SBS 1415+437

SBS 1415+437, also known as PGC 51017, is a blue compact dwarf galaxy and Wolf-Rayet galaxy located in the constellation Boötes approximately 45.3 million light-years away from the Milky Way. It was discovered in 1995 by a team of astronomers from the University of Virginia coordinated by Trinh Thuan.^[1]

It was initially thought that the galaxy hosted only very young stars, but the stars were later found to be up to 1.3 billion years old.^[1][2][3]

SBS 1415+437 is also a starburst galaxy of the rare Wolf-Rayet type, as it contains an unusually large number of Wolf-Rayet stars. These are massive stars (at least 20 solar masses), short-lived, with surface temperatures of over 25,000 kelvin which, due to very strong stellar winds (over 2,000 km/s), lose large quantities of their mass (in about 100,000 years a Wolf-Rayet star can lose the equivalent of the mass of the Sun).^[4][1][5] It is said the galaxy hosted a number of Red-giant branch stars apart from Wolf-Rayets as well.^[6]

In 2019, astronomers found there are traces of ionized gas inside the star-forming regions of SBS 1415+437, hinting the presence of elemental abundances of chemical elements such as nitrogen, argon and sulfur.^[7]