MACHO-1997-BLG-41 [SEP] constellation
MACHO-1997-BLG-41
MACHO-1997-BLG-41, commonly abbreviated as 97-BLG-41 or MACHO-97-BLG-41, was a gravitational microlensing event located in Sagittarius which occurred in July 1999. The source star is likely a giant or subgiant star of spectral type K located at a distance of around 8 kiloparsecs (26,000 light years). The lens star is a binary system approximately 10,000 light years away in the constellation Sagittarius. The two stars are separated from each other by about 0.9 AU and have an orbital period of around 1.5 years. The most likely mass of the system is
about 0.3 times that of our Sun. Star A and star B are both red dwarfs.
The first published model of the MACHO-1997-BLG-41 event using data from Mount Stromlo Observatory, Cerro Tololo Inter-American Observatory and Wise Observatory show the lens system as being located in the galactic bulge at a distance of 6.3 kiloparsecs (21,000 light years), a total system mass of about 0.8 times that of the Sun and a separation of 1.8 AU (the most likely value given a random orientation of the system). The individual