Astrophysics: Deep In The Space With Maanvinder Pilania

S2 EP3: A Guide to the Local Group

Hello and this is Maanvinder and I’m back with another episode. Today I I will tell you about a fascinating group of galaxies, our galaxy is part of. But before I move forward, I want you to imagine no of galaxies in our universe. 1, 2 or 5 million or 1 billion or 200 billion. If your answer is more than 200 billion, then you are correct. There are between 200-300 billion galaxies in our observable universe. And these galaxies are not just scattered through the universe, in fact they are part of a large group of galaxies due to their mutual gravity, just like the star clusters I told you about in the previous episode but in this case its on a large scale, we are talking millions of light years and they are galaxies and not individual stars in a galaxy. Such kind of group of galaxy is “Local Group”. Local Group is dumb-ball shaped like group of galaxies. Our own Milky Way galaxy is part of this group. When I said dumb-ball, I meant it looks like that with Andromeda, our neighbor galaxy at one lobe and Milky Way at the other. The Local Group was first recognized by the American astronomer Edwin Hubble.

The Local Group has around 80 galaxies and most of them are either dwarf galaxies or satellite galaxies. The three largest members of the Local Group are: Andromeda or M31; the biggest, Milky Way; the second- biggest and Trapezium Galaxy; third biggest. The two biggest galaxies in the group are spiral galaxies and accounts for most of the mass in the group. Each of these two galaxies has their own system of satellite galaxies which revolves around them. Another interesting thing about these two galaxies is that they are on a collision course with each other and in about 5 billion years they will completely merge into each other forming a new galaxy and who knows maybe will be called as ‘milkomeda’. Local Group has roughly a diameter of 10 million light years and is part of a very large cluster of galaxy groups called Virgo Supercluster which is located 70 million light years from the centre of Local Group. There’s still debate over the centre of Local Group but it is believed to lie between Andromeda and Milky Way.

The current computer models has predicted the future of Local Group to be a large single elliptical galaxy. Tens of billions of years into the future all galaxies in the system will merge into each other. After Andromeda and Milky Way will merge into each other along with their satellite galaxies, then the third biggest member of this system, the Trapezium galaxy will merge into the newly formed “milkomeda”. And this merger will continue until all the galaxies merge into each other. As you know the universe is expanding so all the galaxies are moving away from ours except those who are part of the Local Group, so in the future there will be just one galaxy as all the other galaxies will pass the horizon and we will never be able to see them, what will be left is that large single elliptical galaxy. So its time to know about some galaxies other than the big three I told you about.

So at number one we have Magellanic Clouds. These are two satellite galaxies of the Milky Way. Large Magellanic and Small Magellanic Cloud are their names. What is more interesting about these two that there is a bridge called “Magellanic Bridge” between them which is a stream of hydrogen connecting these two galaxies where stars from SMC are being pulled towards LMC. SMC is located some 197,000 light years while LMC is located approximately 163,000 light-years from the Earth and is on the collision course with the Milky way. It will merge in about 2.5 billion years.

So this was from me for this episode. I hope you love it and let me know about it in the comments, polls or review section of the platform you are listening this podcast on.

S2 EP2: A Guide to Star Clusters

Hello and welcome back to my podcast. In this episode, I will tell you guys about the star clusters, their types and will also tell you about some of the very famous clusters like the Pleiades Star. So let’s get into it!

Before we start, you guys need to know the process behind the formation of a star. Stars are formed in large cloud of gas and dust called nebula. Gravity begins to form the clumps of the gas and dust, pulling more and more material into it, until it gets massive enough to collapse under their own gravity. Until then, they are proto-stars, and when these collapses they forms a star which is producing light. The leftover from the star formation becomes planets, asteroids, and comets just like what happened when our solar system was born. Stars are born in groups in a nebula and when all the proto stars collapses under their own gravity, they becomes stars and become what is called by astronomers as “star clusters”.

Star Clusters are groups of stars, hold together by their mutual gravity. There are hundreds of them in our galaxy. When talking about their types, then the answer is three: Open, Globular & Embedded Clusters.

Open Clusters are a group of a few to a few thousand stars born from the same cloud of gas and dust. If you are a astrophotographer, then they are a perfect target for you because you can see every star within the cluster using your telescope and sometimes with unaided eyes. The Pleiades is the best example of open star cluster. You can see them looking like a small Ursa Major constellation in the sky. To be honest, at first I literally had no idea what I was looking at until I realized that I was looking at the Pleiades all the time. Pleiades are also known as the “Seven Sisters” cluster because there are 7 stars in it. In fact, there are more than 7, around 1000 stars but these seven are the brightest ones, which appear from the Earth.

Another interesting thing about these open star clusters is that they will not be forever like this. With the passage of time, they will get disperse in the space because of their gravitational disruptions in the space. Our Sun- the star which is source of light and energy was once a part of such cluster and was also separated from the other stars because of such gravitational disruptions. Open clusters are young group of stars and are found in the spiral arms of the spiral galaxies. There are more than 1000 of them in the Milky Way galaxy.

Moving into the Globular Clusters, they are more massive, older than the Open clusters. Globular clusters are a group of thousands to millions of stars, gravitationally bounded by each other. Unlike, the open star clusters they are not easy to photograph because the stars are so densely packed that you cannot distinguish them from each other, not even using the ground based telescopes. Powerful telescopes like Hubble and James Webb are good at doing this job though. According to NASA, they are home to some of the oldest stars in the Universe. As old stars tend to appear red, these globular clusters also appear to glow red. There are around 150 globular clusters in the Milky Way while the neighbor Andromeda has over 400 of these. They are much good at holding them together. They don’t decay with the time and so their strong gravitational attraction keeps all the stars together. The best example of a globular cluster is Messier 13 or M13- located in the constellation Hercules, about 25,000 light years from the Earth. Sometimes, this cluster is also known as the Great Globular Cluster or NGC 6205. The stars in the cluster are about 12 to 13 billion years old, almost as the same ages as our universe.

Now we’re on our last type of star cluster. It was pretty interesting so far. Now that you know about the two star clusters I told you before, the third type is pretty easier one to understand as the word embed in itself gives a lot of hint, as if the stars in these type of clusters are embedded in something. Embedded clusters are a group of stars which are born inside a nebula. It’s like early stage of star clusters in a nebula, while some stars have already born and some are still in the process of formation. The stars are that have already born are still in the nebula. Once the star formation in the nebula ends, the embedded clusters become open clusters. The best example of such an star cluster is Trapezium cluster, located in the Orion Nebula. It’s about 1600 light years from the Earth and is also known as the Orion Trapezium Cluster because of its Trapezium like arrangement of stars and due to its location. This cluster was discovered by the Italian astronomer Galileo Galilei. The cluster is very young about 300,000 years old.

S2 EP1: The Mysterious Himiko Cloud

Hello, Ciao, Bonjour everyone. What’s up guys? Finally, I’m back with Season 2 of this podcast. I know y’all waited for over a year for it to start airing but its finally here. Today I will tell y’all about a mysterious object in our cosmos which is called Himiko Cloud. Confusing right? So let me break it down in simple terms.

Before we understand what this Himiko cloud is, you need to know what a lyman-alpha blob is. Because that is what this Himiko Cloud is. In astronomical terms, a Lyman-alpha blob or LAB is a huge concentration of hydrogen gas that emits the ultraviolet light of the Lyman-alpha emission line. They are the size of galaxies with some of them being more than 400,000 light years across. They are one of the largest objects in the universe. They are the early stage of the formation of galaxies. Now you might wonder what this lyman-alpha emission line is. So let’s make it easier to understand. Lyman-alpha is a spectral line of hydrogen spectrum which is emitted when the electronic transition takes place from 2^nd orbital to the ground state, releasing a photon in the process which is basically the UV light photon. I’m moving forward in this topic thinking y’all know what this electronic transition is. You need to have this basic knowledge in order to better understand what exactly LAB is. Also, as they are UV light photons so how do we see them? The answer is as they are so far away, billions of years, their light gets red-shifted to the optical part of the electromagnetic spectrum. Moving forward, now that you know about lyman-alpha emission line, let’s talk about our Himiko Cloud.

Himiko Cloud was discovered back in 2009 and is indeed an object of interest for the astronomers because it existed at a time when our universe was only 800 million years old compared to today’s 13.1 billion years. It was found at a distance of 12.9 billion light-years and spans some 55,000 light-years. The speed of light is finite. It means the light from this object arrived in 2009 after travelling 12.9 billion light years. So we are seeing it how it looked like as it was 12.9 billion years ago.

The radial velocity of this object is 289575 km/s. Radial Velocity is the speed at which an object in space is travelling away or towards the space. If the speed is in negative then that means the object is coming towards the Sun but if the value is positive, it means the object is going away, which is true in the case of the Himiko Cloud. It is moving away from the Sun with the expansion of universe.

Located in the constellation Cetus, it was named by the scientists after one of the mysterious 3^rd century Japanese Shaman queen Himiko. Imagine how massive this object could be? According to astronomers, it is roughly equivalent to the mass of 40 billion Suns. This object remains a very big mystery to the astronomers till today.

Special EP: Science Behind The Interstellar Space

What do you think when you hears the word interstellar space? You probably think of the famous movie Interstellar. Now tell me what comes in your mind when you hear the word space? You probably thinks that the space is empty. Stars are so far away from each other and so most of the space is empty. But is it true?

Let me help break it down for you. Hi, I’m Maanvinder, your host of this podcast and I’m back with the season 2 of this podcast after two years and we are starting it with a special episode discussing about the interstellar space. The word interstellar is made up of two words- inter which means between and stellar means star. So Interstellar space is a place between the stars. Another question that arises here is where does it begin? So the correct answer based on the best available science is that, it starts where the star’s constant flow of material and the magnetic field stop affecting its surroundings. To put it in simple terms, for us the interstellar space begins where the sun’s constant flow of material and the magnetic field stop affecting its surroundings. And that place is called heliopause. And with the word material I meant electrons, solar wind, etc. It is the last boundary of a star up to where the star’s magnetic field, and any flowing material stop affecting the bodies outside place. The solar wind from our Sun creates a bubble around our solar system and this is called heliosphere. We know about this by detecting the temperature and concentration of solar particles. Inside this bubble, the solar particles are hot but less concentrated compared to the place outside this bubble where particles are cold and are largely concentrated. This is where you enter the interstellar space. Welcome you have finally made it into the interstellar space.

So as I earlier said, the interstellar space is not empty. The interstellar space is largely made up of Hydrogen which accounts for 70%, next is Helium (28%) and the remaining 2% is heavier gases, interstellar dust, and elements that are thrown out into the space in a supernova. If you don’t know heavier elements are born inside the stars and when the star dies, the blast out their outer shells, spewing all the materials out into the space. And it becomes a part of the interstellar space. If a particular region of the interstellar space has enough material for it to accumulate, then it can give birth to new stars in the stellar nurseries called the nebula.

The next question you might be wondering that has anyone or anything from our world entered the interstellar space? Well there is one. NASA’s Voyager-1 mission in 2012 made history by becoming the first man-made object to leave heliosphere and entered the interstellar space. This was confirmed from the detectors onboard the probe which detected the change in the concentration and temperature of particles that were hitting the probe. Voyager-1 was launched in the year 1977 to study the gas giants of our solar system. It actually did not visited them but flew past them, gathering data about the moons, their magnetic field, and most importantly rings. This is when it was discovered that Saturn is not the only planet with the ring system. Jupiter, Uranus and Neptune also have thin ring system around them. Now Voyager-1 is heading towards the Oort Cloud which is the last boundry of our solar system. It is a place where most of the long period comets origin from. It will reach the beginning in about 300 years and in 30,000 years it will exit our solar system completely. It will be lost in the vastness of deep space.

So why is interstellar space important? The simple answer is without it we wouldn’t exist. Because it is a place where the stars are born in the thick region called molecular clouds- where there is so much material for it to accumulate and born as a star. Interstellar Space is also the place from where cosmic rays enter our solar system because when a star dies in a supernova explosion; it not only spews out elements but also the cosmic rays. During day and night there is a constant bombardment of these rays into the Earth’s atmosphere. When cosmic rays collides with the atoms into Earth’s atmosphere, all their energy is converted back to matter and shower down on Earth’s surface. So this was it from me for this week. Thank you for listening. See you next week!

S2 Episodes List Pt.1

Hello folks,

Maanvinder here back again to give y'all about the season 2 of my astronomy podcast= Astrophysics: Deep In The Space With Maanvinder Pilania, which is all set to air from January 13, 2024; that is exactly two years after the release of season 1. I will reveal all episodes in parts: Pt.1 & Pt.2. These two will make up a total of twelve episodes. If everything goes well, I will continue with the Pt.3 and more. But here are the episodes for the Pt.1 that will start to air from the January 13, 2024 to February 24, 2024, every Saturday at Spotify for Podcasters. By that time, you can listen to all 10 episodes of Season 1 at Spotify for Podcasters.

Thank You

EPISODES PT.1

Special EP- The Science Behind The Interstellar Space-January 13, 2024, Saturday

EP-1 The Mysterious Himiko Cloud-January 20, 2024, Saturday

EP-2 A Guide to Star Clusters-January 27, 2024, Saturday

EP-3 A Guide to the Local Group-February 3, 2024, Saturday

EP-4 Neptune's Moon Triton

EP-5 What If Our Sun Became a White Dwarf Star?

EP-6 Exoplanet: Formation & Their Types

Note- that the last three episodes of pt.1 will air in August.

Our Spotify Wrapped

Hello everyone,

I'm here to share about my Spotify Wrapped and thanks to everyone who listened our podcast so far. Today i logged in into spotify for podcasters account to start recording the new episodes which are all set to air from January. We found our Spotify Wrapped. Even with no new episode this year, we had so many new followers and the top percent of listeners were from the Brazil. Thank you to anyone who listened this podcast at any platforms. It means so much to me. The top listened episode was obviously the episode 1 which aired more than a year ago back in January 2022. Stay tuned in because i have a lot in store to share with you guys!!

Top Episode

Top Listeners

Season 2 (시즌 2)

Hello folks,

Maanvinder here to give y'all the latest update about my astronomy podcast- Astrophysics: Deep In The Space With Maanvinder Pilania. Its first season started airing back in January 13, 2022 and ended in June 12, 2022, with a total of 10 episodes. At first i decided to end this show because i barely had the time to record new episodes then share them. It takes a lot of time and energy to do that. Now after giving much thought, i have decided to come back with the Season-2 of the podcast. Season 2 will start airing from January 13, 2024; exactly two years after its first release. And i'm very excited to share what i have recorded so far. There will even be a Special Episode titled- "Science Behind The Interstellar Space". Actually the season 2 will start from this episode and then afterwards there will be EP-1 & so on. This special episode is for someone who is very dear to my heart and that person was the one who suggested it. So this special episode is for my special friend!

Thank You

***********************************************************************************************************

Stream*

Spotify for Podcasters:- https://podcasters.spotify.com/pod/astromaanvinder/

***********************************************************************************************************

Shukrayaan Mission

This is the fifth episode by Maanvinder Pilania for 365 Days Of Astronomy about India’s first mission to the Venus. Note that the episodes of this podcast are not always available to listen because the episodes are archived after some period of time but can be accessed at any time on their official website.

Description

Olbers Paradox: Why The Night Sky Is Dark?- July 12th, 2022, 365 Days of Astronomy.
Fermi Bubbles of the Milky Way Galaxy- September 13th, 2022, 365 Days of Astronomy.
Ring system around astronomical objects- September 21st, 2022, 365 Days of Astronomy.
A Journey to TOI 849b- September 28th, 2022, 365 Days of Astronomy.
Shukrayaan Mission- January 25th, 2023, 365 Days Of Astronomy.

S1 EP10: 3C321, The Death Star Galaxy

In December 2007, NASA announced the discovery of a violent event ongoing in the Universe that was never seen before. For the first time, astronomers observed a galaxy smiting another galaxy with a blast of energy emanating from the vicinity of a Supermassive black hole at the center of one of these two galaxies. This event took place in a system called 3C321, which lies 1.4 billion light years away from us in the constellation Serpens. It contains two galaxies in orbit around one another which are in the process of merging.

Data from NASA’s Chandra X-ray Observatory shows both galaxies have a Supermassive black hole at its center. The larger galaxy dubbed- “the death star galaxy” has been emanating jet from the vicinity of its Supermassive black hole at its center. The smaller galaxy which is in orbit around “the death star galaxy” is 20,000 light years away from it. For instance, the distance of Earth from the centre of Milky Way is about 27,200 light years. The jet emanating from the large galaxy does not terminate after hitting the smaller galaxy but deflects away after the hit and extends beyond up to 1.7 million light years.

Jets from the Supermassive black hole produce high amounts of radiation, especially X-rays and Gamma rays. This can damage the atmospheres of planets lying in the path of the jet. It is possible the radiation and energy from the jet could induce the formation of stars and planets in the galaxy after its initial wake of destruction is complete. The Death Star galaxy was discovered using the combined efforts of both the space and ground based telescopes that include NASA’s Chandra X-ray Observatory, Hubble Space Telescope and Spitzer Space Telescope. The Very Large Array and The Multi Element Radio Linked Interferometer Network in UK were also the part of efforts.

S1 EP9: J2157, Ultra-Massive Black Hole

Cosmos is full of secrets. The more secrets of it you uncover, the more secrets it presents in front of you. Black Holes are mysterious objects that we don’t fully understand. We now know that Black Holes radiates in Hawking Radiation. We know how they are formed but still they fascinate us every time. Hi, I’m your host Maanvinder and today I will tell you about ultra-massive black hole J2157. I will take you into a deep dive about this black hole but before I start, first let’s understand what Ultra-massive black holes are?

Black Hole is a place in space where gravity pulls so much that nothing can escape not even the light. If you want to escape from the immense gravitational force of a black hole then, the escape velocity which is the velocity needed to escape from the force of gravity of a planet or a star, etc; for such a object is greater than the speed of light. For instance, the escape velocity for Earth is 11.2 km/s. And according to Einstein’s Theory of Relativity, nothing can travel faster than the light. So there’s no chance of escaping from such a dense object.

Ultra-massive black holes are more than 10 billion times the mass of our Sun. They are rare and can be wide as the entire solar system. They can weigh as much as all the star in our home galaxy. For example, TON 618 Ultras-massive black hole is the most massive black hole known to date with a mass of about 66 Billion Solar Masses, which is massive than an entire galaxy- “Triangulum Galaxy”. These black holes can kill the entire galaxy in which they reside. Today our journey through cosmos has brought us to a new destination- J2157 Ultra-Massive Black Hole. Let’s get started!!!

In 2018, astronomers at Australian National University (ANU) with the help of University’s Siding Spring Observatory discovered something which shocked everyone. It was a ultra-massive black hole with earlier estimates suggesting it to be 20 solar masses. Later, new research led by the ANU astronomers found that this gargantuan black hole weighs 34 billion solar masses.

The black hole name is J2157 or J2157-3602 and is located 1.2 billion light years from Earth. What surprised astronomers about this behemoth is one of the fastest growing black holes in the Universe. It devours a sun size star every day. It is getting bigger and thus it has been classified as the fastest growing Supermassive black hole in the Universe. Research shows that this monster is growing at a rate of 1% every million years, which is a lot when it comes to its huge size. “J2157 is about 8000 times bigger than the black hole in the center of Milky Way (Sagittarius A*),” astronomer Christopher Onken of ANU, who was the part of the discovery team told Science Alert. He also added that “if the Milky Way’s black hole wanted to grow that fat, it would have to swallow two thirds of all star in our galaxy”.

J2157 is the monster of Universe. This kind of shish eating can have devastating consequences for the galaxy they reside in. Black holes like J2157 are the killers of galaxy. They blasts out so much energy and turbulence into the galaxy that it shut down the star formation taking place in the galaxy.There’s no clear answer to how these ultra-massive black holes were formed because the process of accretion of a black hole takes long time.

Current models suggest it was formed when the universe was 1.2 billion years old only, which raises questions on how you can make black hole that big at a time when there was not enough gas and enough time. This challenges our current models on how black holes grow. If J2157 were to be formed after many small black holes merged into each other, then it raises a problem. As I earlier told you about the current model which suggest that it was formed 1.2 billion years after Universe came into existence. The problem in this case is that the process of black hole accretion would have taken a long time for such a large object to exist so early on. Astronomers are yet to figure out how these ultra-massive black holes were formed. What you can do until then is to listen or read our episodes!!!

S1 EP8: 130 Elektra, First Quadruple Asteroid System

130 Elektra is a large asteroid located in the outer main-asteroid belt. It is 160 miles across on its longest side and completes an orbit of the Sun every five years.

130 Elektra: The First Quadruple Asteroid System

More than 150 asteroids have two moons but with the discovery of third moon of 130 Elektra, it has become the first quadruple asteroid system in the Solar System.

The discovery of third moon around Elektra was announced on November 6, 2021. It was discovered by Anthony Berdeu from the National Astronomical Research Institute of Thailand and his colleagues using images from the Very Large Telescope in Chile to take a closer look at Elektra and they found third moon hidden inside the orbits of other two.

According to their research papers, this newly discovered moon is about 1.6 Km in diameter making it the smallest member of the system. First moon is the largest and outermost moon of Elektra. It is about 6 Km in diameter and completes its orbit around Elektra in 5.3 days. Second moon is 2 Km in diameter and completes its orbit in 1.3 days.

	Year of discovery	Designation	Diameter (in KM)
First Moon	2003	S/2003 (130) 1	6
Second Moon	2014	S/2014 (130) 1	2
Third Moon	2021	S/2014 (130) 2	1.6

Origin

The moons have the same spectrum as that of Elektra which proves the hypothesis that these moons are the chunks of 130 Elektra that were broken off in a collision when another object smashed into the asteroid.

S1 EP7: WASP-12b, an Exoplanet being devoured by its host star

WASP-12b is an exoplanet orbiting around a yellow dwarf star WASP-12 located 1410 light years away in the constellation Auriga.

WASP-12b is an ultra hot Jupiter that orbits very close to its star than Mercury orbits the Sun. It orbits at around 3.4 Million Kilometres from its star. That’s why the year on this exoplanet is just 26 Earth hours. WASP-12b is 1.8 times the radius of Jupiter and 1.4 times the mass of Jupiter. Due to its close proximity to its star, this exoplanet is tidally locked, meaning one side of it always faces towards the star.

The dayside temperature reaches 2200 degree Celsius. As hot Jupiters are tidally locked, there’s a large flow of heat from the highly irradiated dayside to the cooler night side. This is thought to result in very strong winds rushing around the planet’s atmosphere.

The planet is so close to its parent star that it is being torn apart. The tidal forces from the star’s immense gravity have stretched it into an egg shape and the scorching heat from the star is stripping away the atmosphere of the WASP-12b at a rate of 189 quadrillion tons per year. NASA estimates that it will be consumed by its host star in about 10 million years. And I think that doesn’t sound cool.

In September 2017, researchers working on the Hubble Space Telescope announced that instead of reflecting light, this exoplanet absorbs 94% of the light that shines on its surface because being so close to its star it is unable to make clouds that should reflect the light that falls on it.

Now, let me tell you how much time it would take for a trip to WASP-12b. Using the current technology say by the fastest thing made by humans is Voyager-1 spacecraft which is moving at the speed of 38 thousand miles per hour, it would take us 25 million years to visit there. I know that’s too long and by then the planet will be consumed by its host star. So let’s increase the speed. What do you think about the speed of light; which is the fastest speed in our universe. Travelling at the speed of light, it would take us 1 thousand years. Happy, if not yet then I’m sorry nothing can travel faster than the speed of light. Sorry to disappoint you, according to Einstein’s theory of relativity, a body which has mass cannot travel with the speed of light. You will probably need a Warp Drive or something like that to travel faster than light.