Lockman Hole

The Lockman Hole is a relatively clear window on distant objects, which makes it an attractive area of the sky for observational astronomy surveys.

It is located near the pointer stars of the Big Dipper in the constellation Ursa Major and is ~15 square degrees in size.

The Lockman Hole is located at about RA 10h 45m, Dec. +58° and is defined by a region of low neutral hydrogen gas and dust column density.

[3] Column density is a commonly used measure in astronomy for the quantity of a given chemical element or molecule in a certain direction.

[7] The Lockman Hole North-west (LHNW) is a region that appears about as wide as the moon centered at J2000.0 RA 10h 34m Dec +57° 40′.,[8][9] with a column density of NH = 5.72 x 1019 cm−2.

Chandra X-ray Observatory mosaic of the X-ray sources in the Lockman Hole. Color code: Energy (red 0.4–2.0 keV, green 2–8 keV, blue 4–8 keV). Image is about 50 arcmin per side. Credit: X-ray: NASA/CXC/U. Wisconsin/A.Barger et al.; Illustrations: NASA/CXC/M.Weiss.