Hubble has spotted mysterious balls of plasma shooting from a star.


NASA’s Hubble space telescope has detected plasma balls roughly twice the size of Mars being ejected near a dying star at speeds so rapid, it would take them only 30 minutes to travel from Earth to the Moon.

This mysterious ‘cannon fire’ has been detected in the region once every 8.5 years for at least the past 400 years, but this is the first time it’s ever been seen in action, and researchers think they might finally know where it’s coming from.

Plasma is super-hot ionised gas, and the reason these blasts are so confusing for astronomers is that there’s no way they can be coming from the dying star they originate near.

The star in question, called V Hydrae, is a bloated red giant that’s 1,200 light-years away, and it’s dying. It’s already shed at least half of its mass into space in its final death throes, and is now exhausting the rest of its nuclear fuel as it burns out – hardly a likely source of super hot, giant blobs of charged gas.

But the new Hubble data provide researchers with some insight into the strange phenomenon, and it turns out that these plasma cannonballs might explain another space mystery – planetary nebulae.
Planetary nebulae aren’t like regular nebula, which are the birthplace of stars. Instead, they’re swirling rings of glowing gas that are expelled by dead or dying stars. Each one is unique, but no one has been able to explain how they form.

Now NASA researchers suggest that the cannonballs may play a key role.

“We knew this object had a high-speed outflow from previous data, but this is the first time we are seeing this process in action,” said lead researcher Raghvendra Sahai, from NASA’s Jet Propulsion Laboratory in California.

“We suggest that these gaseous blobs produced during this late phase of a star’s life help make the structures seen in planetary nebulae.”

To figure this out, the team pointed the Hubble telescope at V Hydrae over an 11-year period, between 2002 and 2013.

This allowed them to capture the latest cannonball eruption back in 2011, using spectroscopy imaging to reveal information on the plasma’s velocity, temperature, location, and motion.

They were able to show a whole string of the huge plasma balls erupting from the region, each with a temperature of more than 9,400 degrees Celsius (17,000 degrees Fahrenheit) – almost twice as hot as the surface of the Sun.

While the team monitored these news cannonballs, they also mapped the distribution of old plasma blobs fired out as long ago as 1986, some of which were already 60 billion km  (37 billion miles) away from V Hydrae.

These plasma balls cool down and expand the further they get until they’re no longer detectable by Hubble.

So where are they coming from? Based on all this new data, the NASA team modelled several scenarios, and the one that made the most sense is that the cannonballs are being launched by an unseen companion star that orbits close to V Hydrae every 8.5 years, but isn’t seen by Hubble.

The model suggests that as the companion star enters V Hydrae’s outer atmosphere, it gobbles up all the material that V Hydrae is shedding in its death throes, and this material then settles around the companion star as an accretion disk that shoots out balls of plasma.

The researchers have recreated what that would look like below. Step 1 is the two stars orbiting each other. Step 2 shows the companion star orbiting into the red giant’s bloated  atmosphere and sucking up its material into an accretion disk.

In steps 3 and 4, blobs of hot plasma are being ejected from this accretion disk. This happens every 8.5 years as the companion star orbits into V Hydrae’s atmosphere.

hubblecannoball webNASA, ESA & A. Feild (STScI)

Not only could this explain the strange balls, it could also explain how bloated dying stars turn into beautiful, glowing planetary nebulae within just 200 to 1,000 years – which is an astronomical blink of an eye.

Hubble has captured images of planetary nebulae with a range of knotty structures with them, which looked a lot like jets of material ejected from accretion discs. But red giants don’t have accretion discs, so it never quite made sense. Now it’s possible that the knotty structures are produced by hidden companion stars.

“This model provides the most plausible explanation,” said Sahai. 

Another surprise from the study was that the plasma balls aren’t fired in the same direction every 8.5 years, it flip-flops slightly from side to side and back and forth, suggesting that there’s a wobble in the accretion disk.

This wobble means that sometimes the cannonballs would be shot out in front of V Hydrae (from Hubble’s perspective) and sometimes behind, and could explain why the star is obscured from view every 17 years.

“This discovery was quite surprising, but it is very pleasing as well because it helped explain some other mysterious things that had been observed about this star by others,” said Sahai.

More research is needed to verify this new hypothesis, and figure out the ultimate fate of the potential companion star and V Hydrae. But NASA will be watching closely to see what happens as the red giant eventually turns into a beautiful planetary nebula. There are worse ways to go.

The power of plasma – could it help fight diseases?


Most of the matter around us is either solid, liquid, or gas. But there is something often called the fourth state – plasma – that has remarkable properties. Could we use it to fight diseases? We investigate in this edition of Futuris.

“Plasma contains a lot of reactive particles – ions, electrons, radicals and all sorts of other excited particles. When they come into contact with a surface, they change the surface properties – both chemical and physical”

Getting sticky with plasma

Scientists working on a European research project (coordinated bySpinverse in Finland) use plasma to modify physical properties of various surfaces.

For example, plastic well plates, which are used for various biomedical and diagnostic purposes, normally repel liquids which can make them difficult to use.

But after the plasma treatment, liquid sticks to the bottom and the sides of the wells, making them much better suited for medical analysis.

“Plasma contains a lot of reactive particles – ions, electrons, radicals and all sorts of other excited particles,” explained Jochen Borris, a material scientist at the Fraunhofer Institute for Surface Engineering and Thin Filmsin Braunschweig, Germany.

“When they come into contact with a surface, they change the surface properties – both chemical and physical.”

One of the researchers’ goals is to pass this know-how on to industry.

Plasma treatment can become an attractive alternative to current production methods, which rely on using relatively larger quantities of solvents and other chemicals which aren’t always environmentally friendly.

“Many different industries could use this: it could be used for diagnosis of bacterial diseases, diagnostics for tuberculosis and HIV. But also for medical packaging and wound dressings,” said Annika Herrmann, a bio-engineer at the Institute.

Rapid TB and HIV tests

A special machine applies two thin stripes of chemicals on a roll of a synthetic textile specially treated with plasma. These stripes will change colour once in contact with certain antibodies.

It is the main component of innovative rapid tests for tuberculosis and HIV, developed by this enterprise.

“We use a very simple film, which is plasma-coated, we mount that simple film in the cassettes, so no further manufacturing membranes, wicks, micro-fluidic or any kind of system is needed – we just put a drop of the serum, blood or urine on this test,” said Mahavir Singh, Professor of Genetics and Biotechnology, at theTechnical University of Braunschweig and Founder, Owner and Managing Director of Lionex.

“We put the second drop of the reagents for ten minutes, remove it and that’s it, and you see positive or negative results,” he continued.

“So the material cost is going down, the mounting cost is going down, the manufacturing cost is going down, and the greatest advantage is that the sensitivity of test is going to be higher.”

Getting plasma into industry

In Mol, in Belgium, at VITO (Flemish Institute for Technological Research), large scale prototypes are demonstrating how plasma treatment can be integrated into industrial workflows.

A machine uses plasma to cover a piece of synthetic textile with an extremely thin film that turns the fabric from hydrophilic into hydrophobic or vice versa.

This can be useful in wound dressings and other medical products.

“In this technology, we’re really working on a nanometer scale. We’re producing coatings with nanometre thicknesses,” said Bert Verheyde, an organic chemist and expert in plasma technology at VITO.

“Whereas in wet chemical coatings which may be an alternative they’re mainly working on micrometre scale, using much more chemicals.”

Less harmful solvents mean cutting production costs and helping the environment, while fully controlling whether products absorb or repel liquids.

The Plasma Proteome Identifies Expected and Novel Proteins Correlated with Micronutrient Status in Undernourished Nepalese Children.


Micronutrient deficiencies are common in undernourished societies yet remain inadequately assessed due to the complexity and costs of existing assays. A plasma proteomics-based approach holds promise in quantifying multiple nutrient:protein associations that reflect biological function and nutritional status. To validate this concept, in plasma samples of a cohort of 500 6- to 8-y-old Nepalese children, we estimated cross-sectional correlations between vitamins A (retinol), D (25-hydroxyvitamin D), and E (α-tocopherol), copper, and selenium, measured by conventional assays, and relative abundance of their major plasma-bound proteins, measured by quantitative proteomics using 8-plex iTRAQ mass tags. The prevalence of low-to-deficient status was 8.8% (<0.70 μmol/L) for retinol, 19.2% (<50 nmol/L) for 25-hydroxyvitamin D, 17.6% (<9.3 μmol/L) for α-tocopherol, 0% (<10 μmol/L) for copper, and 13.6% (<0.6 μmol/L) for selenium. We identified 4705 proteins, 982 in >50 children. Employing a linear mixed effects model, we observed the following correlations: retinol:retinol-binding protein 4 (r= 0.88), 25-hydroxyvitamin D:vitamin D-binding protein (r = 0.58), α-tocopherol:apolipoprotein C-III (r = 0.64), copper:ceruloplasmin (r = 0.65), and selenium:selenoprotein P isoform 1 (r = 0.79) (all P < 0.0001), passing a false discovery rate threshold of 1% (based on P value-derived q values). Individual proteins explained 34–77% (R2) of variation in their respective nutrient concentration. Adding second proteins to models raised R2 to 48–79%, demonstrating a potential to explain additional variation in nutrient concentration by this strategy. Plasma proteomics can identify and quantify protein biomarkers of micronutrient status in undernourished children. Source:  American Society for Nutrition

ST2 as a Marker for Risk of Therapy-Resistant Graft-versus-Host Disease and Death


BACKGROUND

No plasma biomarkers are associated with the response of acute graft-versus-host disease (GVHD) to therapy after allogeneic hematopoietic stem-cell transplantation.

METHODS

We compared 12 biomarkers in plasma obtained a median of 16 days after therapy initiation from 10 patients with a complete response by day 28 after therapy initiation and in plasma obtained from 10 patients with progressive GVHD during therapy. The lead biomarker, suppression of tumorigenicity 2 (ST2), was measured at the beginning of treatment for GVHD in plasma from 381 patients and during the first month after transplantation in three independent sets totaling 673 patients to determine the association of this biomarker with treatment-resistant GVHD and 6-month mortality after treatment or transplantation.

RESULTS

Of the 12 markers, ST2 had the most significant association with resistance to GVHD therapy and subsequent death without relapse. As compared with patients with low ST2 values at therapy initiation, patients with high ST2 values were 2.3 times as likely to have treatment-resistant GVHD (95% confidence interval [CI], 1.5 to 3.6) and 3.7 times as likely to die within 6 months after therapy (95% CI, 2.3 to 5.9). Patients with low ST2 values had lower mortality without relapse than patients with high ST2 values, regardless of the GVHD grade (11% vs. 31% among patients with grade I or II GVHD and 14% vs. 67% among patients with grade III or IV GVHD, P<0.001 for both comparisons). Plasma ST2 values at day 14 after transplantation were associated with 6-month mortality without relapse, regardless of the intensity of the conditioning regimen.

CONCLUSIONS

ST2 levels measured at the initiation of therapy for GVHD and during the first month after transplantation improved risk stratification for treatment-resistant GVHD and death without relapse after transplantation.

Source: NEJM

 

Extreme Bilirubin Levels as a Causal Risk Factor for Symptomatic Gallstone Disease.


Importance  In individuals without blockage of their bile ducts, levels of plasma bilirubin likely reflect levels of biliary bilirubin; higher biliary bilirubin levels may increase the risk of gallstone disease.

Objective  To test the hypothesis that a lifelong increase in plasma bilirubin levels is a causal risk factor for symptomatic gallstone disease in the general population.

Design, Setting, and Participants  In a prospective study of the Danish general population (N = 61 212), we first tested whether elevated levels of plasma bilirubin predicted greater risk of symptomatic gallstone disease. Second, taking advantage of mendelian randomization, we tested whether a genetic variant in the bilirubin glucoronidating enzyme UGT1A1 (rs6742078) was associated with increased plasma bilirubin levels and, in turn, with an increased risk of symptomatic gallstone disease.

Main Outcomes and Measures  Plasma bilirubin level and symptomatic gallstone disease.

Results  During 34 years of follow-up, 3374 individuals developed symptomatic gallstone disease. In adjusted analyses, persons with plasma bilirubin levels in the 10th decile had a greater risk of symptomatic gallstone disease compared with those with plasma bilirubin levels in deciles 1 through 9; the hazard ratios (HRs) (95% CIs) were 1.57 (1.26-1.96) overall, 1.36 (1.02-1.82) in women, and 2.00 (1.41-2.83) in men. UGT1A1 genotype explained 20% of the total variation in plasma bilirubin levels and was associated with increases in the mean plasma bilirubin level overall of +16% (+0.09 mg/dL) in GT heterozygotes and +90% (+0.50 mg/dL) in TT homozygotes compared with GG homozygotes, with similar effects in women and men (P for trend <.001 for all). The corresponding HRs (95% CIs) for symptomatic gallstone disease were 1.09 (1.02-1.17) for GT heterozygotes and 1.22 (1.09-1.36) for TT homozygotes vs GG homozygotes and similar in women and men (P for trend = .04-<.001).

Conclusions and Relevance  These results are compatible with a causal association between extreme levels of plasma bilirubin and increased risk of symptomatic gallstone disease.

Source: JAMA