diff --git a/ObservationSim/Config/ChipOutput.py b/ObservationSim/Config/ChipOutput.py
index fb3110bb07c5c04838a23d2d7b2f71cf384a9e42..1633e04777bd5942f8c7aca4686e9a9e03a3f869 100755
--- a/ObservationSim/Config/ChipOutput.py
+++ b/ObservationSim/Config/ChipOutput.py
@@ -37,7 +37,7 @@ class ChipOutput(object):
         fh.setFormatter(formatter)
         self.logger.addHandler(fh)
 
-        hdr1  = "obj_ID ID_chip filter xImage yImage ra dec ra_orig dec_orig z mag obj_type "
+        hdr1  = "# obj_ID ID_chip filter xImage yImage ra dec ra_orig dec_orig z mag obj_type "
         hdr2  = "thetaR bfrac hlr_disk hlr_bulge e1_disk e2_disk e1_bulge e2_bulge g1 g2 "
         hdr3  = "sed_type av redden "
         hdr4 = "pm_ra pm_dec RV parallax\n"