Abell 2142

Abell 2142
Chandra X-ray Observatory image of Abell 2142.
Observation data (Epoch J2000)
ConstellationCorona Borealis
Right ascension15h 58m 19.8s
Declination+27° 13′ 45.0″
Number of galaxies> 100
Richness class2
Bautz–Morgan classificationII
Redshift0.09090 (27 251 km/s)
Distance381 Mpc (1.243 billion light years.)
ICM temperatureCentral region (white): 50 million degrees Celsius.

Outer region (magenta): 70 million degrees Celsius.

Around the Cluster (darkish blue/faint magenta): 100 million degrees Celsius.
Binding mass~6.3×1017 M
X-ray flux(6.50 ± 0.70)×10−11 erg s−1 cm−2 (2-10 keV)

Abell 2142, or A2142, is an X-ray luminous galaxy cluster in the constellation Corona Borealis. It is the result of an ongoing merger between two galaxy clusters. The combined cluster is six million light years across, contains hundreds of galaxies and enough gas to make a thousand more. It is one of the most massive objects in the universe.

Abell 2142 is part of the Abell catalogue of rich clusters of galaxies published by astronomer George O. Abell in 1958. It has a heliocentric redshift of 0.0909 (meaning it is moving away from Earth at 27,250 km/s) and a visual magnitude of 16.0. It is about 1.2 billion light years (380 Mpc) away.