Sagittarius A* cluster
The Sagittarius A* cluster is the cluster of stars in close orbit around Sagittarius A*, the supermassive black hole at the center of the Milky Way (in the Galactic Center). The individual stars are often listed as "S-stars", but their names and IDs are not formalized, and stars can have different numbers in different catalogues.
One of the most studied stars is S2, a relatively bright star that also passes close by Sgr A*.
As of 2020, S4714 is the current record holder of closest approach to Sagittarius A*, at about 12.6 astronomical units (1.88×109 km), almost as close as Saturn gets to the Sun, traveling at about 8% of the speed of light. These figures given are approximate, the formal uncertainties being 12.6±9.3 au and 23928±8840 km/s. Its orbital period is 12 years, but an extreme eccentricity of 0.985 gives it the close approach and high velocity.[2]
List of stars
The inferred orbits of stars around supermassive black hole candidate Sagittarius A* at the Milky Way's center are according to Gillessen et al. 2017,[3] with the exception of S2 which is from GRAVITY 2019,[4] S62 which is from Peißker et al. Jan 2020,[5] and S4711 up to S4715, which are also from Peißker et al., Aug 2020.[2]
Here id1 is the star's name in the Gillessen catalog and id2 in the catalog of the University of California, Los Angeles. a, e, i, Ω and ω are standard orbital elements, with a measured in arcseconds. Tp is the epoch of pericenter passage, P is the orbital period in years and Kmag is the K-band apparent magnitude of the star. q and v are the pericenter distance in AU and pericenter speed in percent of the speed of light,[6] and Δ indicates the standard deviation of the associated quantities.
id1 | id2 | a | Δa | e | Δe | i (°) | Δi | Ω (°) | ΔΩ | ω (°) | Δω | Tp (yr) | ΔTp | P (yr) | ΔP | Kmag | q (AU) | Δq | v (%c) | Δv |
---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
S1 | S0-1 | 0.5950 | 0.0240 | 0.5560 | 0.0180 | 119.14 | 0.21 | 342.04 | 0.32 | 122.30 | 1.40 | 2001.800 | 0.150 | 166.0 | 5.8 | 14.70 | 2160.7 | 6.7 | 0.55 | 0.03 |
S2 | S0-2 | 0.1251 | 0.0001 | 0.8843 | 0.0001 | 133.91 | 0.05 | 228.07 | 0.04 | 66.25 | 0.04 | 2018.379 | 0.001 | 16.1 | 0.0 | 13.95 | 118.4 | 0.2 | 2.56 | 0.00 |
S4 | S0-3 | 0.3570 | 0.0037 | 0.3905 | 0.0059 | 80.33 | 0.08 | 258.84 | 0.07 | 290.80 | 1.50 | 1957.400 | 1.200 | 77.0 | 1.0 | 14.40 | 1779.7 | 25.1 | 0.57 | 0.01 |
S6 | S0-7 | 0.6574 | 0.0006 | 0.8400 | 0.0003 | 87.24 | 0.06 | 85.07 | 0.12 | 116.23 | 0.07 | 2108.610 | 0.030 | 192.0 | 0.2 | 15.40 | 860.3 | 4.4 | 0.94 | 0.00 |
S8 | S0-4 | 0.4047 | 0.0014 | 0.8031 | 0.0075 | 74.37 | 0.30 | 315.43 | 0.19 | 346.70 | 0.41 | 1983.640 | 0.240 | 92.9 | 0.4 | 14.50 | 651.7 | 22.5 | 1.07 | 0.01 |
S9 | S0-5 | 0.2724 | 0.0041 | 0.6440 | 0.0200 | 82.41 | 0.24 | 156.60 | 0.10 | 150.60 | 1.00 | 1976.710 | 0.920 | 51.3 | 0.7 | 15.10 | 793.2 | 36.9 | 0.93 | 0.02 |
S12 | S0-19 | 0.2987 | 0.0018 | 0.8883 | 0.0017 | 33.56 | 0.49 | 230.10 | 1.80 | 317.90 | 1.50 | 1995.590 | 0.040 | 58.9 | 0.2 | 15.50 | 272.9 | 2.0 | 1.69 | 0.01 |
S13 | S0-20 | 0.2641 | 0.0016 | 0.4250 | 0.0023 | 24.70 | 0.48 | 74.50 | 1.70 | 245.20 | 2.40 | 2004.860 | 0.040 | 49.0 | 0.1 | 15.80 | 1242.0 | 2.4 | 0.69 | 0.01 |
S14 | S0-16 | 0.2863 | 0.0036 | 0.9761 | 0.0037 | 100.59 | 0.87 | 226.38 | 0.64 | 334.59 | 0.87 | 2000.120 | 0.060 | 55.3 | 0.5 | 15.70 | 56.0 | 3.8 | 3.83 | 0.06 |
S17 | 0.3559 | 0.0096 | 0.3970 | 0.0110 | 96.83 | 0.11 | 191.62 | 0.21 | 326.00 | 1.90 | 1991.190 | 0.410 | 76.6 | 1.0 | 15.30 | 1755.3 | 16.4 | 0.57 | 0.02 | |
S18 | S0-18 | 0.2379 | 0.0015 | 0.4710 | 0.0120 | 110.67 | 0.18 | 49.11 | 0.18 | 349.46 | 0.66 | 1993.860 | 0.160 | 41.9 | 0.2 | 16.70 | 1029.3 | 3.8 | 0.77 | 0.01 |
S19 | S0-28 | 0.5200 | 0.0940 | 0.7500 | 0.0430 | 71.96 | 0.35 | 344.60 | 0.62 | 155.20 | 2.30 | 2005.390 | 0.160 | 135.0 | 14.0 | 16.00 | 1063.3 | 4.5 | 0.83 | 0.20 |
S21 | 0.2190 | 0.0017 | 0.7640 | 0.0140 | 58.80 | 1.00 | 259.64 | 0.62 | 166.40 | 1.10 | 2027.400 | 0.170 | 37.0 | 0.3 | 16.90 | 422.7 | 3.6 | 1.32 | 0.02 | |
S22 | 1.3100 | 0.2800 | 0.4490 | 0.0880 | 105.76 | 0.95 | 291.70 | 1.40 | 95.00 | 20.00 | 1996.900 | 10.200 | 540.0 | 63.0 | 16.60 | 5903.7 | 9.7 | 0.32 | 0.10 | |
S23 | 0.2530 | 0.0120 | 0.5600 | 0.1400 | 48.00 | 7.10 | 249.00 | 13.00 | 39.00 | 6.70 | 2024.700 | 3.700 | 45.8 | 1.6 | 17.80 | 910.5 | 1.6 | 0.85 | 0.06 | |
S24 | S0-26 | 0.9440 | 0.0480 | 0.8970 | 0.0049 | 103.67 | 0.42 | 7.93 | 0.37 | 290.00 | 15.00 | 2024.500 | 0.030 | 331.0 | 16.0 | 15.60 | 795.3 | 30.8 | 0.99 | 0.07 |
S29 | 0.4280 | 0.0190 | 0.7280 | 0.0520 | 105.80 | 1.70 | 161.96 | 0.80 | 346.50 | 5.90 | 2025.960 | 0.940 | 101.0 | 2.0 | 16.70 | 952.2 | 67.4 | 0.87 | 0.05 | |
S31 | S0-8 | 0.4490 | 0.0100 | 0.5497 | 0.0025 | 109.03 | 0.27 | 137.16 | 0.30 | 308.00 | 3.00 | 2018.070 | 0.140 | 108.0 | 1.2 | 15.70 | 1653.7 | 14.6 | 0.63 | 0.02 |
S33 | S0-33 | 0.6570 | 0.0260 | 0.6080 | 0.0640 | 60.50 | 2.50 | 100.10 | 5.50 | 303.70 | 1.60 | 1928.000 | 12.000 | 192.0 | 5.2 | 16.00 | 2106.5 | 179.7 | 0.56 | 0.03 |
S38 | S0-38 | 0.1416 | 0.0002 | 0.8201 | 0.0007 | 171.10 | 2.10 | 101.06 | 0.24 | 17.99 | 0.25 | 2003.190 | 0.010 | 19.2 | 0.0 | 17.00 | 208.4 | 1.5 | 1.91 | 0.01 |
S39 | 0.3700 | 0.0150 | 0.9236 | 0.0021 | 89.36 | 0.73 | 159.03 | 0.10 | 23.30 | 3.80 | 2000.060 | 0.060 | 81.1 | 1.5 | 16.80 | 231.2 | 3.3 | 1.86 | 0.09 | |
S42 | 0.9500 | 0.1800 | 0.5670 | 0.0830 | 67.16 | 0.66 | 196.14 | 0.75 | 35.80 | 3.20 | 2008.240 | 0.750 | 335.0 | 58.0 | 17.50 | 3364.4 | 24.8 | 0.44 | 0.13 | |
S54 | 1.2000 | 0.8700 | 0.8930 | 0.0780 | 62.20 | 1.40 | 288.35 | 0.70 | 140.80 | 2.30 | 2004.460 | 0.070 | 477.0 | 199.0 | 17.50 | 1050.2 | 1.9 | 0.86 | 0.78 | |
S55 | S0-102 | 0.1078 | 0.0010 | 0.7209 | 0.0077 | 150.10 | 2.20 | 325.50 | 4.00 | 331.50 | 3.90 | 2009.340 | 0.040 | 12.8 | 0.1 | 17.50 | 246.1 | 4.1 | 1.70 | 0.02 |
S60 | 0.3877 | 0.0070 | 0.7179 | 0.0051 | 126.87 | 0.30 | 170.54 | 0.85 | 29.37 | 0.29 | 2023.890 | 0.090 | 87.1 | 1.4 | 16.30 | 894.5 | 1.7 | 0.89 | 0.02 | |
S62 | 0.0897 | 0.00005 | 0.9760 | 0.0020 | 72.76 | 4.58 | 122.61 | 0.57 | 42.62 | 0.40 | 2003.330 | 0.010 | 9.9 | 0.0 | 16.10 | 16.4 | 1.5 | 7.03 | 0.04 | |
S66 | S1-2 | 1.5020 | 0.0950 | 0.1280 | 0.0430 | 128.50 | 1.60 | 92.30 | 3.20 | 134.00 | 17.00 | 1771.000 | 38.000 | 664.0 | 37.0 | 14.80 | 10712.4 | 620.5 | 0.21 | 0.02 |
S67 | S1-3 | 1.1260 | 0.0260 | 0.2930 | 0.0570 | 136.00 | 1.10 | 96.50 | 6.40 | 213.50 | 1.60 | 1705.000 | 22.000 | 431.0 | 10.0 | 12.10 | 6511.2 | 360.6 | 0.29 | 0.01 |
S71 | S0-71 | 0.9730 | 0.0400 | 0.8990 | 0.0130 | 74.00 | 1.30 | 35.16 | 0.86 | 337.80 | 4.90 | 1695.000 | 21.000 | 346.0 | 11.0 | 16.10 | 803.8 | 1.4 | 0.99 | 0.06 |
S83 | S0-15 | 1.4900 | 0.1900 | 0.3650 | 0.0750 | 127.20 | 1.40 | 87.70 | 1.20 | 203.60 | 6.00 | 2046.800 | 6.300 | 656.0 | 69.0 | 13.60 | 7738.6 | 22.5 | 0.27 | 0.05 |
S85 | 4.6000 | 3.3000 | 0.7800 | 0.1500 | 84.78 | 0.29 | 107.36 | 0.43 | 156.30 | 6.80 | 1930.200 | 9.800 | 3580.0 | 2550.0 | 15.60 | 8277.1 | 29.6 | 0.30 | 0.33 | |
S87 | S1-12 | 2.7400 | 0.1600 | 0.2240 | 0.0270 | 119.54 | 0.87 | 106.32 | 0.99 | 336.10 | 7.70 | 611.000 | 154.000 | 1640.0 | 105.0 | 13.60 | 17390.5 | 2572.9 | 0.17 | 0.02 |
S89 | 1.0810 | 0.0550 | 0.6390 | 0.0380 | 87.61 | 0.16 | 238.99 | 0.18 | 126.40 | 4.00 | 1783.000 | 26.000 | 406.0 | 27.0 | 15.30 | 3191.8 | 407.2 | 0.46 | 0.04 | |
S91 | 1.9170 | 0.0890 | 0.3030 | 0.0340 | 114.49 | 0.32 | 105.35 | 0.74 | 356.40 | 1.60 | 1108.000 | 69.000 | 958.0 | 50.0 | 12.20 | 10928.4 | 74.5 | 0.22 | 0.02 | |
S96 | S0-96 | 1.4990 | 0.0570 | 0.1740 | 0.0220 | 126.36 | 0.96 | 115.66 | 0.59 | 233.60 | 2.40 | 1646.000 | 16.000 | 662.0 | 29.0 | 10.00 | 10127.0 | 530.0 | 0.22 | 0.02 |
S97 | S1-16 | 2.3200 | 0.4600 | 0.3500 | 0.1100 | 113.00 | 1.30 | 113.20 | 1.40 | 28.00 | 14.00 | 2132.000 | 29.000 | 1270.0 | 309.0 | 10.30 | 12333.9 | 305.9 | 0.21 | 0.08 |
S145 | 1.1200 | 0.1800 | 0.5000 | 0.2500 | 83.70 | 1.60 | 263.92 | 0.94 | 185.00 | 16.00 | 1808.000 | 58.000 | 426.0 | 71.0 | 17.50 | 4580.2 | 1471.2 | 0.37 | 0.10 | |
S175 | 0.4140 | 0.0390 | 0.9867 | 0.0018 | 88.53 | 0.60 | 326.83 | 0.78 | 68.52 | 0.40 | 2009.510 | 0.010 | 96.2 | 5.0 | 17.50 | 45.0 | 0.8 | 4.27 | 0.47 | |
S4711 | 0.0751 | 0.0015 | 0.768 | 0.030 | 114.71 | 2.92 | 20.10 | 3.72 | 131.59 | 3.09 | 2010.85 | 0.06 | 7.6 | 0.3 | 18.4 | 143.7 | 7.4 | 2.2 | 0.2 | |
S4712 | 0.451 | 0.0025 | 0.365 | 0.032 | 117.28 | 1.31 | 166.38 | 3.20 | 238.08 | 3.43 | 2007.12 | 0.08 | 112.0 | 2.9 | 18.4 | 2366 | 120 | 0.48 | 0.02 | |
S4713 | 0.2 | 0.095 | 0.351 | 0.059 | 111.07 | 1.66 | 95.06 | 5.15 | 301.97 | 8.02 | 2000.03 | 0.22 | 33.2 | 2.5 | 18.5 | 1073 | 110 | 0.71 | 0.05 | |
S4714 | 0.102 | 0.0003 | 0.985 | 0.011 | 127.7 | 0.28 | 129.28 | 0.63 | 357.25 | 0.08 | 2017.29 | 0.02 | 12.0 | 0.3 | 17.7 | 12.6 | 9.3 | 8.0 | 3 | |
S4715 | 0.1439 | 0.011 | 0.247 | 0.040 | 129.8 | 3.72 | 282.15 | 2.92 | 359.99 | 5.38 | 2008.05 | 0.3 | 20.2 | 2.4 | 17.8 | 894 | 83 | 0.75 | 0.04 | |
R34 | 1.8100 | 0.1500 | 0.6410 | 0.0980 | 136.00 | 8.30 | 330.00 | 19.00 | 57.00 | 8.00 | 1522.000 | 52.000 | 877.0 | 83.0 | 14.00 | 5314.6 | 856.3 | 0.36 | 0.05 | |
R44 | 3.9000 | 1.4000 | 0.2700 | 0.2700 | 131.00 | 5.20 | 80.50 | 7.10 | 217.00 | 24.00 | 1963.000 | 85.000 | 2730.0 | 1350.0 | 14.00 | 23285.6 | 901.5 | 0.15 | 0.11 | |
id1 | id2 | a | Δa | e | Δe | i (°) | Δi | Ω (°) | ΔΩ | ω (°) | Δω | Tp (yr) | ΔTp | P (yr) | ΔP | Kmag | q (AU) | Δq | v (%c) | Δv |
References
- Eisenhauer, F.; et al. (July 20, 2005). "SINFONI in the Galactic Center: Young Stars and Infrared Flares in the Central Light-Month". The Astrophysical Journal. 628 (1): 246–259. arXiv:astro-ph/0502129. Bibcode:2005ApJ...628..246E. doi:10.1086/430667. S2CID 122485461.
- Peißker, Florian; Eckart, Andreas; Zajaček, Michal; Basel, Ali; Parsa, Marzieh (August 2020). "S62 and S4711: Indications of a Population of Faint Fast-moving Stars inside the S2 Orbit—S4711 on a 7.6 yr Orbit around Sgr A*". The Astrophysical Journal. 889 (50): 5. arXiv:2008.04764. Bibcode:2020ApJ...899...50P. doi:10.3847/1538-4357/ab9c1c. S2CID 221095771.
- Gillessen, S.; et al. (February 2017). "An Update on Monitoring Stellar Orbits in the Galactic Center". The Astrophysical Journal. 837 (1): 30. arXiv:1611.09144. Bibcode:2017ApJ...837...30G. doi:10.3847/1538-4357/aa5c41. S2CID 119087402.
- Abuter, R.; Amorim, A.; Bauböck, M.; Berger, J. P.; Bonnet, H.; Brandner, W.; Clénet, Y.; Coudé Du Foresto, V.; De Zeeuw, P. T.; Dexter, J.; Duvert, G.; Eckart, A.; Eisenhauer, F.; Förster Schreiber, N. M.; Garcia, P.; Gao, F.; Gendron, E.; Genzel, R.; Gerhard, O.; Gillessen, S.; Habibi, M.; Haubois, X.; Henning, T.; Hippler, S.; Horrobin, M.; Jiménez-Rosales, A.; Jocou, L.; Kervella, P.; Lacour, S.; et al. (April 2019). "A geometric distance measurement to the Galactic center black hole with 0.3% uncertainty". Astronomy & Astrophysics. 625: L10. arXiv:1904.05721. Bibcode:2019A&A...625L..10G. doi:10.1051/0004-6361/201935656. S2CID 119190574.
- Peißker, Florian; Eckart, Andreas; Parsa, Marzieh (January 2020). "S62 on a 9.9 year orbit around SgrA*". The Astrophysical Journal. 889 (1): 61. arXiv:2002.02341. Bibcode:2020ApJ...889...61P. doi:10.3847/1538-4357/ab5afd. S2CID 211043784.
- Næss, S. (October 4, 2019). "Galactic center S-star orbital parameters".