It sounds like you're thinking of the heliosphere, which is the bubble in the interstellar medium created by the solar wind. The solar wind, in turn, is created

It sounds like you're thinking of the heliosphere, which is the bubble in the interstellar medium created by the solar wind. The solar wind, in turn, is created by outflowing plasma from the Sun, and is also responsible for auroras and comet tails. The details of how far from the sun the heliosphere extends are complex, but it encompasses all the known planets. The heliosphere does provide us with a significant amount of protect from cosmic rays, which aren't actually electromagnetic radiation. Cosmic rays are extremely energetic particles, typically protons, coming in from outside the solar system. The Earth's atmosphere also does a good job stopping cosmic rays, which means their primarily a hazard to spacecraft, both manned an unmanned. (I don't know what effect cosmic rays would ultimately have on Earth if we didn't have the protection of both the heliosphere and our own atmosphere, but I know they have been investigated for links to mass extinctions.) They're a threat to space travel because they cause soft errors in electronics, and DNA and other radiation damage to human beings. The Sun's magnetic field - aka the interplanetary magnetic field or heliospheric magnetic field - travels with the solar wind and fills the solar system. It is magnetically coupled to solar system bodies like the Earth and Jupiter. As an amateur astronomer, the heliospheric magnetic field doesn't have any significant effects on photons coming into the solar system.