largest Star In The Universe-
largest Star In The Universe, The Sun is the most massive star in our solar system. It contains 99.86% of the mass of the entire solar system. In fact, it accounts for almost four times the total mass of all the planets combined.
Mercury is the smallest planet in our solar system. Its diameter is about 4,900 km (3,100 mi).
Venus is the second-largest planet in our solar system, and the third-most-massive body in the Universe. Venus is larger than Earth and much closer to the Sun. Its surface temperature averages around 450°C (842°F), making it the hottest planet in the Solar System.
Mars is the fourth planet from the Sun. Mars is slightly smaller than Earth, although it takes longer to orbit the Sun than Earth does. Mars orbits farther from the Sun than any other planet in the Solar System, taking approximately 687 days to complete one trip around the Sun. This makes Mars the second slowest orbiting planet after Pluto.
Jupiter is the fifth planet from the Sun. Jupiter is the largest planet in terms of both size and mass. It is over 93 million kilometers (58 million miles) across and nearly 300 times more massive than Earth. At an average distance of 5.2 AU (7.9 billion km; 4.4 billion mi), Jupiter is located some 295 times further away from the Sun than Earth. However, because of its great distance from the Sun, Jupiter receives 16 times more sunlight than Earth. As such, Jupiter experiences extreme temperatures ranging from -423 °C (-676 °F) at the poles to +413 °C (+793 °F) near the equator.
Saturn is the sixth planet from the Sun. Saturn is the second largest of the gas giants, following Jupiter. With a mean radius of 963 km (600 mi), Saturn is nearly three times bigger than Earth. Unlike Earth, however, Saturn’s atmosphere is composed mostly of hydrogen and helium. Although the outer clouds are mostly composed of water ice, there are no weather systems like those on Earth.
Uranus is the seventh planet from the Sun. Uranus is similar in composition to Neptune. Like Neptune, it consists primarily of hydrogen and helium, with a trace amount of methane present. There are 17 confirmed moons orbiting Uranus. These include five large moons—the irregularly shaped Miranda, Ariel, Umbriel, Titania, and Oberon—as well as 12 small moons.
The above list of caveats highlights some of the problems that arise in trying to determine the radius of large stars. For example, there are numerous uncertainties associated with the determination of stellar luminosities, especially for very hot stars. In addition, it is difficult to estimate the exact distance to the star, since the vast majority of stars are too far away to measure directly. This problem becomes even worse when dealing with large stars, because their apparent brightness decreases rapidly with increasing distance, making it nearly impossible to detect them at great distances.
In fact, the distance to a star depends upon how much light we receive from it. If the star is farther away, less light reaches us. As a result, our best estimates of the distance to a star are typically obtained by comparing the observed spectrum of the star to theoretical spectra generated by computer models. However, the accuracy of such comparisons is limited by the quality of the data used, and the reliability of the model spectra themselves.
The following lists are ranked according to their size, based on the distance between us and the center of their galaxies. Each list includes the name of the galaxy, its apparent magnitude, and the number of stars it contains. For example, NGC 4258 is a spiral galaxy located about 25 million light-years away in the constellation Canes Venatici. Its apparent magnitude is 8.6. This means that we see it just like how you see the moon—as a bright dot in the night sky. In fact, it is one of the brightest objects visible to the naked eye. If you could travel there, you would find yourself looking into a star field that is home to over 500 billion stars. This makes it the fourth most massive object in our Milky Way Galaxy.
NGC 4258 is the host galaxy of the well-known double star system called HR 8799. It is also the site of the planet Kepler 22b. This planet is the second closest exoplanet to Earth and orbits its parent star every 2.2 days.
The Magellanic Clouds are two large galaxies located about 50 million light years away in the southern sky. They’re often referred to as “the Southern Hemisphere’s twin moons.”
M31 and M33
The Andromeda Galaxy is one of the most distant objects in our Milky Way galaxy. It takes light 12 million years to reach us. But it could take much longer than that to see it in person. A team of astronomers led by astronomer John Grunsfeld of NASA’s Jet Propulsion Laboratory in Pasadena, California, used Hubble Space Telescope images to make the first detailed map of the outer parts of the Andromeda Galaxy. In addition to studying the shape of the galaxy, the researchers found evidence of dark matter, which makes up about 85% of the mass of galaxies like ours. Dark matter is invisible because it doesn’t emit or absorb light. Instead, it interacts gravitationally with ordinary matter.
The Milky Way Galaxy is one of about 200 billion galaxies in our local Universe. But there are many others out there. In fact, we know of around 2 trillion stars within just 300 million light years of us. This makes up less than 0.01% of the total number of galaxies in the Universe. And it gets even smaller when you consider that there could be millions of other galaxies beyond that. So what do we mean when we say “other galaxies”? We’re talking about galaxies outside our own galaxy cluster. These galaxies are called “field galaxies”. They lie far away from each other and don’t belong to any larger group.