English name for the constellation Antlia.

A large southern constellation lying in rich starfields of the Milky Way. It is the largest of the three sections into which the ancient constellation Argo Navis was divided by Nicolas L. de Lacaille in the mid-eighteenth century. It contains ten stars of the second and third magnitudes.

The change in the colour sensitivity of the human eye that occurs when dark adaption takes place. In daylight, a normal eye detects light in the wavelength range 400-750 nanometres, the peak sensitivity lying in the yellow to green region. Under low levels of illumination, the eye adapts to increase overall sensitivity to light, but is less able to detect the redder end of the spectrum; the peak sensitivity moves further towards the green.

An observatory of the Chinese Academy of Sciences, located on the Purple Mountain near the city of Nanking. It was constructed between 1929 and 1934. The instruments located there include a 43-centimetre 17-inch Schmidt camera, a 1.5-metre 5-foot radio dish for solar observations, a 20-centimetre 8-inch refractor, a 60-centimetre 24-inch reflector and a 40-centimetre 16-inch twin refractor used for planetary work.

An instrument for measuring the total heat energy received from the Sun per unit area per unit time.

A large lunar crater near the north-west limb of the Moon. It is 129 km in diameter and has high walls and a central peak.

A small and insignificant southern constellation introduced by Nicolas L. de Lacaille in the mid-eighteenth century. It contains only one star that is brighter than fourth magnitude.

Abbreviation for photographic zenith tube.