Examples of detection at 70 μm and non-detection at 160 μm. The red cross (arm length equal to 5′′) indicates the common Herschel position. We note that for both sources there exists only one scan map orientation which leads to some residual scan artefacts, in vertical and diagonal direction, respectively; see Table A.3, available in electronic form at CDS, for details. Top: HD 181597, OBSID 1342185451 on OD 146. The bright point source at the right is KIC 11555225. Bottom: HD 15008 (δ Hyi), OBSID 1342189130 on OD 241.