Neutron stars: fast spinning spheres

Can you think of something that is perhaps the size of your city but weighs more than our sun, that's what you call a neutron star!

Neutron stars are the remains of the cores of dying stars. They are formed when a star which has the mass of 6 to 20 suns explodes into a supernova. They are small in size but extremely dense. About a tablespoon of material of neutron stars would weight about one billion ton, more than the Mount Everest. 

They are also the objects with the strongest known magnetic fields, billions of times that of the Earth's.

They spin, much like a lot of objects in the space. But their pace in very fast. These rapid spins, combined with the strong magnetic fields, causes these to emit light. These are called pulsars. The pulsar, PLS J 1748-2446A spins about 43000 times every single minute. 

And for a little bit of a fun fact the signals from the neutron stars first made the astronomers believe that they were messages from aliens .

Well, that is it for this post. See you next Sunday!!!

gravitational waves

Gravitational waves are like 'ripples' in space. They are invisible and travel at the speed of light. 

But before going into their properties, let us discuss how they're formed. 

Just as I mentioned above, imagine you move your finger though a calm water body. Ripples would be formed, right? That is somewhat similar to how gravitational waves are formed.

Picture it like this. Your finger is a body in space that accelerates, and the calm water is the fabric of space time.  That is how these waves are formed. 

They are formed due to the acceleration of anything, even you and me. But the light weighed objects produce very weak waves, which cause no direct effect and cannot be detected using present technologies.

We can only detect waves that are very strong. And the strength of a gravitational wave is directly proportional to the mass of the cause. So, the greater the mass of the objects accelerating, the stronger the wave.

These strong gravitational waves include the ones formed when two black holes merge, or when there is an asymmetrical supernova formation, or neuron star collisions!

Now, let's understand the physics behind this.

When these massive objects accelerate they disrupt the fabric of space time that waves form

Now speaking of their properties, gravitational waves stretch and squeeze the fabric of space time itself as they pass, resulting the stretching and squeezing of the matter that come in the way. 

However, they do impact the matter that comes in way but they do not interact with matter, meaning they don't get blocked by it. This comes as an advantage for research because light and electromagnetic radiations get absorbed or scattered the matter coming in their way. But gravitational waves do not, meaning we can study their sources in detail.

If there is anything in particular about space that fascinates you, please share you enthusiasm in the comments down below!

The observable universe: The part we can see

Observable universe, on hearing, might sound like the amount of universe we have observed so far. But that is not what it is. So the observable universe (with a diameter of 93 billion light-years) is the region from which light has had the time to reach our Earth so far.

Let me explain. So, as we all know, our universe is about 13.8 billion years old. This means that the light from the distant object has to travel about 13.8 billion years. 

And as no object can travel faster than the speed of light. However, the universe or space is expanding faster than the speed of light. So light has to travel this obscure amount of space, and it is getting redshifted (I have discussed redshift in detail in one of my previous posts.)

Some amount of this redshifted light is significant so we can see it. But the light of the bodies far away from us is getting redshifted to the radio spectrum, which cannot be seen by us.

But don't worry as the observable is, in fact, constantly growing.

I hope you found this post helpful. 

See you next Sunday! 

Why were constellations so important so the ancients

 It is truly fascinating how all of the ancient civilisations gave significance to constellations. Then a question arises, why were constellations so important to them? They weren't scientifically developed enough to think an alien life might exist on a planet near any of these. 

So again, why? 

The First reason could be their search for a reason. Ever since its early stages, humanity has tried to find a reason for everything. Whether it be the rain, eclipses, mountains, snow, or our own existence. Constellations also come in this list. That is why they tried to find a reason as to why certain stars always exist in groups and form a certain shape. They used it in storytelling, connected it to mythology and folklore, comparing them to gods and goddesses and connecting them to legends. 

People needed something to guide them philosophically. And hence astrology came into existence. 

But this guidance was not just emotional. They also needed it to guide them through journeys as they did not have maps, and physical features like wind and weather were not reliable. 

But constellations were. They were stationary. 

Constellations appeared at different times of the year. And hence helped in determining the season, helping in determining cropping patterns.

Astroid mining

Today I want to talk about something I read about recently and it truly fascinated me- asteroid mining. I don't think that asteroid mining is talked about enough. So let's discuss that. 

So, for a little bit of context, it is exactly what it sounds like. Extraction of minerals from an asteroid. And just to be clear, we haven't done that yet. It is totally hypothetical but taking recent discoveries into account, I don't think it would be long before we develop enough to do that. NASA and Astro Forge are researching in the area.

Asteroid mining could be useful to counter resource depletion and generate a lot of wealth.

For instance, minerals found in the asteroid 16 Psyche are worth around $700 quintillion!

 Besides, we could also use these resources to make habitats in the outer space. These could also help in space discoveries. 

I know it sounds so cool but it is not feasible. 

For starters, it is so expensive. What if we spend millions of dollars on asteroid mining but the minerals don't cover the cost? What if it actually disrupts the celestial bodies and their orbits? And who would be the legal owner of these minerals? We are talking about mining in zero gravity. Who would agree to do that? And how technologically challenging (and expensive) it would be to create probes such as these!

What I think is that we should focus on conserving the resources on our planet. We wouldn't need to mine resources from asteroids. 

What are your views on the topic? Drop them in the comments down below. 

See you next Sunday! 

Types of stars

In this post, we will discuss the different types of stars according to the Morgan Keegan system. These are further divided by numbers (represented through Roman numbers), i.e. I to V.  These numbers tell us about the size and the brightness of the star.

The major categories of stars are:-

O-type stars

O-type stars are the hottest type of stars in this category, with a temperature of more than 33000K. They appear blue to us.

Examples- Mu Columbae, etc.

B-type stars

B-type stars have a temperature range of about 10000K to 33000 K of the temperature range. They, just like the O-type stars, appear blue to us.

Examples- Spica, Regulus, etc.

A type of star

They have a temperature range of about 7300 K to 10000 K. They appear white or bluish white in colour.

Examples- Vega, Sirius A, Altair

F-type stars 

They appear yellowish white and their temperature range is about 6000 K to 7300 K

Examples- Procyon A

G-type stars

They have a yellow kind of colour and their temperature lies between 5200 K to 6000 K.

Examples- The Sun, Alpha Centauri A, Tau Ceti 

M-type stars 

Their temperature is less than 3700 K. They have a red colour

Examples- Proxima Centauri 

L-type stars

They appear red brown in colour and have a temperature range of 1300 K to 2400 K.

Examples- GD 165B

T-type stars 

These appear purple and their temperature ranges between 600 K to 1300 K.

Examples- Gliese 229B

Y-type stars 

These stars are the coldest ones in this category and their temperature is less than 600 K! They are really dim in Appearance. 

 Examples- WISE 1828+2650

A little note:- These are not the stars' actual colours. This is what they would look like when veiled from the earth. For example, our sun is one of the G-type stars, which are yellow in colour. But the sun is not actually yellow, but it looks yellow when viewed from Earth due to Rayleigh scattering (I have talked about this in detail in the previous posts).

The Shapely supercluster

In one of the previous posts, we discussed the Great Attactor. In that post, I also mentioned the Shapely Supercluster. This post is going to discuss the supercluster in detail. 

The Shapley Supercluster, also known as the Shapley concentration or SCI, is one of the largest known mass concentrations in our universe. Its mass is at least 10¹⁵ solar masses. This mass includes galaxy clusters and groups like Abell 3558 and Abell 3562. It is located in the north of the constellation of Centaurus.

It is more concentrated than the Great Attractor, and it has an even greater force of gravitation. Its force is so much that even the Great Attractor is being pulled towards it!

I know it sounds so insane.

For better understanding, let us compare it to the Laniakea Supercluster from the Great Attractor post. The size of the Laniakea galaxy supercluster is about 530 million light years. The Shapely Supercluster expands roughly over an area of 600 million light years!

That is it for today. I hope you liked it. If I made mistakes or if you want me to write about anything else, feel free to comment. See you next Sunday!