Why do stars appear twinkling

The more atmosphere you are peering through, the more stars (or planets) appear to twinkle. Illustration by Stars twinkle, while planets (usually) shine steadily. Why? Stars twinkle because… they’re so far away from Earth that, even through large telescopes, they appear only as pinpoints. And it’s easy for Earth’s atmosphere to disturb the pinpoint light of a star. As a star’s light pierces our atmosphere, each single stream of starlight is refracted – caused to change direction, slightly – by the various temperature and density layers in Earth’s atmosphere. You might think of it as the light traveling a zig-zag path to our eyes, instead of the straight path the light would travel if Earth didn’t have an atmosphere. Planets shine more steadily because… they’re closer to Earth and so appear not as pinpoints, but as tiny disks in our sky. You can see planets as disks if you looked through a telescope, while stars remain pinpoints. The light from these little disks is also refracted by Earth’s atmosphere, as it travels toward our eyes. But – while the light from one edge of a planet’s disk might be forced to “zig” one way – light from the opposite edge of the disk might be “zagging” in an opposite way. The zigs and zags of light from a planetary disk cancel each other out, and that’s why planets appear to shine steadily. Astronomers use the term ‘scintillation’ to describe the twinkling of stars. Illustration via You might see planets twinkling if you spot them low in the sky...

Last night, I was on my balcony at 1AM (PST) and I looked up and saw two stars near the horizon (I'd guess ~30 degrees above the horizon), and they were "twinkling" about twice as fast as other stars higher in the sky, and I could clearly see them changing from red to white to blue repeatedly. Other stars in the sky only appeared white to me, and didn't seem to "twinkle" as rapidly as these two stars did. The red and blue make me think of red-shift and blue-shift, but I don't know how I would see both from the same object. What was I seeing? I don't know if it helps, but I am in the Los Angeles area, and I was looking in a roughly north direction. almost exactly to the east, according to google maps. Edit: I tried taking a picture, but light pollution from the nearby street lights wouldn't permit me taking a decent picture. However, I noticed a group of three stars close together in nearly a perfect almost vertical line, and managed to find that in Stellarium. I think I found the two stars I am seeing: Procyon and Sirius Is there anything about either of these stars that would make them show as red/blue? As you have already identified the objects you were seeing, I'll explain the effect you were seeing. In that situation there are three things to consider: atmospheric chromatic dispersion, seeing and human color perception. Light entering the atmosphere is refracted, because of the changing speed of light in air compared to the vacuum of space. The amount of refraction dep...

Remove All Ads on Universe Today Join our Patreon for as little as $3! Get the ad-free experience for life If you’re feeling a little silly using the word twinkle over and over again, we can also use the scientific term: astronomical scintillation. You can’t feel it, but you’re carrying the entire weight of the atmosphere on your shoulders. Every single square inch of your skin is getting pushed by 15 pounds of pressure. And even though astronomers need our atmosphere to survive, it still drives them crazy. As it makes objects in space so much harder to see. Stars twinkle, I mean scintillate, because as light passes down through a volume of air, turbulence in the Earth’s atmosphere refracts light differently from moment to moment. From our perspective, the light from a star will appear in one location, then milliseconds later, it’ll be distorted to a different spot. We see this as twinkling. So why do stars appear to twinkle, while planets don’t? Stars appear as a single point in the sky, because of the great distance between us and them. This single point can be highly affected by atmospheric turbulence. Planets, being much closer, appear as disks. We can’t resolve them as disks with our eyes, but it still averages out as a more stable light in the sky. Astronomers battle atmospheric turbulence in two ways: First, they try to get above it. The Hubble Space Telescope is powerful because it’s outside the atmosphere. The mirror is actually a quarter the size of a large groun...

Some stars appear to flicker between different colours as their light is distorted by our atmosphere, as this composite image of Rigel, Betelgeuse and Sirius shows. Here, the differences in colour are picked up by a DSLR camera. Credit: Amanda Cross There is even a scientific term for stars' twinkling, and that's 'atmospheric scintillation'. This is the astronomical term for those quick changes in the apparent brightness of a star (more on this in our guide to A panorama showing the Milky Way (centre) and planets. Mars is bright to the left, Saturn is dimmer and bright Jupiter is right. The arcing line joining the planets defines the arc of the ecliptic. Credit: Alan Dyer / Stocktrek Images / Getty Images Why do stars twinkle, but planets don't? Stars twinkle while planets don't because stars are so much further away from Earth. This makes them appear as concentrated points of light, and that light is more easily disturbed by the effects of Earth's atmosphere.

ChaNaWiT / Getty Images Gazing up at the heavens at night, it’s easy to get lost in the beauty and immensity of the universe: the moon’s silvery glow, planets moving through their orbits, distant stars twinkling with light emitted millions of years ago. This dancing of light we see when we look at stars has fascinated humans for centuries – even the smallest humans. “Twinkle twinkle little star, how I wonder what you are” is one of the first songs we learn as children. As we grow older, we learn the names of the stars and constellations. But what about that twinkle? Why do stars “dance” in the night sky? We must first turn our gaze to ground level. Picture the wavy motion of air just above burning hot sand. We see this effect because the hot air has a different density to the cooler air above it, and it moves up. As it does, the heat dissipates and alters the density of the air, making it refract light, bending and redirecting it in a slightly different way than the cooler air it meets. To our eyes, it almost appears as if the air is liquid. The way light travels can be manipulated and redirected by forces altering something called the refractive index. Essentially, this index refers to how much a beam of light can bend in a new direction: a high refractive index means the light will be bent a lot; a low index, a little. To get back to our star subject (pun intended): between us and the billions of suns above and around us is a thick film of atmosphere. While this is respo...

The twinkling of stars in our night sky is down to the Earth’s atmosphere. As light from the stars travels towards Earth it can easily move in a straight line, but once it starts travelling through the Earth’s atmosphere it gets bounced around in different directions by the particles in the air. For astronomers this twinkling can be a huge problem, especially when they’re trying to accurately image a particular star. The more the star twinkles, the blurrier the image will be. If telescopes are launched into space then all images can be taken without Earth’s atmosphere in the way, but this is expensive. It is possible to use a system called ‘adaptive optics’, when tiny motors alter the surface of the telescope’s mirror to correct for this blur caused by the air. Answered by Megan Whewell, Education Team Presenter for the National Space Centre. Image courtesy of NASA Keep up to date with the latest reviews in All About Space – available every month for just £4.99. Alternatively you can subscribe here for a fraction of the price! Tags:

On the rainy day, Ram reached his grandfather's place in village. On the way to house he saw a beautiful rainbow in the sky. In night, he saw lots of twinkling stars in the clear sky. He was very excited to see these beautiful natural phenomena, which he was not able to see in the city, where he lived with his father. Answer the following questions based on the situation given above. (i) Do you think that pollution in atmosphere affects the formation of rainbow and twinkling of stars? (ii) Do you agree with the fact that pollution-free environment will strengthen such natural phenomena in the cities as well? (iii) What steps can be taken so that the natural phenomena can be enjoyed in cities as well?

If you look up at the stars at night, then you might think the stars flicker, blink, wink, or twinkle. You might ask yourself, “why do the stars appear to twinkle?”While you may think that the stars are twinkling, they are shining steadily. They only appear to twinkle because of the interaction between your eyes, the starlight, and the Earth’s atmosphere. The Earth’s atmosphere is made up of different levels of temperatures and densities. In addition to the temperature and density differences, there is a lot of wind in the atmosphere. When the star’s light enters the Earth’s atmosphere, it must pass through these layers of temperature differences, density differences, and wind. Moving air in the atmosphere can be called turbulence. The star’s light must enter our atmosphere, but the star’s light does not necessarily move in a straight line through the atmosphere. Instead, the starlight is refracted or is spread around in different directions in the atmosphere. The starlight becomes bent as it moves towards the Earth. As the light disperses or spreads, the star’s brightness changes, causing us to see the star “twinkle.” Additionally, as the bent starlight reaches us, the star also twinkles. The two effects of the atmosphere on the light causes us to see a twinkle. However, you should remember that the star itself is not twinkling. The bending and spreading of light only makes you think it is twinkling. If the atmosphere on a particular night is windier or the temperatures a...