2006-08-05 20:00:26 · 15 answers · asked by Anonymous in Science & Mathematics ➔ Astronomy & Space
The numbers are staggering just in our Galaxy. They used to say 100 Billion and then for years it was 150 Billion. The latest estimate is actually 300 Billion and it will probably not grow from that. (The estimate.) It's considered accurate. What is true is that the number of other Galaxies is thought to be about the same. (Like other people stated.) Most stars that you see with the naked eye (even when you are away from city lights)...are under 1000 light years away from us. That's close considering that the diameter of the milky way is 100,000 light years across and about 3000 light years thick at the edge and 10,000 L.Y. thick in the middle. Our sun of course is a star, and is about 1/2 way through its life.
2006-08-05 21:14:30 · answer #1 · answered by Smart Dude 6 · 6⤊ 0⤋
EricG is about right in his approximate estimate of 10^22 stars in the Universe, 10^11 of them in our galaxy which is one of 10^11 galaxies. But he is stuck for a name for that number.
Well there are two scales, the American (short) scale and the British (long) scale. The short scale would call 10^22 10 sextillion (billion is 10^9, trillion is 10^12, quadrillion is 10^15, quintillion is 10^18 and sextillion is 10^21) but on the long scale it is 10,000 trillion (10^18 is a trillion and 10^12 is a billion on the long scale) or 10 trilliard (10^21 is a trilliard).
The long scale was developed by Nicholas Chuquet, a French mathematician in the late 15th Century. The short scale came much later.
The number of visible stars in the sky is between 3,000 and 6,000 depending on the amount of light pollution, eg whether there is a Full Moon, whether you are observing from cities with street lights on, and atmospheric pollution. In built up areas and in the mountains you will not see stars on the horizon that you would see if you were in a flat low-lying area like the Norfolk Broads ior in Holland (Les Pays Bas, the Low Country).
Other factors include the visual acuity of the observer (older people have less sharp eyesight) and how long you have been outside: the visual purple or rhodopsin in the eye takes a while to adjust to seeing in the dark, after being in a brightly-lit room.
A good test of how clear the night sky is, is when you look at the Pleiades (The Seven Sisters, a famous open cluster in Taurus) are you able to see all seven of them or only 5 or 6? or more than 7? (there are 500 stars in the cluster and in excellent viewing conditions 14 of them can be seen with the naked eye.
THE BRIGHTEST 11 MEMBERS OF THE PLEIADES CLUSTER
Name / Designation / Apparent magnitude
Alcyone Eta (25) Tauri 2.86
Atlas 27 Tauri 3.62
Electra 17 Tauri 3.70
Maia 20 Tauri 3.86
Merope 23 Tauri 4.17
Taygeta 19 Tauri 4.29
Pleione 28 (BU) Tauri 5.09 (var.)
Celaeno 16 Tauri 5.44
Asterope 21 and 22 Tauri 5.64 & 6.41
18 Tauri 5.65
How many of the Pleiades you can see with the naked eye is like a litmus test for how clear the night sky is.
BB
2006-08-06 08:31:52 · answer #2 · answered by brucebirchall 7 · 0⤊ 1⤋
In 2003 a very carefully detailed count was made of of a representative portion of the sky by the Austrailian National University Observatory. This was then extrapolated to fit the known universe. The number arrived at is 70 sextillion which is 70 followed by 21 zeros. This number is beleived to be quite accurate for the known universe visible to the world's largest telescopes, and is estimated to be about ten times the grains of sand on all the Earth's beaches. Our galaxy the Milky Way has about 100 billion stars of which about 5000 are visible to the unaided eye when viewed from a dark location on a clear night.
2006-08-06 09:24:14 · answer #3 · answered by M31 2 · 0⤊ 1⤋
About 3 to 6 thousand stars are visible in the night sky with naked eyes and the numbers depend on the clearness of the sky. These number includes some galxies as visible as single stars with naked eyes. But actually there are billions of stars in billions of galaxies in the sky which are not visible with naked eyes, and from the Hubble radio telescope scientists observed only few billions of stars in the sky so far.
2006-08-06 04:24:46 · answer #4 · answered by Lutfor 3 · 1⤊ 0⤋
Over 100 billion stars in our galaxy and over 100 billion galaxies means more than 1 followed by 22 zeroes (10 icositillion?). Of course, you can only see a VERY small fraction of those from your back yard (an I don't care how good a telescope you might have).
2006-08-06 03:21:00 · answer #5 · answered by Eric G 2 · 1⤊ 0⤋
How many stars are there in the sky?
If you mean the ones we can see with the naked eye, it is around 5000.
Estimates say around 300 billion in the whole of the universe.
2006-08-06 05:48:44 · answer #6 · answered by blind_chameleon 5 · 0⤊ 1⤋
million of stars in the sky but why u ask this ulluoooo
2006-08-06 04:39:49 · answer #7 · answered by usman 1 · 0⤊ 1⤋
stars are present in specific galaxy and there are hundred thousand million stars in a galaxy and just for a joke the answer is one ha ha
2006-08-06 06:01:27 · answer #8 · answered by lisa francis 1 · 0⤊ 1⤋
They are like millions there, trillions more like, but it is possible to see around 5000 with the naked eye on a very clear night.
2006-08-06 08:58:22 · answer #9 · answered by Vasudha 3 · 0⤊ 1⤋
an uncountable number in our galaxy alone. there are about as many galaxys as tere are stars in our galaxy. there are as many universes that have just as many galaxys that are uncountable lightyears away. in other words either uncountable or infinite
2006-08-06 03:05:38 · answer #10 · answered by Anonymous · 1⤊ 0⤋