Who painted "Portrait of Dr. Gachet"?

Portrait of Dr. Gachet is one of the most revered paintings by the Dutch artist Vincent van Gogh. It depicts Dr. Paul Gachet, a homeopathic doctor and artist with whom van Gogh resided following a spell in an asylum at Saint-Rémy-de-Provence. Gachet took care of Van Gogh during the final months of his life.

There are two authenticated versions of the portrait, both painted in June 1890 at Auvers-sur-Oise. Both show Gachet sitting at a table and leaning his head on his right arm, but they are easily differentiated in color and style. In May 1990, the first version was sold at auction for $82.5 million ($158.2 million today).