M46, or Messier 46, is an open star cluster located in the constellation Puppis. It is approximately 5,400 light-years away from Earth and contains around 150 stars. The cluster is estimated to be about 300 million years old, making it relatively young in astronomical terms. One of the notable features of M46 is its proximity to a planetary nebula known as NGC 2438. This nebula appears to be part of the cluster but is actually located in the foreground, creating an interesting visual effect when observed through telescopes. M46 is best viewed during the winter months in the Northern Hemisphere.