Radio Telescope Resolution - Centaurus A

Thread starter Timiop2008
Start date Nov 22, 2008
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Radio Radio telescope Resolution Telescope

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To determine the size of Centaurus A, which is 15 million light years away, the discussion focuses on calculating the circumference of a circle with that radius. One arcsecond is defined as 1/3600 of a degree, and using this measurement, the circumference can be calculated to find the physical size represented by that angular resolution. The result shows that 1 arcsecond corresponds to approximately 75 light years across at this distance. This calculation illustrates the vast scale of astronomical structures and the limitations of radio telescope resolution. Understanding these measurements is crucial for interpreting data from distant celestial objects.

Nov 22, 2008

Timiop2008

Problem:
Centaurus A is 15 million light years away and a radio telescope can resolve structures of 1s of arc across. Show that the Structure is 75 light years across.
Please Help!

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Nov 22, 2008

mgb_phys

Science Advisor

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1 sec of arc is 1 / 60 * 1/60 of a degree.
Imagine a circle 15M light years in radius with you at the centre, what length of the circumference would 1arcsec measure?

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