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Hubble and Gaia Telescopes Uncover Ancient Galactic Collision That Transformed the Milky Way

Hubble and Gaia Telescopes Uncover Ancient Galactic Collision That Transformed the Milky Way

New data from the NASA/ESA Hubble Space Telescope, combined with measurements from ESA's Gaia mission, has provided definitive evidence of an ancient collision between the young Milky Way galaxy and a dwarf galaxy named LKH (Low-energy–Kraken–Heracles) approximately 11.8 billion years ago. This event, occurring just 2 billion years after the Big Bang, predates previously identified major mergers in the Milky Way's history, such as the collision with the Gaia–Sausage–Enceladus (GSE) galaxy 10 billion years ago. Researchers identified a third population of globular clusters within the Milky Way that are neither native to our galaxy nor from the GSE merger. By precisely measuring the age and metal content of these clusters, scientists determined they originated from LKH, a dwarf galaxy with a total mass of about 500 million times the mass of our sun, which was a significant fraction of the Milky Way's mass at that early stage.

Astronomers Observe Dead Star's Material Recycling into Galaxy, Predicting Sun's Future

Astronomers Observe Dead Star's Material Recycling into Galaxy, Predicting Sun's Future

Astronomers have for the first time observed a dead star, specifically the Helix Nebula, being recycled back into the interstellar gas from which it originated. This observation, led by Yale University's Pieter van Dokkum, provides a complete picture of a star's life cycle. Stars, after millions or billions of years, eventually exhaust their fuel. Sun-like stars, at their end, transform into planetary nebulae, like the Helix Nebula located 650 light-years away in the constellation of Aquarius. The Helix Nebula's central star ran out of hydrogen for nuclear fusion, causing its core to contract and its outer layers to expand into a red giant before detaching to form the nebula. The inert core became a white dwarf. As the nebula expands, its material disperses into the interstellar medium (ISM), enriching gas clouds that will eventually form new stars. This process, where stellar debris transitions into diffuse gas, has been challenging to observe until now. The discovery was made during the calibration of a ...

JWST Detects Water and Dust Near Milky Way's Supermassive Black Hole

JWST Detects Water and Dust Near Milky Way's Supermassive Black Hole

The James Webb Space Telescope (JWST) has detected water, dust, and other oxygen-based chemical products in the vicinity of the Milky Way's supermassive black hole, Sagittarius A*. This discovery was made by observing a dying star named IRS 3, an asymptotic giant branch (AGB) star, located just 0.55 light-years from the galactic center. IRS 3 is in a late stage of its life, shedding its outer layers into space at high speeds, creating an immense dusty envelope. Astronomers, led by Florian Peißker, an astrophysicist at the University of Cologne, utilized JWST's Mid-Infrared Instrument (MIRI) to collect a continuous mid-infrared spectrum from IRS 3. This allowed them to identify silicate dust and the star's chemical composition, demonstrating that stars can continue to enrich their surroundings with molecular material even in extreme environments dominated by intense radiation.

Star Near Milky Way's Black Hole Losing Mass at Astonishing Rate, Reveals JWST

Star Near Milky Way's Black Hole Losing Mass at Astonishing Rate, Reveals JWST

New observations from the James Webb Space Telescope (JWST) indicate that IRS 3, a mature star located near the Milky Way's supermassive black hole, Sagittarius A* (Sgr A*), is undergoing an exceptionally rapid phase of mass loss. This star is shedding vast amounts of gas and dust into space, causing its surrounding envelope to continuously expand. Researchers, led by PD Dr. Florian Peißker of the University of Cologne’s Institute for Astrophysics, utilized JWST’s Mid-Infrared Instrument (MIRI) to study IRS 3, which is approximately 0.6 light-years from Sgr A*. The findings, published in the journal Astronomy & Astrophysics, suggest that IRS 3 is experiencing a 'superwind,' a period of extreme mass loss near the end of a massive star's life. The star is estimated to be losing material equivalent to Earth's mass every 18 days, contributing to the unusual size and density of its envelope. Surprisingly, water molecules were detected within this harsh environment, challenging previous assumptions about molecul...

UWM Astronomer David Kaplan Identifies 'Rosetta Stone' in Space, Deciphering Long-Period Radio Transients

UWM Astronomer David Kaplan Identifies 'Rosetta Stone' in Space, Deciphering Long-Period Radio Transients

Scientists, including Professor David Kaplan from the University of Wisconsin-Milwaukee (UWM), have identified the source of mysterious 'long-period radio transients' as a white dwarf star accreting material from a neighboring star. These transients, characterized by short bursts of radio waves at distinct intervals, had previously puzzled astronomers. Kaplan co-authored a paper published in 'Nature Astronomy' detailing this discovery. The research focused on a specific transient located approximately 3,000 light-years away in the Milky Way Galaxy. This breakthrough provides a crucial understanding of these celestial phenomena, which were previously distinguished from known objects like quasars and pulsars but remained unexplained.

This astronaut set to make history during next spacewalk outside ISS

This astronaut set to make history during next spacewalk outside ISS

The ESA's Sophie Adenot will become the first French woman to conduct a spacewalk during the next excursion outside the International Space Station.

The Milky Way devoured a smaller galaxy about 11.8 billion years ago

The Milky Way devoured a smaller galaxy about 11.8 billion years ago

By Will Dunham WASHINGTON, Aug 18 (Reuters) - The Milky Way, a large and spiral-shaped galaxy that is home to hundreds of billions of stars including our sun, has taken a long and complicated path to achieve its current dimensions, as illustrated by new research documenting a milestone event early

Mimas's Subsurface Ocean Discovered to be Younger Than the Himalayas, Challenging Ocean World Assumptions

Mimas's Subsurface Ocean Discovered to be Younger Than the Himalayas, Challenging Ocean World Assumptions

In 2024, an international team of scientists reported the discovery of a global ocean beneath the surface of Mimas, one of Saturn's moons. This finding was unexpected because Mimas's surface appears old, heavily cratered, and shows no obvious signs of geological activity, unlike other ocean worlds like Enceladus or Europa. The evidence for the ocean came from analyzing tiny details of Mimas's rotational wobble and the precession of its periapsis, using data from NASA's Cassini mission. These movements could only be reconciled by the presence of a liquid layer beneath 20 to 30 kilometers of ice. Crucially, the ocean is estimated to have formed less than 25 million years ago, making it younger than the Himalayas. This youth may explain why Mimas's ancient-looking exterior has not yet betrayed the significant changes occurring beneath its surface.

James Webb Space Telescope Identifies 'Black Hole Star' MoM-BH-1, Challenging Early Universe Formation Theories

James Webb Space Telescope Identifies 'Black Hole Star' MoM-BH-1, Challenging Early Universe Formation Theories

Astronomers utilizing the James Webb Space Telescope (JWST) have identified a unique celestial object, MoM-BH-1, which they've dubbed a 'black hole star.' This object, observed from approximately 660 million years after the Big Bang, appears as an unusually bright red dot. Led by astronomer Rohan P. Naidu, the research, published in Nature, suggests MoM-BH-1 is a black hole encased within an extraordinarily dense, turbulent envelope of hydrogen gas, roughly the size of our solar system. This configuration allows the black hole to generate energy at a scale 100 billion times greater than a typical star, mimicking stellar features despite its non-fusion energy source. The discovery was made during the 'Mirage or Miracle' (MoM) survey, which aimed to study luminous galaxies from the early universe. MoM-BH-1's distinct spectral characteristics, particularly a strong Balmer break and hydrogen features, led researchers to model it as an actively feeding black hole surrounded by a vast gas cocoon, rather than a c...

NASA's Pioneer Network Gave Scientists Multiple Views of Solar Activity

NASA's Pioneer Network Gave Scientists Multiple Views of Solar Activity

The Pioneer 6, 7, 8, and 9 space probes, part of NASA's broader Pioneer program, represented a significant leap in humanity's ability to understand...

NASA Extends Voyager 2 Mission Life Through Innovative Power Management

NASA Extends Voyager 2 Mission Life Through Innovative Power Management

NASA engineers at the Jet Propulsion Laboratory have successfully implemented a power-saving strategy, nicknamed the 'Big Bang,' to extend the operational life of the Voyager 2 spacecraft. Launched nearly 50 years ago, Voyager 2 relies on radioisotope thermoelectric generators, which convert heat from decaying plutonium into electricity. As the plutonium decays, the available power steadily declines by about 4 watts annually. To counteract this, the team simultaneously shut down certain powered devices and replaced them with alternatives requiring less electricity, while ensuring the spacecraft remained warm enough to function. This intervention is expected to allow Voyager 2's three remaining science instruments to continue operating for at least one additional year, preventing the need to shut down another instrument before the end of 2026.

Unusual Black Hole at Universe's Dawn Presents Dusty Mystery to Astronomers

Unusual Black Hole at Universe's Dawn Presents Dusty Mystery to Astronomers

Astronomers, using the James Webb Space Telescope (JWST), have discovered an unusual object from the early universe, approximately 660 million years after the Big Bang. This object, one of the 'little red dots' (LRDs) observed by JWST, is believed to be a rapidly growing supermassive black hole surrounded by an enormous and dense cloud of hydrogen gas. The light from this object, which has traveled over 13 billion years to reach Earth, exhibits a colossal 'Balmer break' in its spectrum, indicating the presence of a large and turbulent quantity of hydrogen gas. This finding challenges the previous assumption that the red color of LRDs was primarily due to dust. Instead, the team's model suggests that the color is explained by this massive gas cocoon, which is estimated to have around 100 billion particles per cubic centimeter and extends millions of kilometers around the black hole. The research, published in Nature, proposes that this dense gas environment allows the black hole to grow much faster than con...