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

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An Explanation for Rogue Planets. They Were Eroded Down by Hot Stars

Universe Today - Fri, 11/08/2024 - 11:06am

The dividing line between stars and planets is that stars have enough mass to fuse hydrogen into helium to produce their own light, while planets aren’t massive enough to produce core fusion. It’s generally a good way to divide them, except for brown dwarfs. These are bodies with a mass of about 15–80 Jupiters, so they are large enough to fuse deuterium but can’t generate helium. Another way to distinguish planets and stars is how they form. Stars form by the gravitational collapse of gas and dust within a molecular cloud, which allows them to gather mass on a short cosmic timescale. Planets, on the other hand, form by the gradual accumulation of gas and dust within the accretion disk of a young star. But again, that line becomes fuzzy for brown dwarfs.

The problem arises in that, if brown dwarfs form within a molecular cloud like stars, they aren’t massive enough to form quickly. If a cloud of gas and dust has enough mass to collapse under its own weight, it has enough mass to form a full star. But if brown dwarfs form like planets, they would have to accumulate mass incredibly quickly. Simulations of planet formation show it is difficult for a planet to form with a mass of more than a few Jupiters. So what gives? The answer may lie in what are known as Jupiter-mass binary objects, or JuMBOs.

The Orion nebula is a stellar nursery. Credit: NASA, ESA, M. Robberto

JuMBOs are binary objects where each component has a mass between 0.7 and 13 Jupiter masses. If they form like planets, they should be extremely rare, and if they form like binary stars, they should have more mass. Recent observations by the JWST of the Orion nebula cluster discovered 540 free-floating Jupiter mass objects, so-called rogue planets. This was surprising in and of itself, but more surprising was the fact that 42 of them were JuMBOs. Far from being rare, they make up nearly 8% of these rogue objects. So how do they form?

One clue lies in their orbital separation. The components of JuMBOs are most commonly separated by a distance of 28–384 AU. This is similar to that of binary stars with components around the mass of the Sun, which typically are in a range of 50–300 AU. Binary stars are extremely common. More common than single stars like the Sun. The environment of stellar nurseries, such as the Orion nebula, is also extremely intense. Massive stars that form first can blast nearby regions with ionizing radiation. Given how common JuMBOs are, it is likely they began as binary stars, only to have much of their masses blasted away by photo-erosion. Rather than being binary planets, they are the failed remnants of binary stars.

This could also explain why so many rogue planets have super-Jupiter masses. The same intense light that would cause photo-erosion would also tend to push them out of star systems.

Reference: Diamond, Jessica L., and Richard J. Parker. “Formation of Jupiter-Mass Binary Objects through photoerosion of fragmenting cores.” The Astrophysical Journal 975.2 (2024): 204.

The post An Explanation for Rogue Planets. They Were Eroded Down by Hot Stars appeared first on Universe Today.

Categories: Astronomy

Chimps do better at difficult tasks when they have an audience

New Scientist Space - Space Headlines - Fri, 11/08/2024 - 11:00am
An analysis of thousands of cognitive tests carried out by chimpanzees finds that the number of spectators influenced their performance in different ways depending on the difficulty of the task
Categories: Astronomy

Chimps do better at difficult tasks when they have an audience

New Scientist Space - Cosmology - Fri, 11/08/2024 - 11:00am
An analysis of thousands of cognitive tests carried out by chimpanzees finds that the number of spectators influenced their performance in different ways depending on the difficulty of the task
Categories: Astronomy

Watch elephants use a hose to shower themselves – and prank others

New Scientist Space - Space Headlines - Fri, 11/08/2024 - 11:00am
Asian elephants at Berlin Zoo show impressive skill when using a hose as a tool, and even appear to sabotage each other by stopping the flow of water
Categories: Astronomy

Watch elephants use a hose to shower themselves – and prank others

New Scientist Space - Cosmology - Fri, 11/08/2024 - 11:00am
Asian elephants at Berlin Zoo show impressive skill when using a hose as a tool, and even appear to sabotage each other by stopping the flow of water
Categories: Astronomy

On ancient Mars, carbon dioxide ice kept the water running. Here's how

Space.com - Fri, 11/08/2024 - 11:00am
Huge shells of frozen carbon dioxide at Mars' south polar cap resulted in subsurface meltwater, which fed a huge system of rivers, lakes and even a sea, a new study suggests.
Categories: Astronomy

Quantum Rubik's cube has infinite patterns but is still solvable

New Scientist Space - Space Headlines - Fri, 11/08/2024 - 10:30am
Allowing for moves that create quantum superpositions makes a quantum version of a Rubik’s cube incredibly complex, but not impossible to solve
Categories: Astronomy

Quantum Rubik's cube has infinite patterns but is still solvable

New Scientist Space - Cosmology - Fri, 11/08/2024 - 10:30am
Allowing for moves that create quantum superpositions makes a quantum version of a Rubik’s cube incredibly complex, but not impossible to solve
Categories: Astronomy

Why does our universe have something instead of nothing?

New Scientist Space - Space Headlines - Fri, 11/08/2024 - 10:00am
In order to figure out how something came from nothing, we first need to explore the different types of nothing
Categories: Astronomy

Why does our universe have something instead of nothing?

New Scientist Space - Cosmology - Fri, 11/08/2024 - 10:00am
In order to figure out how something came from nothing, we first need to explore the different types of nothing
Categories: Astronomy

'Alien: Romulus' bursts onto Hulu for streaming on Nov. 21

Space.com - Fri, 11/08/2024 - 10:00am
The latest entry in the xenomorph franchise chestbursts its way onto Hulu on Nov. 21 when 'Alien: Romulus' finally gets its streaming premiere.
Categories: Astronomy

CODEX Coronagraph Heads to the ISS on Cargo Dragon

Universe Today - Fri, 11/08/2024 - 10:00am

A new space-based telescope aims to address a key solar mystery.

A new experiment will explore a region of the Sun that’s tough to see from the surface of the Earth. The solar corona—the elusive, pearly white region of the solar atmosphere seen briefly during a total solar eclipse—is generally swamped out by the dazzling Sun. Now, the Coronal Diagnostic Experiment (CODEX) will use a coronagraph to create an ‘artificial eclipse’ in order to explore the poorly understood middle corona region of the solar atmosphere.

CODEX launched as part of the cargo manifest on SpaceX’s Cargo Dragon this week, on mission CRS-31. CRS-31 arrived at the ISS and docked at the Harmony forward port of the station on November 5th.

CODEX is a partnership between NASA’s Goddard Spaceflight Center, Italy’s National Institute for Astrophysics (INAE) and KASI (Korea Astronomy and Space Science Institute). Technical expertise for the project was provided by the U.S. Naval Research Laboratory (NRL).

CODEX will be mounted on the EXPRESS (Expedite the Processing of Experiments to the Space Station) Logistics Carrier Site 3 (ELC-3) on the ISS.

An animation of CODEX on the ISS. NASA Why Use Coronagraphs

Coronagraphs work by blocking out the Sun with an occulting disk. The disk used in CODEX is about as wide as an orange. Though coronagraphs can work on Earth, placing them in space is an easy way to eliminate unwanted light due to atmospheric scattering.

The solar corona, as imaged by the High Altitude Observatory’s coronagraph. UCAR/NCAR.

Targeting the middle region of the corona is crucial, as it’s thought to be the source of the solar wind. But what heats this region to temperatures actually hotter than the surface below? This rise is in the order of a million degrees, versus 6000 degrees Celsius for the solar photosphere. The same unknown process accelerates particles to tremendous speeds of over a million kilometers an hour.

CODEX seeks to address this dilemma, and will measure Doppler shifts in charged particles at four filtered wavelengths. The instrument will need to center and track the Sun from its perch on the exterior of the ISS. To this end, this must occur while speeding around the Earth once every 90 minutes. CODEX will be able to see the Sun roughly half of the time, though seasons near either solstice will allow for near-continuous views.

CODEX will work with NASA’s Parker Solar Probe and ESA’s Solar Orbiter (SolO) in studying this coronal heating dilemma. In addition, it will also join the Solar Heliospheric (SOHO’s) LASCO C2 and C3 coronagraph in space. Another new coronagraph instrument in space is the National Oceanic Atmospheric Administration’s CCOR-1 (Compact Coronagraph) aboard the GOES-19 satellite in geosynchronous orbit.

A Solar Wind Riddle

“CODEX measures the plasma’s temperature, speed and density around the whole corona between 3 and 10 solar radii, and will measure how those parameters evolve in time, providing new constraints on all theories of coronal heating,” Niicholeen Viall (GFSC-Solar Physics Laboratory) told Universe Today. “Parker Solar Probe measures these plasma parameters in the upper corona (getting as close as 10 solar radii) in great detail, but it makes those measurements in situ (from one one location in space and time) and only briefly that close to the Sun.”

The CODEX team with the instrument, ahead of launch. Credit: CODEX/NASA.

The goal of CODEX is to provide a holistic view of solar wind activity. “In contrast, CODEX provides a global view and context of these plasma parameters and their evolution,” says Viall. “Additionally, CODEX extends the measurements much closer to the Sun than Parker Solar Probe (PSP), linking the detailed measurements made at PSP at 10 solar radii through the middle corona, down to ~3 solar radii, closer to their source. This is important because most of the coronal heating has already taken place by 10 solar radii, where PSP measures.”

A Dual Mystery

Two theories vie to explain the solar heating mystery. A first says that tangled magnetic fields are converted into thermal power. These are in turn fed into the corona as bursts of energy. Another says that oscillations known as Alfvén waves inject energy in a sort of feedback loop in the lower corona.

“Solar Orbiter has (an) EUV (Extreme ultraviolet) and white light imager that could be used to connect the CODEX measurements to their sources on the Sun,” says Viall.

Understanding this region and the source of the solar wind is crucial to predicting space weather. This is especially vital when the Sun sends powerful corona mass ejections our way. Not only can these spark low latitude aurorae, but these can also impact communications and pose a hazard to satellites and astronauts in space.

“CODEX is similar to all coronagraphs, in that they block light out from the photosphere to see the much fainter corona.” Says Viall. CODEX’s field of view has overlap with, but is different than SOHO’s coronagraphs and CCOR. The largest difference though, is that CODEX has special filters that can provide the temperature and speed of the solar wind, in addition to the density measurements that white light coronagraphs always make.”

The Past (and Future) of Coronagraphs in Space

Furthermore, there’s also a history of coronagraphs aboard space stations. This goes all the way back to the white-light coronagraph aboard Skylab in the early 1970s.

Looking to the future, more coronagraphs are headed space-ward. ESA’s solar-observing Proba-3 launches at the end of November. Proba-3 will feature the first free-flying occulting disk as part of the mission. PUNCH (the Polarimeter to UNify the Corona and Heliosphere) will feature four micro-sat orbiters. The mission will rideshare launch with NASA’s SPHEREx mission early next year.

“PUNCH is a white light coronagraph and set of heliospheric imagers that together image from six solar radii out through the inner heliosphere.” Says Viall. PUNCH will be able to watch the structures that CODEX identifies as they as they evolve and are modulated father out in the heliosphere.”

Fianlly, astronomers can also use coronagraph-style instruments to image exoplanets directly. The Nancy Grace Roman Space telescope (set to launch in 2027) will feature one such instrument.

It will be exciting to see CODEX in action, as it probes the mysteries of the solar wind.

The post CODEX Coronagraph Heads to the ISS on Cargo Dragon appeared first on Universe Today.

Categories: Astronomy

Let African Communities Manage Their Climate Adaptation Plans

Scientific American.com - Fri, 11/08/2024 - 10:00am

Outside groups often offer their solutions for climate adaptation in Africa. But the best people to manage the climate crisis are the people in those communities themselves. For climate adaptation to succeed in Africa, let communities and local leaders show the way

Categories: Astronomy

Beaverlab Finder TW2 AI-enhanced telescope review

Space.com - Fri, 11/08/2024 - 10:00am
Beaverlab claims that this inexpensive AI-powered telescope will let you capture the cosmos in stunning 4K — we put it to the test.
Categories: Astronomy

Week in images: 04-08 November 2024

ESO Top News - Fri, 11/08/2024 - 9:10am

Week in images: 04-08 November 2024

Discover our week through the lens

Categories: Astronomy

3D map reveals our solar system's local bubble has an 'escape tunnel'

Space.com - Fri, 11/08/2024 - 8:00am
A 3D map of our cosmic neighborhood has revealed hot and cold regions as well as an "escape tunnel" from our local bubble.
Categories: Astronomy

Happy Martian New Year!

Scientific American.com - Fri, 11/08/2024 - 6:45am

The Martian new year arrives with the Red Planet’s vernal equinox. Explaining why requires a deep dive into celestial mechanics and Earth’s calendrical history

Categories: Astronomy

Saturn and the moon put on a celestial show Sunday night. Here's how to see it

Space.com - Fri, 11/08/2024 - 6:00am
Saturn gets close to the moon tonight, and some skywatchers in Florida, Central America and South America will see the ringed planet briefly disappear behind our lunar companion.
Categories: Astronomy

Consciousness Might Hide in Our Brain’s Electric Fields

Scientific American.com - Fri, 11/08/2024 - 6:00am

A mysterious electromagnetic mechanism may be more important than the firing of neurons in our brains to explain our awareness

Categories: Astronomy

Is Weight Really the Problem?

Scientific American.com - Fri, 11/08/2024 - 6:00am

Focusing on size in health care might be doing more harm than good.

Categories: Astronomy