All about the Sun
The Sun
is the Massive star at the center of the Solar System. The Sun is the largest
object within our solar system. The Sun comprising 99.8% of the system’s mass.
It is a nearly perfect sphere of hot plasma, heated to incandescence by nuclear
fusion reactions in its core, radiating the energy mainly as visible light and
infrared radiation. It is by far the most important source of energy for life
on Earth.
Sun’s
gravity holds the solar system together, keeping everything from the biggest
planets to the smallest particles of debris in its orbit. Electric currents in
the Sun generate a magnetic field that is carried out through the solar system
by the solar wind—a stream of electrically charged gas blowing outward from the
Sun in all directions.
The Sun’s Location in Solar System
The Sun
is located at the centre of our solar system, and Earth orbits 93 million (150
million kilometers) miles away from it.
Mean
distance from Earth is 1 AU ≈1.496×10⁸ km or 8 min 19 s at light speed.
The Sunlight’s takes 8 min 19 s to reach on Earth.
The Sun
still isn’t as large as other types of stars. It’s classified as a yellow dwarf
star.
The
Sun’s magnetic field spreads throughout the solar system via the solar wind.
The
Sun ,the heart of our solar system, is a yellow dwarf star, a hot ball of glowing
gases.
Size and Distance of the Sun
Sun has
a radius of 432,168.6 miles (695,508 kilometres), it is not an especially large star, many stars
are several times bigger than Sun, but it is still far more massive than our
home planet Earth. Sun’s mass is about 330,000 times that of Earth, and
accounts for about 99.86% of the total mass of the Solar System. The Sun’s
volume would need 1.3 million Earths to fill it.
Characteristics of the Sun ⛅
|
Mean distance From Earth |
1 AU ≈ 1.496×10⁸ km 8 min 19 s at light speed |
|
Orbital characteristics of the Sun |
|
|
Mean distance From Milky Way core |
2.7×10¹⁷ km ≈ 29,000 light-years |
|
Galactic period |
(2.25–2.50)×10⁸ years |
|
Orbital Velocity |
≈ 220 km/s
(orbit around the center of the Milky Way) ≈ 20 km/s
(relative to average velocity of other stars in stellar neighborhood) ≈ 370 km/s (relative to the cosmic microwave
background) |
|
Physical characteristics of the
Sun |
|
|
Equatorial radius |
695,700 km, (109
× Earth) |
|
Equatorial circumference |
4.379×10⁶ km
(109 × Earth) |
|
Surface area |
6.09×10¹² km² (12,000 × Earth) |
|
Volume |
1.41×10^18 km³ (1,300,000 × Earth) |
|
Equatorial surface gravity |
274 m/s² (28
× Earth) |
|
Escape velocity (from the surface) |
617.7 km/s (55 × Earth) |
|
Rotation characteristics of the Sun |
|
|
Sidereal rotation period |
25.05 days (at equator), 25 d 9 h 7 min 12 s (at 16 degree latitude) 34.4 days (at poles) |
|
Rotation velocity at equator |
7.189×10^3 km/h |
Orbit and Rotation of the Sun
The Sun, and everything that orbits it, is located in the Milky Way galaxy. More specifically, Thr Sun is in a spiral arm called the Orion Spur that extends outward from the Sagittarius arm. From there, the Sun orbits the center of the Milky Way Galaxy, bringing the planets, asteroids, comets and other objects along with it.
Our solar system is moving with an average velocity of 450,000 miles per hour (720,000 kilometres per hour). But even at this speed, it takes us about 230 million years to make one complete orbit around the Milky Way.
The Sun rotates as it orbits the center of the Milky Way. Its spin has an axial tilt of 7.25 degrees with respect to the plane of the planets’ orbits. Since the Sun is not a solid body, different parts of the Sun rotate at different rates. At the equator, the Sun spins around once about every 25 days, but at its poles the Sun rotates once on its axis every 36 Earth days.
The Sun’s Formation
The Sun and the rest of the solar system formed from a giant, rotating cloud of gas and dust called a solar nebula about 4.5 billion years ago. As the nebula collapsed because of its overwhelming gravity, it spun faster and flattened into a disk. Most of the material was pulled toward the center to form our Sun, which accounts for 99.8% of the mass of the entire solar system.
Like all stars, the Sun will someday run out of energy. When the Sun starts to die, it will swell so big that it will engulf Mercury and Venus and maybe even Earth. Scientists predict the Sun is a little less than halfway through its lifetime and will last another 6.5 billion years before it shrinks down to be a white dwarf.
Structure of the Sun
The Sun, like others stars, is a ball of gas. In terms of the number of atoms, it is made of 91.0% hydrogen and 8.9% helium. By mass, the Sun is about 70.6% hydrogen and 27.4% helium.
The Sun has six regions: the core, the radiative zone, and the convective zone in the interior; the visible surface, called the photosphere; the chromosphere; and the outermost region, the corona.
The Sun’s enormous mass is held together by gravitational attraction, producing immense pressure and temperature at its core. The Sun has six regions: the core, the radiative zone, and the convective zone in the interior; the visible surface, called the photosphere; the chromosphere; and the outermost region, the corona.
In its core the Sun currently fuses about 600 million tons of hydrogen into helium every second, converting 4 million tons of matter into energy every second as a result. At the core, the temperature is about 27 million degrees Fahrenheit (15 million degrees Celsius), which is sufficient to sustain thermonuclear fusion. This is a process in which atoms combine to form larger atoms and in the process release staggering amounts of energy. Specifically, in the Sun’s core, hydrogen atoms fuse to make helium.
The energy produced in the core powers the Sun and produces all the heat and light the Sun emits. Energy from the core is carried outward by radiation, which bounces around the radiative zone, taking about 170,000 years to get from the core to the top of the convective zone. The temperature drops below 3.5 million degrees Fahrenheit (2 million degrees Celsius) in the convective zone, where large bubbles of hot plasma (a soup of ionized atoms) move upwards. The part of the surface we can see is about 10,000 degrees Fahrenheit (5,500 degrees Celsius). That’s much cooler than the blazing core, but it’s still hot enough to make carbon, like diamonds and graphite, not just melt, but boil.
Surface of the Sun
The surface of the Sun, the photosphere, is a 300-mile-thick (500-kilometer-thick) region, from which most of the Sun’s radiation escapes outward. This is not a solid surface like the surfaces of planets. Instead, this is the outer layer of the gassy star.
We see radiation from the photosphere as sunlight when it reaches Earth about eight minutes after it leaves the Sun. The temperature of the photosphere is about 10,000 degrees Fahrenheit (5,500 degrees Celsius).
Atmosphere of the Sun
Above
the photosphere lie the tenuous chromosphere and the corona (crown), which make
up the thin solar atmosphere. This is where we see features such as sunspots
and solar flares
Photospheric composition (by mass) | |
Hydrogen | 73.46% |
Helium | 24.85% |
Oxygen | 0.77% |
Carbon | 0.29% |
Iron | 0.16% |
Neon | 0.12% |
Nitrogen | 0.09% |
Silicon | 0.07% |
Magnesium | 0.05% |
Sulphur | 0.04% |
Visible light from these top regions is usually too weak to be seen against the brighter photosphere, but during total solar eclipses, when the moon covers the photosphere, the chromosphere looks like a red rim around the Sun, while the corona forms a beautiful white crown with plasma streamers narrowing outward, forming shapes that look like flower petals.
Strangely, the temperature in the Sun’s atmosphere increases with altitude, reaching as high as 3.5 million degrees Fahrenheit (2 million degrees Celsius). The source of coronal heating has been a scientific mystery for more than 50 years
Potential for Life on the Sun
The Sun itself is not a good place for living things, with its hot, energetic mix of gases and plasma. But the Sun has made life on Earth possible, providing warmth as well as energy that organisms like plants use to form the basis of many food chains.
Moons
The Sun and other stars don’t have moons; instead, they have planets and their moons, along with asteroids, comets, and other objects.
Rings of Sun
The Sun does not have rings.
Magnetosphere of Sun
The electric currents in the Sun generate a complex magnetic field that extends out into space to form the interplanetary magnetic field. The volume of space controlled by the Sun’s magnetic field is called the heliosphere.
The Sun’s magnetic field is carried out through the solar system by the solar wind—a stream of electrically charged gas blowing outward from the Sun in all directions. Since the Sun rotates, the magnetic field spins out into a large rotating spiral, known as the Parker spiral.
The Sun
doesn’t behave the same way all the time. It goes through phases of its own
solar cycle. Approximately every 11 years, the Sun’s geographic poles change
their magnetic polarity. When this happens, the Sun’s photosphere, chromosphere
and corona undergo changes from quiet and calm to violently active. The height
of the Sun’s activity, known as solar maximum, is a time of solar storms:
sunspots, solar flares and coronal mass ejections. These are caused by
irregularities in the Sun’s magnetic field and can release huge amounts of
energy and particles, some of which reach us here on Earth. This space weather
can damage satellites, corrode pipelines and affect power grids.
Important Facts of the Sun
Radius
432,168.6
miles | 695,508 kilometres
The Sun’s volume would need 1.3 million Earths to fill it.
Star Type
Yellow dwarf
Distance from Earth
92.92
million miles | 149.60 million kilometres | 1 astronomical unit.
The
connection and interactions between the Sun and Earth drive the seasons, ocean
currents, weather, climate, radiation belts and aurorae. Though it is special
to us, there are billions of stars like our Sun scattered across the Milky Way
galaxy.
So Massive
The Sun
is the center of our solar system and makes up 99.8 percent of the mass of the
entire solar system.
Sun’s mass is about 330,000 times that of Earth.
Our solar system is moving with an average velocity of 450,000 miles per hour (720,000 kilometres per hour). But even at this speed, it takes us about 230 million years to make one complete orbit around the Milky Way.
Different Spins
At the equator, the Sun spins once about every 25 days, but at its poles the Sun rotates once on its axis every 35 Earth days..
Can't Stand on it
As a star, the Sun is a ball of gas (92.1% hydrogen and 7.8% helium) held together by its own gravity.
Energy for Life
Without the Sun’s intense energy, there would be no life on Earth.
Nuclear Fusion
The Sun’s core is about 27 million degrees Fahrenheit (15 million degrees Celsius).
Moonless
But
orbited by eight planets, at least five dwarf planets, tens of thousands of
asteroids, and up to three trillion comets and icy bodies.
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