Betelgeuse

Not quite. The North Star, Polaris, is about six-tenths of a degree away from being directly above the North Pole. Considering that this happened completely by chance, the coincidence is very handy.

The red giant star Betelgeuse, in the shoulder of the constellation Orion, is one of the brightest stars in the winter sky. It has been known since antiquity.

We really have no way of knowing "who was first" or "what year..." for things that happened over 3,000 years ago. Mostly, the records were lost, or destroyed, or for things THAT long ago, they were never "recorded" at all.

Surprisingly perhaps, it is fairly cool for a star. Betelgeuse is a red giant, meaning it is reaching the end of its life. When a star like our sun, a moderate Main Sequence Star begins to run out of fuel, there is a reaction in the collapsing core that briefly (in the lifetime of a star..briefly can be millions of years) causes the outer layers to expand outward. The gases cool off as they move farther from the core. Red light holds the least energy, which is why the star's outer layers turn red. It is also the coolest light.

Our sun will one day become a red giant like Betelguese, and its outer layers will expand far enough to engulf Mars.

One day, Betelgeuse will loose its outer layers in a nova, and all that will be left will be a white dwarf core.

Look up the Hertsprung-Russell diagram and you'll get more exact temperatures for red giants, but red stars of any type are the coolest.

Betelgeuse is generally brighter than Antares. Betelgeuse is a red supergiant star in the constellation of Orion and is one of the brightest stars in the night sky, while Antares is a red supergiant in the constellation Scorpius and appears slightly dimmer than Betelgeuse from Earth's perspective.

I would like to explain that in fact, Betelgeuse is closer to 640 light-years away than it is to 425 ly. So, if it goes supernova tonight, the light from this massive explosion would take 640 years to get to Earth. So, we would observe this supernova only 640 years after it has actually happened.

The red giant star Betelgeuse is the bright reddish star at the "shoulder" of Orion, the Hunter. Orion is one of the most distinctive constellations in the winter sky, and is easily visible in the winter and early spring.

In this season, Orion is setting as the Sun goes down, and it will not be especially visible until the late fall again, when it will rise at sunset.

The star Betelgeuse (or "beetlejuice") is a Type M red supergiant in the constellation Orion. It is pronounced "bet- L (like the letter L) -geese," meaning armpit of the giant.

It is very luminous, and one of the largest stars known [See Link]. For comparison, if the star was at the centre of our solar system its surface would extend out between the orbits of Mars and Jupiter, engulfing Mercury, Venus, Earth and Mars.

It has a mass 20 times that of our Sun (Sun = 1.9891 × 1030kg = 333,000 times that of Earth)

It's approximately 600 light years from us.

The name is a corruption of an Arabic word meaning "hand of the central one".

It is likely that Betelgeuse will become a supernova. Because of its size and age of 8.5 million years it may explode within the next thousand years. (However, due to its distance from us, it may have already happened!!!)

[It's also a name of a film]

For plutonium (or any other radionuclide) to decay to one eighth of its original activity, it will take 3 half-lives of the material. In one half-life, half is gone. Half will be left. In another half-life, half of the half that was left is gone, and one quarter will be left. In a third half-life, half the one quarter will be left, and that's one eighth of the original. In the case of plutonium, there are a number of isotopes of this highly radioactive stuff. The isotope 239Pu, which is commonly used in nuclear weapons, has a half-life of 2.41 x 104 years. That's 24,100 years. For 239Pu to decay to 1/8 th of its original amount, it will take 3 time the half-life, which is 7.23 x 104 years, or 72,300 years. And yes, that is a long time. A very long time....

Betelgeuse's distance from Earth according to various well-respected astronomical agencies is between 310 and 640 light years. Taking an average of the ten measurements that I've dug out the average is 480 light years.

As I'm writing this from England and the distance to Betelgeuse is taken from the Equator, it's average distance is actually 480 light years PLUS 3,521miles!

Dr. Peter

It is a cool star.

Betelgeuse is one of the larger stars, while Barnard's star is just a little red dwarf star. So, yes- Betelgeuse is far larger than Barnard's.

The light coming from it takes hundreds of years to reach us, so what you see when you look at it is light that left it hundreds of years ago. So if it did explode and die, then it would take hundreds of years for us to see it happen.

When we look at stars, we are seeing the light that they are emitting. That light could have left them many years ago. The light from Betelgeuse takes over 640 years to reach us. So if it exploded today, we would not see that explosion for over 640 years. So it is possible that it is already gone, but the light that left before it went is still coming towards us.

No. It is in the Milky Way galaxy, like all the stars that we can see are.

It's a fairly cool star

It's hotter

Betelgeuse, a red supergiant star in the constellation Orion, has an estimated radius about 700 times that of the Sun. Its massive size means it could encompass the orbit of Mars if it were placed at the center of our solar system. Betelgeuse's exact size can vary due to its pulsating nature, but it remains one of the largest known stars.

When talking about stars, "cool" is a relative term. Betelgeuse has a variable surface temperature of 5,200 to 6,100 degrees Fahrenheit. Such a temperature may seem extremely hot to us and is easily hot enough to emit bright light but it is fairly cool as stars go. The comparatively low temperature of Betelgeuse means that it gives off less light per square meter than a hotter star would, but it makes up for it with its massive size, more than 900 times the diameter of the sun. As massive size means a large surface are and thus a huge output of light.

The density of Betelgeuse is extremely low: 1,119.10 ex.-8 from the density of the sun.

No. While Betelgeuse is larger and brighter than the sun, it actually has a lower surface temperature.

Yes, the Sun is much smaller than Betelgeuse.

well my reason is that the betelgeuse must be very large , because they said that the betelgeuse is located far from earth .

The runaway crimson Super Giant named Betelguese was estimated in 2008 to be approximately 640 light years away from our Earth.

Betelgeuse will die in a massive explosion called a supernova. When this happens it will appear brighter than the full moon.

Yes it is, as all stars that you can see with the naked eye are in the Milky Way galaxy.