The term Sagittarius A, sometimes mentioned in news, refers to

The term Sagittarius A, sometimes mentioned in news, refers to

1. a supermassive black hole in our Milky Way Galaxy
2. two giant black holes spiralling around each other several light-years away from the Earth
3. a Supernova explosion seen in real time for the first time ever by scientists
4. a huge asteroid that passed by very close to the Earth