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tokens: all slices. This signature clearly indicates the existence of an antinode near the footpoints of the fan loop. 3.3. Estimation of Loop Length and Velocity of the Oscillations The footpoint of the fan loop that was away from the active region was distributed, and therefore not seen clearly in normal-intensity images of 171 or 193 Å. Thus, it was not straightforward to measure the length of the fan loops. Moreover, the shape and appearance of fan loops also changed with time (see animations a and b). To estimate the length, we chose the frames where the fan loops were best seen in normal-intensity images. We chose several points along the visible segment of the fan loops and interpolated a cubic spline between them. The length of the interpolated curve should be approximately equal to the projected length of the fan loops. The orange curves in Figure 2 are the fitted spline curves that represent the projected length of fan loops at the location of three artificial slices. We found the length of the fan loops at the locations of S1, S2, and S3 to be 62, 74, and 54 Mm, respectively (see Table 1 ). Note that the estimated length is the projected length in the plane of sky. Assuming the length of the fan loop is the same in 171 and 193 Å, we estimated the phase velocity of oscillations in 171 (193) Å to be 75 (85), 83 (101), and 65 (91) km s −1 at the locations of S1, S2, and S3, respectively. The phase velocity of oscillations, v , are comparable to the speed of sound in 171 and 193 Å. 3.4. Temperature and Density of the Fan Loop We estimated the temperature and density of the fan loop using the automated differential emission measure technique as developed by Aschwanden et al. ( 2013 ). The temperature of the fan loops was found to be ∼0.7 MK, which is much cooler than the hot loops as observed by hot SUMER lines (Wang et al. 2002 ) and in the AIA 94 Å channel (Wang et al. 2015 ). We also observed that the electron density decreased along the loop. Since the temperature of fan loops is low, they appear brighter in the 171 Å channel and diffuse in hotter channels like 193 Å. We should point out that a fan loop may consist of several finer strands and we have not considered that scenario here. 4. Discussion and Conclusions We observe intensity oscillations in a non-flaring fan loop system as seen in AIA 171 and 193 Å images. The intensity variations were out of phase close to two footpoints of fan loops, and the amplitude of the intensity oscillations varied along fan loops at the location of artificial slices. The amplitude of intensity oscillations first decreased and then increased while moving from one footpoint to another along the fan loop. It should be noted that it is difficult to identify the differences between standing and propagating waves without spectroscopic signatures. Recently, Yuan et al. ( 2015 ) have performed forward modeling of standing slow magnetoacoustic waves in flaring loops. They have reported that the variation of