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Why can't you see stars during the day? (Beginner)

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I'm a teacher in a daycare. Each week we have a theme for are program. Last week it was the stars in the sky. This little boy asked me "why do stars glow at night and not during the day?" I did't know what to answer so maybe you can help me answer this question for the little boy.
Stars do glow during the day, but we can't see them because of the glare of sunlight. When the sun is up, the blue color in sunlight gets scattered all over the atmosphere, turning the sky the familiar bright blue color. This blue light is much brighter than the faint light coming from the stars, so it prevents us from seeing them.

If you were standing on the Moon, for instance, where there is no atmosphere, you would see the stars both day and night.
This page updated on June 27, 2015

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Why can't you see stars during the day? (Beginner)

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(Beginner) >" onclick="window.open(this.href,'win2','status=no,toolbar=no,scrollbars=yes,titlebar=no,menubar=no,resizable=yes,width=640,height=480,directories=no,location=no'); return false;" rel="nofollow"> I'm a teacher in a daycare. Each week we have a theme for are program. Last week it was the stars in the sky. This little boy asked me "why do stars glow at night and not during the day?"

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Is the other stars can be bigger than the sun? 

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Is the other stars can be bigger than the sun? 

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(For example,Sirius)

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Why can we see stars when the moon is up, but not when the sun is up?

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Why can we see stars when the moon is up, but not when the sun is up?

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why do you think star can be bigger than the sun?

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why do you think star can be bigger than the sun?

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The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields. It has a diameter of about 1,392,684 km, about 109 times that of Earth, and its mass (about 2×10 ³⁰ kilograms, 330,000 times that of Earth) accounts for about 99.86% of the total mass of the Solar System. Chemically, about three quarters of the Sun's mass consists of hydrogen, while the rest is mostly helium. The remainder (1.69%, which nonetheless equals 5,628 times the mass of Earth) consists of heavier elements, including oxygen, carbon, neon and iron, among others.

Excerpt from Wikipedia.

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An interactive 3D visualization of the stellar neighborhood, including over 100,000 nearby stars. Created for the Google Chrome web browser.

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Of all the bodies in our solar system, the sun is probably the one we want to give the widest berth. It gushes radiation, and even though its surface is the coolest part of the star, it burns at about 9,940°F, hot enough to incinerate just about any material. As such, there are no plans to send a manned mission in its direction anytime soon (Mars is much more interesting, anyway), but it can't hurt to figure out at what distance a person would want to turn back. You can get surprisingly close. The sun is about 93 million miles away from Earth, and if we think of that distance as a football field, a person starting at one end zone could get about 95 yards before burning up.

That said, an astronaut so close to the sun is way, way out of position. "The technology in our current space suits really isn't designed to withstand deep space," says Ralph McNutt, an engineer working on the heat shielding for NASA's Messenger, a new robotic Mercury probe. The standard space suit will keep an astronaut relatively comfortable at external temperatures reaching up to 248°. Heat coming off the sun dissipates over distance, but a person drifting in space would begin encountering that kind of heat (the five-yard line) some three million miles from the sun. "It would then be a matter of time before the astronaut died," McNutt says. Above 248°, the suit would transform into a close-fitting sauna-the temperature would climb above 125° and the person would become dehydrated and pass out, eventually dying of heatstroke.

Riding in the space shuttle, though, someone could get much closer to our star. The ship's reinforced carbon-carbon heat shield is designed to withstand temperatures of up to 4,700° to ensure that the spacecraft and its passengers can survive the friction heat generated when it reenters the atmosphere from orbit. If the shield wrapped the entire shuttle, McNutt says, astronauts could fly to within 1.3 million miles of the sun (roughly the two-yard line). But the integrity of the shield degrades rapidly above 4,700°, and the cockpit would begin to cook. "I would advise turning away from the sun well before that point," McNutt says. Much hotter than that, the shields would fail altogether, and the vehicle would combust in less than a minute.

Of course, just getting that close to the sun would be quite an accomplishment, says NASA radiation-health officer Eddie Semones. The constant exposure to cosmic radiation during the voyage would most likely prove fatal before the astronauts crossed the 50-yard line.

This article originally appeared in the August 2010 issue of Popular Science_ magazine._

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How Close Could I Get To The Sun And Survive?

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Of all the bodies in our solar system, the sun is probably the one we want to give the widest berth. It gushes radiation, and even though its surface is the coolest part of the star, it burns at about 9,940°F, hot enough to incinerate just about any material.

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http://www.squarespace.com/minutephysics
https://www.youtube.com/watch?v=u70lZSMP9Bo

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Science and reason - for a better, more rational tomorrow. www.youtube.com/Best0fScience www.youtube.com/ScienceTV "Equipped with his five senses, man explores the universe around him and calls the adventure Science".~Edwin Powell Hubble "If we long to believe that the stars rise and set for us, that we are the reason there is a Universe, does science do us a disservice in deflating our conceits?

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A monster version of our sun has been found, the largest known member of the family of yellow stars to which our sun belongs.

The whopper sun emits light in similar wavelengths as our sun but its diameter is over 1300 times larger. That means it would engulf all the planets between Mercury and Jupiter if placed at the centre of our solar system. The star's size also means it is touching its smaller, companion star (see diagram, below).

(Source&colon; ESO)
Dubbed HR 5171 A, the star is located in the constellation Centaurus around 12,000 light years from Earth. It was already known to be a hypergiant, the largest class of stars, but its exact size hadn't been well studied.

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Now a team led by Oliver Chesneau of the Côte d'Azur Observatory in Nice, France, has taken a closer look with the Very Large Telescope in Atacama, Chile. They report that it is twice as large as expected.

It still isn't the largest star we know about - that crown goes to UY Scuti, which is around 1700 times larger than our sun. But UY Scuti is in a different stage of stellar evolution and so belongs to a different family of stars called red stars.

Peanut sun

Both red and yellow stars can be hypergiants, but yellow hypergiants were previously thought to be at most 700 times the size of the sun. The new measurement of HR 5171 A shows they can be much bigger. HR 5171 A is 50 per cent larger than the red hypergiant Betelgeuse, which is located in the constellation Orion and is the ninth brightest star in the night sky.

Another surprise for Chesneau's team was the discovery that HR 5171 A has a little brother. Previous observations suggested the star varied in brightness. Now the team has shown that this is due to a companion star that is around one third its size.

The two stars orbit each other, forming a binary system. However, though their centres are separated by more than the distance between our sun and Saturn, HR 5171 A is so large that the two are touching, forming a continuous peanut-shaped structure. Guess this star system ain't big enough for two.

Reference&colon; arxiv.org/abs/1401.2628v2

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Largest ever yellow star is 1300 times bigger than sun

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A monster version of our sun has been found, the largest known member of the family of yellow stars to which our sun belongs. The whopper sun emits light in similar wavelengths as our sun but its diameter is over 1300 times larger.