Universe Today

November 21, 2024November 21, 2024 by Evan Gough

The First Close-Up Picture of Star Outside the Milky Way

WOH G64 is a massive red supergiant star in the Large Magellanic Cloud. Thanks to the ESO's Very Large Telescope Interferometer, this is the first close-up picture of a star in another galaxy. Image Credit: ESO/K. Ohnaka et al.

Like a performer preparing for their big finale, a distant star is shedding its outer layers and preparing to explode as a supernova.

Astronomers have been observing the huge star, named WOH G64, since its discovery in the 1970s. It’s one of the largest known stars, and also one of the most luminous and massive red supergiants (RSGs). The star is surrounded by an envelope of expelled star-stuff, which could indicate it’s getting ready to explode.

November 21, 2024November 21, 2024 by Mark Thompson

Here’s What We Know About Earth’s Temporary Mini-Moon

For a little over a month now, the Earth has been joined by a new ‘mini-moon.’ The object is an asteroid that has been temporarily accompanying Earth on its journey around the Sun. By 25th November it will have departed but before then, astronomers across the world have been turning their telescopes to study it. A new paper of 2024 PT5 reveals its basaltic nature – similar to volcanic rocks on Earth – with a composition that makes it similar to lunar material. There have been many close encounters to Earth allowing many of its secrets to be unveiled.

November 21, 2024November 21, 2024 by Matt Williams

New Study Suggests Black Holes Get their “Hair” from their Mothers

This artist’s impression of a supermassive black hole and accretion disk, along with a relativistic jet emanating from its poles. Credit & ©: ESO/L. Calçada

Despite decades of study, black holes are still one of the most puzzling objects in the Universe. As we know from Einstein’s Theory of General Relativity, the gravitational force of these stellar remnants alters the curvature of spacetime around them. This causes gas, dust, and even photons (light) in their vicinity to fall inwards and form disks that slowly accrete onto their faces, never to be seen again. However, astronomers have also noted that they can produce powerful jets that accelerate charged particles to close to the speed of light (aka. relativistic jets).

These jets lead to powerful gamma-ray bursts (GRBs), which have been observed with black holes that have powerful magnetic fields. However, where these magnetic fields come from has remained a mystery to astrophysicists for some time. According to new research led by scientists from the Flatiron Institute, the source of these fields may have finally been revealed. Based on a series of simulations they conducted that modeled the life cycle of stars from birth to collapse, they found that black holes inherit their magnetic fields from the parent stars themselves.

November 21, 2024November 21, 2024 by Evan Gough

Gaze at New Pictures of the Sun from Solar Orbiter

The Solar Orbiter has captured the highest resolution images of the Sun ever during a recent close encounter. The detail is extraordinary. Image Credit: ESA - European Space Agency

74 million kilometres is a huge distance from which to observe something. But 74 million km isn’t such a big deal when the object is the Sun.

That’s how far away from the Sun the ESA/NASA Solar Orbiter was when it captured these new images.

November 21, 2024November 21, 2024 by Brian Koberlein

Are Fast Radio Bursts Caused by Interstellar Objects Crashing Into Neutron Stars?

This magnetar is a highly magnetized neutron star. This artist's illustration shows an outburst from a magnetar. Neutron stars that spin rapidly and give out radiation are called pulsars, and specific pulsars are rare in the core of the Milky Way. Credit: NASA/JPL-CalTech

Every now and then, astronomers will detect an odd kind of radio signal. So powerful it can outshine a galaxy, but lasting only milliseconds. They are known as fast radio bursts (FRBs). When they were first discovered a couple of decades ago, we had no idea what might cause them. We weren’t even sure if they were astronomical in origin. FRB’s were so localized and so short-lived, it was difficult to gather data on them. But with wide-field radio telescopes such as CHIME we can now observe FRBs regularly and have a pretty good idea of their source: magnetars.

November 21, 2024November 14, 2024 by Paul M. Sutter

Here’s How to Weigh Gigantic Filaments of Dark Matter

Artist concept of how a galaxy might accrete mass from rapid, narrow streams of cold gas. These filaments provide the galaxy with continuous flows of raw material to feed its star-forming at a rather leisurely pace. Credit: ESA–AOES Medialab

How do you weigh one of the largest objects in the entire universe? Very carefully, according to new research.

November 20, 2024November 20, 2024 by Mark Thompson

How Could Astronauts Call for Help from the Moon?

Exploring the Moon poses significant risks, with its extreme environment and hazardous terrain presenting numerous challenges. In the event of a major accident, assistance might take days or even weeks to arrive. To address this, Australian researchers have created a distress alert system based upon the COSPAS-SARSAT technology used for Earth-based search and rescue operations. It relies on low-power emergency beacons that astronauts could activate with minimal setup and use a planned lunar satellite network for communication and rescue coordination.

November 20, 2024November 20, 2024 by Mark Thompson

There Was a 15 Minute Warning Before Tonga Volcano Exploded

Infrared satellite image (10.4 ?m) taken by Himawari-8 for the last reported event on January 14

Volcanoes are not restricted to the land, there are many undersea versions. One such undersea volcano known as Hunga Tonga-Hunga Ha’apai off the coast of Tonga. On 15th January 2022, it underwent an eruption which was one of the most powerful in recent memory. A recent paper shows that seismic waves were released 15 minutes before the eruption and before any visible disruption at the surface. The waves had been detected by a seismic station 750km away. This is the first time a precursor signal has been detected.

November 20, 2024November 20, 2024 by Evan Gough

Main Sequence and White Dwarf Binaries are Hiding in Plain Sight

This ALMA image shows the binary HD101584. The pair of stars share a common envelope, and are surrounded by complex clouds of gas. Image Credit: By ALMA, CC BY 4.0, https://commons.wikimedia.org/w/index.php?curid=86644758

Some binary stars are unusual. They contain a main sequence star like our Sun, while the other is a “dead” white dwarf star that left fusion behind and emanates only residual heat. When the main sequence star ages into a red giant, the two stars share a common envelope.

This common envelope phase is a big mystery in astrophysics, and to understand what’s happening, astronomers are building a catalogue of main sequence-white dwarf binaries.

November 20, 2024November 20, 2024 by Evan Gough

What a Misplaced Meteorite Told Us About Mars

The Lafayette Meteorite was chipped off the surface of Mars and then sped through space for roughly 11 million years. It eventually found its way into a drawer at Purdue University in 1931 and has since been teaching scientists about Mars. (Photo provided by Purdue Brand Studio.)

11 million years ago, Mars was a frigid, dry, dead world, just like it is now. Something slammed into the unfortunate planet, sending debris into space. A piece of that debris made it to Earth, found its way into a drawer at Purdue University, and then was subsequently forgotten about.

Until 1931, when scientists studied and realized it came directly from Mars. What has it told them about the red planet?