S2 passes pericentre and its light is measurably redshifted

Assembled from 36 blocks · 1 evidence · 25 related

1. Story
2. The star S2 made its closest approach to Sagittarius A*, passing within roughly 120 astronomical units at about two and a half per cent of the speed of light. Interferometric astrometry and spectroscopy with the GRAVITY instrument at Paranal detected the combined gravitational redshift and transverse Doppler shift predicted by general relativity, at a level clearly distinguishable from the Newtonian expectation. It was the first detection of that effect in the gravitational field of a supermassive black hole.
3. Knowledge
4. Time dilation near a horizon
5. Sagittarius A* - the black hole at the centre of the Milky Way
6. S2 - the star that measured the Galactic centre
7. Paranal Observatory and the GRAVITY interferometer
8. S2 passes pericentre and its light is measurably redshifted
9. Connections
10. Paranal Observatory and the GRAVITY interferometer
11. Time dilation near a horizon
12. S2 - the star that measured the Galactic centre
13. Sagittarius A* - the black hole at the centre of the Milky Way
14. Paranal Observatory and the GRAVITY interferometer
15. Schwarzschild radius
16. Oppenheimer and Snyder compute continued gravitational contraction
17. S2 passes pericentre and its light is measurably redshifted
18. Sagittarius A* - the black hole at the centre of the Milky Way
19. A star is tracked through a complete close approach to the Galactic centre
20. S2 passes pericentre and its light is measurably redshifted
21. The orbit of S2 is shown to precess as general relativity predicts
22. The Nobel Prize in Physics recognises black holes twice over
23. The black hole at the centre of our own galaxy is imaged
24. M87* - the supermassive black hole in Messier 87
25. S2 - the star that measured the Galactic centre
26. A star is tracked through a complete close approach to the Galactic centre
27. The Event Horizon Telescope observes M87* and Sagittarius A*
28. S2 passes pericentre and its light is measurably redshifted
29. The orbit of S2 is shown to precess as general relativity predicts
30. The Nobel Prize in Physics recognises black holes twice over
31. The black hole at the centre of our own galaxy is imaged
32. S2 passes pericentre and its light is measurably redshifted
33. S2 passes pericentre and its light is measurably redshifted
34. The orbit of S2 is shown to precess as general relativity predicts
35. Evidence
36. Reports the combined gravitational and transverse Doppler shift in S2's spectrum at its 2018 pericentre passage, inconsistent with Newtonian prediction. V55 VERIFICATION BASIS: not consulted in session; no research tool was available. Volume and article number are from recall and must be checked.