"One night in June of last year, a telescope in Hawaii captured something noteworthy in its nightly scan. A luminous dot appeared where nothing had been before, as if someone had switched on a light. A message immediately went out on the Astronomer’s Telegram, an alert system for astronomers around the world.
A scramble ensued. There’s no guarantee unexpected objects in the night sky will stick around. Astronomers directed telescopes of all kinds at the point of light, observing the target in every wavelength of the electromagnetic spectrum, from optical light to invisible X-rays. Early data revealed the light originated outside the Milky Way galaxy, from a small, nearby galaxy about 200 million light-years away. (Yes, this is actually considered nearby in cosmic standards.)