PKS 2155-304

PKS 2155-304
Image of PKS 2155-304 obtained in R band at ESO-NTT
Observation data (Epoch J2000)
ConstellationPiscis Austrinus
Right ascension21h 58m 52.0651817803s
Declination−30° 13 32.120657891
Redshift0.116
Distance1.5 Gly
TypeBL Lac
Apparent magnitude (V)13.09
Other designations
QSO B2155-304,
See also: Quasar, List of quasars

PKS 2155-304 is a BL Lac object, a galaxy hosting a type of blazar. It is a strong emitter from radio to high-energy frequencies.

PKS 2155-304 is at redshift z = 0.116 (Falomo, Pesce & Treves 1993). It is one of the brightest and most studied BL Lacs, one of the first identified through X-ray observations.