PA-99-N2: First Extragalactic Planet Beyond Milky Way

Scientists have a firm belief that there are millions of planets in our neighboring, Andromeda Galaxy. However, they have only identified one so far, named PA-99-N2, due to a microlensing event in 1999. Therefore, this confirmation makes it the very first extragalactic planet.

Finding planets in space is challenging because they don’t emit their own light. Our technology allows us to find lots of exoplanets in our galaxy. As technology gets better, astronomers might find exoplanets outside our galaxy. In 2010, they found a Jupiter-sized planet in the Andromeda Galaxy and called it HIP 13044 b.

PA-99-N2 vs Jupiter: Let’s Know the Differences & Similarities:

Researchers have found that PA-99-N2 is about 6.34 times the mass of Jupiter, which is roughly 2015.5 times the mass of Earth.
To figure out if life could exist on this planet, we must check if it’s in the “Goldilocks zone” of its star system.

The Evidence of Exoplanets in Andromeda Galaxy:

The habitable zone is like a cosmic sweet spot where a planet has the perfect conditions for liquid water, which is vital for life.

Now, here’s the catch: Andromeda, our distant space neighbor, is so far away that astronomers struggle to gather enough info about its stars and planets. It’s like trying to see something tiny from a very, very long distance.

In simple terms, because of the enormous cosmic gap, scientists can’t determine how many planets exist in the Andromeda galaxy.
It’s a bit like counting stars in the night sky with the lights turned off – a real challenge! As time goes on, scientists will probably create advanced tools to find and study new exoplanets not just in the Andromeda Galaxy but also in distant regions of space.

How Scientists Discovers Such Distant Exoplanets & Stars?

To locate planets in distant galaxies, advanced data processing algorithms are employed. These algorithms work diligently to detect even the tiniest changes in areas as small as a single pixel. Because of the huge distances involved, scientists haven’t been able to show us clear pictures of planets or exoplanets, such as PA-99-N2 faraway places. But they’re not giving up! They’re still on the hunt for life on other planets and finding new planets, keeping our dreams alive for more knowledge in the future.

One exciting possibility is a planet that’s about 6.34 times as massive as Jupiter. If they confirm its existence, it would be a groundbreaking discovery: the first known planet in a different galaxy.

The Twin Quasar Event in History!

A similar occurrence took place in 1996 when a group of astronomers detected an unusual fluctuation in the light curve of the Twin Quasar. This fluctuation appeared to be caused by a planet roughly three times the mass of Earth within the lensing galaxy YGKOW G1. However, the validity of these findings remains uncertain because the fortuitous alignment that led to its identification is unlikely to occur again.
If they confirm PA-99-N2 exoplanet, it would set a mind-blowing record as the farthest known planet which is 4 billion light-years away.

Is PA-99-N2 a planet?

Its discovery was initiated by a microlensing event in 1999, yet astronomers are currently in the process of verifying its existence. Locating planets in the expansive realm of space poses a significant challenge.

How big is PA-99-N2 compared to Earth?

Researchers have stated the mass of the PA-99-N2 to be about 6.34 Jupiter masses. That amounts as 2015.5 to the Earth masses.

Does PA-99-N2 have moons?

In Andromeda, there’s a planet called PA-99-N2 D, orbiting another planet called PA-99-N2, but it’s farther from the center. This planet is either a blue gas giant or an ice giant and has a set of rings that don’t line up and two moons.

What star does PA-99-N2 orbit?

PA-99-N2 b is a planet in another galaxy, Andromeda, that orbits the red giant star PA-99-N2.

Where is PA-99-N2?

PA-99-N2 is a red giant star in the Andromeda Galaxy, located incredibly far away from Earth at about 2,185,247 light-years (or 670,000 parsecs).

Is PA-99-N2 bigger than Jupiter?

In 1999, a microlensing event called PA-99-N2 occurred. It is providing an opportunity to find the first exoplanet. The one having a mass 6.34 times that of Jupiter outside our Milky Way galaxy.

How did Andromeda Galaxy get its name?

The most remarkable aspect of our night sky is the grand Andromeda Galaxy. It is one of the closest galaxies to Earth. And one of the rare galaxies that can be seen without telescopic assistance. Besides this, Andromeda gets its name from the princess of Ethiopia, whom the hero Perseus saved from being sacrificed to the sea monster Cetus, according to Greek mythology.

Some Crisp Facts About Andromeda Galaxy:

One more galaxy you should be aware of, besides our Milky Way, is the Andromeda Galaxy. It’s actually the closest galaxy to us. It’s worth noting that the universe boasts around two trillion galaxies in total. The Andromeda Galaxy is about 2.5 million light-years away from us. Astronomers are really curious about the Andromeda Galaxy because it’s our close space neighbor. Let’s dive into what we know about planets in Andromeda. Similar to our Milky Way Galaxy having the Solar System, the Andromeda Galaxy also harbors many intriguing celestial wonders.

Andromeda Galaxy Planets – Facts That You Didn’t Know

Does Andromeda galaxy planets occur? If so, are they habitate too? Let’s answer your queries in this blog post!

As galaxies fill the universe, there is a belief system that the observable universe holds around two trillion of them. Among these galaxies, the closest one to us is the Andromeda galaxy, located approximately 2.5 million light-years away.

Given its proximity, astronomers are constantly seeking answers to our curiosity about Andromeda. They wonder whether it harbors any planets, and what these planets might look like. And most importantly, whether they could be habitable.

Facts about the Andromeda Galaxy:

  • The Andromeda Galaxy gets its name from the constellation Andromeda, a name after the mythological Greek princess Andromeda.
  • It is believed to be the most massive galaxy in the Local Group, contrary to previous assumptions that the Milky Way held this title due to its dark matter content.
  • A 2006 study revealed that the mass of Andromeda Galaxy planets mass is approximately 80% of the Milky Way’s mass.
  • Andromeda houses around 1 trillion stars, whereas the Milky Way contains about 200-400 billion stars.
  • In about 3.75 billion years, the Andromeda and Milky Way galaxies will collide and merge, forming a giant elliptical galaxy.
  • Astronomers theorize that the Andromeda Galaxy was formed 5 to 9 billion years ago when two smaller galaxies collided and merged.
  • With an apparent magnitude of 3.4, the Andromeda Galaxy is bright enough to be visible to the naked eye on moonless nights.
  • The Andromeda Galaxy is approaching the Milky Way at a speed of approximately 110 kilometers per second (68 mi/s).
  • Furthermore, a microlensing event called PA-99-N2 suggests the possibility of an extragalactic planet, estimation to be 6.34 times as massive as Jupiter. If confirmed, it would be the first exoplanet known to exist beyond the Milky Way.

A Quick Look at the Numbers:

  • Designation/s: Messier 31 (M31), NGC 224
  • Type: Spiral Galaxy
  • Constellation: Andromeda
  • Apparent Magnitude: 3.44
  • Size: 220,000 light-years across
  • Mass: 1,230 billion M☉ (solar masses)
  • Number of Stars: Approximately 1 trillion
  • Distance: 2.5 million light-years

What challenges astronomers are facing in locating the planets?

Currently, there is one very strong candidate planet in the Andromeda Galaxy, temporarily name PA-99-N2, which was detected during a microlensing event in 1999. Astronomers are diligently working to confirm its existence, and if successful, it would become the first officially recognized extragalactic planet ever discovered.

Andromeda Galaxy
Andromeda Galaxy – Credit: David Dayag

While the Andromeda Galaxy likely hosts millions or even billions of planets orbiting its numerous stars, none of them have been fully confirmed as of yet.

Detecting planets beyond our Solar System poses significant challenges because planets do not emit light. All confirmed exoplanets (planets outside the Solar System) are presently found within our galaxy. As our optical technology and data processing techniques continue to improve, we hope to extend our search for planets farther into the universe.

In 2010, several scientific publications reported the discovery of a Jupiter-like planet in the Andromeda Galaxy, known as HIP 13044 b. However, further analysis of the data raised multiple concerns, leading to the rejection of this planet candidate.

What is the likelihood of habitable planets in the Andromeda Galaxy?

As of now, we lack sufficient data about the stars and planets in the Andromeda Galaxy to determine with certainty whether any of its planets can support life. The best chance for a planet to be habitable is for it to be located within the “Goldilocks zone” or habitable zone of its star system.

The Goldilocks zone is the region around a star where a planet’s distance is just right to maintain liquid water on its surface.

Given the vast distance between Earth and the Andromeda galaxy, our knowledge about its stars and planets is not vast. Consequently, we cannot accurately ascertain the number of planets within the habitable zones.

Statistically, however, it is reasonable to infer that some planets in the galaxy might reside in the Goldilocks area of their respective stars. As our imaging techniques and telescopes advance in the future, we hope to confirm or refute these theories, gaining a better understanding of the potential for life within the Andromeda Galaxy.

What are the technological advancements made in Andromeda planets for further discoveries?

As of now, we do not have direct evidence to determine whether there are habitable planets in the Andromeda Galaxy. Due to the immense size of the galaxy and the distance from Earth, it is challenging to study its planets in detail using current technology.

The Andromeda Galaxy contains over a trillion stars, and many of these stars likely have sun-like characteristics, making it reasonable to assume that some of them might have planets. However, without detailed observations, we cannot confirm the presence of habitable planets in the galaxy.

As our technology advances, particularly with the potential development of NASA’s liquid lens telescopes, we hope to gain more detailed insights into the objects within the Andromeda Galaxy. With improved capabilities, we may discover more planets and solar systems in Andromeda in the future.

Regarding the Andromeda constellation, its genitive form, used for naming stars, is Andromeda. The constellation Andromeda from Greek mythology comes after the figure Andromeda. Cassiopeia’s daughter, Andromeda, was chain to a rock for sacrifice to the sea monster Cetus. Additionally, the constellation occupies a position north of the celestial equator.

Andromeda-Milky Way Collision – One of the Closest Galaxy to the Milky Way

The collision between the Andromeda Galaxy and the Milky Way is predict to occur in approximately 4 billion years. This galactic collision will be a momentous event involving the two largest galaxies in the Local Group.

Andromeda, also known as the Andromeda Galaxy, is the closest galaxy to the Milky Way. Therefore, its name originates from the constellation Andromeda, the area of the sky where it appears. Scientists consider Andromeda to be the closest large galaxy to our Milky Way.

Is there any possible planet in andromeda for habitant perspective?

As for the possible planet in the Andromeda galaxy, PA-99-N2, this detection through a microlensing event. Moreover, this event is an astronomical phenomenon, and the reason for this is the gravitational lens effect. Which helps in detecting objects of varying masses, from planets to stars, regardless of the light they emit. Additionally, the exoplanet have a mass approximately 6.34 times that of Jupiter.

While no confirmed data currently exists regarding the existence of planets in the Andromeda galaxy. Statistical inferences suggest the possibility of planets existing within the habitable zones of their stars. Where liquid water could potentially support life.

Carbon-Rich Dust Grains Have Been Seen By Webb

Webb has recently discovered carbon-rich dust grains, and it is one of the billion cosmic years happening! Yes, it is true. Let’s uncover some of the crisp, and valuable knowledge about this discovery in the following paragraphs.

What groundbreaking discovery did Webb make regarding carbon-rich dust particles in the early universe?

The NASA/ESA/CSA James Webb Space Telescope has made an unprecedented discovery, detecting chemical traces of carbon-rich dust particles at Redshift, around one billion years following the inception of the universe. The presence of polycyclic aromatic hydrocarbons (PAHs), intricate carbon-based compounds, has been associated with comparable occurrences in more contemporary cosmic observations. However, it was previously believed that PAHs did not emerge during the initial billion years of the universe.

So, this finding raises the exciting possibility that Webb may have seen a different type of carbon-based molecule. For example, the first stars or supernovae may have made tiny grains that look like graphite or diamond. This observation opens up interesting questions about how cosmic dust is made and about the first stars to form in our universe. It was made possible by Webb’s incredible sensitivity.

Now, you must be wondering how Webb used high sensitivity telescope to view it. That is why we have curated the following part too.

Ancient Carbon-Rich Dust Grains: Insights from Webb Telescope’s High Sensitivity

Most of the time, clouds of gas and cosmic dust are in the places in our universe that look like they are empty. The dust consists of a variety of grains, each with distinct sizes and shapes. These grains are formed through diverse processes and subsequently released into space, often propelled by phenomena like supernovas. This stuff is important to the development of the universe because dust clouds are where new stars and planets are born.

But dust can also make it hard for scientists to see certain parts of space because it absorbs light from stars at certain wavelengths. On the other hand, one good thing is that certain molecules will always absorb or react in some other way with certain colors of light.

This means that scientists can figure out what cosmic dust is made of by looking at the light wavelengths that it blocks. With this method and Webb’s high sensitivity, a group of scientists from around the world were able to find carbon-rich dust grains only a billion years after the universe was created.

Aside from this, we will give you some knowledge about the importance of this discovery. The following mentioned information is just for you!

What is the significance of carbon-rich dust grains with a 217.5-nanometer pattern in very early galaxies?

Joris Witstok of the University of Cambridge, the lead author of this work, elaborates:

“Carbon-rich dust grains can be particularly efficient at absorbing ultraviolet light with a wavelength around 217.5 nanometers, which for the first time we have directly observed in the spectra of very early galaxies.”

This 217.5-nanometer pattern has been seen before in a universe that is much closer to us and much more recent, both in our own Milky Way galaxy and galaxies up to Redshift. It has been linked to two different types of carbon-based species: polycyclic aromatic hydrocarbons (PAHs) and Nano-sized graphitic grains.

Modern models say that it should take a few hundred million years for PAHs to form because they are very complicated chemicals. So, it would be strange if the team had seen the chemical evidence of a mix of dust grains that included species that were unlikely to have formed yet. But the science team says that this finding is the earliest and farthest direct sign of this type of carbon-rich dust grain.

Besides this, we are also going to tell you what are the compositions of carbon-rich dust grains.

Cosmic Dust Composition: Clues from a 226.3-nanometer Pattern Shift

The facts of what was seen may hold the answer. As was already said, the pattern at 217.5 nanometers is linked to the mixture of PAHs and tiny graphitic grains in space dust. However, the peak of the pattern that the team saw was 226.3 nanometers. A nanometer is a millionth of a millimeter, and this difference of fewer than ten nanometers could be due to measurement mistakes. Another interpretation could be that the team discovered a shift in the composition of cosmic dust from the early universe.

Witstok, added:

“This slight shift in wavelength of where the absorption is strongest suggests we may be seeing a different mix of grains, for example, graphite- or diamond-like grains. This could also potentially be produced on short timescales by Wolf-Rayet stars or supernova ejecta.”

Galaxy JADES
Galaxy JADES-GS-z6 in the GOODS-S field: JADES (NIRCam image)

Now, if you are confused about the “if & but” points of the dust grains, then the following information is just for you.

What are the potential causes behind the surprising blend of dust grains discovered in the early universe?

The discovery of this feature in the early universe came as a complete surprise to scientists, prompting them to ponder over the potential causes behind the intriguing blend of dust grains. This requires using what you already know from data and models.

Witstok thinks that diamond grains formed in the ejecta from a supernova because models have shown that this is how Nano-diamonds could form. Wolf-Rayet stars are a good choice because they get very hot at the end of their lives, and very hot stars tend to live quickly and die young.

This means that in less than a billion years, enough generations of stars will have been born, lived, and died to spread carbon-rich dust into the surrounding space dust. Models have also shown that certain types of Wolf-Rayet stars can make carbon-rich grains, and, just as important, that these grains can survive the violent deaths of these stars.

However, elucidating these findings remains challenging, given our current understanding of the historical formation of cosmic dust. Consequently, these observations will serve as valuable input for refining models and directing future investigations.

As carbon-rich dust grains give the signs of the early universe, so let’s see how Webb’s telescope is describing it.

Webb Telescope Gives Valuable Knowledge About Cosmic Dust Origins in the Early Universe

Before Webb, scientists had to combine the views of several galaxies to get strong enough signals to figure out the number of stars in the galaxies and how the dust in space affected their light. Importantly, scientists could only study galaxies that were pretty old and had been around for a long time, giving stars and dust plenty of time to form. This made it hard for them to find the real sources of cosmic dust.

With Webb, scientists can now look at the light from individual dwarf galaxies in the first billion years of the universe’s history in great detail. Webb finally makes it possible to find out where cosmic dust comes from and what part it plays in the first important stages of galaxy evolution.

A team member Roberto Maiolino of the University of Cambridge and University College London, said:

“This discovery was made possible by the unparalleled sensitivity improvement in near-infrared spectroscopy provided by Webb, and specifically its Near-Infrared Spectrograph (NIRSpec).

The increase in sensitivity provided by Webb is equivalent, in the visible, to instantaneously upgrading Galileo’s 37-millimeter telescope to the 8-meter Very Large Telescope (one of the most powerful modern optical telescopes).”

Webb Telescope Unveils Cosmic Dust Origins in Early Dwarf Galaxies

As part of the JWST Advanced Deep Extragalactic Survey, or JADES, these observations were made. The camera was used for about 32 days to find and study faint, faraway galaxies. This program has helped find hundreds of galaxies that were around when the universe was only 600 million years old.

Carbon-Rich Dust Grains
Crop of the GOODS-S field: JADES (NIRCam image, clean)

This includes some of the most distant galaxies that have been found so far. The number of galaxies and how old they were much more than what had been seen before Webb was launched. This recent discovery concerning dust grains from the early universe offers valuable insights into the evolution of stars and galaxies during the initial billion years of cosmic history.

A team member Renske Smit of the Liverpool John Moores University in the United Kingdom, said:

“This discovery implies that infant galaxies in the early universe develop much faster than we ever anticipated. Webb shows us a complexity of the earliest birthplaces of stars (and planets) that models are yet to explain.”

“Dark Stars” – Captured by Webb Telescope

James Webb Telescope identified three objects and named as “dark stars”. What are they? And how are they different from ordinary stars? Let’s dig into the deep details and uncover valuable information.

Enigmatic Dark Stars- Exploring Celestial Bodies

Over the last 15 years, researchers have dedicated their efforts to uncovering proof of a unique type of celestial body that has long been theorized but remains unseen: a star that derives its energy not from atomic fusion like traditional stars, including our sun, but from an enigmatic entity called dark matter. The first good candidates for “dark stars” have been detected thanks to the James Webb Space Telescope’s ability to see back to the beginning of the cosmos.

The three objects found by Webb, which was launched in 2021 and began collecting data last year, were initially identified last December as some of the universe’s earliest-known galaxies but may instead be massive black stars, according to astronomers.

Dark Stars Captured by Webb Telescope
These three objects were identified by the James Webb Space Telescope Advanced Deep Extragalactic Survey (JADES) in December 2022. NASA/ESA/Handout via REUTERS

Now, you must be thinking about what these dark stars depict and what is the actual connection to the dark matter! If so, please continue reading!

Unveiling the Mysterious Connection to Invisible Dark Matter

Dark matter, an invisible substance whose presence is known primarily by its gravitational effects on a galactic scale, would be a minor but critical component of dark stars. These stars are claimed to be almost entirely made of hydrogen and helium, the two elements that existed in the early universe, with dark matter accounting for 0.1% of their mass. Their engine, however, would be self-annihilating dark matter.

We are unable to detect dark matter because it cannot emit or directly interact with light. However, it is estimated that it accounts for approximately 85% of all weight in the universe. The remaining 15% consists of ordinary matter, including familiar objects like stars, planets, gas, dust, and everyday items such as pizza and people found on Earth.

Aside from this, if you think that dark stars are DARK! Then we suppose you might be wrong. Let’s find out how!

Dark Stars are Giants with Big Masses and Brightness

Dark stars have the astounding potential to amass a mass surpassing the sun by at least a millionfold, while their luminosity could exceed a billion times, leaving a blazing trail of light in their wake. These colossal celestial bodies possess a diameter approximately ten times the vast expanse between Earth and the sun.

Katherine Freese, a theoretical astrophysicist at the University of Texas at Austin and senior author of the research published in the journal Proceedings of the National Academy of Sciences, said:

“They’re big puffy beasts,”

Freese added:

“They are made of atomic matter and powered by the little bit of dark matter that’s inside them,”

Unlike conventional stars, they would be able to grow mass by absorbing gas from space.

Colgate University astrophysicist and study lead author Cosmin Ilie said:

“They can continue to accrete the surrounding gas almost indefinitely, reaching supermassive status.”

Additionally, they also uncover crisp knowledge about ancient enigmas and valuable information on cosmic origins. In the next paragraph, we will see about it.

They are Ancient Enigmas Challenging Cosmic Origins

They would not have been as hot as the first generation of regular stars in the universe. The nuclear fusion that took place in the centers of those stars created elements heavier than hydrogen and helium.

The three hypothetical black stars are too young in the universe’s history, with one occurring 330 million years after the Big Bang event 13.8 billion years ago and the others occurring 370 million and 400 million years afterward.
Based on the Webb data, these objects could be either early galaxies or dark stars.

Freese said:

“One supermassive dark star is as bright as an entire galaxy so that it could be one or the other.”

Dark Stars & Cosmic Mysteries? HOW?

While there is not enough data to make a definitive judgment about these three, Freese said, Webb may be able to obtain fuller data on other similarly primordial objects that could provide “smoking gun” evidence of a dark star.
During the nascent stages of the universe, the prevailing circumstances might have been conducive to the emergence of enigmatic entities known as dark stars.

These celestial formations could have arisen due to the presence of substantial concentrations of dark matter near regions rich in hydrogen and helium, where star formation was taking place.

In 2008, Freese and two colleagues postulated the existence of dark stars, naming them after the 1960s Grateful Dead song “Dark Star.”

Freese said:

“It would be super exciting to find a new type of star with a new kind of heat source. It might lead to the first dark matter particles being detected. And then you can learn about the properties of dark matter particles by studying a variety of dark stars of different masses.”

In the next part of the blog, we will be answering some of the commonly asked questions about dark stars that will continue your thoughts.

What is a dark star called?

In astronomy, there are three different concepts referred to as “dark stars.” The first type, under Newtonian mechanics, is a star with an exceptionally powerful gravitational force, leading to the trapping of light according to Newton’s theory of gravity.

The second type involves dark matter, where a star is heated through the process of annihilation of dark matter particles that occur within its core. Lastly, a dark-energy star is an object primarily composed of dark energy and exhibits external similarities to a black hole in appearance. These distinct dark star phenomena present fascinating areas of study within the realm of astrophysics.

What is a dark star made of?

These stars are characterized by their composition, consisting mainly of hydrogen and helium, the two predominant elements during the early universe. Remarkably, they contain a mere 0.1% of their mass in the form of dark matter. However, what sets them apart is that their source of energy is attributed to the process of self-annihilating dark matter.

Is A black hole a dark star?

In the cosmic journey of stars exceeding three solar masses, an inevitable fate awaits them. After the cessation of thermonuclear reactions, they are destined to transform into what is known as a “dark star” or, more commonly, a “black hole.” This term, “black hole,” was coined by the physicist John Wheeler, who comprehensively described these enigmatic objects as entities where no known source of pressure can counterbalance their immense gravitational force.