Vincent van Gogh’s private letters and Irving Penn’s celebrity portraits will be among star exhibits at European art shows in 2010. The most important Van Gogh show that London has seen in 40 years opens at the Royal Academy this month. Meanwhile, Vincent’s old houseguest Paul Gauguin is the star of a tightly focused show at the Van Gogh Museum, Amsterdam. “Quilts 1700-2010” at the V&A (March 20 to July 4), will include textitles from 18th-century bedding to the expletives-not-deleted efforts of Tracy Emin.