The Sun Compared to UY Scuti

This Star’s Size Will Amaze You.

Image by Jill Wellington from Pixabay

British spelling.

I write easy-to-understand stories regarding the universe and life, here are two. Enjoy.

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Here is a comparison between the sun and the massive star UY Scuti.

Our closest star, the sun, is at the centre of the solar system. This ball of plasma is heated by nuclear fusion in its core and is the most important energy source for all life on Earth.

Although we have to thank the sun for our existence, it is nothing special when considering some other stars.

It is difficult to calculate how many stars there are in our galaxy, the Milky Way; one estimate is 200 billion. And remember, there are an estimated two trillion galaxies in that gargantuan area we call the universe.

One such star within the Milky Way is arguably the largest; its name is UY Scuti. The next few lines will give you a better idea of how massive a star it is.

Eight planets orbit the Sun. The inner rocky planets are Mercury, Venus, Earth, and Mars. Then, much farther out, are the gas giants Jupiter, Saturn, Uranus, and the most distant planet, Neptune.

Planet Mars circles the Sun at an average distance of 228 million kilometres, but it can be much closer or farther away at certain times.

The gas giant Jupiter orbits the Sun at roughly 778 million kilometres.

Now it is time to use your imagination. It is the only way to make sense of UY Scuti’s size.

Imagine taking the sun away and replacing it with UY Scuti. That would be a disaster for most of the eight planets: Mercury, Venus, Earth, Mars, and Jupiter would all be inside this supergiant star.

The diameter of the Sun is 1,392,680 kilometres, but this monster star is 1,700 times wider than the Sun. The surface of UY Scuti would be almost as far out as Saturn’s orbit.

Well, there you have it; our sun is minuscule compared to countless other stars.

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The amazing range of complex eyes

We take light for granted and give it little thought as we go through our daily lives.

Photo by Harry Quan on Unsplash

Within the broad light spectrum, gamma rays are at one end with short wavelengths, and radio waves with longer wavelengths are at the opposite end.

Within that broad spectrum of light, the wavelengths visible to the human eye occupy a narrow band.

The colours we see are governed by the wavelengths reflected from the surface of objects. An object appears black when all the wavelengths are absorbed and white when all the wavelengths are reflected. We can also see the different colours when light travels through a prism, and they can be seen in a rainbow.

Photo by Yulia Gadalina on Unsplash

The first primitive eyes found on a fossil animal can be traced back to about 540 million years ago, which is not very long considering that life has been on our planet for over 3.5 billion years.

Animals with no eyes had to manage as best they could due to their lack of vision.

Primitive eyes quickly evolved so that animals were finally aware of their surroundings, which may have been the catalyst for the rapid expansion of different life forms on our planet; we call that time the Cambrian explosion.

Since that time, eyes have evolved into the thousands of different and complex types that exist today.

Scientists analyse light emanating from stars and other objects in space to gain more information.

Within the spectrum of light, there are dark or bright spectral lines that can be observed, we call them emission or absorption lines; they correspond to certain atoms and molecules contained within an object being viewed.

Spectral lines can give valuable information regarding temperatures, densities, and magnetic fields of stars.

When a star or object is moving away from us, it is known as red-shifted because the light waves are being stretched, and when an object is coming towards us, the light waves are being compressed, and that is known as blue-shifted. This is called the relativistic Doppler effect.

Now you can see why light is so important for astronomers.

When we look at an object, say, a red rose, green grass, or blue sky, most of us would think that other animals would see the same colours, but no, other animals will see less or they will see more of the light spectrum.

When we look at an object, say a cucumber, the reflected light determines what colour we see.

The light waves reflect off the cucumber and hit the light-sensitive retina at the back of our eye. In the retina, humans have three cone types: tiny cells that respond to red, green, and blue colours. From there, the cones send signals to the brain, which provide us with colours.

Photo by Jakob Kac on Unsplash

My dog Kobi will not see a red apple the way I see it; dogs, cats, and most mammals have only two cones, the missing one being red. Other animals, including insects, can have poorer or much better sight than we have; some animals can see parts of the light spectrum that we cannot see.

Some animals have no eyes, like the star-nosed mole, the Texas blind salamander, or the Mexican tetra, to mention a few.

They have evolved this way because they live in pitch-black surroundings, like caves, beneath the ground, or in the depths of oceans.

Human eyes are known as “camera-type eyes” as they cannot function without some light.

The end.

Come and Join Me on a Fictional Space Journey.

By the time we arrive at our final destination, you should have gained a far better understanding of how vast and ancient the universe is and how it has evolved over 13.8 billion years.

[embed]Come and Join Me on a Fictional Space Journey medium.com