Planet Vs Star – What’s the Difference?
Stars and planets are two different types of celestial bodies that can be seen in our skies. Understanding the differences between them is important if you want to get a clear understanding of how the universe works.
Stars are much larger and brighter than planets. They also have higher temperatures and are able to produce their own light.
Stars are bigger
A star is a big, hot ball of gas, formed when a cloud of interstellar material collapses under its own gravity. Pockets of gas clump together, accumulating until it becomes a dense mass that can ignite nuclear fusion in its core.
It takes a lot of energy for this to happen, so the star has to be huge before it can light up. The most massive stars, like the Sun, have enough mass to fuse hydrogen in their cores.
But there are other stars that can’t make it big enough to spark fusion. These are called brown dwarfs, and while they do emit radiation, they aren’t big enough to ignite fusion in their cores.
Stars are hotter
Stars become hotter the bigger they get, because of the pressure generated by their mass. They also get hotter because they produce more energy in the form of light.
In addition to that, stars get very luminous, mainly due to nuclear fusion in their cores. This means that their light has more energy to heat planets farther away from them.
The only way that a planet can be hotter than Earth is if it has an atmosphere, which traps heat on its surface and prevents it from escaping into space. This is what makes Venus so hot despite its distance from the Sun.
A new exoplanet, called KELT-9b, is so close to its blue star that it reaches temperatures almost as high as our own sun’s dayside. It’s so hot that its molecules are constantly ripped apart by the star, according to a study using data from NASA’s Spitzer Space Telescope.
Stars are brighter
One of the most noticeable differences between stars and planets is how bright they appear. This is a result of the inverse-square law, which states that as you increase your distance from a light source, the brightness decreases by a factor of 4.
Stars are much brighter than planets because they are closer to Earth and reflect more sunlight toward us. This is why the sun appears so bright when viewed from Earth.
Astronomers have developed a system of magnitude to measure a star’s apparent brightness. This scale ranks stars from first magnitude (brightest) to sixth magnitude (dimest).
Stars have more mass
Stars vary in mass because more massive stars have a stronger gravitational force acting inwards. This means their core gets hotter and nuclear reactions occur at a faster rate.
Generally, high mass main sequence stars are much larger and brighter than low mass ones. This is because the main fusion reaction of converting hydrogen into helium occurs at a higher temperature in the massive stars.
They also have shorter lifetimes than low-mass main sequence stars. While the Sun will spend 10 billion years on the main sequence, a high-mass ten solar-mass star only spends 20 million years.
Stars have more gravity
Stars are a blazing ball of plasma (a state of matter) that is held together by gravity. They also produce heat and light by nuclear fusion.
Planets are celestial bodies that orbit around a star. They are smaller than stars but have enough mass for their own gravity to overcome the star’s gravitational force.
Gravity is a force that attracts physical matter to itself, a natural phenomenon that’s fundamental to life on Earth. It’s also responsible for keeping astronomical objects spherical and in predictable orbits.
It also produces more complicated and chaotic behaviors in a star system, especially when three or more bodies interact. Astronomers study these interactions as part of a field called gravitational dynamics. It helps researchers understand the Solar System, asteroids, and exoplanet systems. It’s also important for understanding how a star system can become unstable or stable.
Stars have more moons
The number of moons in the solar system is huge, with 184 known moons around planets and dwarf planets. But around other stars, the count is even greater.
For instance, Saturn has 83 confirmed moons. This is more than Jupiter, which has 80.
Astronomers have discovered a new moon that orbits a world beyond our own, nearly 6,000 light-years away. It’s a gas-dominated exomoon called Kepler-1708 b-i.
The research by astronomer Fathi Namouni shows that when gas giants migrate toward their stars, they lose their moons and get ejected as they move closer to their host star. The process can last millions of years.
Stars have more rings
The four largest planets in the Solar System, Jupiter, Saturn, Uranus and Neptune, have rings. These are formed by dust and small rocks that cannot unite through gravity to form a single planet – which would be the most natural process.
Rings are often found around galaxies, too. Some examples include the Cartwheel galaxy, which has a ring of stars and a smaller nucleus; NGC 4650A, which has an outer ring; and Seyfert galaxy M77, which has a polar ring.
Researchers believe that a significant portion of the galaxy-sized rings are formed by tidal forces as small galaxies are pulled apart from their hosts. This process creates a stream of stars and gas that eventually coalesces into the ring.
Stars have more planets
In recent years, telescopes have spotted thousands of planets orbiting not only stars similar to the Sun but also in binary star systems; small, cool stars called red dwarfs; and even ultradense neutron stars.
The most common exoplanets found around stars are planets in Earth-like orbits. They are incredibly rare in larger orbits, however.
This is because planets are extremely faint light sources compared to their host stars and reflect very little of the star’s light.
This means that astronomers must use techniques like gravitational microlensing to detect them. The technique uses the way the gravitational field of a star magnifies the light from a background star, making it easier to spot exoplanets.
Stars have more brown dwarfs
When a star forms, it fuses hydrogen atoms into helium. The center of a star needs to reach a certain temperature to ignite this process. For stars that are too small to ignite fusion, they become what are known as brown dwarfs.
They are relatively cool, compared to the Sun, and glow in infrared light. Astronomers have discovered dozens of brown dwarfs since 1995, and hundreds more are waiting to be spotted in sensitive surveys currently underway.
In the search for brown dwarfs, astronomers have focused on finding them as companions to nearby stars. However, they have also found a large number of brown dwarfs freely floating among the stars.