Science & Technology

Betelgeuse is bright again, and it's a bit cooler

Brian Koberlein
Universe Today
Sat, 18 Apr 2020 12:00 UTC

Everyone's favorite red supergiant star is bright again. The American Association of Variable Star Observers (AAVSO) has been tracking Betelgeuse as it has gradually returned to its more normal brilliance. As of this writing, it is about 95% of its typical visual brightness. Supernova fans will have to wait a bit longer.

Betelgeuse created quite a stir back in February when it became particularly dim. So dim that experienced observers could easily tell with the naked eye. As a variable star, Betelgeuse does go through bright and dim periods, but it was unusual enough that many wondered what might have been the cause.

There are several ways a star can vary in brightness. Cepheid variable stars, for example, vary because they expand and contract. As helium in the star's outer layer is heated it expands, causing the star to swell. The helium then cools and the star shrinks again. This pulsation effect is so regular that astronomers can use Cepheids as standard candles to measure the distances of nearby galaxies.

Comment: The researchers speculate that the dimming could be due to dust, but, as noted in a SOTT comment, there is another possibility:

Betelgeuse defied official science by alternatively dimming and brightening. Does it give credence to the Electric Universe Theory that posits that the brightness of a star is the result of the difference in electric potential between the star and its surrounding space?

Interstellar comet 2I/Borisov's abundant carbon monoxide points to birth around cooler star

ESA/Hubble Information Centre
Phys.org
Mon, 20 Apr 2020 19:43 UTC

Interstellar comet 2I/Borisov is providing a glimpse of another star system's planetary building blocks, using new observations from NASA's Hubble Space Telescope.

Borisov is the first known comet to originate from a different star system than our own. Measurements find that it has an unusual abundance of carbon monoxide largely unlike comets belonging to our solar system. Researchers say its unusual composition points to a likely birthplace of a carbon-rich circumstellar disk around a cool red dwarf class of star. These observations are a prime opportunity to sample the chemistry of the material in a primordial disk around another star.

Comets are condensed samples of gas, ice, and dust that form swirling in the disk around a star during the birth of its planets. Studying comets is important because astronomers are still trying to understand the role they play in the buildup of planets. They can also redistribute organic material among young planets, and may have brought water to the early Earth. These activities are likely happening in other planetary systems, as demonstrated by Borisov's makeup.

Comment: See also: The Seven Destructive Earth Passes of Comet Venus

Achingly beautiful image shows us the chaos and wonder of Jupiter

Michelle Starr
Science Alert
Fri, 17 Apr 2020 17:37 UTC

On April 10, as we humans were struggling through our new normal in a world wracked by a pandemic, a little space probe millions of kilometres away was marking a mission milestone. NASA spacecraft Juno made its 26th perijove, swooping in for a close flyby of Jupiter.

From this practically cuddling altitude of 4,200 kilometres (2,600 miles), the spacecraft can take close measurements of our Solar System's biggest planet. And, using its JunoCam instrument, it can take photographs that reveal the glorious details of Jupiter's swirling, turbulent clouds.

This image, processed from the raw images by NASA software engineer Kevin Gill and enhanced by space enthusiast Michael Galanin, shows the planet's north, an area raging with intense storms known as a folded filamentary region, the clouds stretched and folded by Jupiter's constant winds.

Milky Way could be blasting stars into far reaches of the galaxy

Steph Panecasio
CNET
Sun, 19 Apr 2020 17:19 UTC

In an era of social distancing, it turns out even our twisted home galaxy, the Milky Way, is following suit, catapulting its stars farther away from the center.

A study, published Monday in the Monthly Notices of the Royal Astronomical Society, demonstrated how hyper-realistic cosmological simulations were used as a base for scientists from the University of California, Irvine, to show how clusters of supernova -- explosions from dying stars -- can create a scattering of hot suns in the outer reaches of the Milky Way.

Enabled by the Feedback in Realistic Environments 2 (FIRE-2) project, these simulations not only illustrate plumes of stars as they've been flung from the center of the Milky Way, but also demonstrate how the galaxy may be evolving and expanding.

If damaged, the adult brain repairs itself by going back to the beginning

Neuroscience News
Wed, 15 Apr 2020 00:00 UTC

© UC San Diego Health Sciences
A cross-section of a rat brain depicts cells (in blue) expressing normal levels of the Huntingtin gene while cells (in red) have had the gene knocked out. The latter cells, without the Huntingtin gene, displayed less regeneration.

Summary: Mouse models of corticospinal injuries reveal adult neurons begin a natural regeneration process by reverting back to an embryonic state. The regeneration is sustained with the help of a gene more commonly associated with Huntington's disease.

When adult brain cells are injured, they revert to an embryonic state, according to new findings published in the April 15, 2020 issue of Nature by researchers at University of California San Diego School of Medicine, with colleagues elsewhere. The scientists report that in their newly adopted immature state, the cells become capable of re-growing new connections that, under the right conditions, can help to restore lost function.

Repairing damage to the brain and spinal cord may be medical science's most daunting challenge. Until relatively recently, it seemed an impossible task. The new study lays out a "transcriptional roadmap of regeneration in the adult brain."

Microbiome collaborate to cheat death

Carnegie Institution for Science
Thu, 05 Mar 2020 00:13 UTC

Baltimore, MD — Antibiotics can make easy work of infections. But how do they affect the complex ecosystems of friendly bacteria that make up our microbiome?

"When a doctor prescribes antibiotics, it sets up a multi-faceted experiment in your gastrointestinal system," explains Carnegie's Will Ludington "What can it teach us about the molecular principles of species interactions in nature?"

New work led by Ludington and Stanford University's K.C. Huang set out to answer this challenging question and discovered a new form of antibiotic tolerance. Their findings, which have important health implications, are published by eLife.

This is one of several research fronts on which Ludington uses the fruit fly microbiome to understand interactions between species in a bacterial community. It poses an ideal environment for probing both natural bacterial populations and the human microbiome.

The human microbiome is an ecosystem of hundreds to thousands of microbial species living within our guts. It affects our health and even our longevity. But it's difficult to elucidate the myriad ways that the different species that comprise our microbiome interact with and influence each other, even under normal conditions. Once antibiotics are introduced, little is understood about how these vital communities are impacted on a biochemical level.

This is why the fruit fly makes such an excellent model. Unlike the human microbiome, it consists of only a handful of bacterial species.

When the map doesn't work: Evolutionary trees can't reveal speciation and extinction rates

Mark Pagel
Nature
Sat, 18 Apr 2020 17:22 UTC

Living species of the genus Equus

Scientists often want to make inferences about what the biological past was like, and how that past gave rise to the present, because doing so allows them to understand the processes that drive evolution. But, writing in Nature, Louca and Pennell¹ challenge a major aspect of that enterprise.

Specifically, their work regards the issue of estimating past rates of speciation and extinction, which are, respectively, the rates at which new species arise and existing species go extinct. These rates determine the number of contemporary species of various forms. There are, for instance, around 6,600 species of songbird (passerines), which constitute more than half of all existing bird species, and we might therefore be tempted to say that songbirds have a high rate of speciation in comparison with that of other birds. But it's also possible to speculate that they have a low extinction rate. Louca and Pennell show that the uncertainty is even worse than this: not only can we not estimate these two rates, but also there is an infinite number of different sets of these two parameters that are equally good at describing any particular outcome, such as the number of species of contemporary songbird.

Comment:

Timing of Earth's biggest earthquakes follows a 'devil's staircase' pattern

Brooks Hays
UPI.com
Tue, 14 Apr 2020 17:30 UTC

© Angelo_Giordano/Pixabay
Scientists have found global earthquake sequences tend to occur in clusters -- outbursts of seismic events separated by long but irregular intervals of silence.

The timing of large, shallow earthquakes across the globe follows a mathematical pattern known as the devil's staircase, according to a new study of seismic sequences.

Previously, scientists and their models have theorized that earthquake sequences happen periodically or quasi-periodically, following cycles of growing tension and release. Researchers call it the elastic rebound model. In reality, periodic earthquake sequences are surprisingly rare.

Instead, scientists found global earthquake sequences tend to occur in clusters -- outbursts of seismic events separated by long but irregular intervals of silence.

The findings, published this week in the journal Bulletin of the Seismological Society of America, suggest large earthquakes increase the probability of subsequent seismic events.

Previous models failed to account for the interconnected nature of global fault systems. Seismic event don't occur in isolation. Each major quake alters the dynamics of other fault systems.

While the research suggests large quake sequences are "burstier" than previously thought, they remain as unpredictable as ever. The gaps between bursts are irregular, making it exceedingly difficult to anticipate the next cluster.

"Mathematically described as the devil's staircase, such temporal patterns are a fractal property of nonlinear complex systems, in which a change of any part -- e.g., rupture of a fault or fault segment -- could affect the behavior of the whole system," scientists wrote in their paper.

'Longest animal ever' discovered in deep-sea canyon off Australia's Ningaloo coast

Rachael Rettner
Live Science
Mon, 13 Apr 2020 21:15 UTC

Does it really count as one animal though?

Underwater explorers found a 150-foot-long (45 meters) siphonophore — a translucent, stringy creature that, like coral, is made up of smaller critters — living in a submarine canyon off the coast of Australia. It's "seemingly the largest animal ever discovered," they said.

Every individual siphonophore is made up of many little "zooids," which each live lives that are more similar to animals we're used to talking about, albeit always connected to the larger colony. Zooids are born axsexually, and each one performs a function for the siphonophore's larger body, according to a research article published in the journal Developmental Dynamics in 2005. Linked together in long chains, the colonies were already known to reach lengths of up to 130 feet (40 m) according to the Monterey Bay Aquarium — though each siphonophore is only about as thick as a broomstick.

New Comet P/2020 G1 (Pimentel)

Ernesto Guido & Adriano Valvasori
Remanzacco Blogspot
Fri, 17 Apr 2020 18:11 UTC

CBET 4754 & MPEC 2020-H06, issued on 2020, April 17, announce the discovery of a comet (magnitude ~15) by Eduardo Pimentel on CCD images taken by Jacques, Pimentel, and J. Barros with a 0.28-m f/2.2 astrograph of the "Southern Observatory for Near Earth Research" (SONEAR) at Oliveira, Brazil. The new comet has been designated P/2020 G1 (Pimentel).

We performed follow-up measurements of this object while it was still on the PCCP webpage.

Stacking of 7 unfiltered exposures, 24 seconds each, obtained remotely on 2020, April 15.4 from Q62 (iTelescope network) through a 0.50-m f/6.8 astrograph + CCD + focal reducer, shows that this object is a comet with a compact coma about 15" in diameter and a tail 20" long in PA 90.

Our confirmation image (click on it for a bigger version)

Quote of the Day

State power has its own limits defined by the fact that it is authority that reaches people from outside. State power cannot oversee and dictate the creative states of the soul and mind, the inner states of love, freedom and goodwill. The state cannot demand from its citizens faith, prayer, love, goodness and conviction. It cannot regulate scientific, religious and artistic creation. It should not intervene in moral, family and daily private life, and only when extremely necessary should it impinge on people's economic initiative and creativity.

- Ivan Ilyin

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Science & Technology

Betelgeuse is bright again, and it's a bit cooler

Interstellar comet 2I/Borisov's abundant carbon monoxide points to birth around cooler star

Achingly beautiful image shows us the chaos and wonder of Jupiter

Milky Way could be blasting stars into far reaches of the galaxy

If damaged, the adult brain repairs itself by going back to the beginning

Microbiome collaborate to cheat death

When the map doesn't work: Evolutionary trees can't reveal speciation and extinction rates

Timing of Earth's biggest earthquakes follows a 'devil's staircase' pattern

'Longest animal ever' discovered in deep-sea canyon off Australia's Ningaloo coast

New Comet P/2020 G1 (Pimentel)

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