RATIR is a multi-channel optical and infrared imager for the robotic 1.5-meter Johnson telescope at the Observatory Astronómico Nacional in Mexico.

RATIR was designed for follow-up observations of the afterglows of gamma-ray bursts (GRBs) detected by the Neil Gehrels Swift Observatory, but is also used for other science.

The images above show the fading afterglow of GRB 130327A. The image on the left was taken with RATIR 1.7 hours after the GRB was detected by Swift. The image on the right was taken about 24 hours later. The images are in the i band and are about 1.3 arcmin to a side. In the earlier image, the afterglow is clearly visible in the green circle with i ≈ 21.2. In the later image, it is no longer visible, having faded by 1.3 magnitudes or more. The afterglow was also detected and seen to fade in the r, Z, Y, and J bands. See GCN Circulars 14334 and 14352.

RATIR is a collaboration between:

and is lead by:

RATIR benefits from the generous loan of a H2RG detector by Teledyne Scientific and Imaging.