All Questions
Tagged with event-horizon-telescope observational-astronomy
6
questions
6
votes
2
answers
107
views
In terms of results, how similar is a bunch of telescopes across the globe to an Earth-sized telescope?
The Event Horizon Telescope emulates an Earth-sized telescope by syncing a bunch of radio telescopes across the planet to do take pictures with a small enough angular resolution to take pictures of a ...
- 1,758
2
votes
0
answers
94
views
Why hasn't the EHT taken an image of Sgr A*? [duplicate]
The Event Horizon Telescope or EHT took an image or the black hole at the center of M87 in 2019, and in 2021 it measured the polarization of the light from M87*. Right after the first image of M87* ...
- 17.6k
3
votes
1
answer
201
views
How, precisely, do radio astronomers detect (and record) the phases of waves for interferometry?
Interferometry is always in the news, and at radio frequencies it has been for a long time...
The popular press always talks about directly 'interfering' two waves as they come in, but can they tell ...
- 5,307
4
votes
1
answer
328
views
Will the first Event Horizon Telescope image of the Milky Way's black hole Sgr A* just be another lumpy orange donut?
@HDE226868's answer to Why doesn't the black hole in the center of the Milky Way glow similarly to the famous M87 image? explains that neither black hole is orange and any Event Horizon Telescope ...
- 30.7k
5
votes
1
answer
119
views
Could images of (very) nearby targets be recovered from Event Horizon Telescope data?
Reading this question I was struck by the fact that the "pointing" of an interferometer is effectively done in the correlator, at least within the common field of view of all the telescopes, which is ...
- 10.3k
3
votes
1
answer
403
views
Do the "schwarzschild metric" or the "isotropic metric" fit the Event Horizon telescope data on Messier 87 better?
The "Schwarzschild solution" in "Schwarzschild metric" looks like:
$$\text -c^2d\tau^2=-\left(1-\frac{2GM}{rc^2}\right)c^2dt^2+\left(1-\frac{2GM}{rc^2}\right)^{-1}dr^2+r^2(d\theta^2+\sin^2\theta\,d\...
- 457