I had heard in news recently but didn't catch everything. Something about Pluto not being a planet and now believed to be hotter than our Sun. So what is the definition of a star? What makes the Sun a star? They gave another name for it but I didn't catch it. What this all about? anyone know?
2007-03-14 15:53:06 · 10 answers · asked by sabatha 1 in Science & Mathematics ➔ Astronomy & Space
The Sun is a star, in fact, our closest star. The other name you're looking for is probably Helios, that's the Greek name for the Sun (I'm Greek myself so I'd better now that!). Or perhaps you're looking for a classification for the Sun? If so, you'll be pleased to know that the Sun is a 'yellow dwarf' star.
What makes an object a star is its mass. If a body has enough mass above a mass that we call 'critical', it can start nuclear reactions in its core so it becomes a star. In that respect, a big body in our Solar System like Jupiter is not a star because its mass is below that critical mass to start nuclear reactions in its core.
Regarding the other part of your question, Pluto is too far away from the Sun to be any hot at all. In fact, it is a very cold object. Actually, we suspect that Pluto is a captured asteroid except that its shape does not look like a potato like other asteroids do! Pluto is now classified as a 'dwarf planet', it's not a planet any more.
2007-03-15 03:51:52 · answer #1 · answered by stardom65 3 · 0⤊ 0⤋
Wow, I really hope you just weren't actually listening to the news report. Because that would horrible if they actually said that.
Pluto is not a planet. It's too small and hasn't cleared it's orbit. It's also a big chunck of rock and ice. It's definitely not hot at all.
A star is a body capable of fusing hydrogen, which requires a certain amount of mass - about 13 times the size of Jupiter. Pluto is much MUCH smaller than Jupiter - it's actually smaller than our moon.
EDIT: In response to JayGal - Pluto is NOT a planet, under the new definition of planet from the International Astronomical Union.
The Sun is NOT a red giant. It will be in about 5 billion years, but now it's just a yellow dwarf star on the main sequence.
2007-03-14 16:14:34 · answer #2 · answered by eri 7 · 1⤊ 0⤋
Pluto is no longer defined as a planet, it is now called a dwarf planet. It is almost as cold as interstellar space (due to the fact its too small to generate any internal heat and its too far from the sun to get any significant heat from that). Other dwarf planets in our system are Ceres and Eris.
A star is an object in space that has collected sufficient mass to have ignited nuclear fusion in its core and generates its own light and heat.
Some stars are very small and cool (relatively speaking) and are called brown dwarf stars. They are very faint and only as hot as a kitchen oven, but they are fueled by nuclear fusion and so qualify as a star.
2007-03-14 16:02:07 · answer #3 · answered by Anonymous · 2⤊ 0⤋
the sun is definately a star, it is sorta older than other stars, though.
pluto is not a planet bc the new definition of a planet includes a bigger size than what pluto is, they actually believe pluto was a moon from neptune that flew further off into space.
Pluto is SUPER cold...think about it...it's way far away from our solar system's heat source (the sun).
2007-03-14 15:58:58 · answer #4 · answered by Anonymous · 0⤊ 0⤋
I have studied astronomy and physics for more than 40 years, and have yet to meet an astronomer or astrophysicist (or anyone else with a fifth grade education or above) who does not think the sun is a star.
And nobody has suggested that Pluto is hot.
So you must have been distracted at the time. I hope it was fun.
2007-03-14 16:36:19 · answer #5 · answered by aviophage 7 · 2⤊ 0⤋
There is no difference between the sun and a star. They are the same thing. If we lived in the Epsilon Eridanus star system (which has more than one star but lets say it only had one star) we would call it the sun. The sun is the same as every other star. Just it's size, brightness and its fate (neutron star, black hole, dead star, etc.).
Hope I helped.
2007-03-14 16:24:15 · answer #6 · answered by T-Bob Squarepants 3 · 0⤊ 0⤋
using fact we can not see radar or x-ray with our eyes, scientists are compelled to create what's termed "fake shade" pictures from the pictures that the telescopes take. So the pictures taken which you spot that are packed with vegetables and purples are of honestly remember, although that's shop in mind this is reflecting purely that that's invisible to our eyes. do no longer difficulty. The astronomers be attentive to what they are doing and what they are speaking approximately.
2016-11-25 20:56:37 · answer #7 · answered by slagle 4 · 0⤊ 0⤋
they concluded that Pluto is now a planet. yes the sun is a star . you know stars have life cycles so the sun is still a red giant. i think i can remember reading that it will take the a billion years before it becomes a super giant. a star is a hot glowing ball of gas (mainly hydrogen) that gives a tremendous light energy
2007-03-14 16:07:18 · answer #8 · answered by jay gal 3 · 0⤊ 3⤋
a sun is a star, a star is a sun.
2007-03-14 15:55:44 · answer #9 · answered by Adam B 2 · 0⤊ 0⤋
Errrmmmm........ Maybe you should try to catch it all next time.
Doug
2007-03-14 16:04:06 · answer #10 · answered by doug_donaghue 7 · 2⤊ 0⤋