JWST observation of Interstellar comet 3I/ATLAS.

An illustration depicting a reconstruction of what the Firefly Sparkle galaxy looked like about 600 million years after the Big Bang if it was not stretched and distorted by a natural effect known as gravitational lensing. This concept is based on images and data from NASA’s James Webb Space Telescope.
| Photo Credit: Reuters

NASA’s James Webb Space Telescope has spotted a young galaxy dating to the early universe – called Firefly Sparkle because its gleaming star clusters resemble the bioluminescent bugs – in a discovery that is giving astronomers a peek at what our Milky Way may have looked like in its infancy.

Researchers said the galaxy, still in the process of assembling, dates to when the universe was roughly 5% of its current age, about 600 million years after the Big Bang event that initiated the cosmos. It has a mass equal to about 10 million stars the size of our sun, and has two other relatively small galaxies as neighbors, dubbed Firefly-Best Friend and Firefly-New Best Friend.

It is comprised of 10 densely packed star clusters embedded in a diffuse arc of stars, eight in its central region and two along its extended arm. Its main visible portion spans about 1,000 light-years across. A light year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km).

The galaxy is estimated to have formed 100-400 million years before its evolutionary stage that was observed by Webb, the most capable space telescope ever deployed.

“The Milky Way began forming very early in the universe’s history, likely around the same time as Firefly Sparkle,” said astronomer Lamiya Mowla of Wellesley College in Massachusetts and the Center for Astronomy, Space Science and Astrophysics in Bangladesh, co-lead author of the study published on Wednesday in the journal Nature.

“This observation gives us a direct look at what galaxies like our Milky Way might have looked like in their infancy. Using simulations and statistical methods, we find that the Firefly Sparkle’s mass is consistent with what we’d expect for a Milky Way ancestor at that early time. At this stage, the galaxy was about 10,000 times less massive than our current Milky Way, which is typical of galaxies at that epoch,” Mowla added.

So how did the firefly name come about?

“A group of fireflies – which is what this galaxy looks like – is called a sparkle,” Mowla said.

Firefly Sparkle is located about 6,500 light-years from Firefly-Best Friend and about 42,000 light-years from Firefly-New Best Friend. All three would fit neatly inside the present-day Milky Way, which measures about 100,000 light-years across.

“The Milky Way continued to grow and evolve over billions of years through mergers with other galaxies and continued star formation, while we’re seeing Firefly Sparkle in its initial formation stages,” said astronomer and study co-lead author Kartheik Iyer, a NASA Hubble Fellow at Columbia University in New York.

“Early galaxies like Firefly Sparkle appear to form through the collapse of dense gas clouds in the early universe. Current theory and simulations suggest several possible mechanisms for how stars form from gas in the extreme conditions of the early universe. Our analysis suggests that these galaxies can build up through the formation of massive star clusters in regions of extreme pressure and density, which then merge or grow together over time,” Iyer added.

Its star clusters display slightly different colors, indicating they did not all form simultaneously. For instance, hotter, younger stars look more blue, while older stars are more red.

Webb has been able to look across vast distances – thus back in history because of the time it takes light to travel – to see galaxies dating to the first few hundred million years after the Big Bang roughly 13.8 billion years ago, an age called cosmic dawn.

Firefly Sparkle is one of the earliest low-mass galaxies currently known, observed with the help of a phenomenon called gravitational lensing. This occurs when a massive object with tremendous gravitational strength – in this case, a galaxy cluster – bends light from more distant objects behind it from the vantage point of Earth, acting like a natural magnifying glass.

“In this study, the foreground galaxy cluster magnified the light from Firefly Sparkle by about 16-26 times, making it possible to see details that would otherwise be too faint to observe,” Iyer said.

Scientists have successfully captured the first detailed image of a dying star outside our Milky Way galaxy, wrapped in a strange, egg-shaped cocoon. The star, identified as WOH G64, is located 160,000 light-years from us in the Large Magellanic Cloud and is surrounded by a plume of gas and dust — suggesting it was in the final stage of its life. During a star’s last phase, it transforms into a red supergiant before dying in a huge cosmic explosion, known as a supernova.

“For the first time, we have succeeded in taking a zoomed-in image of a dying star in a galaxy outside our own Milky Way,” said Keiichi Ohnaka, an astrophysicist from Universidad Andrés Bello in Chile and the lead author of the study.

WOH G64 was captured using the GRAVITY instrument at the European Southern Observatory’s (ESO) Very Large Telescope Interferometer (VLTI). With a size roughly 2000 times that of our Sun, WOH G64 provides insights into the lifecycle of a star and how it goes out with a fascinating bang.

“We discovered an egg-shaped cocoon closely surrounding the star. We are excited because this may be related to the drastic ejection of material from the dying star before a supernova explosion,” Mr Ohnaka added.

Also Read | Milky Way Blasts Neighbouring Galaxy’s Mass Like A ‘Giant Hairdryer’, Hubble Finds

Years of research

Scientists have been interested in the red supergiant for nearly two decades. In 2005 and 2007, Mr Ohnaka and his team used ESO’s VLTI in Chile’s Atacama Desert to learn more about the star’s features and carried on studying it in the years since. However, an actual image of the star remained elusive. To click the first, detailed image, the team had to wait for the development of one of the VLTI’s second-generation instruments.

“Massive stars explode with an energy equivalent to the Sun shining for all of its 10 billion years of life. People have seen these supernova explosions, and astronomers have found some of the stars that exploded in older images. But we have never seen a star change in a way that signals its imminent death.”

The researchers believe that the gas and dust around the star, also known as shed material, might be responsible for the dimming and for the unexpected shape of the cocoon around the star. The new image shows that the cocoon is stretched out, which surprised scientists, who expected a different shape based on previous observations and computer models.

The team believes that the cocoon’s egg-like shape could be explained by either the star’s shedding or by the influence of a yet-undiscovered companion star.

Scientists have made a new finding that provides a fascinating insight into the future of our solar system. A new exoplanet, about 1.9 times the mass of Earth, has been discovered around a white dwarf star, according to ScienceAlert. This extraordinary discovery throws light on the possible fate of our own planet as the Sun finally turns into a white dwarf.

Despite the planet’s hostile conditions caused by the star’s destructive red giant phase, the discovery provides insights into planetary evolution. White dwarfs, which are leftovers of stars such as the Sun, arise following the red giant period. This study, led by Keming Zhang of the University of California, focusses on how planets might survive this chaotic period, expanding our understanding of planetary survival and evolution.

“The simplest explanation is that the planet survived through the red giant host star,” Zhang told ScienceAlert.

“The white dwarf lens was nearly perfectly aligned with the background source star during the event, causing it to be magnified by over 1,000 times,” Zhang explained.

“For these rare ultra-high magnification microlensing events, a companion as small as a terrestrial planet could significantly affect the magnification pattern, enabling us to accurately infer the lens configuration across a wide range of masses and orbital separations.”

This allowed the researchers to not just determine the mass and orbital separation of the Earth-like, or terrestrial, exoplanet, but the presence of a brown dwarf orbiting the white dwarf, too, an object about 30 times the mass of Jupiter.

This handout image obtained on May 30, 2024 courtesy of NASA/ESA/CSA STScI shows an infrared image from NASA’s James Webb Space Telescope. A galaxy, JADES-GS-z14-0 (shown in the pullout), was determined to be at a redshift of 14.32 (+0.08/-0.20), making it the current record-holder for the earliest known galaxy.
| Photo Credit: AFP

NASA’s James Webb Space Telescope has spotted the earliest-known galaxy, one that is surprisingly bright and big considering it formed during the universe’s infancy— at only 2% its current age.

Webb, which by peering across vast cosmic distances is looking way back in time, observed the galaxy as it existed about 290 million years after the Big Bang event that initiated the universe roughly 13.8 billion years ago, the researchers said. This period spanning the universe’s first few hundred million years is called cosmic dawn.

The telescope, also called JWST, has revolutionized the understanding of the early universe since becoming operational in 2022. The new discovery was made by the JWST Advanced Deep Extragalactic Survey (JADES) research team.

This galaxy, called JADES-GS-z14-0, measures about 1,700-light years across. A light year is the distance light travels in a year, 5.9 trillion miles (9.5 trillion km). It has a mass equivalent to 500 million stars the size of our sun and was rapidly forming new stars, about 20 every year.

Before Webb’s observations, scientists did not know galaxies could exist so early, and certainly not luminous ones like this.

“The early universe has surprise after surprise for us,” said astrophysicist Kevin Hainline of Steward Observatory at the University of Arizona, one of the leaders of the study published online this week ahead of formal peer review.

“I think everyone’s jaws dropped,” added astrophysicist and study co-author Francesco D’Eugenio of the Kavli Institute for Cosmology at the University of Cambridge. “Webb is showing that galaxies in the early universe were much more luminous than we had anticipated.”

Until now, the earliest-known galaxy dated to about 320 million years after the Big Bang, as announced by the JADES team last year.

“It makes sense to call the galaxy big, because it’s significantly larger than other galaxies that the JADES team has measured at these distances, and it’s going to be challenging to understand just how something this large could form in only a few hundred million years,” Mr. Hainline said.

“The fact that it’s so bright is also fascinating, given that galaxies tend to grow larger as the universe evolves, implying that it would potentially get significantly brighter in the next many hundred million years,” Mr. Hainline said.

While it is quite big for such an early galaxy, it is dwarfed by some present-day galaxies. Our Milky Way is about 100,000 light years across, with the mass equivalent to about 10 billion sun-sized star.

The JADES team in the same study disclosed the discovery of the second oldest-known galaxy, from about 303 million years post-Big Bang. That one, JADES-GS-z14-1, is smaller – with a mass equal to about 100 million sun-sized stars, measuring roughly 1,000 light years across and forming about two new stars per year.

“These galaxies formed in an environment that was much more dense and gas-rich than today. In addition, the chemical composition of the gas was very different, much closer to the pristine composition inherited from the Big Bang – hydrogen, helium and traces of lithium,” Mr. D’Eugenio said.

Star formation in the early universe was much more violent than today, with massive hot stars forming and dying quickly, and releasing tremendous amount of energy through ultraviolet light, stellar winds and supernova explosions, Mr. D’Eugenio said.

Three main hypotheses have been advanced to explain the luminosity of early galaxies. The first attributed it to supermassive black holes in these galaxies gobbling up material. That appears to have been ruled out by the new findings because the light observed is spread over an area wider than would be expected from black hole gluttony.

It remains to be seen whether the other hypotheses – that these galaxies are populated by more stars than expected or by stars that are brighter than those around today – will hold up, Mr. D’Eugenio said.

The Event Horizon Telescope (EHT) collaboration, who produced the first ever image of our Milky Way black hole released in 2022, has captured a new view of the massive object at the centre of our Galaxy: how it looks in polarised light. This is the first time astronomers have been able to measure polarisation, a signature of magnetic fields, this close to the edge of Sagittarius A*. This image shows the polarised view of the Milky Way black hole. The lines overlaid on this image mark the orientation of polarisation, which is related to the magnetic field around the shadow of the black hole.
| Photo Credit: Reuters

Astronomers on Wednesday announced that they have detected a strong and organised magnetic field twisted in a spiral pattern around the Milky Way’s supermassive black hole, revealing previously unknown qualities of the immensely powerful object lurking at the center of our galaxy.

The structure of the magnetic field emanating from the edge of the black hole called Sagittarius A*, or Sgr A*, closely resembles one surrounding the only other black hole ever imaged, a larger one residing at the center of a nearby galaxy called Messier 87, or M87, the researchers said. This indicates that strong magnetic fields may be a feature common to black holes, they added.

The magnetic field around the M87 black hole, called M87*, enables it to launch powerful jets of material into space, the researchers said. This indicates that while such jets have not been detected to date around Sgr A*, they might exist – and might be observable in the near future, they added.

The researchers released a new image showing the environment around Sgr A* in polarised light for the first time, revealing the magnetic field structure. The polarised light comes from subatomic particles called electrons gyrating around magnetic field lines.

Sgr A* possesses 4 million times the mass of our sun and is located about 26,000 light-years – the distance light travels in a year, 5.9 trillion miles (9.5 trillion km) – from Earth.

“For a while, we’ve believed that magnetic fields play a key role in how black holes feed and eject matter in powerful jets,” said astronomer Sara Issaoun of the Center for Astrophysics – Harvard & Smithsonian and co-leader of the research.

“This new image, along with a strikingly similar polarisation structure seen in the much larger and more powerful M87* black hole, shows that strong and ordered magnetic fields are critical to how black holes interact with the gas and matter around them,” Issaoun added.

Black holes are extraordinarily dense objects with gravity so strong that not even light can escape, making viewing them extremely challenging.

“The magnetic field appears to be organised into a spiral, similar to M87*. This magnetic field geometry implies that the black hole can power very efficient jets that shoot off into the galaxy,” said another of the researchers, Center for Astrophysics astronomer Angelo Ricarte.

The new image, like the previous images of Sgr A* and the M87 black hole, was obtained using the Event Horizon Telescope (EHT) international scientific collaboration’s global network of observatories working collectively to observe radio sources associated with black holes.

A black hole’s event horizon is the point of no return beyond which anything – stars, planets, gas, dust and all forms of electromagnetic radiation – gets dragged into oblivion.

“By imaging polarised light from hot glowing gas near black holes, we are directly inferring the structure and strength of the magnetic fields that thread the flow of gas and matter that the black hole feeds on and ejects,” Issaoun said.

“Compared to the previous results, polaried light teaches us a lot more about the astrophysics, the properties of the gas, and mechanisms that take place as a black hole feeds,” Issaoun added.

Light is an oscillating electromagnetic wave that lets objects be seen. Light sometimes oscillates in a specific orientation, and that is called polarised light.

The M87 black hole has a mass 6 billion times that of our sun and inhabits the center of a giant elliptical galaxy. It ejects a powerful jet of plasma – gas so hot that some or all its atoms are split into the subatomic particles electrons and ions – visible at all wavelengths.

The evidence for a jet flowing from Sgr A* is mounting, the researchers said.

“One thing we’re really excited about is the prediction for a powerful jet. As our instrumentation improves in the upcoming years, if it exists, we should be able to tease it out of the data,” Ricarte said.

The findings were published in the Astrophysical Journal Letters.