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 100 stars, with its brightest members being of magnitude 9. One of the notable features of Messier 46 is the presence of a planetary nebula, known as NGC 2438, which appears to be superimposed on the cluster. This nebula is about 2,000 light-years away and is not physically associated with the cluster, making it an interesting object for astronomers studying stellar evolution.