NGC 4151 is an intermediate spiral Seyfert galaxy with weak inner ring structure located  from Earth in the constellation Canes Venatici. The galaxy was first mentioned by William Herschel on March 17, 1787; it was one of the six Seyfert galaxies described in the paper  which defined the term.
NGC 4151 is a medium-sized spiral galaxy with minimal inner ring features situated approximately from Earth in the Canes Venatici constellation. The galaxy was initially noted by William Herschel on March 17, 1787; it was one of six Seyfert galaxies discussed in the paper that introduced the term.