noaoann07032 — Announcement

Most Massive Stellar Black Hole

17 October 2007

Astronomers have located an exceptionally massive black hole in orbit around a huge companion star in the nearby galaxy M33. The mass of the black hole, known as M33 X-7, was determined to be 15.7 times that of the Sun. This result, published in the journal Nature, has intriguing implications for the evolution and ultimate fate of massive stars. Data from NASA’s Chandra X-ray Observatory, Gemini North, and the 2.1-meter and WIYN 3.5-meter telescopes at Kitt Peak were combined to make this discovery, which includes contributions from NOAO astronomer Lucas Macri regarding the precise distance to M33. For more, see Chandra Press Release.