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.

S1 EP6: NASA's Webb captures its first image of HD 84406

The James Webb Space Telescope (JWST) is the NASA’s largest and most powerful space observatory. The $10 billion James Webb Space Telescope mission launched last Christmas on 25 December 2021 has captured its first image of star HD 84406. NASA released the images in a virtual press conference held on Wednesday (16th March 2022). I still remembers that day when I was discussing about this telescope in the school with my friends; we were discussing about how far James can see and how it will uncover the secrets of universe.

The first target star of JWST is located in the Big Dipper, which is a part of the Ursa Major constellation. HD 84406 is a star like our sun located about 260 light years away. On 4 February 2022, it was the first star viewed by James Webb Space Telescope. The star is 100 times fainter than what can be seen with the naked eye. The star has a visual magnitude of about 6.9 which is too dim to see with naked eye. You will need a telescope to see it. The image released by NASA shows a bright shining Orangish star. Even more interesting thing in the image is its background revealing dozens of specks and dots- each a distant galaxy that was previously out of reach.

S1 EP5: Two Mini-Neptunes losing atmosphere, becoming Super Earth

Exoplanets are planets orbiting around other stars outside our solar system. Exoplanets comes in different shape, size. Astronomers using Hubble Space Telescope & W.M Keck Observatory have observed two Mini-Neptunes losing their atmospheres and becoming Super-Earths. The new findings were published in two separate papers in The Astrophysical Journal.

According to NASA, Mini-Neptunes are smaller and denser versions of the planet Neptune and consist of a rocky core blanketed with thick gas. Mini-Neptunes are between 2 and 4 times the size of Earth. Super-Earths are rocky and are large as 1.6 times the size of Earth.

In this study, a team of astronomers used NASA’s Hubble Space Telescope to study the HD 63433c which is a mini-Neptune orbiting HD 63433, a G-type star located 73 light years away. They used the W.M Keck Observatory in Hawaii to study the mini-Neptune TOI 560.01 which orbits TOI 560 & is located at 103 light years away. TOI 560.01 is about two times the size of Earth and has a puffy atmosphere, made up of mostly Hydrogen & Helium. These two mini-Neptunes are losing their puffy atmosphere & likely transforming into super-Earths. Radiation from their host star is stripping away their atmospheres.

Using W.M. Keck observatory in Hawaii scientists revealed that Helium is escaping from the TOI 560-01. The observed helium around TOI 560-01 is moving as fast as 20kms/second, while the Hydrogen around HD 63433c is moving as fast as 50Kms/Second. The gravity of these mini-Neptunes is not strong enough to hold on to such fast moving gas. This means in several hundred years to millions of years, they will lose their atmospheres, leaving behind rocky cores. The study also found that the gas around TOI 560.01 was escaping toward the star. “This was unexpected as most models predict that the gas should flow away from the star,” said Heather Knutson, professor of Planetary Science at Caltech & co-author of this study. This new discovery will help astronomers understand how these worlds evolve.

S1 EP4: WASP-103b, a Rugby Ball Shaped Exoplanet

Exoplanets are planets that orbits stars located outside our solar system. They are gas giants and rocky. They can big or small. So far, 5000 plus exoplanets have been discovered.

WASP-103b is an exoplanet that was discovered in 2014. It orbits an F-type main sequence star and is located at a distance of 1,225 light years away from Earth in the constellation Hercules. Its host star WASP-103 is 200 degree hotter and 1.7 times larger than our Sun. It is a Hot Jupiter, which means it orbits very close to its star and is a gas giant planet. It is twice the size of Jupiter & is 20 times hotter than Jupiter. That’s why it falls in another category of exoplanets called Ultra Hot-Jupiter. It is also a Ultra Short Period planet, which means it completes its orbit in less than a day. It completes its orbit around its host star in 22 hours.

What makes this exoplanet unique is its shape. Using European Space Agency’s CHEOPS (Characterizing Exoplanets Satellite) space telescope; astronomers have discovered that WASP-103b is shaped like a rugby ball or a potato. Out of all the exoplanets discovered so far it is the first that isn’t a sphere. WASP-103b is deformed to its rugby ball shape by strong tidal forces between the planet and its host star. Since it is very close to its star, this exoplanet is tidally locked with its host star, which means it does not rotate on its axis but revolves around the host star with one side always facing towards the star. This makes the one side or dayside very hot and other side cold in comparison to day side. Back in 2018, a study of the complete orbit of WASP-103b was conducted using the NASA’s Hubble Space Telescope that enabled scientist to detect dayside temperatures of between 2000-3000 degree Celsius.

S1 EP3: What If Our Sun Became a Black Hole?

A black hole is a place in space, where gravity pulls so much that even light cannot escape. The gravity is so strong because matter is squeezed into a tiny space. This happens when a star dies in supernova explosion. There is a sphere around a black hole. If something goes inside the sphere, nothing can get out of it. This is called the Event Horizon. The escape velocity for such an object is equal to or greater than the speed of light. According to Einstein’s theory of relativity it is not possible to achieve a velocity greater than the speed of light or c. Thus, nothing can escape from such a dense material.

What if our Sun became a Black hole?

If you ask me whether our sun will become a black hole or not? Then hold on and take a deep breath because our Sun will never become a black hole. But let’s just try to imagine, what will it be like if a black hole replaced our sun? Will there be any life on Earth? Will black hole suck our Earth & other bodies in our solar system? No idea let me tell you!

Our Sun will never become a black hole because our sun lacks enough mass needed by a star to go supernova explosion and become a black hole. Replacing our sun with a black hole is possible only in science fiction films only but as you all are curious to know about this, I’m going to give you its answer. If the Sun were replaced with a black hole of the same mass of Sun, nothing would change regarding the planet’s orbits if the black hole had the same mass as the Sun, the orbits would remain the same. Planets will keep on orbiting around the black hole because the black hole would apply the same gravitational force as the sun. But here things go wrong. Here’s why

As a black hole does not emits any light or heat the life on Earth will not be possible because without the heat & light. Plants & animals will start dying & Earth will enter a new ice age which will never end, if Earth keeps on orbiting around black hole. Now imagine, if our Sun had an equal mass black hole orbiting near it. What will happen next? According to astrophysicist Sean Raymond, who works at the observatory of Bordeaux in France, the orbits of solar system planets would not change much. “Still assuming these planets kept the same distance from the sun, as they do now, the gravitational pull of the sun and its black hole partner would lead these worlds to complete their orbits a bit more quickly, with Earth’s year decreasing from 365 days to 258 days”, he said to Space.com. “In the above scenario, the sun and the black hole would complete an orbit with one another every 2.9 days. This means the amount of energy that Earth would receive from the Sun would fluctuate between 90% and 110% of its average as the Sun moved farther from or closer to Earth”, said Raymond.

S1 EP2: What If Our Sun became a Red Giant Star?

A red giant star is an evolutionary stage of a star in which it ran out of fuel and starts burning helium. A red-giant has a mass of about one-half to ten times the mass of our Sun. In this stage, a star will get brighter; sometimes as much as ten thousand times as bright as when it was on the main-sequence. A red giant reaches the sizes of 100 million to 1 billion kilometers in diameter & because the energy is spread across a larger area, surface temperatures are actually cooler, reaching only 2,200 to 3,200 degrees Celsius, a little over half as the sun. This temperature change causes stars to shine in the redder part of the spectrum, leading the name red giant but in fact they are Orangish in appearance.

What if Our Sun became a Red Giant?

Now, what if our Sun became a red giant? Will it engulf everything in its path? Or will it give a new chance to life to exist in outer solar system? Will Earth survive this expansion? Our Sun was formed 4.6 billion years ago and its total lifespan is around `10 billion years. Since then, Sun has been in what is known as a Main-Sequence star, in which a star burns hydrogen into helium through fusion to create energy & light. Roughly 5 billion years from now, the Sun will enter its red giant phase, in which it will ran out of fuel after burning all its hydrogen into helium. The center will start to get smaller due to sun’s gravity. This will make the layer just outside the center get hotter. This layer will still have hydrogen &it will fuse to make helium. The outside layer of the sun will get much bigger & bigger and will begin to expand. The sun will grow so large that ii will engulf the closest planet orbiting around it Mercury, then Venus & Earth, maybe even Mars & part or the entire asteroid belt.

Long before Sun will enter its red giant phase; its habitable zone will be gone. Habitable zone or the Goldilocks zone is a region around a star where liquid water can exist on a planet’s surface. Astronomers estimate that this zone will expand past the Earth’s orbit in about a billion years. As star ages, its brightness increases which increases the heat amount a planet receives from its host star. The brightness of our sun is increasing 10% every billion years & this will have deadly consequences for life on Earth. Earth’s Oceans will evaporate & the solar radiation will blast away hydrogen from the water. The Earth will never have oceans again, & it will become a new Venus. When Sun will become a red giant, Earth will become molten & soon it will be engulfed by the Sun. Once inside the sun’s atmosphere, Earth will collide with the particles of gas. Its orbit will decay and it will spiral inward. The engulfing of Earth will shift the new habitable zone that will stretch from 49.4 AU to 71.4 AU- well into the Kuiper belt. During the red giant stage, Earth could expand to an orbit around 50% more distant where it is today. Currently Earth is at 1 AU from Sun & during expands of the Earth’s orbit; it will expand to 1.5 AU. If Earth were just a little further where it is right now to 1.5 AU then we could possibly survive if Sun does not expand to mars or asteroid belt. Imagining in mind that currently Earth is at 1.5 AU & during the expand of its orbit to 2 AU (50% more), then still life will not be possible on Earth.

In 2016, a research was conducted by Ramirez & Lisa Kaltenegger, which was later published in the Astrophysical Journal that titled- “Habitable Zones of Post-Main Sequence Stars”. In this research, the two astronomers looked for new habitable zone after a main-sequence star will become a red giant which may heat frozen worlds into habitable planets. “Currently objects in these outer regions are frozen in our own solar system like Europa & Enceladus- moon orbiting around Jupiter & Saturn”. “Long after our own plain yellow yellow sun expands to become a red giant star and turns Earth into a sizzling hot wasteland, there are still regions in our solar system as well as where life might thrive”, said Lisa Kaltenegger.

After Sun will become a red giant, it will warm distant worlds like Jupiter, Saturn, Neptune & their moons in a newly established habitable zone.  “For stars like our sun, but older such thawed planets could stay warm up to half a billion years. That’s no small amount of time”, said Ramirez. The atmospheres of gas giants like Jupiter & Saturn will eventually erode under the increased radiation from the Sun. However, there are gas giant exoplanets called Hot-Jupiter’s which revolve closely around their stars that have managed to hold on their atmospheres. So Jupiter’s fate is far from certain. When Sun will become a red giant, it will give a second chance for life to evolve in our solar system on one of the 82 moons of Saturn- ‘Titan’. Titan is the only known natural satellite with a significant atmosphere. Conditions on Titan are similar to the Early Earth. During red giant phase of Sun, Titan could enjoy the several hundred million years of potentially habitable conditions with oceans of water ammonia on its surface. According to Southwest Research Institute astronomer S. Alan Stern when sun will turn into a red giant, the temperature on Pluto, Neptune’s moon & other Kuiper belt objects will be similar to those in tropical locations like Miami Beach on Earth today. Stars spend a few thousand to 1 billion years as red giants, meaning life on the new world could thrive to around a billion years.

After around a billion years, helium in the core of red giants runs out and fusion stops. The star shrinks again until a new helium shell reaches the core. When the helium ignites, the outer layers of star are blown off in huge clouds of gas and dust known as Planetary Nebulae. The core continues to collapse in on itself. Smaller stars such as our Sun will end their life as White Dwarf, while bigger stars end up as Black holes or neutron stars in a Supernova explosion.

S1 EP1: What If Our Sun became a Black Dwarf?

A black dwarf is a hypothetical star in our universe that do not exists now but will exist in future after a white dwarf star will cooled down.  Black dwarfs takes quadrillions of years to form. At less than 14 billion years old, the universe is too young to have any existing black dwarf.

Our sun is a main-sequence star. A main-sequence star lacks the mass necessary to explode into supernova to become a black hole or a neutron star. Instead, it will become a white dwarf, which is a kind of dead star that has burned through all of its fuel, meaning it’s no longer capable of continuing the fusion of hydrogen into helium that makes a star to glow and produce heat. In about 8 billion years our sun will become a white dwarf & over trillions of years it will no longer emit any light.  But the white dwarf will remain hot for other trillions of years. After, long time all the heat will radiated away & our sun will become a black dwarf.  The estimated time for our sun to cool enough to become a black dwarf is 1015 (1 quadrillion) years.

The Possible Fate of Earth

After the first week without the Sun’s heat, the Earth’s surface temperature would drop to 0°C (32°F). After a year, it would go down even more – dropping to a freezing cold -100°C (-150°F). By that time, all our oceans would be covered in ice. Despite that, the only warm place on the planet that you’d have even a slight chance for survival would be near the Earth’s geothermal vents at the bottom of one of these oceans. Temperatures on Earth will hit -100°C only if Earth survived the expansion of Sun when it will become a red giant in about 5 billion years from now. But this is not possible when Sun will become a red giant, it will expand beyond the orbit of Earth, engulfing up to asteroid belt. So, there is no chance that Earth will survive this expansion.