What are the main differences between the sun and other stars? - Windows to the Universe
Similar to other stars in the process of nuclear fusion. Sun is a typical Normal sized Star in the universe. These normal sized stars are called. Our Sun is pretty impressive, but how does it compare to other stars? And there are many, many more in the rest of the universe. Is our Sun. It may be the biggest thing in this neighborhood, but the sun is just average compared to other stars. Betelgeuse, a red giant, is about times.
The sun's circumference is about 2, miles 4, km. It may be the biggest thing in this neighborhood, but the sun is just average compared to other stars. Betelgeusea red giant, is about times bigger than the sun and about 14, times brighter. Alex Youngif the sun were hollow, it would take about one million Earths to fill it. It's possible that the sun is even larger than previously thought. Xavier Jubier, an engineer and solar eclipse researcher, creates detailed models of solar and lunar eclipses to determine precisely where the moon's shadow would fall during the solar eclipse.
But when he matched actual photos and historical observations with the models, he found precise eclipse shapes only made sense if he scaled up the sun's radius by a few hundred kilometers. That could be a problem if you are planning to skirt the edges of the next solar eclipse.
The Sun - Universe Today
The mass of the sun is 1. The sun contains Lissauer, authors of the textbook " Planetary Sciences ," to refer to the solar system as "the sun plus some debris. But the sun's weight isn't constant. Over time, the solar wind has carried particles, and thus mass, away from the star. Meanwhile, in the heart of the star, mass is converted into energy.
The powerhouse of the star converts more than 4 million tons of solar material into energy every second, Plait said. Altogether, Plait estimated that the sun has lost a total of tons of material over its 4. While that sounds like a lot, it's only about 0. The Sun is a G-type main-sequence star that comprises about On average, it has a density of 1. However, models of the Sun estimate that it has a density of Although our Sun appears to be yellow, it is actually white.
It merely appears to be yellow because of the effect of the atmosphere. The Sun is a member of the Population I group of stars, which describes luminous, hot, and young stars that are typically found in the spiral arms of galaxies. Within the center, temperature are estimates to be as high as It has north and south magnetic poles like the Earth, and the magnetic field lines create the activity we see on the surface.
Sunspots appear in cycles and sometimes there are none visible at all. Coronal mass ejections and solar flares occur when these magnetic field lines snap and reconfigure. The amount of activity on the Sun rises and falls over an year cycle. At the low point, called solar minimumthere are few, if any sunspots. And then at the high point of the cycle, solar maximumthere are the most sunspots and the greatest amount of solar activity.
The Sun is by far the brightest object in the sky, with an apparent magnitude of At this average distance, light travels from the Sun to Earth in about 8 minutes and 19 seconds.
Looking at the sky
The Sun is composed primarily of the chemical elements hydrogen and helium, which account for The interior of the Sun is differentiated between multiple layers, which includes a core, a radiative zone, a convective zone, a photosphereand an atmosphere.
The Sun takes about 1 month to rotate once on its axis; however, this is a rough estimate because the Sun is a ball of plasma. Recent analysis has indicated that the core has a rotation rate that is faster than the outer layers of the Sun. At the outer layers, near the equator, it rotates about once every The rest of the Sun is heated by this energy, which is transferred outwards to the solar photosphere before escaping into space as sunlight or high-energy particles.
The interior structure of the Sun. In this layer, the temperature drops with increasing distance from the core, from approximately 7 million K in the interior to 2 million K at the outer edge. Between the radiative zone and the convective zone, there is a transition layer known as the tachocline.
This region is defined by a sharp change in the uniform rotation of the radiative zone and the differential rotation of the convection zone, which results in a large shear. In the convective zone, which extends from the surface to approximatelykm below the surface 0.
This allows thermal convection to develop as material heated below expands and rises, which then cools and contracts once it reaches the photosphere, causing it to sink again and for the convective cycle to continue. The visible surface of the Sun, otherwise known as the photosphere, is the layer below which the Sun becomes opaque to visible light.
Above the photosphere, visible sunlight is free to propagate into space, and its energy escapes the Sun entirely.
The photosphere is tens to hundreds of kilometers thick, being slightly less opaque than the air on Earth. Because the upper part of the photosphere is cooler than the lower part, an image of the Sun appears brighter in the center than on the edge or limb of the solar disk.
At the photosphere, temperature and density reaches its lowest point — approximately 5, K and a density of 0. This, combined with the brightness of the photosphere, makes the chromosphere normally invisible.
However, during a total eclipse, its reddish color can be seen. Above the chromosphere is the thin transition region km thickwhere temperatures rise rapidly from 20, K in the upper layer to close to 1, K at the corona. This is facilitated by the full ionization of helium in the transition region, which significantly reduces radiative cooling of the plasma.
This layer is not well-defined, instead forming a kind of nimbus around features in the chromosphere, and is in constant, chaotic motion. Lastly, there is the corona. In the lower region, the particle density is extremely low and the average temperature is about 1 — 2 million K — with the hottest regions ranging between 8 and 20 million K. This is known as the heliospherea magnetic sphere that extends beyond the heliopause more than 50 AU from the Sun and protects the Solar System from charged particles coming from the interstellar medium aka.
The current scientific consensus is that the Sun formed around 4. As one fragment of the cloud collapsed, it also began to rotate because of conservation of angular momentum and heated up with the increasing pressure.
Much of the mass became concentrated in the center, whereas the rest flattened out into a disk that would eventually accrete to form the planets and other Solar System bodies. Gravity and pressure within the core of the cloud generated a lot of heat as it accreted more matter from the surrounding disk, eventually triggering nuclear fusion.
From this grand explosion, the Sun was formed. Currently, more than four million tonnes of matter is converted into energy within the core, producing neutrinos and solar radiation.
How Big is the Sun? | Size of the Sun
At this rate, the Sun has converted times the mass of our Earth into energy about 0. The core is therefore shrinking, allowing the outer layers of the Sun to move closer to the center and experience a stronger gravitational force. This stronger force increases the pressure on the core, which in turn is making the core denser. At the end of its main sequence phase, the Sun will not go supernova since it does not have sufficient mass.
Instead, once the hydrogen in the core is exhausted in 5. But much will happen in this amount of time. The Sun will then shrink to around 10 times its current size and 50 times its luminosity, with a temperature a little lower than today.
For the next million years, it will continue to burn helium in its core until it is exhausted. By this point, it will be in its Asymptotic-Giant-Branch AGB phase, where it will expand again much faster this time and become more luminous. Over the course of the next 20 million years, the Sun will then become unstable and begin losing mass through a series of thermal pulses. Planets in the Outer Solar System are likely to change dramatically, as more energy is absorbed from the Sun, causing their water ices to sublimate — perhaps forming dense atmosphere and surface oceans.
The post AGB evolution is even faster, as the ejected mass becomes ionized to form a planetary nebula and the exposed core reaches 30, K. The final, naked core temperature will be overK, after which the remnant will cool towards a white dwarf.
The planetary nebula will disperse in about 10, years, but the white dwarf will survive for trillions of years before fading to black.