whats the source of light which enables us to see the stars in sky?

Question

does the stars produce light of their own or does they reflect light .

Answer 1

The interior of a stable, main sequence star is in a state of equilibrium in which the forces in any small volume almost exactly counterbalance each other. The balancing forces consist of inward directed gravitational force and the opposing pressure from the thermal energy of the plasma gas. For these forces to balance out, the temperature at the core of a typical star has to be on the order of 107 K or higher. The resulting temperature and pressure at the hydrogen-burning core of a main sequence star are sufficient for nuclear fusion to occur, and for sufficient energy to be produced to prevent further collapse of the star.[80]

As atomic nuclei are fused in the core, they emit energy in the form of gamma rays. These photons interact with the surrounding plasma, adding to the thermal energy at the core. Stars on the main sequence convert hydrogen into helium, creating a slowly but steadily increasing proportion of helium in the core. Eventually the helium content becomes predominant and energy production ceases at the core. Instead, for stars of greater than 0.4 solar masses, fusion occurs in a slowly expanding shell around the degenerate helium core.[81]

In addition to hydrostatic equilibrium, the interior of a stable star will also maintain an energy balance of thermal equilibrium. There is a radial temperature gradient throughout the interior that results in a flux of energy flowing toward the exterior. The outgoing flux of energy leaving any layer within the star will exactly match the incoming flux from below.


This diagram shows a cross-section of a solar-type star. NASA imageThe radiation zone is the region within the stellar interior where radiative transfer is sufficiently efficient to maintain the flux of energy. In this region the plasma will not be perturbed and any mass motions will die out. If this is not the case, however, then the plasma becomes unstable and convection will occur, forming a convection zone. This can occur, for example, in regions where very high energy fluxes occur, such near the core or in areas with high opacity as in the outer envelope.[80]

The occurrence of convection in the outer envelope of a main sequence star depends on the spectral type. Stars with several times the mass of the Sun have a convection zone deep within the interior and a radiative zone in the outer layers. Smaller stars such as the Sun are just the opposite, with the convective zone located in the outer layers.[82] Red dwarf stars with less than 0.4 solar masses are convective throughout, which prevents the accumulation of a helium core.[2] For most stars the convective zones will also vary over time as the star ages and the constitution of the interior is modified.[80]

The portion of a main sequence star that is visible to an observer is called the photosphere. This is the layer at which the plasma gas of the star becomes transparent to photons of light. From here, the energy generated at the core becomes free to propagate out into space. It is within the photosphere that sun spots, or regions of lower than average temperature, appear.

Above the level of the photosphere is the stellar atmosphere. In a main sequence star such as the Sun, the lowest level of the atmosphere is the thin chromosphere region, where spicules appear and stellar flares begin. This is surrounded by a transition region, where the temperature rapidly increases within a distance of only 100 km. Beyond this is the corona, a volume of super-heated plasma that can extend outward to several million kilometres.[83] The existence of a corona appears to be dependent on a convective zone in the outer layers of the star.[82] Despite its high temperature, the corona emits very little light. The corona region of the Sun is normally only visible during a solar eclipse.

From the corona, a stellar wind of plasma particles expands outward from the star, propagating until it interacts with the interstellar medium.

Answer 2

U see our SUN is a star ,it means that stars r those which produce light on their own ,but planets r those which reflect light

Answer 3

The thing is, most of that light that you are seeing has been travelling for a couple of billion years just to reach your eyes tonight.

Some of those lights are stars, and a few of them are galaxies, which are made up of Billions of stars.

If you can get away from the city lights and let your eyes get used to the dark (in a couple of weeks because it's a full Moon now), then look up and you will see what looks like a faint cloud. That is our own Galaxy, The Milky Way.

The reason it looks like a faint cloud is because it's made up of about 100 Milllion stars that are almost blended together from our view.

There are also 5 planets that you can actually see with your bare eyes.

Mack

Answer 4

Stars create their own light, just like the sun. Planets and moons reflect light.

Answer 5

Star is a burning ball of fire which produces its own light. They are millions of light year away from the earth & hence appear tiny & white in colour.Even the Sun in our solar system is a star which produces its own light.

Answer 6

Dobsonian are most (optical) value for your bucks, mostly because nearly all the money spend is in the optics. However they have severe drawbacks: you cannot do photography with those as they do not turn with the sky, and they are generally larger (but not heavier) than the other usual types of telescopes. I'd go for a used telescope for a beginner. Chances are you'll otherwise spend a lot of money (for a good telescope) or waste some money (for a cheap low-quality one). Better to get a used one from someone who took good care of his/her telescope. Make sure the optics are still ok: no scratches, and stars still look like dots and not like anything else. I personally get a refractor: they are easy to understand (point it at what you would like to look at) and they can be used later, when you outgrew it, for travelling. Make sure to get a good eyepiece and the mount is stable. People tend to forget those 2 parts of a telescope and saving money here will not compensate for a more expensive tube.

Answer 7

The energy produced by stars, as a by-product of nuclear fusion, radiates into space as both electromagnetic radiation and particle radiation. The particle radiation emitted by a star is manifested as the stellar wind (which exists as a steady stream of electrically charged particles, such as free protons, alpha particles, and beta particles, emanating from the star’s outer layers) and as a steady stream of neutrinos emanating from the star’s core.

The production of energy at the core is the reason why stars shine so brightly: every time two or more atomic nuclei of one element fuse together to form an atomic nucleus of a new heavier element, gamma ray photons are released from the nuclear fusion reaction. This energy is converted to other forms of electromagnetic energy, including visible light, by the time it reaches the star’s outer layers.


I hope that helps provide a little background to the answers already given - the 2nd paragraph refers specifically to visible light, but the first paragraph contextualises it somewhat.

Answer 8

All those stars we're looking at are just like our sun! Well, not just like it, always, but the same basic deal.
The other things we can see - the moon, Mars, Venus, Mercury, and the other planets if it's clear - are reflecting light from the sun.

Answer 9

stars produce their own light.when a cloud of debris gets hydrogen and helium it starts collapsing under its own gravity.this makes the star grow hotter and hotter and thus produce light.

another fact-did u know that the light from distant stars take millions of years to reach earth?so, if u look at a fading star or a weak lighted star,u r looking millions of years back!!!!!

Answer 10

sun due to the solar energy, which is nearer to the earth and dangerous , Infrared rays u.v rays , due to the emition of light , due to the bright ligtht , as the moon is also a star it recevie the source of light from the sun . and the stars are far way from us stars have more source of energy than the sun star emit thier own energy