OPAL has followed the northern pole now tipping toward the Sun. With OPAL, Hubble first imaged Uranus after the spring equinox, when the Sun was last shining directly over the planet's equator.
The one Hubble studied, designated 3C 273, is one of the closest of these extreme objects to Earth. 3C 273 is incredibly luminous — so much so that, if it were tens of thousands of light-years from ...
Hubble's imaging spectrograph was the instrument used to dive into 3C 273. This instrument acted like a coronagraph, a cover that astronomers use to block the sun's photosphere to observe its ...