Welcome to Sott.net
Tue, 28 Mar 2017
The World for People who Think

Strange Skies


Sun

Sun halo awes visitors to Anhui province in China

© VCG
On March 26, a solar halo appeared in the sky above the historic city of Huangshan, in east China's Anhui Province.

According to local media, the halo appeared at around 11am and lasted for almost two hours.

Photographers were able to snap some stunning pictures, as the bright halo rings reflected rainbow colors.

China Meteorological Administration describes solar halos as optical phenomena that form when hexagonal ice crystals in cirrus clouds refract and reflect the sun light.

Solar halos often appear in spring and summer. This was the first solar halo to be observed in Huangshan's Shexian county since 2012.

Comment: Rare double sun halos appeared the same day in Yongzhou City, central China.

© Central China Television



Sun

Sun halo spotted in Tennessee Valley, Alabama

© Ramona Edwards
Did you see a halo around the sun Wednesday?

If you did, you spotted an atmospheric optical phenomenon known as a 22-degree halo.

Earthsky.org explains it very simply: "Halos are a sign of high thin cirrus clouds drifting 20,000 feet or more above our heads.

These clouds contain millions of tiny ice crystals. The halos you see are caused by both refraction, or splitting of light, and also by reflection, or glints of light from these ice crystals."

It is called a 22-degree halo because the ring has a radius of approximately 22 degrees around the sun or moon.

Cassiopaea

Supernova spotted in constellation Lupus

© Racheal Beaton/Carnegie Institution for Science
When most people hear the word supernova, they envision a massive star reaching the end of its life and exploding outwards to leave a ghostly remnant in its place. This is called a Type II supernova — the spectacular Supernova 1987A, which recently celebrated its 30th anniversary, was a Type II.

Alternatively, a Type Ia supernova occurs when a white dwarf, the remnant of a Sun-like star, grows too massive after stripping a binary companion star of its outer layers. When the white dwarf reaches a critical mass, a runaway fusion reaction occurs in its core and the star explodes in a Type Ia supernova. Such a supernova has just been spotted occurring in a galaxy about 55 million light-years away.

Announced by Rachael Beaton at the the Observatories of the Carnegie Institution for Science in Pasadena, CA, and known as 2017cbv (though Beaton has nicknamed it Bob), the explosion was spotted in NGC 5643, a spiral galaxy in the constellation Lupus.

The area of the sky it inhabits is also part of the area covered by the Carnegie-Irvine Galaxy Survey, a project aimed at gathering optical and near-infrared images of bright Southern Hemisphere galaxies. NGC 5643 was also the home galaxy of SN 2013aa, which occurred in early 2013.

Fireball

SOTT Earth Changes Summary - February 2017: Extreme Weather, Planetary Upheaval, Meteor Fireballs

Februrary 2017 continued on as January started. Massive flooding in California due to "atmospheric rivers" dumping large amounts of rain on coastal areas and snow on the Sierra Nevada. The snow melt from this caused further flooding in Nevada. Eastern Canada also experienced record snowfall, as did Iran, Kazakhstan, Afghanistan and Japan.

Wildfires broke out in Eastern Australia and New Zealand while record rainfall inundated Western Australia. Major flooding also hit several South American nations including Chile, Peru and Colombia.

There are at least 30 active volcanoes around the world right now, including a really impressive one in Guatemala. Massive earth cracks opened in Pakistan and Italy.

These are just some of the chaotic events we present in this month's Sott 'Earth Changes' video compilation.


Info

Ultra-bright star in the Crab Nebula, breaks all the rules

© NASA/Getty Images
Multiple images of the Crab Nebula made over a span of several months with NASA's Chandra X-ray Observatory show matter and antimatter propelled to nearly the speed of light by the Crab pulsar, a rapidly rotating neutron star the size of Manhattan.
Well, bang go those theories. Astrophysicists have identified a neutron star that overturns not one but three well supported hypotheses.

The star, known as NGC 5907 ULX, is emitting far more x-rays than any other ever observed.

So huge is the output that it has been classified as an "ultraluminous x-ray source" (ULX). It is by no means the first ULX to be recorded in nearby galaxies, but all the others are confidently predicted to be generated by black holes - this is the first one that uses star-power.

So there goes the first theory.

But there are still more baffling elements to the discovery, made by a team led by Gianluca Israel from the National Institute of Astrophysics in Rome, Italy, and reported in Science.

Sun

Sunday's 'Ring of fire' eclipse visible in the southern half of our planet is a treat or omen of upheaval? (Video)

Space nerds are in for a treat on Sunday when the moon blocks out the sun in an annual solar eclipse that will cloak more than two dozen countries and three continents in momentary darkness.

Astronomers can see the cosmic display from 8:16am ET (US), but, unfortunately for northern hemisphere stargazers, the eclipse will only be visible in the southern half of our planet, moving across South America, the Atlantic Ocean, Antarctica, and Africa.

Info

Rare nebula, ELAN discovered - No obvious source of power for the light it is emitting

© Figure 2 of Cai et al., Astrophysical Journal
MAMMOTH-1 is an extended blob of gas in the intergalactic medium called an enormous Lyman-alpha nebula (ELAN). The color map and contours denote the surface brightness of the nebula, and the red arrows show its estimated spatial extent.
Astronomers have found an enormous, glowing blob of gas in the distant universe, with no obvious source of power for the light it is emitting. Called an "enormous Lyman-alpha nebula" (ELAN), it is the brightest and among the largest of these rare objects, only a handful of which have been observed.

ELANs are huge blobs of gas surrounding and extending between galaxies in the intergalactic medium. They are thought to be parts of the network of filaments connecting galaxies in a vast cosmic web. Previously discovered ELANs are likely illuminated by the intense radiation from quasars, but it's not clear what is causing the hydrogen gas in the newly discovered nebula to emit Lyman-alpha radiation (a characteristic wavelength of light absorbed and emitted by hydrogen atoms).

The newly discovered nebula was found at a distance of 10 billion light years in the middle of a region with an extraordinary concentration of galaxies. Researchers found this massive overdensity of early galaxies, called a "protocluster," through a novel survey project led by Zheng Cai, a Hubble Postdoctoral Fellow at UC Santa Cruz.

"Our survey was not trying to find nebulae. We're looking for the most overdense environments in the early universe, the big cities where there are lots of galaxies," said Cai. "We found this enormous nebula in the middle of the protocluster, near the peak density."

Attention

HAARP lives! US military weapon reactivated 'for experiment to create and study artificial auroras'

© KTUU
This week at the High-frequency Active Auroral Research Program (HAARP) about a half dozen scientists are running experiments, including Chris Fallen, Assistant Research Professor with the University of Alaska Fairbanks Geophysical Institute.

Over the course of four nights, Fallen has been attempting to create and study the artificial aurora.

"The more we understand about the artificial aurora, it helps us understand the natural aurora and vice versa," says Fallen.

Natural aurora occurs because high speed electrons hit the upper atmosphere and collide with gases there. The resulting light appears as aurora to the human eye and camera lens.

Fallen is trying to reproduce that using radio waves from HAARP as the energy source. "We're accelerating the electrons with radio waves through processes that are not fully understood and those electrons are accelerated to high velocities and collide with the gases in the atmosphere and create air-glow in basically the same colors as the natural aurora."

Comment: Uhm, didn't they say they were shutting down HAARP in 2014?

So now it's in civilian hands. Or so they say...


Bizarro Earth

Purple rain: Thunderstorms turn Houston sky to vivid shades pink and purple

© Bruna Pantarotto Souza
Bruna Pantarotto Souza shares a view of a cloudy purple sky in Spring, Texas.

Houston-area residents woke up to a colorful view as severe thunderstorms began to roll in Monday morning, and this time, it wasn't a rainbow.

The sky lit up with vivid shades of pink and purple as the sun rose — and social media users couldn't help but connect the stunning sky's magenta hue with Prince's famous "Purple Rain" song.

It was unlike anything residents had seen before.

"It was raining pretty bad and I just woke up to see what was going on and saw this amazing sky," Bruna Pantarotto Souza from Spring, Texas, told CBS News. "I've never seen this before."

Rainbow

Rare 'fire rainbow' lights up the sky over Singapore

© Chi Navarro
The fire rainbow above Singapore

Observers say fleeting phenomenon lasted 15 minutes


Singapore was treated to a rare weather phenomenon as an apparent "fire rainbow" lit up the sky.

Weather watchers on the island state in south-east Asia were treated to the multi-coloured glow yesterday.

The stunning scene may also have been cloud iridescence. Both phenomena can be caused by the refraction of light through ice crystals, or in the case of iridescence, by water droplets.

For iridescence to occur clouds must be thin so the sun's rays encounter very little water.

The technical name for a fire rainbow is a "circumhorizontal arc".

The light show persisted for about 15 minutes and could reportedly be seen across the island.