348 K0IIICNpvar
52 Sgr h2 52 207 184707 96465 19h 36m 42.39s −24° 53′ 00.8″ 4.59 0.77 189 B8/B9V
γ1 Sgr γ1 26 W 164975 88567 18h 05m 01.22s −29° 34′ 48.3″ 4.66 −4.36 2076 G0Ib/II Nash; W Sgr; Cepheid variable
HD 167818 51 167818 89678 18h 18m 03.19s −27° 02′ 33.5″ 4.66 −2.00 700 K3III
ω Sgr ω 58 248 188376 98066 19h 55m 50.23s −26° 17′ 58.9″ 4.70 2.82 78 G3/G5III part of the Terebellum; also named "Terebellum"
4 Sgr 4 15 163955 88116 17h 59m 47.56s −23° 48′ 57.6″ 4.74 −0.89 436 B9V
HD 189831 268 189831 98761 20h 03m 33.41s −37° 56′ 25.8″ 4.77 −0.70 405 K4III
21 Sgr 21 65 169420 90289 18h 25m 21.04s −20° 32′ 29.8″ 4.81 −1.50 597 A1/A2V
60 Sgr A 60 255 189005 98353 19h 58m 57.18s −26° 11′ 45.0″ 4.84 −0.25 340 G8II/III part of the Terebellum
HD 172910 91 172910 91918 18h 44m 19.36s −35° 38′ 30.9″ 4.86 −0.84 451 B2V Nóngzhàngrén (農丈人)[3]
ν1 Sgr ν1 32 111 174974 92761 18h 54m 10.18s −22° 44′ 41.4″ 4.86 −3.91 1852 K1II Ainalrami, Ain al Rami [2]
ψ Sgr ψ 42 155 179950 94643 19h 15m 32.40s −25° 15′ 23.8″ 4.86 −0.16 330 K0/K1III+..
56 Sgr f 56 229 186648 97290 19h 46m 21.82s −19° 45′ 39.2″ 4.87 0.88 205 K0III
43 Sgr d 43 160 180540 94820 19h 17m 38.09s −18° 57′ 10.4″ 4.88 −1.20 535 K0III
1 Sgr 11 40 166464 89153 18h 11m 43.33s −23° 42′ 04.2″ 4.96 0.59 244 K0III
HD 190056 270 190056 98842 20h 04m 19.56s −32° 03′ 22.6″ 4.99 0.00 324 K1III/IV
14 G. Sgr 14 163755 88060 17h 59m 05.28s −30° 15′ 10.8″ 5.00 −2.29 934 K5/M0III
ν2 Sgr ν2 35 113 175190 92845 18h 55m 07.07s −22° 40′ 16.5″ 5.00 0.41 270 K1Ib/II Ain al Rami [2]
61 Sgr g 61 253 188899 98258 19h 57m 57.02s −15° 29′ 28.5″ 5.01 0.25 292 A2V
ξ1 Sgr ξ1 36 119 175687 93057 18h 57m 20.48s −20° 39′ 22.8″ 5.02 −5.92 5015 B9.5Ib
χ1 Sgr χ1 47 181 182369 95477 19h 25m 16.45s −24° 30′ 30.4″ 5.02 0.87 221 A4IV/V Namalsadirah III
55 Sgr e2 55 225 186005 96950 19h 42m 31.09s −16° 07′ 26.3″ 5.06 1.42 175 F3IV/V On 12 January 2006 it was occulted by Venus, but Venus was not visible.[4]: 164 
76 G. Sgr 76 170680 90806 18h 31m 26.30s −18° 24′ 09.5″ 5.12 1.04 213 B9/B9.5V
29 Sgr 29 104 174116 92390 18h 49m 40.11s −20° 19′ 29.1″ 5.22 −1.59 749 K2III
77 G. Sgr 77 171034 91014 18h 33m 57.76s −33° 00′ 59.5″ 5.28 −3.90 2233 B2III/IV
15 Sgr 15 43 167264 89439 18h 15m 12.91s −20° 43′ 41.8″ 5.29 B0/1Ia/ab
54 Sgr e1 54 221 185644 96808 19h 40m 43.34s −16° 17′ 35.3″ 5.30 0.92 245 K1III
θ2 Sgr θ2 256 189118 98421 19h 59m 51.28s −34° 41′ 51.5″ 5.30 1.89 157 A4/A5IV
V3961 Sgr 235 V3961 187474 97749 19h 51m 50.59s −39° 52′ 27.6″ 5.32 0.24 339 A0p α² CVn variable
HR 7703 279 191408 99461 20h 11m 11.61s −36° 05′ 50.6″ 5.32 6.41 20 K2V nearby binary star
V4050 Sgr 59 V4050 168733 90074 18h 22m 53.08s −36° 40′ 10.2″ 5.33 −1.06 619 B7Ib/II α² CVn variable
7 Sgr 7 20 164584 88380 18h 02m 51.10s −24° 16′ 56.7″ 5.37 −2.28 1105 F2/F3II/III
75 G. Sgr 75 170479 90763 18h 31m 04.85s −32° 59′ 20.4″ 5.37 0.22 350 A5V
28 Sgr 28 99 173460 92111 18h 46m 20.59s −22° 23′ 31.9″ 5.37 −2.60 1278 K5III
χ3 Sgr χ3 49 182 182416 95503 19h 25m 29.67s −23° 57′ 44.7″ 5.45 −0.50 505 K3III
193 G. Sgr 193 183275 95865 19h 29m 52.17s −26° 59′ 07.8″ 5.46 1.00 254 K1/K2III
212 G. Sgr 212 184985 96536 19h 37m 34.48s −14° 18′ 05.2″ 5.46 3.01 101 F7V
14 Sgr 14 42 167036 89369 18h 14m 15.91s −21° 42′ 47.2″ 5.49 −0.46 505 K2III
24 Sgr 24 78 171115 91004 18h 33m 53.49s −24° 01′ 56.2″ 5.49 −4.62 3432 K3III
134 G. Sgr 134 177074 93667 19h 04m 25.06s −31° 02′ 49.3″ 5.49 −0.63 546 A0V
226 G. Sgr 226 186185 97063 19h 43m 33.45s −15° 28′ 10.8″ 5.49 2.67 120 F5V
126 G. Sgr 126 176162 93225 18h 59m 23.80s −12° 50′ 25.7″ 5.51 −0.48 514 B4V
153 G. Sgr 153 179497 94437 19h 13m 15.52s −12° 16′ 57.0″ 5.51 −0.68 565 K3III
228 G. Sgr 228 186500 97260 19h 46m 01.22s −31° 54′ 30.7″ 5.51 −0.61 545 B8III
32 G. Sgr 32 165687 88816 18h 07m 48.40s −17° 09′ 15.5″ 5.52 1.10 249 K0III
60 G. Sgr 60 168838 90124 18h 23m 28.82s −36° 14′ 16.8″ 5.52 0.57 319 K0III
37 G. Sgr 37 166023 89020 18h 10m 05.81s −30° 43′ 43.0″ 5.53 0.31 360 K1III + (F)
114 G. Sgr 114 175317 92882 18h 55m 31.02s −16° 22′ 34.3″ 5.56 3.03 104 F5/F6IV/V
V4024 Sgr 144 V4024 178175 93996 19h 08m 16.70s −19° 17′ 25.0″ 5.56 −2.80 1531 B2V γ Cas variable; Be star
50 Sgr 50 185 182629 95564 19h 26m 19.13s −21° 46′ 36.1″ 5.57 −0.59 556 K1/K2III
18 Sgr 18 63 169233 90260 18h 25m 01.51s −30° 45′ 23.0″ 5.58 −0.93 653 K0III
162 G. Sgr 162 180885 94986 19h 19m 39.99s −35° 25′ 17.1″ 5.59 −3.17 1842 B4III
165 G. Sgr 165 181240 95077 19h 20m 38.16s −22° 24′ 09.4″ 5.59 1.81 186 A6:m...
κ1 Sgr κ1 292 193571 100469 20h 22m 27.48s −42° 02′ 57.7″ 5.60 1.23 244 A0V
74 G. Sgr 74 170433 90687 18h 30m 11.84s −18° 43′ 42.9″ 5.63 0.86 293 K0III
131 G. Sgr 131 176704 93498 19h 02m 27.69s −24° 50′ 47.0″ 5.63 0.99 276 K2III
51 Sgr h1 51 204 V5548 184552 96406 19h 36m 01.65s −24° 43′ 08.5″ 5.64 0.89 290 A1m... V5548 Sgr; δ Sct variable
κ2 Sgr κ2 294 193807 100591 20h 23m 53.19s −42° 25′ 22.5″ 5.64 0.36 370 A3V
262 G. Sgr 262 189245 98470 20h 00m 20.16s −33° 42′ 09.9″ 5.65 4.05 68 F7V
186 G. Sgr 186 182681 95619 19h 26m 56.47s −29° 44′ 35.2″ 5.66 1.46 225 B8/B9V
209 G. Sgr 209 184835 96496 19h 37m 03.33s −18° 13′ 51.7″ 5.66 0.00 442 K0III
33 Sgr 33 110 174947 92747 18h 54m 00.09s −21° 21′ 35.3″ 5.68 −2.95 1734 G8/K0II
63 Sgr 63 266 189741 98633 20h 01m 58.58s −13° 38′ 14.1″ 5.69 0.80 309 A1IV
189 G. Sgr 189 183007 95823 19h 29m 23.77s −43° 26′ 41.7″ 5.70 1.91 187 Am
187 G. Sgr 187 182645 95557 19h 26m 11.03s −15° 03′ 11.7″ 5.71 −1.40 862 B7IV
21 G. Sgr 21 164402 88298 18h 01m 54.38s −22° 46′ 49.0″ 5.72 B0Iab...
184 G. Sgr 184 182477 95485 19h 25m 21.56s −13° 53′ 50.2″ 5.72 −1.01 723 K2III
12 G. Sgr 12 163652 88038 17h 58m 55.68s −36° 51′ 30.3″ 5.74 0.49 365 G8III
10 G. Sgr 10 163318 87836 17h 56m 41.82s −28° 03′ 55.3″ 5.76 2.25 164 A7III/IV
Y Sgr 57 Y 168608 89968 18h 21m 22.99s −18° 51′ 35.9″ 5.76 −2.23 1294 F8II
84 G. Sgr 84 171961 91405 18h 38m 30.72s −23° 30′ 17.4″ 5.78 0.01 465 B8III
152 G. Sgr 152 179323 94434 19h 13m 13.67s −25° 54′ 24.3″ 5.79 −3.27 2117 K2III
259 G. Sgr 259 189198 98512 20h 00m 48.32s −45° 06′ 46.6″ 5.80 0.59 359 A8III
50 G. Sgr 50 167720 89609 18h 17m 11.63s −17° 22′ 25.9″ 5.81 −1.72 1045 K2III
94 G. Sgr 94 173117 91974 18h 44m 49.60s −25° 00′ 39.1″ 5.82 −1.11 793 B8III
ρ2 Sgr ρ2 45 175 181645 95188 19h 21m 50.83s −18° 18′ 29.4″ 5.84 0.63 359 K0III
HD 172051 86 172051 91438 18h 38m 53.45s −21° 03′ 05.4″ 5.85 5.28 42 G5V
296 G. Sgr 296 194215 100738 20h 25m 26.82s −28° 39′ 47.8″ 5.86 −0.24 541 G8II/III
57 Sgr 57 238 187739 97783 19h 52m 12.01s −19° 02′ 41.5″ 5.88 0.98 312 K0III
9 Sgr 9 24 164794 88469 18h 03m 52.44s −24° 21′ 38.6″ 5.89 −5.01 4939 O6Vf
V4089 Sgr 201 V4089 184035 96234 19h 34m 08.48s −40° 02′ 04.7″ 5.89 0.26 435 A5IV-III Algol variable
HD 169830 66 169830 90485 18h 27m 49.48s −29° 49′ 00.8″ 5.90 3.10 118 F8V has two planets (b & c)
116 G. Sgr 116 175360 92931 18h 56m 00.67s −23° 10′ 25.4″ 5.91 −1.27 891 B6III
180 G. Sgr 180 182286 95456 19h 25m 04.05s −29° 18′ 33.2″ 5.91 1.32 270 K3III
83 G. Sgr 83 171856 91347 18h 37m 54.43s −21° 23′ 51.2″ 5.93 1.01 314 A5IV
138 G. Sgr 138 177517 93763 19h 05m 41.18s −15° 39′ 37.4″ 5.93 −1.20 869 B8IIIsp...
29 G. Sgr 29 165185 88694 18h 06m 23.64s −36° 01′ 11.3″ 5.94 4.74 57 G3V
260 G. Sgr 260 189195 98461 20h 00m 15.92s −37° 42′ 06.2″ 5.95 1.02 316 G8/K0III
16 Sgr 16 44 167263 89440 18h 15m 12.97s −20° 23′ 16.7″ 5.96 B0.5Ib/II
132 G. Sgr 132 176884 93537 19h 03m 03.80s −19° 14′ 44.4″ 5.96 −2.33 1482 K0II/III
218 G. Sgr 218 185467 96760 19h 40m 07.15s −23° 25′ 44.6″ 5.97 0.45 415 K0III
25 G. Sgr 25 164870 88550 18h 04m 50.39s −35° 54′ 04.9″ 5.98 0.79 355 K2III
13 G. Sgr 13 163685 88012 17h 58m 39.05s −28° 45′ 32.7″ 5.99 −2.06 1331 B3II/III
141 G. Sgr 141 177817 93855 19h 06m 52.12s −16° 13′ 45.2″ 6.00 −1.19 893 B7V
264 G. Sgr 264 189561 98575 20h 01m 23.84s −22° 44′ 14.2″ 6.01 1.10 313 K0III
RS Sgr 47 RS 167647 89637 18h 17m 36.25s −34° 06′ 26.0″ 6.03 −1.13 881 B3/B4IV/V 47 G. Sgr
179 G. Sgr 179 182180 95408 19h 24m 30.17s −27° 51′ 57.3″ 6.03 −2.00 1315 B2Vnn
233 G. Sgr 233 187098 97515 19h 49m 11.53s −28° 47′ 19.4″ 6.04 2.75 149 F3V
V4387 Sgr 45 V4387 167356 89470 18h 15m 30.76s −18° 39′ 41.7″ 6.05 −4.35 3928 Ap Si α² CVn variable
140 G. Sgr 140 177846 93925 19h 07m 30.84s −28° 38′ 12.4″ 6.05 −1.19 916 K3III
295 G. Sgr 295 194184 100764 20h 25m 48.01s −40° 47′ 45.5″ 6.08 0.91 352 K3III
121 G. Sgr 121 175794 93134 18h 58m 21.31s −31° 02′ 09.1″ 6.09 0.46 436 K3III
163 G. Sgr 163 180928 94929 19h 19m 00.15s −15° 32′ 09.2″ 6.09 0.09 517 K4III
148 G. Sgr 148 178555 94144 19h 09m 48.13s −19° 48′ 12.4″ 6.11 0.71 392 K1III
197 G. Sgr 197 183545 95965 19h 30m 54.04s −21° 18′ 43.9″ 6.11 −1.78 1235 A2V
232 G. Sgr 232 186984 97423 19h 48m 03.01s −13° 42′ 12.8″ 6.11 2.13 204 A6:IIIm...
258 G. Sgr 258 189140 98485 20h 00m 26.47s −43° 02′ 36.0″ 6.11 −1.53 1101 M0III
108 G. Sgr 108 174631 92643 18h 52m 37.05s −29° 22′ 46.4″ 6.12 0.22 493 K1III
38 G. Sgr 38 166197 89086 18h 10m 55.35s −33° 48′ 00.2″ 6.13 B2II/III
178 G. Sgr 178 181925 95396 19h 24m 21.45s −43° 43′ 19.4″ 6.13 −0.12 579 M1/M2III
V4333 Sgr 208 V4333 184705 96440 19h 36m 26.06s −18° 51′ 10.4″ 6.13 1.80 240 F0V δ Sct variable
62 G. Sgr 62 169236 90290 18h 25m 21.70s −35° 59′ 31.3″ 6.14 0.39 461 K0III
123 G. Sgr 123 175892 93140 18h 58m 24.83s −22° 31′ 46.3″ 6.14 1.67 255 A1V
224 G. Sgr 224 186042 97067 19h 43m 37.62s −37° 32′ 19.4″ 6.14 −0.95 853 B8IV/V
58 G. Sgr 58 168646 90012 18h 22m 00.13s −28° 25′ 47.8″ 6.15 0.33 475 A3III
3 G. Sgr 3 161664 87099 17h 47m 45.60s −22° 28′ 40.0″ 6.18 −2.54 1811 G3/G5Ib
63 Oph (63) 8 162978 87706 17h 54m 54.04s −24° 53′ 13.5″ 6.18 O7/O8III
49 G. Sgr 49 167666 89622 18h 17m 24.08s −28° 39′ 07.3″ 6.18 0.75 397 A5V
70 Sgr 56 V4028 168574 89980 18h 21m 31.36s −24° 54′ 55.0″ 6.19 −1.57 1164 M3III V4028 Sgr
71 G. Sgr 71 169990 90494 18h 27m 56.48s −17° 48′ 01.3″ 6.19 −0.01 567 B8III/IV
280 G. Sgr 280 191584 99570 20h 12m 23.86s −42° 46′ 47.3″ 6.20 1.08 344 K2III
16 G. Sgr 16 164028 88125 18h 00m 00.08s −20° 20′ 22.2″ 6.22 −0.88 858 K0III
HD 165516 30 165516 88760 18h 07m 11.35s −21° 26′ 38.2″ 6.22 −4.35 4234 O+...
26 Sgr 26 88 172546 91689 18h 41m 51.61s −23° 50′ 00.1″ 6.22 2.20 208 A3m...
V4200 Sgr 242 V4200 188088 97944 19h 54m 17.82s −23° 56′ 24.3″ 6.22 5.46 46 K3/K4V BY Draconis variable
297 G. Sgr 297 194433 100852 20h 26m 53.14s −37° 24′ 09.5″ 6.24 3.25 129 K1IV
128 G. Sgr 128 176537 93423 19h 01m 37.74s −22° 41′ 43.3″ 6.25 −2.10 1523 K3III
V5652 Sgr 157 V5652 179949 94645 19h 15m 33.15s −24° 10′ 44.8″ 6.25 4.09 88 F8V Gumala; has a planet (b)
V4199 Sgr 173 V4199 181558 95159 19h 21m 37.11s −19° 14′ 03.9″ 6.25 −0.34 679 B5III
6 Sgr 6 18 164358 88258 18h 01m 23.12s −17° 09′ 24.7″ 6.27 −2.50 1852 K2III
206 G. Sgr 206 184574 96365 19h 35m 33.46s −12° 15′ 11.0″ 6.27 1.14 346 K0III
254 G. Sgr 254 188981 98351 19h 58m 56.37s −30° 32′ 17.7″ 6.27 2.18 214 K1III
69 G. Sgr 69 169938 90510 18h 28m 06.17s −26° 45′ 25.8″ 6.28 1.69 269 A3/A4V
109 G. Sgr 109 174630 92635 18h 52m 28.32s −26° 39′ 02.2″ 6.28 0.91 386 G8/K0III
V4198 Sgr 142 177863 93887 19h 07m 08.33s −18° 44′ 17.3″ 6.28 −0.45 724 B8V
150 G. Sgr 150 178840 94272 19h 11m 18.80s −29° 30′ 08.1″ 6.28 0.34 502 B8/B9V
30 Sgr 30 105 174309 92480 18h 50m 50.50s −22° 09′ 43.6″ 6.61 1.91 245 F2IV
17 G. Sgr 17 164245 88294 18h 01m 48.30s −36° 22′ 40.1″ 6.30 −0.42 721 B7/B8II/III
64 G. Sgr 64 169398 90336 18h 25m 54.61s −33° 56′ 44.5″ 6.30 −1.05 962 B7III
143 G. Sgr 143 178075 93993 19h 08m 14.56s −24° 39′ 26.5″ 6.30 −0.27 672 B9.5V
282 G. Sgr 282 192433 99878 20h 15m 50.59s −30° 00′ 19.1″ 6.30 −1.43 1148 K4III
V4434 Sgr 283 V4434 192472 99920 20h 16m 23.61s −36° 27′ 12.7″ 6.30 −0.78 851 M4III
V3894 Sgr 4 V3894 161756 87163 17h 48m 27.84s −26° 58′ 29.8″ 6.31 −1.40 1136 B3Vn
68 G. Sgr 68 169851 90478 18h 27m 43.76s −26° 38′ 05.1″ 6.31 1.87 252 A7V
90 G. Sgr 90 172875 91901 18h 44m 07.93s −36° 43′ 05.6″ 6.31 1.11 357 K0III
129 G. Sgr 129 176593 93418 19h 01m 33.52s −15° 16′ 57.4″ 6.31 0.14 559 K0III
263 G. Sgr 263 189388 98579 20h 01m 26.76s −40° 48′ 51.3″ 6.31 1.64 280 A2/A3V
V3879 Sgr 89 V3879 172816 91781 18h 42m 55.11s −19° 17′ 02.9″ 6.32 −1.55 1221 M4III
39 G. Sgr 39 166393 89114 18h 11m 14.79s −19° 50′ 30.8″ 6.33 1.09 365 A2V
167 G. Sgr 167 181401 95211 19h 22m 09.57s −42° 00′ 57.4″ 6.33 1.36 321 K1III
53 Sgr 53 217 185404 96729 19h 39m 49.46s −23° 25′ 39.4″ 6.33 0.85 406 A0V
V4405 Sgr 98 V4405 173425 92079 18h 46m 01.15s −19° 36′ 22.9″ 6.34 −0.43 738 M2/M3III
96 G. Sgr 96 173282 92016 18h 45m 18.64s −21° 00′ 05.6″ 6.35 2.58 185 F5/F6V
127 G. Sgr 127 176246 93315 19h 00m 24.78s −24° 56′ 32.2″ 6.35 −0.62 809 K0III
48 G. Sgr 48 167665 89620 18h 17m 23.66s −28° 17′ 19.0″ 6.36 4.00 97 F8V
80 G. Sgr 80 171416 91172 18h 35m 59.64s −29° 41′ 56.7″ 6.36 −1.20 1058 K1III
125 G. Sgr 125 176123 93234 18h 59m 26.78s −18° 33′ 59.0″ 6.37 −0.66 830 G5/G6II
133 G. Sgr 133 176903 93543 19h 03m 06.99s −19° 06′ 10.9″ 6.37 1.82 265 F5V
36 G. Sgr 36 165978 89010 18h 09m 59.96s −32° 43′ 09.4″ 6.39 1.15 365 K0III
151 G. Sgr 151 179201 94372 19h 12m 28.02s −21° 39′ 30.0″ 6.39 0.66 457 K0III
34 G. Sgr 34 165784 88876 18h 08m 38.59s −21° 26′ 58.4″ 6.42 −3.41 3019 A2/A3Iab
269 G. Sgr 269 190009 98785 20h 03m 44.33s −22° 35′ 44.3″ 6.44 2.64 188 F7V
115 G. Sgr 115 175390 92972 18h 56m 27.23s −31° 41′ 20.4″ 6.45 −0.30 731 K2III
103 G. Sgr 103 173928 92301 18h 48m 45.41s −18° 36′ 04.2″ 6.46 −0.48 795 A1V + K1III
290 G. Sgr 290 193302 100332 20h 20m 51.87s −35° 40′ 25.4″ 6.46 0.79 444 K3III
234 G. Sgr 234 187150 97484 19h 48m 50.17s −12° 19′ 09.7″ 6.47 −2.04 1638 K5III
V505 Sgr 240 V505 187949 97849 19h 53m 06.39s −14° 36′ 11.1″ 6.47 1.14 380 A1V
244 G. Sgr 244 188158 98012 19h 55m 05.11s −33° 02′ 46.5″ 6.47 −1.46 1259 K2/K3III
9 G. Sgr 9 163245 87782 17h 55m 54.96s −18° 48′ 07.6″ 6.48 1.25 363 A1V
166 G. Sgr 166 181321 95149 19h 21m 29.70s −34° 58′ 59.6″ 6.48 4.88 68 G1/G2V
196 G. Sgr 196 183577 96095 19h 32m 14.11s −44° 32′ 47.3″ 6.48 3.37 137 F6V
V4190 Sgr 79 V4190 171369 91132 18h 35m 21.31s −20° 50′ 25.6″ 6.49 1.64 304 F0IV/V δ Sct variable
25 Sgr 25 171237 91066 18h 34m 32.76s −24° 13′ 20.6″ 6.53 −3.45 3228 F2II
65 Sgr 65 274 190454 98953 20h 05m 26.33s −12° 39′ 54.2″ 6.53 1.07 402 A0V
RY Sgr 156 RY 180093 94730 19h 16m 32.76s −33° 31′ 20.3″ 6.58 −5.64 9056 Cp 156 G. Sgr
HD 163296 163296 87819 17h 56m 21.29s −21° 57′ 21.87″ 6.85 329 A3VaekA1mA1 protoplanetary disk
17 Sgr 17 167570 89567 18h 16m 35.37s −20° 32′ 40.1″ 6.89 0.55 605 A7:
HD 187085 187085 97546 19h 49m 33.97s −37° 46′ 50.0″ 7.22 3.95 147 G0V has a planet (b)
χ2 Sgr χ2 48 182391 95486 19h 25m 22.34s −24° 24′ 43.5″ 7.27 −0.53 1185 B7IV Namalsadirah IV
HD 181342 181342 95124 19h 21m 04.23s −23° 37′ 10.5″ 7.55 2.24 377 K0III has a planet (b)
HD 180902 180902 94951 19h 19m 17.71s −23° 33′ 29.359″ 7.78 2.48 374 K0III/IV has a planet (b)
HD 190647 190647 99115 20h 07m 19.67s −35° 32′ 19.1″ 7.78 4.11 177 G5V has a planet (b)
HD 181720 181720 95262 19h 22m 52.99s −32° 55′ 08.6″ 7.86 4.12 182 G1V has a planet (b)
HD 169142 169142 18h 24m 29.8s −29° 46′ 50″ 8.16 473 A7V has a planet (b)
HD 171238 171238 91085 18h 34m 43.67s −28° 04′ 20.3″ 8.66 5.44 144 K0V has a planet (b)
HD 165155 165155 88650 18h 05m 57.0s −29° 55′ 02″ 9.36 212 G8V has a planet (b)
HD 164604 164604 88414 18h 03m 06.93s −28° 33′ 38.3″ 10.04 7.14 124 K2V has a planet (b)
Ross 154 92403 18h 49m 49.36s −23° 50′ 10.4″ 10.44 13.08 9.68 M3.5V V1216 Sgr; 9th nearest star; flare star
WASP-123 19h 17m 55.0s −32° 51′ 36″ 11.1 G5 has a transiting planet (b)
Sakurai's Object V4334 17h 52m 32.7s −17° 41′ 08″ 11.6 F2Ia C~
WASP-110 20h 23m 30.0s −44° 03′ 30″ 12.3 1044 G9 has a transiting planet (b)
WASP-67 19h 42m 59.0s −19° 56′ 58″ 12.5 734 K0V has a transiting planet (b)
OGLE-TR-10 V5125 17h 51m 28.25s −29° 52′ 34.9″ 14.93 5000 G or K has a transiting planet (b)
OGLE-TR-56 V5157 17h 56m 35.31s −29° 32′ 21.2″ 16.56 5000 G has a transiting planet (b)
SWEEPS
J175853.92−291120.6		 17h 58m 53.92s −29° 11′ 20.6″ 18.80 ~6500 F5V has a planet SWEEPS-04
OGLE-2005-BLG-169L 18h 06m 05s −30° 43′ 57″ 19.4 8800 M? has a planet (b)
OGLE-2003-BLG-235 18h 05m 16s −28° 53′ 42″ 19.7 17000 K has a planet (b)
SWEEPS
J175902.67−291153.5		 17h 59m 02.67s −29° 11′ 53.5″ 19.83 ~6500 has a planet (SWEEPS-11)
MOA-2007-BLG-400L 18h 09m 42s −29° 13′ 27″ 22 20000 M3V? has a planet (b)
SWEEPS
J175902.00-291323.7		 17h 59m 02.00s −29° 13′ 23.7″ 26.23 ~6500 has a possible shortest period planet (SWEEPS-10)
MOA-2007-BLG-192L 18h 08m 04s −27° 09′ 00″ 7040 M has a planet (b)
Pistol Star V4647 17h 46m 15.3s −28° 50′ 04″ >28 25000 LBV hypergiant; member of the Quintuplet star cluster
V6392 Sgr V6392 18h 21m 59.36s −28° 23′ 25.1″ 18,700 Mira Variable[5]
V4998 Sgr V4998 17h 46m 05.62s 28° 51′ 31″ 26000 LBV luminous blue variable; member of the Quintuplet star cluster
LBV 1806-20 18h 08m 40.3s −20° 24′ 41″ 28000 LBV luminous blue variable; member of the 1806-20 cluster
WR 102ea 17h 46m 15.13s −28° 49′ 37.0″ 26000 WN9h Wolf–Rayet star; member of the Quintuplet star cluster
S2 17h 45m 40.04s −29° 00′ 28″ n/a 26000 B0V orbits the supermassive black hole Sgr A*
KW Sgr KW 316496 87433 17h 52m 00.7s −28° 01′ 20.6″ 11.0 9000-
13000		 M1.5 Iab hypergiant; one of the largest known stars. B magnitude = 11.
Table legend:

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References

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List of stars in Sagittarius

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The list of stars in Sagittarius comprises the numerous stars positioned within the boundaries of Sagittarius, one of the 88 officially recognized modern constellations defined by the (IAU). This zodiacal constellation, visible predominantly in the , represents a archer drawing a bow and occupies a prominent position along the band, directing its arrow toward the . Sagittarius is notable for its rich stellar population, including several bright stars that form the distinctive "" asterism—a of four main stars resembling a teapot with a handle and spout—making it easily identifiable in the summer evening sky for mid-northern latitude observers. The brightest star in the constellation is Kaus Australis (ε Sagittarii), a blue-white of spectral type B9.5 III with an apparent visual magnitude of 1.79, located approximately 145 light-years from and possessing an of -1.44. The second-brightest is Nunki (σ Sagittarii), a hot blue main-sequence star of spectral type B2.5 V shining at magnitude 2.05, situated about 224 light-years away with an of -2.14. Other prominent stars include Kaus Media (δ Sagittarii), an orange giant in a paired with a companion, and Kaus Borealis (λ Sagittarii), an orange giant of type K1IIIb marking the northern tip of the Teapot's "lid." These stars, along with fainter ones like Ascella (ζ Sagittarii) and Alnasl (γ Sagittarii), contribute to the constellation's visibility and have been cataloged in various astronomical surveys for their positions, magnitudes, and physical properties. Beyond bright stars, Sagittarius hosts thousands of fainter members, many obscured or enhanced by the dense interstellar and gas in this direction toward the .

Introduction

Constellation Overview

Sagittarius is a large zodiacal constellation in the , ranking as the 15th largest among the 88 modern constellations with an area of 867 square degrees. It lies between to the west and to the east, occupying the fourth quadrant of the sky (SQ4). The constellation's position places it along the , making it one of the 12 zodiac signs, and it encompasses a rich field of the . The boundaries of Sagittarius extend approximately from right ascension 17h 40m to 20h 25m and +12° to -45°, centered around 19h and -25° , as defined by the IAU's irregular polygonal boundaries along lines of and . It is best observed during and from latitudes between +55° and -90°, when it reaches its highest point in the evening sky. Observers often recognize the constellation through its distinctive "" asterism, formed by eight prominent stars that outline the shape of a teapot with a handle, body, and spout. First cataloged by the Greek astronomer in the 2nd century CE as part of his 48 ancient constellations, Sagittarius represents the archer or centaur from . Its modern boundaries were formally delimited by the (IAU) in 1930, standardizing the polygonal outlines for all constellations along lines of and . Notably, the constellation hosts the , the central region of the galaxy, near the radio source Sagittarius A*.

Astronomical Importance

Sagittarius holds profound astronomical significance due to its position along the to the Milky Way's galactic center, where the Sagittarius A* resides at equatorial coordinates of 17h 45m 40s and −29° 00′ 28″. This region is heavily obscured by interstellar dust, rendering visible-light observations nearly impossible and necessitating the use of and to probe its structure and dynamics. These wavelengths penetrate the dust, enabling detailed studies of the dense stellar environment, gas clouds, and high-energy phenomena at the galaxy's core, which provide critical insights into galactic and physics. In ancient mythology, Sagittarius is depicted as a archer, a half-human, half-horse figure drawing a bow, often linked to the wise from Greek lore, who served as a teacher to heroes like Achilles and . associated the constellation with the god , a of and the portrayed as a winged, centaur-like being with a bow, reflecting early cultural interpretations of the stars as symbols of power and conflict. As the ninth sign of the zodiac, Sagittarius spans approximately 30 degrees along the , the apparent path of the Sun, , and against the , with the Sun transiting this region from late to late December. This positioning influences astrological traditions, where it symbolizes exploration, , and optimism, guiding interpretations of celestial influences on human affairs. The constellation hosts a rich stellar density, with approximately 217 stars brighter than magnitude 6.5 visible to the under dark skies, encompassing diverse populations that include young, massive O- and B-type stars indicative of active . The asterism within Sagittarius aids in its identification, resembling a kettle in the summer .

Principal Stars

Brightest Stars

The of a star measures its as seen from on a , where a decrease of 1 magnitude corresponds to an increase in by a factor of approximately 2.512; thus, lower numerical values indicate brighter stars. Stars brighter than magnitude 2.5 are readily visible to the even in moderately light-polluted skies and often define the primary shape of a constellation's asterism. In Sagittarius, these include (the brightest at magnitude 1.85) and (magnitude 2.05). These stars contribute to the distinctive asterism in Sagittarius, where (Kaus Australis) forms part of the body near the base of the spout, and (Nunki) lies at the top of the handle. Kaus Australis is a blue-white giant of spectral type B9.5 III, located approximately 143 light-years away. Nunki is a blue main-sequence star of spectral type B2.5 V at about 228 light-years.
Bayer DesignationProper NameApparent MagnitudeSpectral TypeDistance (ly)Coordinates (J2000)
ε SgrKaus AustralisB9.5 III143RA 18h 24m 10s, Dec -34° 23' 05"
σ SgrNunkiB2.5 V228RA 18h 55m 16s, Dec -26° 17' 49"

Named Stars

The (IAU) formalized 17 proper names for stars in Sagittarius during its 2016–2017 standardization efforts, drawing from ancient , Babylonian, Greek, Latin, and other cultural traditions to preserve diverse astronomical heritage. These names predominantly evoke the constellation's archer motif, referencing anatomical features like knees and armpits or implements such as the , as documented in historical texts like those of and Al Sufi. origins dominate, stemming from medieval catalogues that translated and adapted earlier Babylonian and Greek designations, while a few reflect later Latin interpretations or indigenous proposals submitted during IAU's global naming initiatives. Etymological roots highlight Sagittarius's cross-cultural legacy: Alnasl derives from the Arabic phrase "nasl al-sahm," denoting the "arrowhead" and symbolizing the arrow's tip in the archer's grasp. The Kaus trio—Kaus Australis, Kaus Media, and Kaus Borealis—originates from Arabic "qaws" (bow) combined with Latin directional suffixes, specifying the bow's southern, middle, and northern segments, respectively. Nunki traces to Babylonian "Šu-nun-ki," likely referencing a sacred site, while Rukbat comes from Arabic "rukbah" (knee), marking the archer's leg. Ascella, of Latin origin meaning "armpit," illustrates the blend of Roman anatomical terms with earlier Arabic descriptions. Newer approvals like Pincoya incorporate indigenous elements, honoring a Chilean water spirit from Mapuche-Chilote mythology, and Gumala draws from Malay lore as a "magic bezoar stone" associated with mythical creatures. Belel reflects Wolof language from Senegal, denoting a rare water source, and Sika evokes cultural terms for natural phenomena in Polynesian or Asian contexts, though specifics remain tied to proposal submissions. These names were ratified to promote inclusivity beyond Eurocentric traditions. Several named stars contribute to the Teapot asterism, a popular asterism within Sagittarius resembling a teapot, with Nunki forming part of the handle and Kaus Australis part of the body.
Proper NameBayer DesignationApparent MagnitudeOrigin
Ainalramiν¹ Sagittarii5.80Arabic "ʽAin al-Rāmī," the "eye of the archer"
Albaldahπ Sagittarii2.88Arabic "al-balda," the "city" or "town"
Alnaslγ² Sagittarii2.98Arabic "nasl al-sahm," the "arrowhead"
Arkab Posteriorβ² Sagittarii4.27Arabic "arkab al-dhira," the "posterior hamstring"
Arkab Priorβ¹ Sagittarii3.96Arabic "arkab al-sadira," the "anterior hamstring"
Ascellaζ Sagittarii2.60Latin "axilla," the "armpit"
BelelHD 1813425.30Wolof (Senegal), a "rare water source"
GumalaHD 1680976.20Malay, "magic bezoar stone" from mythical lore
Kaus Australisε Sagittarii1.85Arabic "qaws australis," the "southern bow"
Kaus Borealisλ Sagittarii2.82Arabic "qaws borealis," the "northern bow"
Kaus Mediaδ Sagittarii2.72Arabic "qaws media," the "middle bow"
Nunkiσ Sagittarii2.05Babylonian "Šu-nun-ki," possibly a sacred city
PincoyaHD 1809026.40Mapuche-Chilote mythology, a "female water spirit"
Polisμ Sagittarii3.85Coptic Egyptian "poulis," the "foal"
Rukbatα Sagittarii3.97Arabic "rukbah," the "knee"
SikaHD 1695566.10Cultural proposal, linked to indigenous natural terms (etymology pending full IAU documentation)
Terebellumω Sagittarii4.66Latin "terebellum," a "small quadrilateral" or "calf's muzzle"

Specialized Star Categories

Variable Stars

Variable stars in the constellation Sagittarius display brightness fluctuations arising from mechanisms such as radial pulsations, dust obscuration, and eclipses in binary systems. These stars are valuable for studying and galactic structure, with Sagittarius's position toward the revealing a rich population influenced by the Milky Way's bulge and disk. Pulsating variables dominate, including classical Cepheids used as standard candles and long-period giants undergoing thermal pulses on the . Eclipsing binaries contribute additional photometric variability, though their study in this crowded field requires careful separation from intrinsic changes. Classical Cepheids in Sagittarius, such as W Sgr, exhibit regular pulsations with periods tied to luminosity via the , enabling distance estimates to the galaxy's inner regions. W Sgr has a pulsation period of 7.0136 days and a visual light amplitude of about 0.85 magnitudes, making it a prototypical example for studies. Other Cepheids like X Sgr (period 7.01 days) and U Sgr (period 6.67 days) further populate the short-period end, with amplitudes typically 0.5-1.0 magnitudes due to the expansion and contraction of their envelopes. Long-period variables, primarily Mira-type stars, show dramatic amplitude changes over hundreds of days, driven by surface convection and mass loss. R Sgr is a classic Mira with a period of 270 days and a visual amplitude spanning 5.2 magnitudes (from 7.3 to 12.5), reflecting cycles of brightening and fading as the star's atmosphere expands. RY Sgr, an R Coronae Borealis (RCB) variable, combines pulsation with erratic fades caused by carbon dust formation, with a short pulsation period of 38.6 days and amplitudes up to 8 magnitudes during declines; it was first noted for variability in the 1890s. These stars highlight Sagittarius's role in probing AGB evolution, as their variability traces mass ejection phases. A 1978 study examined seven variables in the constellation, including five long-period types, one eclipsing binary, and one irregular, using finder charts from D. Hoffleit to refine periods and behaviors. Eclipsing binaries in Sagittarius, often discovered through surveys, show periodic dips from mutual occultations, with periods ranging from hours to days. V1357 Sgr, initially classified as an RR Lyrae but reidentified as eclipsing, has a period of about 0.4 days and small amplitudes, illustrating challenges in classification amid field contamination. Variability in brighter stars like Delta Sgr arises from its binary nature, though with minimal photometric impact compared to dedicated eclipsing systems.
StarTypePeriod (days)Amplitude (mag, V)Discoverer/Notes
W SgrClassical Cepheid7.010.85Variability noted early 20th c.; key for PL relation calibration
R Sgr2705.2Long-period giant; monitored by AAVSO
RY SgrRCB38.6 (pulsation)Up to 8 (fades)Discovered ~1895; southern counterpart to R CrB
V1357 SgrEclipsing binary~0.4SmallReclassified from RR Lyr in 1980

Binary and Multiple Stars

Sagittarius contains a variety of binary and multiple star systems, many of which are visually resolved or detected through spectroscopic means, reflecting the constellation's rich toward the . The dense stellar field in this direction increases the observed multiplicity rate, as line-of-sight alignments can mimic physical associations, though true physical multiples are also prevalent among its stars. Visual binaries in Sagittarius include systems where components are spatially separated and observable with telescopes, such as the optical double Beta Sagittarii (Arkab), consisting of Beta¹ Sgr (a binary with a B2 V primary and 7th-magnitude dwarf companion) and Beta² Sgr (an A2 V star), separated by 0.36 degrees but not physically bound. Spectroscopic binaries, detected via Doppler shifts in spectral lines, are also common, exemplified by RS Sagittarii, a double-lined eclipsing system with an of 2.416 days. Some of these systems exhibit variability due to eclipses, though detailed light curves are beyond this section's scope. Among notable examples, Delta Sagittarii (Kaus Media) comprises an orange giant primary (K3 III, post-asymptotic giant branch stage) and a companion; the remains undetermined, but the system's evolutionary stage suggests the companion is a remnant from prior . forms a triple system with an A3 III primary, an A4 IV companion in a close binary (~0.6 arcseconds separation), and an outer visual companion at a projected separation corresponding to ~13 AU ( ~21 years). The multiple system 21 Sagittarii features an orange K-type primary paired with a contrasting blue secondary, offering a visually striking example of color difference in bound pairs.
SystemComponents' TypesSeparation (arcsec)Period (years)
Delta SgrK3 III giant + UnresolvedUnknown
Zeta SgrA3 III + A4 IV + outer companion~0.6 (inner), ~0.5 ( outer)~21 (outer)
21 SgrK + blue secondary~6.5Unknown
Beta¹ SgrB2 V + dwarf~28Unknown

Exoplanet-Hosting Stars

Sagittarius is home to 22 confirmed exoplanet-hosting stars, collectively harboring over 114 exoplanets as of mid-2025. These systems are diverse, ranging from close-in hot Jupiters to distant cold giants and low-mass worlds, detected primarily through measurements, transit surveys, and events enabled by the constellation's alignment with the dense . The prevalence of microlensing detections reflects Sagittarius's unique vantage point toward the Milky Way's inner regions, where foreground lenses amplify signals from background sources. Recent analyses, such as the 2024 study of KMT-2020-BLG-0414Lb, indicate that some may survive host star evolution through dynamical interactions like stellar flybys. Radial velocity surveys have identified several multi-planet systems among brighter Sagittarius stars. For instance, HD 169830, an F6V star located 119 light-years away, hosts two gas giants: HD 169830 b (2.53 masses, 225.6-day ) and HD 169830 c (7.67 masses, ~2,102-day ), both discovered in 2000 using the CORALIE spectrograph at . Similarly, HD 179949, an F8V star 90 light-years distant, features the hot HD 179949 b (0.98 masses, 3.09-day ), the first such planet found in the constellation via in 2000. Another example is HD 190647, a G5V star 187 light-years away, with HD 190647 b (0.59 masses, 1,038-day ) detected in 2010 through HARPS observations. These discoveries highlight the method's effectiveness for massive, short-period planets around nearby hosts. Transit photometry has revealed compact systems, particularly in crowded fields. The 2006 Sagittarius Window Eclipsing Extrasolar Planet Search (SWEEPS) using the surveyed ~250,000 stars in the , confirming b as a (1.12 radii, 4.2-day ) around a G-type host ~28,000 light-years away, the first planet detected via transit in the bulge. Later surveys like HATSouth and added more, such as HATS-8 b (1.38 radii, 3.58-day ; low-density super-Neptune) around a G9V star 829 light-years distant, found in 2013. Gravitational microlensing dominates discoveries of distant, low-mass planets in the bulge, with collaborations like OGLE and KMTNet identifying ~80 systems. These events probe planets at separations of 0.5–10 AU around M-dwarf or solar-type hosts up to 26,000 light-years away. A standout is KMT-2020-BLG-0414L b, an Earth-mass (0.96 masses, 2.8-year at 1.26 AU) around a host ~4,000 light-years distant, detected in 2020; 2024 analyses indicate it survived engulfment during the host's phase via a close stellar flyby. Microlensing has also uncovered free-floating "rogue" planets without detectable hosts, such as OGLE-2016-BLG-1928, a Mars-sized world (~0.28 Earth masses) identified in 2016 as isolated within at least 8 AU of any star. A few hosts, like HD 180902, are known binaries, complicating orbital dynamics. The following table summarizes selected representative systems:
Host StarBayer/HD DesignationPlanet(s)Mass / Key Orbital ParametersDiscovery Year / Method
HD 169830HD 169830b, cb: 2.53 , 225.6 d; c: 7.67 , 2,102 d2000 /
HD 179949HD 179949b0.98 , 3.09 d2000 /
SWEEPS-04SWEEPS J175853.92-291120.6b~1.0 , 4.2 d2006 / Transit
HD 190647HD 190647b0.59 , 1,038 d2010 /
KMT-2020-BLG-0414L-b0.96 , 2.8 yr (1.26 AU)2020 / Microlensing
OGLE-2016-BLG-1928(Rogue, no host)-~0.28 , free-floating2016 / Microlensing

Stars Near the Galactic Center

Sgr A* Orbiting Stars

The S-stars represent a population of young, massive stars orbiting the Sgr A* at the center of the , providing critical probes of the gravitational dynamics in this extreme environment. These stars, primarily early-type main-sequence objects, execute highly elliptical orbits within the central , enabling precise measurements of Sgr A*'s mass and . Observations reveal approximately 30 such young stars in this region, with their motions tracked over decades to map the black hole's influence. Among these, the star S2 (also designated S0-2) is the most extensively studied, featuring an of 16.05 years and a closest approach (periapsis) of about 120 AU to Sgr A*. Classified as a B0 V spectral type with an estimated mass of 10 solar masses (M⊙), S2 reaches velocities up to 2.7% of the during periapsis. Its 2018 periapsis passage allowed astronomers to confirm Sgr A*'s mass as 4.3 million M⊙ through detailed astrometric and spectroscopic data, refining earlier estimates and validating Keplerian orbital models in strong gravity. Other notable S-stars include members of the S0-2 family, such as S0-102, which has an of 11.5 years, making it one of the shortest-period objects in the cluster. These stars collectively form a clockwise-rotating disk-like structure, with orbits ranging from 10 to over 100 years, highlighting the diversity of dynamical interactions near Sgr A*. Infrared observations of the S-stars began in the 1990s using systems like NAOS-CONICA (NACO) on the European Southern Observatory's (VLT), enabling high-resolution tracking despite the galactic center's dust obscuration. More recent efforts with the instrument on the VLT Interferometer have captured relativistic effects, including during S2's 2018 periapsis, where the star's light shifted by approximately 200 km/s, consistent with predictions from . The formation of these young S-stars remains debated, with theories proposing either star formation in the dense central environment or migration from about 1 away via dynamical processes like cluster infall. These mechanisms explain the presence of massive stars in a region otherwise hostile to star formation due to tidal forces and .

Hypergiants and Massive Stars

The constellation Sagittarius hosts several of the Milky Way's most extreme stellar objects, including rare hypergiants and clusters rich in massive stars. Hypergiants represent the upper end of , with luminosities exceeding 100,000 times that of the Sun and masses often surpassing 100 solar masses, leading to intense mass loss and short lifespans of a few million years. These stars are typically found in dense star-forming regions near the , where high and crowding facilitate their formation. In Sagittarius, such objects illuminate nebulae and contribute to galactic feedback through powerful stellar winds and . One prominent example is the (V4647 Sagittarii), a blue located approximately 25,000 light-years away in the Quintuplet cluster, about 100 light-years from Sagittarius A*. Discovered in the 1990s, it has an estimated initial mass of 200-250 solar masses (per older evolutionary models) or a current mass of ~27.5 solar masses, and a current of about 3.3 million solar luminosities, making it one of the most luminous known stars in the galaxy. Its spectral type is approximately OfpeWN5, indicative of a (LBV) phase, characterized by episodic mass ejections that have sculpted the surrounding Pistol Nebula with up to 10 solar masses of material expelled roughly 6,000 years ago. The star's radius is estimated at 340 solar radii, and its surface temperature reaches about 12,000 K, driving strong ultraviolet radiation that ionizes nearby gas. Another notable hypergiant is VX Sagittarii, a red in the Sgr OB1 association at a of 1.56 kpc (about 5,100 light-years). Classified as M4e–M10eIa, it is a semi-regular variable with a pulsation period of around 732 days and an unusually large amplitude, varying by up to 7 magnitudes in the . Its is approximately 195,000 solar luminosities, with a radius potentially exceeding 1,400 solar radii (ranging 1,120-1,550 ⊙), placing it among the largest known stars. As one of the most massive red s in the galaxy, VX Sagittarii exhibits strong OH/IR emission and a enriched with silicates and dust, indicative of high mass-loss rates exceeding 10^{-5} solar masses per year. Observations of its H₂O and SiO masers reveal an extended atmosphere, supporting its evolved status. Beyond individual hypergiants, Sagittarius is home to dense clusters harboring hundreds of massive stars, which dominate the region's high-energy output. The Arches cluster, situated 25,000 light-years away near the , is the densest known in the , containing over 100 young, massive O-type stars within a 1-parsec , with ages of 2–4 million years. These stars, with masses up to 120 solar masses and luminosities reaching millions of solar units, drive intense and sculpt ionized hydrogen regions through their winds, which collectively expel material at rates of 10^{-7} solar masses per year per star. Similarly, the Quintuplet cluster, also ~25,000 light-years distant and 30 parsecs from Sagittarius A* in projection, hosts about 100 massive stars, including Wolf-Rayet objects and the , with a total mass of around 10,000 solar masses. These clusters exemplify the violent starbirth in the , where massive stars (>8 solar masses) evolve rapidly into supergiants and hypergiants, influencing the .
Star/ClusterTypeDistance (ly)Key PropertiesCitation
Pistol StarBlue hypergiant (LBV)~25,000Initial M ≈ 200-250 M⊙ (older models), current M ≈ 27.5 M⊙, L ≈ 3.3 × 10^6 L⊙, R ≈ 340 R⊙
VX SagittariiRed hypergiant~5,100L ≈ 1.95 × 10^5 L⊙, variable period ~732 days, high mass-loss
Arches ClusterMassive O/B stars~25,000>100 stars, ages 2–4 Myr, core density ~several × 10^5 stars/pc³
Quintuplet ClusterMassive stars (incl. WR, LBVs)~25,000~100 stars, total M ≈ 10,000 M⊙, hosts Pistol Star

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