The radiative zone is the part of the sun?s interior that is between the inner core and the outer convective zone. In this zone, energy is efficiently transferred by photons to the surrounding region. The electromagnetic radiation of the radiative zone is the result of the energy of nuclear fusion at the core.
The radiative zone accounts for 45 percent of the sun?s radius. The core energy is carried outside as photons, which travel one micron before being absorbed by gas molecules. After the absorption of photons, the gas molecules heat up and emit additional photons of the same wavelength. The re-emitted photons move another micron and are absorbed by more gas molecules, and the cycle repeats. Nearly, 10^25 absorptions and re-emissions are estimated to occur before a photon to reaches the surface.
The part of the sun at the core and the radiative zone spin differently than the outer convective zone. The boundary between these two zones is called the tacholine. Stars that are cooler and smaller than the sun do not have radiative zones; instead, they have convective zones that extend to their cores. In larger stars, radiative zones appear to be larger, and convective zones appear to be smaller.Learn More
When a ring appears in the sky around the sun, it is called a halo. Halos have also been observed around the moon in the night sky.Full Answer >
The sun is almost a perfectly round sphere. The sun is the one of the roundest natural objects ever measured, according to scientists at the University of Hawaii.Full Answer >
The surface temperature of the sun is about 5,800 kelvins. The temperature at the core of the sun is at least 15,000,000 kelvins. Most of the sun's constituent particles at the surface are gaseous atoms, as no liquid or solid can exist at such high temperatures.Full Answer >
Scientists expect the sun to burn for another 5 billion years. However, just because the sun continues to burn does not mean that Earth necessarily remains habitable.Full Answer >