- Hubble Deep Field (Wikipedia)
The Hubble Deep Field (HDF) is an image of a small region in the constellation Ursa Major, constructed from a series of observations by the Hubble Space Telescope. It covers an area about 2.6 arcminutes on a side, about one 24-millionth of the whole sky, which is equivalent in angular size to a tennis ball at a distance of 100 metres. The image was assembled from 342 separate exposures taken with the Space Telescope’s Wide Field and Planetary Camera 2 over ten consecutive days between December 18 and 28, 1995.
- Zeta Leonis (Wikipedia)
Zeta Leonis (ζ Leonis, abbreviated Zeta Leo, ζ Leo), also named Adhafera /ædəˈfɪərə/, is a third-magnitude star in the constellation of Leo, the lion. It forms the second star (after Gamma Leonis) in the blade of the sickle, which is an asterism formed from the head of Leo.