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Astronomers find hot stars peppered with massive magnetic spots

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June 1 (UPI) — Astronomers have discovered giant magnetic spots on the surfaces of hot stars hidden away in stellar clusters. Scientists also found evidence of superflare events, eruptions featuring several times more energy than those observed on the surface of the sun.

The new survey of extreme horizontal branch stars, published Monday in the journal Nature Astronomy, could help scientists unravel some of the mysterious of these unusual stellar objects.

“These hot and small stars are special because we know they will bypass one of the final phases in the life of a typical star and will die prematurely,” lead researcher Yazan Momany, scientist at the INAF Astronomical Observatory of Padua in Italy, said in a news release. “In our galaxy, these peculiar hot objects are generally associated with the presence of a close companion star.”

Momany and his colleagues were surprised to find that most of the extreme horizontal branch stars they found inside the dense structures known as stellar clusters are without companions.

Using several European Southern Observatory telescopes, scientists observed several extremely hot stars inside three different stellar clusters. Their observations revealed surprisingly large levels of brightness variability over short periods of time.

“After eliminating all other scenarios, there was only one remaining possibility to explain their observed brightness variations,” said study co-author Simone Zaggia, researcher at the INAF Astronomical Observatory. “These stars must be plagued by spots!”

On the sun, spots appear dark because they’re cooler than the surrounding plasma. On the extremely hot stars described in the latest paper, the spots are hotter — and brighter — than their surroundings.

The massive magnetic spots are also bigger and more persistent than sunspots. Whereas sunspots last a matter of weeks, the massive magnetic spots found by Momany and his research partners can last for years.

Though both sunspots found on our sun and the giant spots found on extreme horizontal branch stars are quite different, they’re both fueled by magnetic fields.

While observing the massive spots, scientists also witnessed a couple of superflare events.

“They are similar to the flares we see on our own Sun, but ten million times more energetic,” said study co-author Henri Boffin, an astronomer at ESO’s headquarters in Germany. “Such behavior was certainly not expected and highlights the importance of magnetic fields in explaining the properties of these stars.”

Astronomers have spent more than half a century studying the behavior of extreme horizontal branch stars. In addition to helping astronomers understand these peculiar stars, the latest findings could also help scientists unravel the complexities of magnetic phenomena on other types of stars, including the sun.

“The bigger picture though is that changes in brightness of all hot stars — from young sun-like stars to old extreme horizontal branch stars and long-dead white dwarfs — could all be connected,” said researcher David Jones, scientist with Spain’s Canary Islands Institute of Astrophysics. “These objects can thus be understood as collectively suffering from magnetic spots on their surfaces.”



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Google honors physician and microbiologist Dr. Stamen Grigorov with new Doodle

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Oct. 27 (UPI) — Google is celebrating Bulgarian physician and microbiologist Dr. Stamen Grigorov with a new Doodle Tuesday, on what would have been his 142nd birthday.

Grigorov, who was born in 1878 in the village of Studen Izvor in the Trun region of Bulgaria, is the first scientist to discover the bacterium essential to the fermentation of yogurt. He also helped with the development of the first tuberculosis vaccine.

Google’s homepage features artwork of Grigorov being surrounded by multiple bowls of yogurt.

Grigorov, who worked as a research assistant at the Medical University of Geneva, Switzerland, started to inspect yogurt under a microscope after being intrigued by its reported health benefits.

The scientist found the rod-shaped microorganism that causes yogurt’s fermentation in 1905 after thousands of experiments. The bacterium was named Lactobacillus bulgaricus, in honor of his home nation of Bulgaria.

The following year, Grigorov released a groundbreaking paper demonstrating the first use of penicillin fungi against tuberculosis while working as chief physician at a hospital in Trun.

Studen Izvor is home to the world’s only yogurt museums.



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Vampire bats socially distance when they fall ill

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Oct. 27 (UPI) — New research suggests vampire bats are better at following CDC guidelines than some humans.

When a vampire bat gets sick, they spend less time around other members of the colony, helping to slow the spread of disease, according to a new study published Tuesday in the journal Behavioral Ecology.

Scientists had previously observed vampire bats practicing social distancing in captivity, but the latest research suggests wild bats also work to flatten the curve.

For the study, researchers captured 31 adult female vampire bats from a roost located in a hollow tree in Belize. To simulate the influence of illness, scientists injected half the bats with lipopolysaccharide, an immune-challenging substance. The control bats were injected with saline.

After attaching proximity sensors to the bats, researchers released them back into the wild.

The data revealed shifting interaction patterns among the different bats during the six-hour treatment period — before the effects of the injection wore off. The sick bats interacted with fewer members of the colony and spent less time their peers.

In the hours following their release back into the wild, the data showed a control bat had a 49 percent chance of interacting with another control bat, but only a 35 percent of interacting with a sick bat. Sick bats also spent 25 fewer minutes with their partners than control bats.

“The sensors gave us an amazing new window into how the social behavior of these bats changed from hour to hour and even minute to minute during the course of the day and night, even while they are hidden in the darkness of a hollow tree,” lead study author Simon Ripperger said in a news release.

“We’ve gone from collecting data every day to every few seconds,” said Ripperger, an ecologist at Ohio State University.

For most species, illness symptoms, such as lethargy and sleep, or reduced movement and sociality, prevent infected individuals from interacting with the rest of the community — a kind of involuntary social distancing. But the latest research suggests bats are part of a minority group of animals that purposefully self-isolate in cooperation with their colony mates.



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SpaceX launches public beta test of Starlink Internet service

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Oct. 27 (UPI) — SpaceX has launched public beta testing of its Starlink communications satellite program that aims deliver high-speed Internet globally, particularly in underserved areas.

The Elon Musk-founded aerospace manufacturer sent out emails to invite people who signed up on its Starlink website to hear updates about the program.

The initial Starlink service is called “Better Than Nothing Beta,” according to multiple screenshots of an email, CNBC reported.

Joining the public beta test costs $99 a month on top of a $499 upfront cost for the ground equipment, which includes a user terminal to connect to the satellites, a mounting tripod and a Wi-Fi router.

SpaceX also has a Starlink app listed on the Google Play and Apple iOS app stores, which helps users set up their systems and allows them to search areas of the sky for unobstructed views.

“As you can tell from the title, we are trying to lower your initial expectations,” the Starlink Team signed email said. “Expect to see data speeds vary from 50 Mb/s to 150Mb/s and latency from 20ms to 40ms over the next several months as we enhance the Starlink system. There will also be brief periods of no connectivity at all.”

SpaceX said that “nearly 700,000” individuals across the United States had expressed interest in potentially subscribing to the service.

“Under Starlink’s Better Than Nothing Beta program, initial service is targeted for the U.S. and Canada in 2020, rapidly expanding to near global coverage of the populated world by 2021,” SpaceX said in the description of its Starlink mobile app.

The company rolled out private beta testing over the summer for which users had to agree to keep their experience confidential.

“You may NOT discuss your participation in the Beta Program online or with those outside or your household, unless they are SpaceX employees,” the Starlink website said.

SpaceX said the network will cost about $10 billion or more to build, but the company’s leadership estimates that it could bring in up to $30 billion a year, which is more than 10 times the annual revenue of its rocket business.

On Saturday, SpaceX launched its Falcon 9 rocket into space, carrying 60 Internet satellites into orbit to help establish connections to remote areas.

Earlier this month, Musk tweeted that Starlink’s constellation had grown large enough to begin beta-testing the Internet service system in the United States and southern Canada.

The company has launched nearly 900 Starlink satellites to date, which is only a fraction of what’s needed for global coverage, but enough to provide service in some areas.

Last week, SpaceX announced that it would offer Starlink’s broadband service free to families in Texas’ Ector County Independent School District, where more than one-third of the children and their families lack Internet access.



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