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Astronomers have assembled the largest-ever compilation of high-precision galaxy distances, called Cosmicflows-4. Galaxies, such as the Milky Way, are the building blocks of the universe, each comprised of up to several hundred billion stars. Galaxies beyond our immediate neighborhood are rushing away, faster if they are more distant, which is a consequence of the expansion of the universe that began at the moment of the Big Bang. Measurements of the distances of galaxies, coupled with information about their velocities away from us, determine the scale of the universe and the time that has elapsed since its birth.

“Since galaxies were identified as separate from the Milky Way a hundred years ago, astronomers have been trying to measure their distances,” said Brent Tully, astronomer at the University of Hawaii at Manoa. “Now by combining our more accurate and abundant tools, we are able to measure distances of galaxies, and the related expansion rate of the universe and the time since the universe was born with a precision of a few per cent.”

From the newly published measurements, the researchers derived the expansion rate of the universe, called the Hubble Constant, or H0. The team’s study gives a value of H0=75 kilometers per second per megaparsec or Mpc (1 megaparsec = 3.26 million light years), with very small statistical uncertainty of about 1.5 percent.

There are a number of ways to measure galaxy distances. Generally, individual researchers focus on an individual method. The Cosmicflows program spearheaded by Tully and Kourkchiincludes their own original material from two methods, and additionally incorporates information from many previous studies. Because Cosmicflows-4 includes distances derived from a variety of independent, distinct distance estimators, intercomparisons should mitigate against a large systematic error.

Astronomers have assembled a framework that shows the universe’s age to be a little more than 13 billion years old, however, a dilemma of great significance has arisen in the details.

Physics of the evolution of the universe based on the standard model of cosmology predicts H0=67.5 km/s/Mpc, with an uncertainty of 1 km/s/Mpc. The difference between the measured and predicted values for the Hubble Constant is 7.5 km/s/Mpc – much more than can be expected given the statistical uncertainties. Either there is a fundamental problem with our understanding of the physics of the cosmos, or there is a hidden systematic error in the measurements of galaxy distances.

Cosmicflows-4 is also being used to study how galaxies move individually, in addition to flowing with the overall expansion of the universe. Deviations from this smooth expansion arise due to the gravitational influences of clumps of matter, on scales ranging from our Earth and Sun up to congregations of galaxies on scales of a half billion light years. The mysterious dark matter is the dominant component on larger scales. With knowledge of the motions of galaxies in response to the mass around them, we can recreate the orbits that galaxies have followed since they were formed, giving us a better understanding of how the universe’s vast, dark-matter-dominated structures have formed over the eons of time.

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Super Earths are Quite Common Outside the Solar System, New Study Reveals

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April 26, 2025

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Super Earths are Quite Common Outside the Solar System, New Study Reveals

A team of international astronomers, led by Weicheng Zang from the Centre for Astrophysics | Harvard & Smithsonian (Cfa), had announced the discovery of a planet whose size is twice that of Earth, and orbits around its star at a distance farther out than Saturn. These findings reveal how planets differ from our existing solar system. The discovery was first published in the Journal Science on April 25, 2025. Scientists fetched this data from the Korea Microlensing Telescope Network (KMTNet), also known as the largest microlensing survey to date.

This Super Earth, called a planet due to its size being bigger than Earth but smaller than Neptune, is more significant as it is a large study where the masses of many planets have been measured relative to the stars that they orbit. As per physics.org, the team of researchers found fresh information about the number of planets that surround the Milky Way.

Study by KMTNet

According to the study conducted using Korean Microlensing data in which light from faraway objects is amplified through the use of an interfering body, called a planet. This technique is very effective for finding planets at a far distance, between Earth and Saturn’s orbit.

This study is considered to be large for its kind because there are about three times more planets, including planets that are eight times smaller than the previous planets found with the help of microlensing. Shude Mao, a professor, said that the current data gives a hint of how cold planets are formed. With the help of KMTNet data, we can know how these planets were formed and evolved. KMTNet has three telescopes in South Africa, Chile and Australia.

Understanding the Exoplanets

Such studies show that the other systems can have a small, medium and large variety of planets in Earth’s orbit. CFA-led research suggests that there can be more Super Earth Planets in other solar systems’ outer regions. Jennifer Yee says that there is a possibility that outside the Earth’s trajectory, other galaxies may have more such planets that are bigger than Earth’s size yet smaller than Neptune.

Findings and Implications

Youn Kii Jung, who operates KMTNet, says that in Jupiter-like orbits, the other planetary systems may not be similar to ours. Scientists will try to determine how many such planets exist. A study indicates that there are at least as many super-Earths as there are Neptune-sized planets in the universe.

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Magnetic Fields Could Significantly Influence Oscillations in Merging Neutron Stars, Study Finds

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April 26, 2025

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Magnetic Fields Could Significantly Influence Oscillations in Merging Neutron Stars, Study Finds

Magnetic fields may significantly complicate how scientists interpret gravitational wave signals from neutron star mergers, a new study has revealed. These collisions, where two super-dense stellar remnants merge, have long offered astrophysicists a way to probe matter under extreme pressure. The results from the University of Illinois Urbana-Champaign and the University of Valencia reveal that robust magnetic fields form more complex and lengthy patterns in gravitational waves, thereby making it harder to decipher the inner workings of neutron stars. Results could doom post-merger signal interpretation strategies and the equation of states of dense matter as scientists prepare to observe the next generation of gravitational wave observatories.

Magnetic Fields Found to Distort Frequency Signals in Neutron Star Mergers

As per the study published in Physical Review Letters, the researchers simulated general relativistic magnetohydrodynamics — how the strength and arrangement of magnetic fields affect the frequency signals from the remnants left behind after a merger. They went represent real-world conditions by applying two different equations of state (EoS) for neutron stars, different magnetic field configurations, and several mass combinations.

According to lead researcher Antonios Tsokaros, the magnetic field can cause frequency shifts that can misidentify scientists into misattributing them as indications of other physical phenomena like phase transitions or quark-hadron crossover.

The discoveries also imply that scientists need to be cautious about how they interpret signals from neutron-star mergers, lest they slip into assuming how they form. They found that strong magnetic fields can change the emitted signals’ typical oscillation frequency, shifting them from what they should be and from what was predicted by one or another of the competing equations of state at play within these ferocious events.

They also discovered that in the most straightforward type of galaxy mergers they considered in their simulations, the magnetic field became overly amplified so that a greater proportion of the remnants of the merger are more likely to produce further gravitational wave emissions.

Magnetic Fields Hold Key to Unlocking Secrets of Neutron Star Mergers

Neutron stars are what remains of massive stars that have collapsed, and they contain matter so dense that a full teaspoon would weigh billions of tonnes. They have thermodynamic properties that are determined by the EoS and magnetic fields, some orders of magnitude stronger than those that one can produce in a human laboratory.

These extreme features also make neutron stars useful for probing the laws of physics under intense pressure and magnetism. Ever since it was detected in both gravitational waves and gamma rays in 2017, the scientific community has been buzzing about research on neutron star mergers, leading to ever-growing numbers of studies related to these types of mergers.

Professor Milton Ruiz also warns that it would be a mistake to misinterpret observations in the future without considering the effects of the magnetic fields. Higher-resolution simulations are needed, the researchers said, to refine our understanding of how magnetic fields shape cosmic happenings, and endeavours like the Einstein Telescope and Cosmic Explorer loom on the horizon.

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Hubble Captures Mars, Cosmic Nebulae, and Distant Galaxies in Spectacular 35th Anniversary Photos



Landline Now Available for Streaming on Amazon Prime Video: What You Need to Know

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Hubble Captures Mars, Cosmic Nebulae, and Distant Galaxies in Spectacular 35th Anniversary Photos

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April 26, 2025

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Hubble Captures Mars, Cosmic Nebulae, and Distant Galaxies in Spectacular 35th Anniversary Photos

The Hubble Space Telescope is celebrating 35 years in orbit with an amazing batch of new images, including everything from seasonal changes on Mars to a moth-shaped planetary nebula and a distant spiral galaxy. Hubble was deployed from the space shuttle Discovery on April 24, 1990, and has delivered unparalleled cosmic views from low Earth orbit. Its history as a tool for science and exploration has led to nearly 1.7 million observations, more than 22,000 peer-reviewed scientific papers, and about 400 terabytes of archival data. This data has continued to provide generations with glimpses of stunning views of distant and often dynamic universes.

Hubble Reveals Mars and a Celestial Moth in Dazzling 35th Anniversary Image Collection

According to a celebratory statement, officials at the European Space Agency (ESA), which jointly runs Hubble with NASA, lauded the observatory as a way to link the past and future knowledge of the cosmos. As per ESA, the updated slate was announced to celebrate the 35th year of the telescope, during which the instrument has proven it can uncover unseen beauty and detail in the cosmos. “No generation before Hubble ever saw such vibrant and far-reaching images,” ESA officials mentioned in the official blog post.

Among the newly unveiled images is a stunning pair of ultraviolet portraits of Mars taken in December 2023, when the Red Planet was about 60 million miles from Earth. The left image reveals the Tharsis volcanic plateau and Olympus Mons rising through thin water-ice clouds, while the right side captures the “shark fin” shape of Syrtis Major and high-altitude evening clouds, coinciding with spring’s arrival in Mars’s northern hemisphere.

Another image shows a haunting view of NGC 2899, a planetary nebula about 4,500 light-years away in the constellation Vela. Sculpted by a dying star and possibly two stellar companions, the nebula glows with hydrogen and oxygen. Its gaseous tendrils appear to point back toward a pair of white stars at the core, illuminating the violent winds and radiation shaping this celestial moth.

Hubble Captures Star Birth in Rosette Nebula and Distant Spiral Galaxy NGC 5335

In a close-up of the Rosette Nebula — a stellar nursery 5,200 light-years away — dark clouds of gas and dust are seen being carved by radiation from massive stars. A young star at the upper right is actively creating and ejecting jets of plasma, which glow bright red due to shock waves from their collision with surrounding gases.

The image shows a continuing process of star birth in a region spanning four light years, part of a much larger 100-light-year expanse. Hubble also snapped NGC 5335, a barred spiral galaxy found 225 million light-years away in the constellation of Virgo. This flocculent galaxy lacks clear spiral arms, instead featuring patchy bursts of star formation scattered across its disk.

A central bar channels gas inward, supporting new star formation in a galactic dance that astronomers say will continue for billions of years before reshaping again.

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