Index: trunk/psphot/src/psphotApResid.c
===================================================================
--- trunk/psphot/src/psphotApResid.c	(revision 20411)
+++ trunk/psphot/src/psphotApResid.c	(revision 20414)
@@ -136,6 +136,12 @@
     // XXX choose a better value here?
     if (Npsf < APTREND_NSTAR_MIN) {
-        psError(PSPHOT_ERR_APERTURE, true, "Only %d valid aperture residual sources (need %d), giving up",
-                Npsf, APTREND_NSTAR_MIN);
+        psWarning("Only %d valid aperture residual sources (need %d), giving up", Npsf, APTREND_NSTAR_MIN);
+	// save nan values since these were not calculated
+	psMetadataAdd (recipe, PS_LIST_TAIL, "SKYBIAS",  PS_DATA_F32 | PS_META_REPLACE, "aperture sky bias",   NAN);
+	psMetadataAdd (recipe, PS_LIST_TAIL, "SKYSAT",   PS_DATA_F32 | PS_META_REPLACE, "aperture-determined saturation",   NAN);
+	psMetadataAdd (recipe, PS_LIST_TAIL, "APMIFIT",  PS_DATA_F32 | PS_META_REPLACE, "aperture residual",   NAN);
+	psMetadataAdd (recipe, PS_LIST_TAIL, "DAPMIFIT", PS_DATA_F32 | PS_META_REPLACE, "ap residual scatter", NAN);
+	psMetadataAdd (recipe, PS_LIST_TAIL, "APLOSS",   PS_DATA_F32 | PS_META_REPLACE, "aperture loss (mag)", NAN);
+	psMetadataAdd (recipe, PS_LIST_TAIL, "NAPMIFIT", PS_DATA_S32 | PS_META_REPLACE, "number of apresid stars", 0);
         return false;
     }