Event Horizon Telescope

Assembled from 30 blocks · 2 evidence · 18 related

1. Story
2. A collaboration and an observing array that links millimetre-wave radio telescopes across the planet into an interferometer with an effective aperture the size of the Earth. The April 2017 campaign that produced the M87* image used eight stations at six geographic sites - two on Chajnantor in Chile, two on Maunakea, and single stations in Spain, Mexico, Arizona and at the South Pole - observing at about 230 gigahertz, a wavelength of 1.3 millimetres, with the longest baselines approaching ten thousand kilometres and an angular resolution of some tens of microarcseconds. The data volume is too large to transmit: petabytes were recorded onto helium-filled hard drives and physically flown to correlators at MIT Haystack Observatory and the Max Planck Institute for Radio Astronomy in Bonn. The South Pole recordings could not leave until flights resumed at the end of the austral winter, which is why an April observation was not correlated until the following year. Four teams reconstructed images independently and with different methods before comparing results. Not a place on Earth in itself; its stations are.
3. Knowledge
4. Very long baseline interferometry
5. Event Horizon Telescope
6. The Event Horizon Telescope observes M87* and Sagittarius A*
7. Connections
8. The Event Horizon Telescope observes M87* and Sagittarius A*
9. Very long baseline interferometry
10. Atacama Large Millimeter/submillimeter Array
11. South Pole Telescope
12. The Event Horizon Telescope observes M87* and Sagittarius A*
13. The first image of a black hole shadow is published
14. The M87* ring is imaged in polarised light
15. The black hole at the centre of our own galaxy is imaged
16. A second epoch shows the ring persists and the bright spot moves
17. Event Horizon Telescope
18. The first image of a black hole shadow is published
19. Event Horizon Telescope
20. Atacama Large Millimeter/submillimeter Array
21. South Pole Telescope
22. Very long baseline interferometry
23. M87* - the supermassive black hole in Messier 87
24. Sagittarius A* - the black hole at the centre of the Milky Way
25. Event Horizon Telescope
26. The Event Horizon Telescope observes M87* and Sagittarius A*
27. The first image of a black hole shadow is published
28. Evidence
29. Reports the first image of a black hole shadow, an asymmetric ring about 42 microarcseconds across, together with the array, observing campaign and imaging methodology. V55 VERIFICATION BASIS: not consulted in session; WebFetch to iopscience.iop.org and eventhorizontelescope.org was refused by the egress proxy and no search could be issued. Volume and article number are from recall of a canonical citation.
30. Reports an image of Sagittarius A* with a ring diameter of about 51.8 microarcseconds, consistent with the mass derived from stellar orbits, and describes the variability that made the imaging difficult. V55 VERIFICATION BASIS: not consulted in session; no research tool was available. Volume and article number are from recall and must be checked.