heat
Wikipedia lists a surface temperature of 4300 K.
Roughly 12.57 times the square of its radius.
red and yeller
New energy star models are about 470 kWh per year.
For a star shaped figure, as many as the number of points. For a real star (like the ones up in the sky) either infinitely many or none - depending on the level of detail that you look at. The surface of any star has lots of dimples and bumps caused by stellar activity and these will break up any symmetry. If you ignore these fine details, then the star is a smooth ellipsoid and has infinitely many rotational symmetries. These symmetries are along the star's axis of rotation. For any other axis, the star's rotation will make the equatorial region bulge out and so there will be no symmetries.
The energy output of a star is from nuclear fusion. The particles involved with both input and output are atomic (and sub-atomic) in nature not cellular.
The surface temperature is not a reliable indicator about how long a star will last. However, the total energy output is. If a star produces a lot of energy, it will burn through its fuel faster.
The same as everywhere else. Every mass has associated energy. Every energy has associated mass. Possibly this question is about the energy output of stars. Usually, the more mass a star has the higher its rate of energy output.
A star's luminosity is the measure of the total energy radiated by the star in one second.
A supernova is the catastrophic death of a star, characterized by a massive output of energy.
The temperature in the core of a star depends, to a great extent, on:* The star's mass. The general tendency is that high-mass stars are hotter. * Where the star is in its life cycle. The star's core temperature will vary over time. On the other hand, the star's surface temperature also depends on its size. Thus, it is possible that PRECISELY because a star is hotter in the core, it gets bigger, and the surface temperature DECREASES (though its total energy output increases).
The temperature of a yellow star's photo sphere is hotter than that of and orange star. However the total energy output of an orange star may be greater than that of a yellow star.
Distance from the Sun (for star systems not our own, distance from the primary star(s)) the closer to a star the more energy reaches the planet. Atmospheric composition - how much energy gets to the surface and how much is trapped in. Terrestrial composition; what the solid stuff is made of and how it reacts with stellar/solar energies. Some things reflect light back, others absorb the energy and radiate it back as heat. Also, for planets not around the Sun, the size and energy output (heat) of the star(s) would be factored in. :P
400 Octillion Joules. (400,000,000,000,000,000,000,000,000,000) It's not really a fair question, however. The Death Star, as depicted in the Star Wars movies, is grossly overpowered for its purpose. It would take a tiny fraction of that energy to simply vaporize the surface and wipe out all life. Okay, I admit I did not actually calculate the energy required to vaporize a planet. I simply assumed that the energy output of a Sun like star would be sufficient if it were all turned on puny little Alderaan (or Earth). The Sun outputs 400 Octillion Joules / second.
They cannot be the same size. The red star must be larger. Red stars are cooler that blue stars and so radiate less energy for a given amount of surface area. In order to radiate the same amount of energy as a blue star, the red star must therefore have a larger surface area.
At a higher temperature, the star will shine more brightly for each square meter of surface. The total luminosity per square meter is approximately proportional to the fourth power of its absolute temperature. This refers to the energy output, considering all types of electromagnetic waves, not just visible light.
The color of light is an indication of the energy it carries, and the energy is a function of wavelength and frequency. Higher frequencies have shorter wavelengths and carry higher energies. The red end of the visible spectrum has the longest wavelengths and lower frequencies, so represent relatively lower energies. Blue light carries higher energies, so a star that has a strong output of blue (or ultraviolet) light has the higher surface temperature.