R136a1's heat would probably vaporize all of the planets.
Both are stars. Other than that, not much: R136a1 is a Wolf-Rayet star, and is both the most massive and the most luminous star known, making it quite different to our Sun. Its large mass (and corresponding high energy output) also make it relatively short-lived.
R136a1 is the brightest known star. VY Canis Majoris. Its bolometric luminosity is estimated at 8.7 million times that of our Sun. VY Canis Majoris has a bolometric luminosity estimated at 450,000 that of the Sun, which is still very powerful. Bolometric luminosity refers to the entire radiation emitted at all wavelengths (not only visible light), so it is a measure of the power emitted by the star.
it melts
It's a similar star in most respects to our Sun, slightly larger, but the increase in size, would probably be offset by an increase in revolution. So probably not much. It might be a little warmer and the years should be shorter, but in all other aspects - life would go on as normal.
oceans would dry
R136a1 is a blue hypergiant star located in the Large Magellanic Cloud. It is estimated to be approximately 265 times the mass of our Sun, making it one of the most massive stars known in the universe.
R136a1 is the most luminous at about 8,700,000 times more than the Sun. VY Canis Majoris is only 450,000 times more luminous than our Sun.
R136a1 is one of the hottest known stars, with surface temperature around 50,000 degrees Celsius (90,000 degrees Fahrenheit). Its extreme heat causes it to emit intense ultraviolet radiation and it is a supergiant star, approximately 250 times more massive than the sun.
An average blue giant is about 5-10 times the size of the Sun and are much hotter than the Sun is. If our Sun were a blue giant, life, as we know it would never have happened. The Earth would have been vastly too hot to support abiogenesis.
Both are stars. Other than that, not much: R136a1 is a Wolf-Rayet star, and is both the most massive and the most luminous star known, making it quite different to our Sun. Its large mass (and corresponding high energy output) also make it relatively short-lived.
there are many stars larger than the sun. for ex. vy canis majoris, the largest star known, rigel, sirius, r136a1 etc.
The sun would win.
It would melt.
Because the new moon would have a higher gravitational pull, the earth would start to orbit around it as if it was the new moon's moon. This would cause the new moon to become a sun causing the Sun to crash into the new sun causing a supernova erasing the entire galaxy.
If Betelgeuse replaced our Sun, it would likely cause drastic changes in our solar system. Betelgeuse is a red supergiant star, much larger and hotter than our Sun, so Earth would be too close to it and would likely be engulfed by the star's expanded outer layers. The intense radiation and heat would also have significant effects on the other planets in our solar system.
If the sun was replaced by a star with twice as much mass the gravitational force would be unbalanced and the new sun would burn the earth because if the gravitational force cannot hold than the sun would plummet towards the earth and burn it.
The sun does not get replaced, firstly it goes through many stages and then when there is no more hydrogen to burn, it will explode. For the Earth that means we will all DIE!!!! But that won't happen for a long while.