A hyper extremely red object in the field near 53W002

Hyper extremely red objects (HEROs) are objects that are very red in near-IR colors (J-K greater than or similar to 3). They are speculated to be intrinsically red galaxies at z greater than or similar to 2 or Lyman break galaxies at z > 10. We report the discovery of a HERO in the field that includes a known radio galaxy, 53W002, and a possible cluster of galaxies both at z = 2.39. The HERO, which we name HERO J171411.91+501541.8, or 53W002-HERO1 for brevity, is visible in the Hubble Space Telescope Near-Infrared Camera and Multi-Object Spectrometer H-band data and deep K'-band data from the Subaru Telescope (K' similar or equal to 21.5 mag) but not visible in B-, V-, I-, and J-band images (J-K > 4.45, 2 sigma). Its spectral energy distribution is consistent with that of a dusty star- forming or old galaxy at z similar or equal to 2.4, which may suggest that 53W002-HERO1 is a member of the group of galaxies associated with 53W002. Alternatively, the HERO could be at z similar or equal to 12.5, if its red color is due to the redshifted Lyman break. If 53W002- HERO1 is an old galaxy at z similar to 2.4, the implied stellar age is similar to2- 3 Gyr, meaning that stars in the HERO formed at the reionization epoch of z greater than or similar to 10.