Bright star of the dark side

QUESTION Which planetary body is closest to the centre of our galaxy?

A BLACK hole is a region of space with such a strong gravitational effect that nothing — not even light — can escape from inside it.

Supermassive black holes are thought, by astronomers, to be at the centre of galaxies, including ours, the Milky Way.

The Earth is in one of the Milky Way’s spiral arms, the Orion Arm, which lies two-thirds of the way out from the centre of the galaxy.

When viewed from Earth, the centre of the galaxy is in the Sagittarius constellation. Astronomers have calculated this by observing radio waves, infrared light and X-ray wavelengths.

The bright radio source Sagittarius A*, a strong concentration of mass around which stars orbit, is at the centre of the Milky Way. It takes the nearest star, S2, 15.2 years to orbit it.

From the movement of stars, astronomers have concluded there is a supermassive black hole with a diameter of 9.6 million miles at the centre of the Milky Way.

J. Beresford, Chesterfield, Derbys.

QUESTION Who found the cure for leprosy? How common is the disease today?

THE previous answer described how in the past, leprosy patients were stigmatised and shunned by their communities.

This was not always the case. In my parish church of St Andrew’s, there is a small window that once looked inward through an outside wall. It is a leper’s squint — a window through which sufferers could view the church service.

It has bevelled sides to let those peering in view the altar from one side and the congregation from the other, hence the squint.

This was a common feature in early Roman catholic churches and is a testament to the compassion felt towards those poor wretches.

John Orritt, Leyland, Lancs.