The Sun is the star at the center of the Solar System. It has a diameter of about 1,392,000 km, about 109 times that of Earth, and its mass (about 2×1030 kilograms, 330,000 times that of Earth) accounts for about 99.86% of the total mass of the Solar System. About three quarters of the Sun's mass consists of hydrogen, while the rest is mostly helium. Less than 2% consists of heavier elements, including oxygen, carbon, neon, iron, and others.......
The Sun was formed about 4.57 billion years ago when a hydrogen molecular cloud collapsed Solar formation is dated in two ways: the Sun's current main sequence age, determined using computer models of stellar evolution and nucleocosmochronology, is thought to be about 4.57 billion years. This is in close accord with the radiometric date of the oldest Solar System material, at 4.567 billion years ago...
The Sun is about halfway through its main-sequence evolution, during which nuclear fusion reactions in its core fuse hydrogen into helium. Each second, more than four million metric tons of matter are converted into energy within the Sun's core, producing neutrinos and solar radiation. At this rate, the Sun has so far converted around 100 Earth-masses of matter into energy. The Sun will spend a total of approximately 10 billion years as a main sequence star.
The Sun does not have enough mass to explode as a supernova. Instead, in about 5 billion years, it will enter a red giant phase, its outer layers expandi
Re: Sun
by om shanti on Feb 07, 2011 11:00 PM
it will enter a red giant phase, its outer layers expanding as the hydrogen fuel in the core is consumed and the core contracts and heats up. Helium fusion will begin when the core temperature reaches around 100 million K and will produce carbon, entering the asymptotic giant branch phase.
Earth's fate is precarious. As a red giant, the Sun will have a maximum radius beyond the Earth's current orbit, 1 AU (1.5�011 m), 250 times the present radius of the Sun. However, by the time it is an asymptotic giant branch star, the Sun will have lost roughly 30% of its present mass due to a stellar wind, so the orbits of the planets will move outward. If it were only for this, Earth would probably be spared, but new research suggests that Earth will be swallowed by the Sun owing to tidal interactions. Even if Earth would escape incineration in the Sun, still all its water will be boiled away and most of its atmosphere would escape into space. Even during its current life in the main sequence, the Sun is gradually becoming more luminous (about 10% every 1 billion years), and its surface temperature is slowly rising. The Sun used to be fainter in the past, which is possibly the reason life on Earth has only existed for about 1 billion years on land. The increase in solar temperatures is such that in about another billion years the surface of the Earth will likely become too hot for liquid water to exist, ending all terrestrial life.
Re: Re: Sun
by om shanti on Feb 07, 2011 11:02 PM
Following the red giant phase, intense thermal pulsations will cause the Sun to throw off its outer layers, forming a planetary nebula. The only object that will remain after the outer layers are ejected is the extremely hot stellar core, which will slowly cool and fade as a white dwarf over many billions of years. This stellar evolution scenario is typical of low- to medium-mass stars...
Re: Re: Re: Re: Re: Sun
by mahammad naragund on Feb 08, 2011 08:53 AM | Hide message
the sun describes in QURAN 1400 YEARS AGO its shape and rotation etc .
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Re: Re: Re: Sun
by ravi kumar on Feb 08, 2011 06:54 PM
thanks for enlightening :) looking at next 30 years it seems things wont change much though.
Re: Re: Re: Sun
by iype george on Mar 08, 2012 04:55 PM
Dont worrry we wil generate electricity free of cost and keep the planet cool and condense all the water putting up condensors. Human beings know how to survive.
fantastic photos - carona,plasma,outer surface of sun - temperatures of sun - all a puzzle - yet a curious subject which difficult to imagine yet its true that sun at 360-degrees puzzles scientists & layman alike - may be earth & other eight planets have passed that phaze of high temperatures billions of years ago - yet a puzzle for all alike - opinions differ - thankyou
fantastic photos - carona,plasma,outer surface of sun - temperatures of sun - all a puzzle - yet a curious subject which difficult to imagine yet its true that sun at 360-degrees puzzles scientists & layman alike - may be earth & other eight planets have passed that phaze of high temperatures billions of years ago - yet a puzzle for all alike - opinions differ - thankyou
There is lot of randomness within and on the surface of the OBJECT. This can be due to different type of elements with varying energy levels dissipating energy while interacting with each other. If the dissipation can be studied and the number of elements can be narrowed down then the process can be replicated to have the same result for a PEACEFUL PURPOSE.
Where is the FAKE PICTURE of MOON of Chandrayan Chandrayan was a FLOP SHOW THIS IS TRUE ISRO IS RECENTLY INVOLVED IN SPECTRUM SCAMMM OF 2 LAKH CRORE IS A CORRUPT COMPANY
Re: techie
by ALOK BHATTACHARYA on Feb 07, 2011 08:25 PM
How you are sure that Chandrayan project was a flop show? It is very important for you to clarify. All of a sudden ISRO has become a corrupt company because of some un confirm news of ISRO scam. I have close contact and sure of Chandrayan success. Just wait n watch. Alok Bhattacharya
Re: Re: techie
by techie on Feb 07, 2011 08:30 PM
What to watch ? YOUR HEAD Have you seen in any COLOUR GOOD photos of Moon from Chandrayan Please show me the link Coming to SPECTRUM SCAMMM, THE CAG HAS CONFIRMED THE NEWS
YOU NEED TO UPDATE THE SOFTWARE IN YOUR HEAD IF YOU HAVE
Re: Re: Re: techie
by Telveer on Feb 07, 2011 09:18 PM
Nonsense. You better watch your head. Chandrayaan was not sent to take color photos of moon. There is a website dedicated to Chandrayaan and several countries with payloads that participated in this experiment.
As to Spectrum scam, it has nothing to do with Chandrayaan. So, dont mix the two things.
Re: Re: Re: Re: techie
by techie on Feb 07, 2011 09:37 PM
CHANDRAYAN WAS A FLOP SHOW CARRYING PAYLOAD LIKE INSTRUMENTS DOES NOT CONFIRM ANYTHING OF SUCCESS
YOU MEAN TAKING DULL BLACK AND WHITE FAKE PHOTOS WILL PROVE THE SUCCESS YOU ARE SOME JOKE
I AM NOT MIXING ANYTING IN YOUR PAN HEAD, JUST ITS TO TELL ABOUT ISRO A CORRUPT COMPANY
ALL THE SPECTRUM ALLOCATION FROM PAST 25 YEARS OF CORRUPT ISRO SHOULD BE VERIFIED
NASA has News Filtering agency...i.e they always hide most important and threating facts...for example some UFO landings and tons of other UFO stories.
The FACT is Sun is supposed to be growing faster but at some pace, the water on earth will slowly but surely is boiling and eventually the red or saffron monster will eventually kill earth and all animals, plants etc...and the way i smell a story is like the hydrogen 71% and helium 27% levels are surely changed recently...
This is the Indian character,politics & incredible picture never mach,thank you NASA,sorry Mr.Sing,never comment on those things where we Indian can go after 50years,only for you Indian politicians.
