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Superstar Eta Carinae’s Cosmic Rays May Reach Earth: Study

Astronomers know that cosmic rays with energies greater than one billion electron volts (eV) come to us from beyond our solar system.

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Superstar Eta Carinae's Cosmic Rays May Reach Earth: Study
Superstar Eta Carinae's Cosmic Rays May Reach Earth: Study. Pixabay

Eta Carinae, the most luminous and massive stellar system within 10,000 light years, is accelerating particles to speeds comparable to that of light — some of which may reach Earth as cosmic rays, suggests a new study.

“We know the blast waves of exploded stars can accelerate cosmic ray particles to speeds comparable to that of light, an incredible energy boost,” said the lead author of the study Kenji Hamaguchi, an astrophysicist at NASA’s Goddard Space Flight Centre in Greenbelt, Maryland.

“Similar processes must occur in other extreme environments. Our analysis indicates Eta Carinae is one of them,” Hamaguchi said.

Astronomers know that cosmic rays with energies greater than one billion electron volts (eV) come to us from beyond our solar system.

But because these particles — electrons, protons and atomic nuclei — all carry an electrical charge, they veer off course whenever they encounter magnetic fields. This scrambles their paths and masks their origins.

For this study, published in the journal Nature Astronomy, the researchers used data from NASA’s NuSTAR space telescope.

Launched in 2012, NuSTAR can focus X-rays of much greater energy than any previous telescope.

Using both newly taken and archival data, the team examined NuSTAR observations acquired between March 2014 and June 2016, along with lower-energy X-ray observations from the European Space Agency’s XMM-Newton satellite over the same period.

“We’ve known for some time that the region around Eta Carinae is the source of energetic emission in high-energy X-rays and gamma rays,” said Fiona Harrison, the principal investigator of NuSTAR.

Carina Nebula
Carina Nebula. Pixabay

“But until NuSTAR was able to pinpoint the radiation, show it comes from the binary and study its properties in detail, the origin was mysterious,” said Harrison, who also serves as a professor of astronomy at California Institute of Technology (Caltech) in Pasadena.

Eta Carinae, located about 7,500 light-years away in the southern constellation of Carina, is famous for a 19th century outburst that briefly made it the second-brightest star in the sky.

This event also ejected a massive hourglass-shaped nebula, but the cause of the eruption remains poorly understood.

The system contains a pair of massive stars whose eccentric orbits bring them unusually close every 5.5 years.

Also read: Brain Damage Caused by Cosmic Rays Can be Prevented With this Drug

The stars contain 90 and 30 times the mass of our Sun and pass 225 million km apart at their closest approach — about the average distance separating Mars and the Sun. (IANS)

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Human Sperm Retains Viability in Outer Space Conditions: Researchers

The study was presented at an annual meeting of European Society of Human Reproduction and Embryology in Vienna, Austria

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Each sperm has 37.5MB of DNA information in it.
Each sperm has 37.5MB of DNA information in it.

Researchers have found that human sperm retains its complete viability within the different gravitational conditions found in outer space.

The results could be a huge boost to zillionaires like Amazon founder Jeff Bezos who see the “colonisation” of space as an answer to the Earth’s ever threatened resources.

“If the number of space missions increases in the coming years, and are of longer duration, it is important to study the effects of long-term human exposure to space in order to face them,” said Montserrat Boada from Dexeus Women’s Health in Barcelona, whose group worked with microgravity engineers from the Polytechnic University of Barcelona.

“It’s not unreasonable to start thinking about the possibility of reproduction beyond the Earth,” Boada said.

The study was performed using a small aerobatic training aircraft (CAP10), which can provide short-duration hypogravity exposure.

The plane executed a series of 20 parabolic manoeuvres, providing eight seconds of microgravity for each parabola.

Overall, 10 sperm samples obtained from 10 healthy donors were analysed after exposure to the different microgravities found in space and ground gravity.

To overcome regulatory constraints and increase donor numbers, sperm banks in the UK and Australia began to market the act of donating sperm as a confirmation of masculinity. Pixabay

The sperm analysis comprised a full range of measurements currently performed for fertility testing — concentration, motility, vitality, morphology and DNA fragmentation — and results found no difference whatsoever in any of the parameters between the microgravity space samples and the control group samples from Earth.

Indeed, there was 100 per cent concordance in DNA fragmentation rate and vitality, and 90 per cent concordance in sperm concentration and motility, said Boada.

These minor differences, she added, “were more probably related to heterogeneity of the sperm sample than to the effect of exposure to different gravity conditions”.

Boada described this as a preliminary study and her group will now move on to validate the results and then to larger sperm samples, longer periods of microgravity and even fresh sperm.

Also Read: Xiaomi Confirms First Smartphones Under its New CC Series

One reason for using frozen sperm in this study was the known effect of radiation on fresh sperm, Boada noted.

“Radiation impairs the quality and viability of human sperm, and these effects are expected to be greater on fresh sperm than on frozen samples,” she said.

The study was presented at an annual meeting of European Society of Human Reproduction and Embryology in Vienna, Austria. (IANS)