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Astronomers will be alerted to gravitational waves faster than ever before as LIGO and other detectors "listen" to a universal symphony.

Is GRB 191019A a typical burst of gamma rays from a dying star, an anomalously long burst from colliding objects, or something else entirely?

The post Is This Gamma-Ray Burst a Shredded Star in Disguise? appeared first on Sky & Telescope.

The new moon of May 2024 will see the bright constellations of summer begin to rise just as those of winter sink below the horizon.

An infinite number of random events can produce just about anything if you have quintillions of years to wait

The Sun is increasing its intensity on schedule, continuing its approach to solar maximum. In just over a 24-hour period on May 5 and May 6, 2024, the Sun released three X-class solar flares measuring at X1.3, X1.2, and X4.5. Solar flares can impact radio communications and electric power grids here on Earth, and they also pose a risk to spacecraft and astronauts in space.

NASA released an animation that shows the solar flares blasting off the surface of the rotating Sun, below.

NASA’s Solar Dynamics Observatory captured these images of the solar flares — as seen in the bright flashes in the upper right — on May 5 and May 6, 2024. The image shows a subset of extreme ultraviolet light that highlights the extremely hot material in flares and which is colorized in teal. Credit: NASA/SDO

Predicting when solar maximum will occur is not easy and the timing of it can only be confirmed after it happens. But NOAA’s Space Weather Prediction Center (SWPC) currently estimates that solar maximum will likely occur between May 2024 and early 2026. The Sun goes through a cycle of high and low activity approximately every 11 years, driven by the Sun’s magnetic field and indicated by the frequency and intensity of sunspots and other activity on the surface. The SWPC has been working hard to have a better handle on predicting solar cycles and activity. Find out more about that here.  

Solar flares are explosions on the Sun that release powerful bursts of energy and radiation coming from the magnetic energy associated with the sunspots. The more sunspots, the greater potential for flares.

Flares are classified based on a system similar to the Richter scale for earthquakes, which divides solar flares according to their strength. X-class is the most intense category of flares, while the smallest ones are A-class, followed by B, C, M and then X. Each letter represents a 10-fold increase in energy output. So an X is ten times an M and 100 times a C. The number that follows the letter provides more information about its strength. The higher the number, the stronger the flare.

Flares are our solar system’s largest explosive events. They are seen as bright areas on the Sun and can last from minutes to hours. We typically see a solar flare by the photons (or light) it releases, occurring in various wavelengths.

Sometimes, but not always, solar flares can be accompanied by a coronal mass ejection (CME), where giant clouds of particles from the Sun are hurled out into space.  If we’re lucky, these charged particles will provide a stunning show of auroras here on Earth while not impacting power grids or satellites.

Thankfully, missions like the Solar Dynamics Observatory, Solar Orbiter, the Parker Solar Probe are providing amazing views and new details about the Sun, helping astronomers to learn more about the dynamic ball of gas that powers our entire Solar System.

The post Solar Max is Coming. The Sun Just Released Three X-Class Flares appeared first on Universe Today.

The strategy for tracking bird flu in US dairy cattle falls worryingly short of what is needed to prevent the outbreak from widening and potentially spreading to humans

The strategy for tracking bird flu in US dairy cattle falls worryingly short of what is needed to prevent the outbreak from widening and potentially spreading to humans

The strategy for tracking bird flu in US dairy cattle falls worryingly short of what is needed to prevent the outbreak from widening and potentially spreading to humans

The strategy for tracking bird flu in US dairy cattle falls worryingly short of what is needed to prevent the outbreak from widening and potentially spreading to humans

Scientists fighting to save coral reefs amid the climate crisis suggest sending genetic coral material to be preserved on the moon. Is it a good idea?

Every now and then, tiny particles of antimatter strike Earth from cosmic parts unknown. A new balloon-borne experiment launching this spring may at last find their source

A new study provides some theoretical underpinning to sci-fi warp drives, suggesting that the superfast propulsion tech may not forever elude humanity.

WHO now admits the COVID virus and other germs spread “through the air.” This plain language may help improve research and action to fight disease

A study of mice starts to unravel how the brain gets tricked by a particular optical illusion

An implantable heart pump could help children with heart failure awaiting transplants forego bulky devices that require long hospital stays

An implantable heart pump could help children with heart failure awaiting transplants forego bulky devices that require long hospital stays

The historic first crewed launch of Boeing's new Starliner astronaut taxi has been pushed to no earlier than Friday (May 10), due to an issue with the vehicle's rocket ride.

Boeing will launch its first-ever Starliner astronaut mission for NASA as early as this evening (May 6).

An issue with ULA's Atlas V rocket scrubbed the historic 1st crewed launch attempt of Boeing's Starliner capsule on May 6. May 10 is the earliest possible launch date now.

Does another undetected planet languish in our Solar System’s distant reaches? Does it follow a distant orbit around the Sun in the murky realm of comets and other icy objects? For some researchers, the answer is “almost certainly.”

The case for Planet Nine (P9) goes back at least as far as 2016. In that year, astronomers Mike Brown and Konstantin Batygin published evidence pointing to its existence. Along with colleagues, they’ve published other work supporting P9 since then.

There’s lots of evidence for the existence of P9, but none of it has reached the threshold of definitive proof. The main evidence concerns the orbits of Extreme Trans-Neptunian Objects (ETNOs). They exhibit a peculiar clustering that indicates a massive object. P9 might be shepherding these objects along on their orbits.

This orbital diagram shows Planet Nine (lime green colour, labelled “P9”) and several extreme trans-Neptunian objects. Each background square is 100 AU across. Image Credit: By Tomruen – Own work, CC BY-SA 4.0, https://commons.wikimedia.org/w/index.php?curid=68955415

The names Brown and Batygin, both Caltech astronomers, come up often in regard to P9. Now, they’ve published another paper along with colleagues Alessandro Morbidelli and David Nesvorny, presenting more evidence supporting P9.

It’s titled “Generation of Low-Inclination, Neptune-Crossing TNOs by Planet Nine.” It’s published in The Astrophysical Journal Letters.

“The solar system’s distant reaches exhibit a wealth of anomalous dynamical structure, hinting at the presence of a yet-undetected, massive trans-Neptunian body—Planet Nine (P9),” the authors write. “Previous analyses have shown how orbital evolution induced by this object can explain the origins of a broad assortment of exotic orbits.”

To dig deeper into the issue, Batygin, Brown, Morbidelli, and Nesvorny examined Trans-Neptunian Objects (TNOs) with more conventional orbits. They carried out N-body simulations of these objects that included everything from the tug of giant planets and the Galactic Tide to passing stars.

29 objects in the Minor Planet Database have well-characterized orbits with a > 100 au, inclinations < 40°, and q (perihelia) < 30 au. Of those 29, 17 have well-quantified orbits. The researchers focused their simulations on these 17.

This figure from the research shows the 17 planets, their orbits, their perihelions, semi-major axes, and their inclinations. Image Credit: Batygin et al. 2024.

The researchers’ goal was to analyze these objects’ origins and determine if they could be used as a probe for P9. To accomplish this, they conducted two separate sets of simulations. One set with P9 in the Solar System and one set without.

The simulations began at t=300 million years, meaning 300 million years into the Solar System’s existence. At that time, “intrinsic dynamical evolution in the outer solar system is still in its infancy,” the authors explain, while enough time has passed for the Solar System’s birth cluster of stars to disperse and for the giant planets to have largely concluded their migrations. They ended up with about 2000 objects, or particles, in the simulation with perihelia greater than 30 au and semimajor axes between 100 and 5000 au. This ruled out all Neptune-crossing objects from the simulation’s starting conditions. “Importantly, this choice of initial conditions is inherently linked with the assumed orbit of P9,” they point out.

The figure below shows the evolution of some of the 2,000 objects in the simulations.

These panels show the evolution of selected particles within the calculations that attain nearly planar (i < 40°) Neptune-crossing orbits within the final 500 Myr of the integration. “Collectively, these examples indicate that P9-facilitated dynamics can naturally produce objects similar to those depicted in Figure 1” (the previous figure), the researchers explain. The top, middle, and bottom panels depict the time series of the semimajor axis, perihelion distance, and inclination, respectively. The rate of chaotic diffusion greatly increases when particles attain Neptune-crossing trajectories. Image Credit: Batygin et al. 2024.

These are interesting results, but the researchers point out that they in no way prove the existence of P9. These orbits could be generated by other things like the Galactic Tide. In their next step, they examined their perihelion distribution.

This figure from the research shows the perihelion distance for particles in a simulation with P9 (left) and without P9 (right.) The P9-free simulation shows a “rapid decline in perihelion distribution with decreasing q, as Neptune’s orbit forms a veritable dynamical barrier,” the researchers explain. Image Credit: Batygin et al. 2024.

“Accounting for observational biases, our results reveal that the orbital architecture of this group of objects aligns closely with the predictions of the P9-inclusive model,” the authors write. “In stark contrast, the P9-free scenario is statistically rejected at a ~5? confidence level.”

The authors point out that something other than P9 could be causing the orbital unruliness. The star was born in a cluster, and cluster dynamics could’ve set these objects on their unusual orbits before the cluster dispersed. A number of Earth-mass rogue planets could also be responsible, influencing the outer Solar System’s architecture for a few hundred million years before being removed somehow.

However, the authors chose their 17 TNOs for a reason. “Due to their low inclinations and perihelia, these objects experience rapid orbital chaos and have short dynamical lifetimes,” the authors write. That means that whatever is driving these objects into these orbits is ongoing and not a relic from the past.

An important result of this work is that it results in falsifiable predictions. And we may not have to wait long for the results to be tested. “Excitingly, the dynamics described here, along with all other lines of evidence for P9, will soon face a rigorous test with the operational commencement of the VRO (Vera Rubin Observatory),” the authors write.

A drone’s view of the Rubin Observatory under construction in 2023. The 8.4-meter is getting closer to completion and first light in 2025. The Observatory could provide answers to many outstanding issues, like the existence of Planet Nine. Image Credit: Rubin Observatory/NSF/AURA/A. Pizarro D

If P9 is real, what is it? It could be the core of a giant planet ejected during the Solar System’s early days. It could be a rogue planet that drifted through interstellar space until being caught up in our Solar System’s gravitational milieu. Or it could be a planet that formed on a distant orbit, and a passing star shepherded it into its eccentric orbit. If astronomers can confirm P9’s existence, the next question will be, ‘what is it?’

If you’re interested at all in how science operates, the case of P9 is very instructive. Eureka moments are few and far between in modern astronomy. Evidence mounts incrementally, accompanied by discussion and counterpoint. Objections are raised and inconsistencies pointed out, then methods are refined and thinking advances. What began as one over-arching question is broken down into smaller, more easily-answered ones.

But the big question dominates for now and likely will for a while longer: Is there a Planet Nine?

Stay tuned.

The post New Evidence for Our Solar System’s Ghost: Planet Nine appeared first on Universe Today.