Betel-gurz or Beetle-juice has been a favourite among amateur astronomers for many years. However you pronounce it, its unexpected dimming draw even more attention to this red supergiant variable star in Orion. It has a few cycles of variability, one of them occurs over a 2,170 day period, 5 times longer than its normal pulsation period. A paper has just been published that suggests a companion star of 1.17 solar masses could be the cause. It would need an orbit about 2.43 times the radius of Betelgeuse and it might just lead to the modulation of dust in the region that causes the variations we see.
One of the brightest stars in the sky, Betelgeuse is a red supergiant found situated prominently at the upper left of the constellation Orion. It represents the shoulder of the hunter although some translations suggest it refers to ‘the armpit of the giant!’ It’s one of the largest stars visible to the unaided eye with a radius about 1,000 times the Sun. At a distance of 642 light years away, its brightness in our sky tells us it must be giving out about 100,000 times more light than the Sun. Over the last five years it’s been getting special attention due to its unexpected dimming.
Ground-based image of the Constellation of Orion. The Hubble Space Telescope continues to reveal various stunning and intricate treasures that reside within the nearby, intense star-forming region known as the Great Nebula in Orion.The dimming occurred toward the end of 2019 and the returned to normal in the first half of 2020. It’s generally accepted that the dimming was caused by a dust cloud in the event that has now been dubbed ‘The Great Dimming.’ The observations of the dimming led to a change in our understanding of the behaviour of Betelgeuse and its surrounding environment such as the apparent 5km/s surface rotation, models of the nature of its variability and pulsation models (the periodic expansion and contraction of the star’s outer layers.)
As a well known variable star, the light curve of Betelgeuse displays a Long Secondary Period (LSP) of approximately 2100 days. It’s not unusual for stars in the Red Giant Branch of the Hertzsprung-Russell Diagram and can range from a few hundred days to thousands. To date though, the mechanism behind the LSP is unknown but it certainly does seem to be a secondary cycle to a shorter one. Interestingly the duration of the LSP seems to be generally in the region of a few tens of times slower than the stars radial pulsation.
It’s the nature of this longer term variability in Betelgeuse that is the focus of a new paper published by Jared A. Goldberg and his team. A greater understanding will lead to a greater clarity of Betelgeuse’s evolutionary stage and ultimately to its death. One solution points to it simply being the result of the pulsation of the outer layers. If this were the case then it means Betelgeuse is larger than expected and would be further along its evolution branch and that a supernova explosion may be imminent within the next few hundred years! An exciting prospect for the stargazers among us.
Simulation of Betelgeuse’s boiling surfaceInterestingly though, the team conclude that the most likely explanation for the long term variability of Betelgeuse is a low mass companion star, named ? Ori B (Betelgeuse bares the alternative name ? Orionis.) It is possible that this binary star could be modulating the dust surrounding the system and when the companion is in transit, the dust leads to a reduction in brightness. If ? Ori B were to be confirmed, it would have a significant impact on our evolutionary understanding of Betelgeuse. It is expected to go supernova soon but this is largely because observed variations led to the conclusion it was close. Instead, ? Ori B being the cause means we may have some time to wait after all.
Source : A Buddy for Betelgeuse: Binary as the Origin of the Long Secondary Period in Alpha Orionis
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Are we ready for the next potential pandemic? It seems like we are just get over COVID and already we have to worry about the next one. We first covered the monkey pox (now mpox) in 2022. Since then it has continued to be a concern. Where do our efforts to contain this infection stand? To recap, the disease mpox is the […]
The post Are We Ready for Mpox first appeared on Science-Based Medicine.Meanwhile, in Dobrzyn, Hili is showing she is top cat, of course:
Hili: Don’t even think about it.
A: About what?
Hili: I’m speaking to Szaron because he wants to jump here as well.
Hili: Nawet o tym nie myśl!
Ja: O czym?
Hili: Do Szarona mówię, bo on też chce tu wskoczyć.
As humans spread into the cosmos, we will take a plethora of initially Earth-bound life with us for the ride. Some might be more beneficial or potentially harmful than others. And there is no lifeform more prevalent on Earth than bacteria. These tiny creatures and fungi, their long-lost cousins on the evolutionary tree, have a habit of clumping together to form a type of structure known as a biofilm. Biofilms are ubiquitous in Earth-bound environments and have been noticed on space missions for decades. But what potential dangers do they pose? More interestingly, what possible problems can they solve? A paper from a group of scientists focused on life support systems in the journal Biofilm provides a high-level overview of the state of the science of understanding how biofilms work in space and where it might need to go for us to establish a permanent human presence off-world.
The paper is divided into five sub-sections, each of which examines how biofilms might impact them. The first two sub-sections focus on wet and dry areas of an object in space, while the third focuses on the potential impact on human health. Further sections include a focus on in-situ resource utilization (fourth) and biosensors (fifth). Let’s examine each one in turn.
Wet surfaces are probably the place most people would expect to see a biofilm. They are ubiquitous in uncleaned toilets and other areas where a continual source of nutrients and water are available. Unfortunately, space stations and crewed spaceships have the same necessary biological plumbing and could suffer from the same problem if not managed. However, they also have wet storage areas, like the water reclamation system or fuel tanks, that aren’t necessary for Earth-based systems. All that means there are plenty of areas where biofilms can pollute these systems and cause significant problems either mechanically or biologically for the crew.
Bacteria are hardy, as Fraser discusses with Dr. Michael DalyDry surfaces are essentially the same, though tracing the spread of the bacteria is trickier as typical deposition systems, like the settling of an aerosol from a person breathing, which happens to contain thousands of bacteria, isn’t as much of a problem in space. However, astronauts still touch surfaces, which deposits bacteria as well, and their breath does have to be recycled in air cleaners, which could lead to deposits near or even on the HEPA filters that keep the air in the craft fresh.
Either way, those biofilms could prove problematic to the human occupants of any spacecraft. There are two main ways they can create problems—either through infections, especially if the astronauts drink contaminated water, or through allergies, which could be caused by things like black mold. Unfortunately, we don’t understand what, if any, impact microgravity has on all of these processes, including fundamentals like how virulent pathogens might become.
However, it’s not all doom and gloom regarding biofilms in space exploration. Some biofilms can be helpful—especially by filtering valuable materials. Biofilm reactors are becoming more common in Earth-bound processes, whereby they can capture valuable materials like platinum from wastewater streams of mines or recycling plants. A similar tactic could work on Mars, where bioreactors could filter out useful molecules like nitrogen from the atmosphere and allow human-made systems to access those resources.
NASA continues testing the effects of biofilms in space.However, such systems would be useless if they weren’t controlled, and developing biosensors to monitor the health of biofilms —or lack thereof if they happen to be dangerous—will be a crucial innovation for future permanent space exploration missions. Several sensors are coming on the market that could fill that need, but more experimentation is needed to see how effective they are in microgravity.
Ultimately, humans will have to learn to live to co-exist with biofilms in space, just like we do down on Earth. Whether that relationship is adversarial, symbiotic, or some combination of both will be primarily up to us. But, as mentioned by the paper, and that holds for most things in the realm of science, it would be good if we had a better understanding of how these systems work in this new environment. Otherwise, we might be setting ourselves up for a very avoidable disaster.
Learn More:
Justiniano et al. – Mitigation and use of biofilms in space for the benefit of human space exploration
UT – There’s a Surprising Amount of Life Deep Inside the Earth. Hundreds of Times More Mass than All of Humanity
UT – Instead of Building Structures on Mars, we Could Grow Them With the Help of Bacteria
UT – Earth’s toughest bacteria can survive unprotected in space for at least a year
Lead Image:
Graphic depicting the various uses of biofilms.
Credit – NASA
The post How Can Biofilms Help or Hinder Spaceflight? appeared first on Universe Today.
Just outside the Milky Way Galaxy, roughly 210,000 light-years from Earth, there is the dwarf galaxy known as the Small Magellanic Cloud (SMC). Measuring about 18,900 light-years in diameter and containing roughly 3 billion stars, the SMC and its counterpart – the Large Magellanic Cloud (LMC) – orbit the Milky Way as satellite galaxies. Scientists are particularly interested in these satellites because of what they can teach us about star formation and the process where galaxies evolve through mergers, which is something the Milky Way will do with these two galaxies someday.
Another interesting feature of the SMC is the spectacular star cluster known as NGC 346, located near the center of the brightest star-forming region in the SMC, the hydrogen-rich nebula designated N66. Yesterday, NASA released a new image of this star cluster acquired by the venerable Hubble Space Telescope, which provides a unique and breathtaking view of this star cluster. These images were made possible thanks to Hubble’s sharp resolution and unique ability to make sensitive ultraviolet observations.
These two Hubble images of NGC 346 show the star cluster in visible and ultraviolet wavelengths of light. Credit: NASA/ESA/STScI/Gladys KoberThe interaction between the dozens of hot, young, blue stars and the surrounding dust and gas makes this region one of the most dynamic and intricately detailed star-forming clusters ever observed. While NGC 346 has been observed by Hubble in the past and more recently by the James Webb Space Telescope, the images they took combined visible and infrared light, showcasing the gas and dust structure of the surrounding nebula. This latest view combined ultraviolet and some visible light data from Hubble’s Advanced Camera for Surveys (ACS) and Wide Field Camera 3 (WFC3).
The purpose of these observations is to learn more about star formation and how it shapes the interstellar medium (ISM) of low-metallicity galaxies like the SMC. These conditions are believed to be similar to what existed during the early Universe when there were very few heavy elements. It was not until the first generation of stars (Population III) and galaxies emerged – ca. 100 million to one billion years after the Big Bang – that heavier elements began to form. These were distributed throughout space when these stars reached the end of their relatively short life cycle and went supernova.
After more than three decades of service, the Hubble Space Telescope is still fulfilling its original purpose: helping scientists investigate the origins and evolution of the Universe!
Further Reading: NASA
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Any mission to Jupiter and its moons must contend with the gas giant’s overwhelming radiation. Only a judicious orbital pattern and onboard protective measures can keep a spacecraft safe. Even then, the powerful radiation dictates a mission’s lifespan.
However, researchers may have found a way to approach at least one of Jupiter’s moons without confronting that radiation.
When NASA launched its Juno mission to Jupiter in 2011, it knew it was sending its spacecraft into an extreme radiation environment. Jupiter’s radiation is generated by its magnetic field, which is 30,000 times stronger than Earth’s. The magnetic field captures charged particles from Jupiter’s environment and accelerates them to create its powerful radiation belts.
Juno follows an elliptical polar orbit around Jupiter, dipping into the hazardous radiation for periods of time and then leaving it behind. Juno’s most sensitive electronics are inside a titanium vault designed to resist the radiation for as long as possible.
Astronomers are intensely interested in the Jovian system because three of its Galilean moons—Europa, Ganymede, and Callisto—appear to have warm oceans buried under layers of ice. This poses the question of habitability, but the first order of business is to confirm that these oceans are actually there.
ESA’s JUICE (Jupiter Icy Moons Explorer) is en route to Jupiter, and NASA’s Europa Clipper will launch in a few weeks. (The Europa Clipper will overtake JUICE and reach Jupiter first.) Both missions will visit Europa and attempt to determine if its subsurface ocean is real. Both must contend with the intense radiation near Jupiter.
NASA’s Juno mission has created a radiation map of the Jupiter region and found a potential low-radiation route to Europa. How will it affect these and future missions?
“This is the first detailed radiation map of the region at these higher energies, which is a major step in understanding how Jupiter’s radiation environment works.”
Scott Bolton, Principal Investigator, Juno missionNASA’s Juno spacecraft and the people on the mission team get credit for finding the low-radiation route to Europa. Juno used its two low-light cameras used in deep space navigation to map the radiation environment near the icy moon. The result is the first complete 3D radiation map of the Jupiter system.
“On Juno we try to innovate new ways to use our sensors to learn about nature and have used many of our science instruments in ways they were not designed for,” said Scott Bolton, Juno principal investigator from the Southwest Research Institute in San Antonio.
The instruments responsible are the Advanced Stellar Compass (ASC) and the Stellar Reference Unit (SRU). The ASC was designed and built in Denmark, and the SRU is from Italy. Most spacecraft have these types of instruments to help them navigate.
The ASC is actually four cameras on the spacecraft’s magnetometer boom. They orient the spacecraft in space and are also part of the magnetometer’s mission to measure Jupiter’s magnetic field in detail. The SRU helps Juno determine its attitude relative to a horizontal plane. It also serves as an in situ particle detector in Juno’s Radiation Monitoring Investigation.
Together, they’ve been used to create the radiation map.
“This is the first detailed radiation map of the region at these higher energies, which is a major step in understanding how Jupiter’s radiation environment works. That we’ve been able to create the first detailed map of the region is a big deal, because we don’t carry an instrument designed to look for radiation. The map will help planning observations for the next generation of missions to the Jovian system,” says Scott Bolton.
Juno’s elliptical polar orbit means that as the spacecraft approaches the planet, a different part of the surface is directly underneath. While its job isn’t to image Jupiter’s surface, the ASC takes advantage of this. Since Juno has traversed the entire region around Jupiter, so has the ASC.
“Every quarter-second the ASC takes an image of the stars,” said Juno scientist John Leif Jørgensen, professor at the Technical University of Denmark. “Very energetic electrons that penetrate its shielding leave a telltale signature in our images that looks like the trail of a firefly. The instrument is programmed to count the number of these fireflies, giving us an accurate calculation of the amount of radiation,” said Jørgensen.
Advanced Stellar Compass data revealed two important things. There is more very high-energy radiation relative to lower-energy radiation near Europa’s orbit than scientists thought. There is also more high-energy radiation on the moon’s leading orbital edge than on the trailing edge. This is because most electrons in Jupiter’s magnetosphere overtake Europa from behind due to Jupiter’s magnetic field rotation. But the high-energy electrons end up drifting backward, pummeling Europa’s leading edge with high-energy radiation. Interactions with Europa’s surface deplete them.
The Stellar Reference Unit also contributed to a new understanding of how Jupiter’s radiation affects Europa. It has been used as a low-light camera, which is its intended purpose, and as a radiation detector.
An upcoming paper based on these observations will present a complete radiation map of Jupiter and its environment. Earlier this year, the same authors published a paper titled “Europa’s Influence on the Jovian Energetic Electron Environment as Observed by Juno’s Micro Advanced Stellar Compass.” The lead author is Matija Herceg, a Senior Researcher in the Department of Space Research and Technology at the Technical University of Denmark.
“As most of the energetic electrons, drifting retrograde, will encounter Europa and impact its downstream side before they can reach the upstream side, Europa will stop the energetic electron drift shells and will be mostly free from hard radiation on the upstream side,” the authors wrote in their paper.
This graphic shows Europa orbiting Jupiter, with Juno’s looping orbits shown in red. The yellow graph shows the radiation flux measurement during one of Juno’s orbits. High-energy particles end up slamming into Europa’s leading orbital edge while the wake is somewhat protected. The lower-radiation plasma wake is shown in green. Image Credit: Herceg et al. 2024.Juno is on an extended mission now, and more orbits should capture more data on the radiation.
The question is, can this low-radiation environment be used in future missions to avoid radiation exposure? It’s possible, but more work needs to be done.
“The results from the upcoming Juno orbits, during its mission extension, might result in populating the Juno plasma wake with additional crossing observations,” Herceg and his co-authors write. “As the first in situ compilation of energetic electron flux observations of both upstream and plasma wake sides of Europa, the presented data set gives us estimates of the thickness and electron density distribution in the vicinity of Europa. The results from this paper could contribute to dedicated studies aimed at preparation for the upcoming NASA mission Europa Clipper and ESA’s Juice mission.”
One of those dedicated studies, by the same authors as Herceg et al., will present the complete 3D radiation map of Jupiter. However, it’s currently under peer review. Will that research lead to a low-radiation pathway to studying Europa, the most prized target in our search for life elsewhere in the Solar System?
Stay tuned.
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