What was the total integration time for the initial Hubble Deep Field (HDF) observation in December 1995?
More than 100 hours accumulated from 342 separate exposures.
The defining factor that made the Deep Field images revolutionary was the sheer length of time the Hubble Space Telescope dedicated to collecting light, known as the total integration time. For the original HDF observed in December 1995, the process involved taking 342 separate exposures spread out over ten consecutive days. When these exposures were combined, the total integration time added up to significantly more than 100 hours. This extreme duration was medically necessary because the light arriving from the most ancient and distant galaxies is extremely faint, sometimes registering as little as one photon per minute reaching the detector, contrasting sharply with the millions of photons per minute received from nearer galaxies.
