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Black holes quick check

A quick check of 3 questions. After you submit, each question shows the right answer and why.

3 of 9 questions, Advanced level. Aimed at the Advanced level, your current depth. Questions you have not answered yet come first.

Show all 9 questions

ScientistQuestion 1 of 3

The Event Horizon Telescope image of M87* shows a bright ring around a dark centre. Why is the centre dark, and what did the ring let the team measure?

AdvancedQuestion 2 of 3

Sagittarius A* has a mass of about 4 × 10⁶ solar masses (1 solar mass = 1.99 × 10³⁰ kg). Using Rₛ = 2GM/c² with G = 6.67 × 10⁻¹¹ N m² kg⁻² and c = 3.00 × 10⁸ m/s, calculate its Schwarzschild radius in units of 10¹⁰ m.

AdvancedQuestion 3 of 3

What did the LIGO detectors observe on 14 September 2015?