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Why do we see stars when we look up into a clear sky at night?
When we look up at the stars, we are looking back in time. The light entering our eyes from these distant objects set off years, decades or millennia earlier. Every time we look at something ‘up there’ we’re seeing it as it was in the past.
When you see a star How old is the light?
Thus, the light is four years old when we see it. Another nearby star is Barnard’s Star, which is six lightyears from Earth. It’s light takes six years to get here, so that light is six years old when we see it. The star Polaris, which we refer to as the North Star or North Pole Star, is 680 lightyears away.
How can we see stars when they are so far away?
Answer: Even though the stars that we see in the night sky are all very far away, we can see them not by actually being able to resolve their sizes, but by measuring the light that they produce. where F is a measure of the amount of light from the star (called the “flux”) and d is the distance to the star.
What is the flickering star in the sky tonight?
Sirius is the brightest star in the sky and as a result, it can easily be found in the faint constellation of Canis Major. Left and below Orion. Its name comes from ancient Greek meaning “glowing” or “scorcher.” Sirius (a CMa) is the alpha star in this trusty hound and is roughly 8.5 light years away from Earth.
What planet can I see tonight UK?
Planets Visible in Great Britain
| Planetrise/Planetset, Wed, Dec 15, 2021 | ||
|---|---|---|
| Planet | Rise | Set |
| Venus | Tue 10:38 am | Tue 6:16 pm |
| Mars | Wed 6:26 am | Wed 2:29 pm |
| Jupiter | Tue 11:46 am | Tue 9:21 pm |
Are the stars we see at night still there?
For the most part, the stars you see with the naked eye (that is, without a telescope) are still alive. These stars are usually no more than about 10,000 light years away, so the light we see left them about 10,000 years ago.
What can we see during night time?
The term night sky, usually associated with astronomy from Earth, refers to the nighttime appearance of celestial objects like stars, planets, and the Moon, which are visible in a clear sky between sunset and sunrise, when the Sun is below the horizon.
What is the brightest object in the night sky?
It’s possible you have seen Jupiter or Venus, two surprisingly bright planets at certain times of the year. After the Moon, these two objects are the brightest objects in the night sky. A very bright point of light in the sky. It lasts momentarily, then disappears again.
What is the fourth brightest star in the night sky?
With a visual magnitude of −0.04, it is the fourth brightest star in the night sky, after −1.46 magnitude Sirius, −0.86 magnitude Canopus, and −0.27 magnitude Alpha Centauri. It is part of the Boötes constellation, pronounced boo-oh-tes, meaning herdsmen.
What do we see when we look up at night?
When we look up into the sky at night, we see some stars which appear very bright, and others which are so faint that we can barely detect them. The star Sirius, for example, has a magnitude of about -1.5; a bit more than one degree away, the star HD 49980 shines relatively feebly at magnitude 5.8.
Are there intelligent aliens in the Milky Way galaxy?
The finite speed of light has the exact same effect in the other direction: If there are intelligent aliens in this galaxy, when they look at the Milky Way, they are seeing our galaxy as it was at the time of the dinosaurs. In principle, they could see our planet as it was at that time, too. But, one huge caveat.