All's not as it appears, this tale has many twists -
but if I wasn't here documenting the story
would that mean that the plot did not exist?

— Peter Hammill

Astronomy

Explosive, green 'devil comet' has hidden spiral swirling around its icy heart, photo trickery reveals

Space.com - Tue, 03/26/2024 - 1:00pm
New, specially edited photos show a previously unseen swirl of light surrounding the city-size comet 12P/Pons-Brooks, which is currently racing toward the sun and will later zoom past Earth.
Categories: Astronomy

How a Rare Islamic Astrolabe Helped Muslims, Jews and Christians Tell Time and Read Horoscopes

Scientific American.com - Tue, 03/26/2024 - 12:30pm

A rare Islamic astrolabe discovered in Verona, Italy, reveals how the instrument passed through different countries and cultures

Categories: Astronomy

Flavour-predicting AI can tell brewers how to make beer taste better

New Scientist Space - Space Headlines - Tue, 03/26/2024 - 12:00pm
An AI model trained on chemical and perceptual data on 250 Belgian beers can predict the flavour profile of a brew – and how to make it tastier
Categories: Astronomy

Flavour-predicting AI can tell brewers how to make beer taste better

New Scientist Space - Cosmology - Tue, 03/26/2024 - 12:00pm
An AI model trained on chemical and perceptual data on 250 Belgian beers can predict the flavour profile of a brew – and how to make it tastier
Categories: Astronomy

Marvel at stunning echo of 800-year-old explosion

ESO Top News - Tue, 03/26/2024 - 12:00pm
Image:

In the year 1181 a rare supernova explosion appeared in the night sky, staying visible for 185 consecutive days. Historical records show that the supernova looked like a temporary ‘star’ in the constellation Cassiopeia shining as bright as Saturn.

Ever since, scientists have tried to find the supernova’s remnant. At first it was thought that this could be the nebula around the pulsar (dead star) 3C 58. However closer investigations revealed that the pulsar is older than supernova 1181.

In the last decade, another contender was discovered; Pa 30 is a nearly circular nebula with a central star in the constellation Cassiopeia. It is pictured here combining images from several telescopes. This composite image uses data across the electromagnetic spectrum and shows a new spectacular view of the supernova remnant. Allowing us to marvel at the same object that appeared in our ancestors’ night sky more than 800 years ago.

X-ray observations by ESA’s XMM-Newton (blue) show the full extent of the nebula and NASA’s Chandra X-ray Observatory (cyan) pinpoints its central source. The nebula is barely visible in optical light but shines bright in infrared light, collected by NASA’s Wide-field Infrared Space Explorer (red and pink). Interestingly, the radial structure in the image consists of heated sulphur that glows in visible light, observed with the ground-based Hiltner 2.4 m telescope at the MDM Observatory (green) in Arizona, USA, as do the stars in the background by Pan-STARRS (white) in Hawaii, USA.

Studies of the composition of the different parts of the remnant have led scientists to believe that it was formed in a thermonuclear explosion, and more precisely a special kind of supernova called a sub-luminous Type Iax event. During this event two white dwarf stars merged, and typically no remnant is expected for this kind of explosion. But incomplete explosions can leave a kind of ‘zombie’ star, such as the massive white dwarf star in this system. This very hot star, one of the hottest stars in the Milky Way (about 200 000 degrees Celsius), has a fast stellar wind with speeds up to 16 000 km/h. The combination of the star and the nebula makes it a unique opportunity for studying such rare explosions.

[Image description: A composite image of the remnant of supernova 1181. A spherical bright nebula sits in the middle surrounded by a field of white dotted stars. Within the nebula several rays point out like fireworks from a central star.]

Categories: Astronomy

The physicist searching for quantum gravity in gravitational rainbows

New Scientist Space - Space Headlines - Tue, 03/26/2024 - 12:00pm
Claudia de Rham thinks that gravitons, hypothetical particles thought to carry gravity, have mass. If she’s right, we can expect to see “rainbows” in ripples in space-time
Categories: Astronomy

The physicist searching for quantum gravity in gravitational rainbows

New Scientist Space - Cosmology - Tue, 03/26/2024 - 12:00pm
Claudia de Rham thinks that gravitons, hypothetical particles thought to carry gravity, have mass. If she’s right, we can expect to see “rainbows” in ripples in space-time
Categories: Astronomy

Netflix's 'The Signal' is a lyrical sci-fi miniseries with clever twists and turns (review)

Space.com - Tue, 03/26/2024 - 12:00pm
A review of Netflix's newest sci-fi miniseries from Germany, "The Signal."
Categories: Astronomy

Ariane 6 launches: YPSat ‘the witness’

ESO Top News - Tue, 03/26/2024 - 11:50am
Categories: Astronomy

AI forecaster can predict the future better than humans

New Scientist Space - Space Headlines - Tue, 03/26/2024 - 11:00am
An AI forecaster based on the language model GPT-4 can predict the outcome of future events more accurately than single humans. In some cases, it can even outperform the “wisdom of crowds”
Categories: Astronomy

AI forecaster can predict the future better than humans

New Scientist Space - Cosmology - Tue, 03/26/2024 - 11:00am
An AI forecaster based on the language model GPT-4 can predict the outcome of future events more accurately than single humans. In some cases, it can even outperform the “wisdom of crowds”
Categories: Astronomy

SpaceX Crew-7 astronauts share the good and bad of spending 6 months in space

Space.com - Tue, 03/26/2024 - 11:00am
NASA astronaut Jasmin Moghbeli, European Space Agency astronaut Andreas Mogensen and Japan Aerospace Exploration Agency astronaut Satoshi Furukawa spoke about their six months on the space station.
Categories: Astronomy

Merging Stars Can Lead to Blue Supergiants

Universe Today - Tue, 03/26/2024 - 10:56am

In the constellation of Orion, there is a brilliant bluish-white star. It marks the right foot of the starry hunter. It’s known as Rigel, and it is the most famous example of a blue supergiant star. Blue supergiants are more than 10,000 times brighter than the Sun, with masses 16 – 40 times greater. They are unstable and short-lived, so they should be rare in the galaxy. While they are rare, blue supergiants aren’t as rare as we would expect. A new study may have figured out why.

We aren’t entirely sure how these massive stars form, though one idea is that they occur when a massive main sequence star passes through an interstellar cloud. By capturing gas and dust from the cloud, a star can shift off the main sequence to become a blue supergiant. Another idea is that they may form within stellar nurseries with a mass as great as 300 Suns. As a result, they quickly burn so brightly that they never become true main-sequence stars. Both of these models predict that blue supergiants are much more rare than the number we observe.

This new study starts by noting that blue supergiants, particularly the smaller ones known as B-type supergiants, are rarely seen with companion stars. This is odd since most massive stars form as part of a binary or multiple system. The authors propose that B-type blue supergiants aren’t often in binary systems because they typically are the product of binary mergers.

The team simulated a range of models where a giant main-sequence star has a smaller close-orbiting companion and then looked at what would result if the two stars merged. They then compared the results to observations of 59 young blue supergiant stars in the Large Magellanic Cloud. They found that not only can these mergers produce blue supergiants in the mass range of the Magellanic stars, but the spectra of the simulated mergers match the spectra of the 59 blue supergiants. This strongly suggests that many if not most B-type blue supergiants are the result of stellar mergers.

In the future, the team would like to carry this work further to see how blue supergiants evolve into neutron stars and black holes. This could help explain the type of mergers observed by gravitational wave observatories such as LIGO and Virgo.

Reference: Menon, Athira, et al. “Evidence for Evolved Stellar Binary Mergers in Observed B-type Blue Supergiants.” The Astrophysical Journal Letters 963.2 (2024): L42.

The post Merging Stars Can Lead to Blue Supergiants appeared first on Universe Today.

Categories: Astronomy

How to Talk to Kids about Cancer

Scientific American.com - Tue, 03/26/2024 - 10:30am

A social worker explains ways that parents can gently share news about their cancer diagnosis with their children

Categories: Astronomy

Gaia Finds Ancient Streams of Stars That Formed the Milky Way

Universe Today - Tue, 03/26/2024 - 10:19am

Using ESA’s Gaia spacecraft, astronomers have tracked down two streams of stars that likely formed the foundation of the Milky Way. Named “Shakti and Shiva,” the two streams contain about 10 million stars, all of which are 12 to 13 billion years old and likely came together even before the spiral arms and disk were formed. These star streams are all moving in roughly similar orbits and have similar compositions. Astronomers think they were probably separate galaxies that merged into the Milky Way shortly after the Big Bang.,

“What’s truly amazing is that we can detect these ancient structures at all,” said lead author Khyati Malhan of the Max Planck Institute for Astronomy (MPIA) in Heidelberg, Germany, in an ESA press release. “The Milky Way has changed so significantly since these stars were born that we wouldn’t expect to recognize them so clearly as a group – but the unprecedented data we’re getting from Gaia made it possible.”

Astrometry Data

Gaia uses astrometry — the precise measurements of the positions and movements of stars and other celestial bodies – and is building the largest, most precise three-dimensional map of our Galaxy by surveying nearly two billion objects.

With Gaia’s data, the researchers were able to determine the orbits of individual stars in the Milky Way, as well as determine their content and composition. These ancient stars are all moving in very similar orbits and the structure of the two different star streams stood out because their stars contained a certain chemical composition.

“Shakti and Shiva populations possess an unconventional combination of orbital and abundance properties that have not been observed previously,” the researchers wrote in their paper, published in the Astrophysical journal. 

By compiling very detailed chemical abundance patterns for each, the astronomers determined these stars were the oldest stars in the galaxy, all born before the disc of the Milky Way had formed.

The components of the Milky Way Galaxy. This artist’s impression shows our roughly 13 billon-year-old ‘barred spiral galaxy’ that is home to a few hundred billion stars. Credit: Left: NASA/JPL-Caltech; right: ESA; layout: ESA/ATG medialab.

“The stars there are so ancient that they lack many of the heavier metal elements created later in the Universe’s lifetime,” said co-author Hans-Walter Rix, also of MPIA and the lead ‘galactic archaeologist’ in this research, which began in 2022. “These heavy metals are those forged within stars and scattered through space when they die. The stars in our galaxy’s heart are metal-poor, so we dubbed this region the Milky Way’s ‘poor old heart’. Until now, we had only recognized these very early fragments that came together to form the Milky Way’s ancient heart. With Shakti and Shiva, we now see the first pieces that seem comparably old but located further out. These signify the first steps of our galaxy’s growth towards its present size.”

While the two streams are similar, they aren’t exactly the same. Shakti stars orbit a little further from the Milky Way’s center and in more circular orbits than Shiva stars. The streams are named two divine beings from Hindu philosophy who worked together to create the Universe.

Because of Gaia’s ability to provide data to create incredibly detailed celestial maps, the researchers were able to build a dynamical map of that includes the two star streams plus other known components that have played a role in our galaxy’s formation.

“Revealing more about our galaxy’s infancy is one of Gaia’s goals, and it’s certainly achieving it,” said Timo Prusti, Project Scientist for Gaia at ESA. “We need to pinpoint the subtle yet crucial differences between stars in the Milky Way to understand how our galaxy formed and evolved. This requires incredibly precise data – and now, thanks to Gaia, we have that data. As we discover surprise parts of our galaxy like the Shiva and Shakti streams, we’re filling the gaps and painting a fuller picture of not only our current home, but our earliest cosmic history.”

Further reading:
ESA press release
Paper: Shiva and Shakti: Presumed Proto-Galactic Fragments in the Inner Milky Way

The post Gaia Finds Ancient Streams of Stars That Formed the Milky Way appeared first on Universe Today.

Categories: Astronomy

Partial: The Solar Eclipse for the Rest of Us

Sky & Telescope Magazine - Tue, 03/26/2024 - 10:17am

Whether the Sun will become a dented ball or an eerie crescent of fire, a celestial shadow show awaits you anywhere in North and Central America.

The post Partial: The Solar Eclipse for the Rest of Us appeared first on Sky & Telescope.

Categories: Astronomy

Rethinking the Milky Way’s “Galactic Fountain”

Sky & Telescope Magazine - Tue, 03/26/2024 - 10:00am

The Milky Way recycles gas from dying stars to make new ones — but new observations show pristine gas also comes in from outside our galaxy.

The post Rethinking the Milky Way’s “Galactic Fountain” appeared first on Sky & Telescope.

Categories: Astronomy

How long will April's total solar eclipse last?

Space.com - Tue, 03/26/2024 - 10:00am
The duration of April's total solar eclipse will depend on where you are watching it from along the path of totality. Here we explain why.
Categories: Astronomy

Heat pumps: How to speed up the switch to low-carbon home heating

New Scientist Space - Space Headlines - Tue, 03/26/2024 - 10:00am
The rollout of heat pumps and other green heating technologies is going far too slowly in the UK – here’s what’s needed to get it moving
Categories: Astronomy

Heat pumps: How to speed up the switch to low-carbon home heating

New Scientist Space - Cosmology - Tue, 03/26/2024 - 10:00am
The rollout of heat pumps and other green heating technologies is going far too slowly in the UK – here’s what’s needed to get it moving
Categories: Astronomy