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On the early morning of June 7th, before the sun had risen over the mountains, a faint upper tangent arc appeared above the sun. Suddenly, I noticed a small section of a faint colored "arc" in the upper left of the upper tangent arc, and quickly this arc extended to form a large arc, resembling a rainbow! However, it was distinctly different from a rainbow in that it appeared on the same side as the sun and had a non-circular shape. The outer part of the arc was blue, while the inner part was red. It was actually a very rare supralateral arc formed by ice crystals! This was the first time I had seen a supralateral arc, and it drew a large colorful arc in the sky, truly captivating. At that time, the solar altitude angle was 20 degrees, and the image in the upper left corner is a simulated comparison diagram I created using the software HaloSim. If you look carefully, the supralateral arc is actually tangent to the circumzenithal arc at the zenith.