Tag Archives: Celestial

Astronomers Discover Celestial ‘Wake’ Linked to Betelgeuse’s Companion Star

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Recent multi-year observations from the NASA/ESA Hubble Space Telescope, along with data from the Fred Lawrence Whipple and Roque de los Muchachos Observatories, have unveiled how a faint companion star, identified as Siwalha, has carved a path through the vast atmosphere of Betelgeuse. These findings illuminate long-standing mysteries regarding stellar evolution and advance our understanding of large-scale stellar dynamics.

Artist’s concept depicting the red supergiant star Betelgeuse alongside its orbiting companion. Image credit: NASA/ESA/Elizabeth Wheatley, STScI/Andrea Dupree, CfA.

Betelgeuse, an impressive 8-million-year-old red supergiant star, is prominently situated on the shoulder of the Orion constellation, approximately 724 light-years away from Earth.

With a radius roughly 1,400 times that of the Sun, Betelgeuse stands as one of the largest known stars in the universe.

Commonly referred to as Alpha Orionis or Alpha Ori, Betelgeuse is not just renowned for its size but also for its brightness, radiating more light than 100,000 suns combined.

As Betelgeuse nears the end of its life cycle, its impending explosion is expected to be so luminous that it will be visible in daylight for several weeks.

Astronomers have been meticulously monitoring variations in Betelgeuse’s brightness and surface characteristics for decades to uncover the underlying causes of its behavior.

Interest peaked in 2020 when Betelgeuse seemed to exhibit unusual “sneezing” behavior, suddenly dimming unexpectedly.

Two key periods of fluctuations have intrigued scientists: a short 400-day cycle, likely linked to the star’s own pulsations, and a longer 2,100-day period that remains more elusive.

Researchers have theorized various explanations for these fluctuations, including large convective cells, dust clouds, magnetic activities, and the possible presence of hidden companion stars.

A recent comprehensive study suggests that the longer secondary period is best explained by a low-mass companion star that orbits deep within Betelgeuse’s atmosphere. While some scientists reported possible detections, solid evidence was previously lacking—until now.

For the first time, astronomers have gathered compelling evidence that a companion star is indeed influencing the supergiant star’s atmosphere.

Data changes in the spectra of stars—colors of light emitted by different elements—and shifts in the gas’s speed and direction in the outer atmosphere confirm the presence of denser material and wake effects.

This peculiar signature appears soon after the companion star transits in front of Betelgeuse approximately every six years, further endorsing the theoretical model.

Dr. Andrea Dupree, an astronomer at Harvard University & Smithsonian Center for Astrophysics, commented, “It’s akin to a boat sailing through water; the companion star induces a ripple in Betelgeuse’s atmosphere that is directly observable in the data.”

“For the first time, we are witnessing definitive signs of this wake or gas signature, validating that Betelgeuse does indeed harbor a hidden companion that influences its observable characteristics and behavior.”

The team’s research paper will soon be published in the Astrophysical Journal.

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Andrea K. Dupree et al. 2026. Betelgeuse: Expanding trail of the companion star detected. APJ in press. arXiv: 2601.00470

Source: www.sci.news

Unlocking the Universe: Discovering RELHIC – A New Type of Celestial Object

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Astronomers utilizing the NASA/ESA Hubble Space Telescope have verified the presence of a starless, hydrogen-rich object primarily composed of dark matter. These intriguing entities, referred to as reionization-limited HI clouds (RELHICs), are remnants of the early Universe. They pose challenges to traditional theories of galaxy formation and may indicate undiscovered populations of similar cosmic structures.

This image illustrates the location of RELHIC object Cloud-9. Image credits: NASA / ESA / VLA / Gagandeep Anand, STScI / Alejandro Benitez-Llambay, University of Milan-Bicocca / Joseph DePasquale, STScI.

The RELHIC object, known as Cloud-9, was detected using the 500-meter Aperture Spherical Telescope (FAST) and its existence was independently verified by the Very Large Array (VLA) and the Green Bank Telescope (GBT).

“This is the narrative of a failed galaxy,” states astronomer Alejandro Benítez Lambay from the University of Milano-Bicocca.

“Scientific advancements often arise from failures rather than successes. In this case, the absence of stars confirms our theoretical framework,” he adds.

“This discovery reveals primordial components of galaxies yet to form within our local universe.”

The core of Cloud-9 consists of neutral hydrogen and spans approximately 4,900 light-years in diameter.

This object is positioned in proximity to the spiral galaxy Messier 94, shares its recession velocity, and is approximately 14.3 million light-years away from Earth.

“Cloud-9 represents a crucial glimpse into the enigmatic dark universe,” remarked Dr. Andrew Fox, an astronomer at ESA’s Association of Universities for Astronomical Research/Space Telescope Science Institute (AURA/STScI).

“Theoretical models suggest that a majority of the universe’s mass is composed of dark matter, which does not emit light, thus making it challenging to detect.”

“Cloud-9 offers a rare opportunity to study clouds dominated by dark matter.”

Astronomers employed Hubble’s Advanced Camera for Surveys (ACS) to search for bright stellar components within Cloud-9.

The findings discount the presence of dwarf galaxies with detectable stellar masses.

“The lack of observable stars reinforces the interpretation of this system as a RELHIC—a starless dark matter halo filled with hydrostatic gas in thermal equilibrium with the cosmic ultraviolet background,” stated the researchers.

Cloud-9 stands as a prime candidate for a compact HI cloud and offers robust empirical support for the ΛCDM (lambda cold dark matter) model, a leading cosmological framework.

This model predicts the existence of a starless dark matter halo filled with gas on subgalactic mass scales that have yet to form stars.

“The discovery of Cloud-9 also refines the current thresholds for halo mass required for galaxy formation, bringing us closer to understanding why some dark matter halos host galaxies while others remain barren,” concluded the researchers.

For detailed findings, look for the upcoming publication in the Astrophysics Journal Letter.

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Gagandeep S. Anand et al. 2025. The first RELHIC? Cloud-9 is a starless gas cloud. APJL 993, L55; doi: 10.3847/2041-8213/ae1584

Source: www.sci.news

Rediscovery of a Long-Lost Star: Astronomers Find Celestial Object Missing for Over 130 Years

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Telescope Capture at Grasslands Observatory

Credit: Tim Hunter et al. (2025)

A long-lost star, discovered by the legendary astronomer Edward Emerson Barnard in 1892, has been astonishingly rediscovered in its original location.

Barnard was not just any astronomer; he made significant contributions to the field, including the discovery of Jupiter’s fifth moon, Amalthea, in 1892—nearly three centuries after Galileo’s initial discoveries. Recently, his observations have gained renewed interest due to a puzzling article he published in 1906, titled “Unexplained Observations.”

On a particular morning, Barnard noted a star near Venus while using his telescope to search for its satellite. He estimated its brightness to be around 7th magnitude on the astronomical scale, where fainter objects bear higher numbers. Typically, under dark skies, stars of magnitude 6 are the faintest visible to the human eye.

Beneath the stars at the Bonner Cathedral, which cataloged all stars brighter than magnitude 9.5, Barnard’s 7th magnitude star was conspicuously absent. Instead, the only celestial body he found nearby was a significantly dimmer 11th magnitude star—about 100 times less bright.

Could it have been a large asteroid? “Ceres, Pallas, Juno, and Vesta were elsewhere,” he surmised. Some theorized that the 11th magnitude star he eventually observed in that region might have temporarily brightened. Other scientists speculated that Barnard could have been deceived by a “ghost” image of Venus through the telescope. The mystery lingered until late December 2024 when a dedicated group of astronomers sought to unravel it.

“In a weekly Zoom meeting dubbed ‘Asteroid Lunch,’ I brought it up,” says Tim Hunter.

Hunter, an Arizona-based amateur astronomer and co-founder of the International Dark Sky Association, along with both amateur and professional astronomers, evaluated all previous hypotheses and found flaws in them.

As doubts began to consume the group, Roger Ceragioli, an optical engineer from the University of Arizona, revisited the ghost theory by observing Venus at dawn using a vintage telescope similar to Barnard’s. Much to his surprise, although Venus was not positioned where Barnard had seen it, “the star emerged clearly in my field of view,” he noted. This led him to theorize that the star must be bright enough to be visible at dawn, even though the star map revealed it to be only 8th magnitude and therefore relatively faint.

The group’s conclusive findings suggested that Barnard’s purported 7th magnitude star was indeed the 11th magnitude star noted later—appearing brighter due to the dawn light. Using a 36-inch telescope at the Lick Observatory in California, Barnard first spotted this star alongside Venus, but no equally bright stars were visible in the area.

Understanding Star brightness measurement was a specialized skill in Barnard’s era. It had only been refined by astronomers focusing on variable stars, which Barnard had not formally studied. Thus, his mistake was rather excusable, as Ceragioli suggests.

Hunter affirms Barnard’s legacy remains intact, saying, “We’re all big fans of Barnard. It’s a minor error in an impressive career.”

 

Chile: The World Capital of Astronomy

Discover the astronomical wonders of Chile, home to the world’s most advanced observatory and unrivaled stargazing opportunities under some of the clearest skies on Earth.

Source: www.newscientist.com

The Solar Eclipse of 2025: A Guide to Witnessing This Year’s Celestial Phenomenon

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Skywatchers in the northeastern United States, eastern Canada, and parts of Europe are eagerly anticipating a rare astronomical event this spring. On the morning of Saturday, March 29th, 2025, a partial solar eclipse will grace the sky, coinciding with a spectacular “double sunrise.”

Here is all you need to know about the partial solar eclipse, including where to watch, what to expect, and how to safely observe it.

When is the Partial Solar Eclipse in 2025?

The first and only solar eclipse of 2025 will occur on March 29th, starting at 8:50am GMT (4:50am EDT) and ending at 12:43 PM GMT (8:43am EDT). The maximum solar eclipse will take place at 10:47 AM GMT (6:47AM EDT).

In the US, the solar eclipse will begin at 6:13 AM EDT and end at 7:17am EDT, with the exact times varying based on location. The most dramatic views and longest duration of the eclipse, with 85% of the sun obscured, will be experienced in some areas.

In England, the solar eclipse will begin in London at 9:56am GMT, reach its peak at 11:03 AM, and end at 12:00 PM GMT. The extent of the eclipse may vary slightly depending on location, with Scotland witnessing over 40% obscuration in cities like Glasgow.

Where to Watch the Partial Solar Eclipse?

This partial solar eclipse will be visible across a wide area of the Northern Hemisphere, including the Northeastern United States, Eastern Canada, most of Europe, and northwest Africa.

Fourteen US states, including Washington DC, will witness a partial solar eclipse, with Connecticut, Delaware, Maine, Maryland, Massachusetts, New Hampshire, New Jersey, New York, North Carolina, Pennsylvania, Rhode Island, Vermont, Virginia, and West Virginia among them.

The point of greatest obscuration will occur in Nunavique, Quebec, where 94% of the sun will be hidden at the peak of the solar eclipse.

Global map of partial solar eclipse shadow paths for March 29, 2025. A yellow curve tracks the extent of the partial eclipse and the proportion of each of these curves, giving the maximum area of the moon-covered sun during the eclipse. -NASA’s Scientific Visualization Studio

What is a Partial Solar Eclipse?

A partial solar eclipse occurs when the moon passes between the Earth and the Sun but does not fully block the Sun. Instead, it covers only a portion of the solar disk, creating the appearance of the moon taking a bite out of the sun.

This results in a deep but incomplete solar eclipse, with the sun taking on a crescent shape. Unlike a total solar eclipse, where the sky goes completely dark, daylight remains during a partial solar eclipse, albeit with a dim and eerie quality.

What is a Double Sunrise?

“Double Sunrise” is a rare and stunning visual effect that can occur when a solar eclipse coincides with the rising sun.

From parts of eastern Canada and northeastern United States, the sun may appear as a crescent on the horizon during a partial solar eclipse. The tip of the crescent moon, often called the “devil’s horn,” may also be visible, giving the illusion of two separate sunrises.

Maine and parts of Quebec, Canada, offer the best chance to witness this phenomenon.

After the double sunrise, the sun will continue to rise as a thin arc in the sky.

How to Safely Watch a Partial Solar Eclipse

Unlike a total solar eclipse, partial solar eclipses should never be viewed directly with the naked eye, even when most of the sun is covered. Even small slivers of the sun can cause permanent eye damage.

If possible, obtain eclipse glasses that are certified to ISO 12312-2 international safety standards.

Crowds gather around Bryant Park in New York City, wearing eclipse glasses to witness a partial solar eclipse on April 8, 2024.

If using binoculars, cameras, or telescopes, ensure they are equipped with a solar filter on the front end (not the eyepiece).

If you are unable to find glasses or filters, indirect viewing methods are still possible. By creating a small hole (1-2mm) in a card, you can project sunlight onto a flat surface to observe the solar eclipse safely.

Weather plays a significant role in eclipse visibility. A clear sky offers the best viewing conditions, but even in cloudy weather, you may still experience a dimming effect as the moon passes in front of the sun.

How to Watch the Solar Eclipse 2025 Online

If you are unable to witness the partial solar eclipse in person, don’t worry. You can watch it online. The Royal Observatory Greenwich in the UK will be live streaming the event starting at 10am GMT.

https://www.youtube.com/watch?v=nwol-q1fuvm

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Source: www.sciencefocus.com

Exploring Celestial Events: Tonight’s Comet in March 2024

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In March 2024, early risers should be able to view comet C/2021 S3 (PanSTARRS) through binoculars as it approaches Earth.

Comets, often referred to as “dirty snowballs,” are icy objects that travel through space, leaving behind a trail of dust and gas as they approach the Sun.

C/2021 S3 was discovered in September 2021 by one of the PanSTARS telescopes on Mount Haleakala (Hawaii) and is predicted to reach a magnitude between 7 and 9 (the lower the magnitude, the more powerful the comet is). (looks bright).

You can’t see it with the naked eye, but you should be able to spot it with a decent pair of binoculars. However, predicting a comet’s final brightness is somewhat difficult. Comets are difficult to handle and prefer to act independently.

But don’t worry, Comet C/2021 S3 poses no danger to Earth and will pass us safely.

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When can we see Comet Panstars tonight?

A comet is approaching Earth on March 14, 2024. It reached perihelion, the closest point to the Sun in its orbit, on Wednesday, February 14, 2024, when it became visible from the United States and the United Kingdom.

During the second half of the month, around March 18th to March 29th, the Moon begins to interfere as it approaches the full moon on March 25th. Starting on the opposite side of the sky, the moon gradually approaches the comet towards the end of the month.

In late March, especially if you want to spot the comet passing through the Coat Hanger star map (more on how to find the Coat Hanger below), look up around 3 a.m. GMT. Basically, as soon as the comet is above the horizon. As dawn approaches, an interfering moon will spoil the progress.

How to see a comet

Comet C/2021 S3 is heading northeast, passing roughly between the large constellation of Ophiuchus above and the small constellations Scutum and Aquila below. Ophiuchus and Aquila both straddle the celestial equator, while Scutum lies just south of it.

Until about March 18, look to the southeast early in the morning as the sky begins to lighten. By this point, the comet is visible above the horizon and the Moon appears relatively out of the way.

The best time to see the views is around 3am in late March. Also, at this time, Comet C/2021 S3 will pass over the Coathanger Cluster, a small star group. And yes, it’s exactly like the name! Here’s how to find it:

  1. Find the Summer Triangle. Let’s start by identifying the Summer Triangle. This is an easily recognizable asterism, formed by the bright stars Deneb in Cygnus, Vega in Lyra, and Altair in Aquila.
  2. Find the constellation Little Vulgar. Once you find the Summer Triangle, look for the constellation Little Bitis. It is located between Cygnus and Sagittarius and is shaped like an extended M. It can be found by drawing an imaginary line north from the star Altair in the Summer Triangle.
  3. Move to coat hanger. Once you find Vulpecula, look for the Coathanger Asterism. This is very distinctive and looks like a coat hanger or an upside down question mark. The Coathanger is an asterism within Vulpecula and is easy to find once you enter the right area.

If you’re star hopping and having trouble finding the star on your coat hanger, downloading a stargazing app can help. Here are all the best astronomy apps.

Here’s what you can do to help astronomers discover more Comet

astronomer from University of Reading is seeking photos of comet C/2021 S3 As part of a citizen science project to study the solar wind.

Photos from amateur astronomers help researchers improve space weather predictions and influence solar wind technology.

Comet tails, also known as “cosmic windsocks,” can tell us a lot about the strength and direction of the solar wind. For example, if the tail peels off or wobbles, you can infer that there is increased activity.

Please send images, including date, time and location, to researcher Sarah Watson at srwatson@pgr.reading.ac.uk. The research team is particularly interested in observing the broken tail.

The comet is not expected to be bright enough to be seen with the naked eye, so if you want to photograph it you’ll need a small telescope or a camera with a large lens.

Why do comets get brighter when they get closer to the sun?

Comets become more active as they get closer to the sun. Intense heat from the sun and solar radiation can evaporate ice cores and suddenly release dust and gas. This process forms a glowing coma (a cloud of gas and dust) around the nucleus and a bright tail that reflects sunlight.

This tail can span millions of kilometers and is influenced by a combination of different processes. For example, the solar wind, which is made up of charged particles, can interact with these gases to produce ion tails that point away from the sun.

In addition, the sun’s radiation pressure develops and displaces the dust particles. This can lead to the formation of a separate dust tail, which often lags behind the ion tail. A combination of sublimation (the transformation of solid ice directly into gas), ionization, and radiation pressure all affect the appearance of comet tails as they orbit the Sun.

And the closer the comet is to the Sun, the more intense this activity becomes, and the brighter it appears in the night sky.

the current, 3,922 known comets (and its fragments) of our solar system.

But it can also get dark…

However, this is not always the case. When a comet runs out of volatile matter, it may lose its ability to produce a bright coma and tail. Therefore, comets appear darker as they get closer to the Sun. In addition, comets can develop a crust that makes it completely impossible for material to escape.

Scientists hypothesize that comet C/2021 S3 may already have a mineral crust forming on its surface. If this were the case, the comet’s albedo (reflectance) would be much lower because the crust would protect its volatile-rich interior from the sun. In other words, it won’t be as bright as other comets this year. But if the underlying material continues to evaporate and creates enough pressure to break through the Earth’s crust, a flare can occur. That would be fun.

When is the next comet?

Comet C/2021 S3 is one of the few bright comets we’re watching this year. Next up is Comet 12P/Pons-Brooks, also known as the “Devil’s Comet” thanks to its distinctive “horns” that began to widen towards the end of 2023.

It can be easily seen with a telescope or binoculars, and will begin to brighten towards the end of March 2024, so it could be the first comet of 2024 to be visible to the naked eye.

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Source: www.sciencefocus.com