Strange Skies
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Cassiopaea

Most luminous white dwarf eruption spotted by astronomers

University of Leicester contributes to best-ever results on a 'new star' in a nearby galaxy.
Nova
© OGLE survey
Astronomers have today announced that they have discovered possibly the most luminous 'new star' ever - a nova discovered in the direction of one of our closest neighboring galaxies: The Small Magellanic Cloud.

Astronomers from the University of Leicester contributed to the discovery by using the Swift satellite observatory to help understand what was likely the most luminous white dwarf eruption ever seen.

A nova happens when an old star erupts dramatically back to life. In a close binary star system consisting of a white dwarf and a Sun-like companion star, material is transferred from the companion to the white dwarf, gradually building up until it reaches a critical pressure. Then uncontrolled nuclear burning occurs, leading to a sudden and huge increase in brightness. It is called a nova because it appeared to be a new star to the ancients.

Rainbow

Stunning fire rainbow illuminates the sky in a multi-colored display of light in northern Thailand

Fire rainbow over Thailand
This was the stunning moment a large fire rainbow appeared through the clouds.

Onlookers captured the beautiful sight in Chiang Mai province, northern Thailand, last Friday at 4pm local time.

The phenomenon - known as a circumhorizontal arc - is caused by sunlight shining through tiny ice crystals suspended in the atmosphere.

It causes a stunning rainbow-like effect that appears like a glowing ball of multi-coloured bright light in the sky.


Cloud Grey

Tube-shaped funnel cloud spotted in Niigat, Japan

Funnel cloud in Japan
© Screengrab via Daily Mail
An amazing tube-shaped cloud struck awe into witnesses when it was filmed in the sky above Japan.

The tube of pale cloud filmed in the city of Niigata in central Japan's Chubu Region looks only a few inches wide in the clip, snaking down from a sky full of dark grey clouds above, though its apparent size may be an optical illusion.

Japanese media reported that locals who witnessed the tube cloud were 'awe-struck' by the phenomenon.


Info

Picket fence auroras and plasma ropes, electrical phenomenon in Earth's skies intensifies

© JB Hawkins PhotographyA photo of "Steve" as seen from Darrington, Wash. on Sept. 27, 2017
With the geomagnetic storm on September 28-29, 2017 Earths skies were filled with plasma arcing bows stretching horizon to horizon, reforming into what was previously only ever seen twice before as a single strand. Now the amplification is an aural plasma bow. Earlier in the month there were picket auroras, and more red sprites and back in July 2017, incredibly rare ball lightning.


Sources

Camera

Incredible aurora phenomenon captured over Washington and Alberta

© JB Hawkins PhotographyA photo of "Steve" as seen from Darrington, Wash. on Sept. 27, 2017
Getting to see a brilliant display of the Northern Lights is pretty rare around Washington, but Tuesday night's display brought something even less common: A Steve sighting.

No, not the name of the photographers trying to capture the event (although I'm sure there were a few) but it's what citizen researchers have named a type of aurora streak that seems to dance in place as a vertical tube, rather than shimmering lights that sway across the skies.

"Steve" was coined by Chris Ratzlaff, a photographer and the administrator for "The Alberta Aurora Chasers" Facebook group. He and the site's members had noticed a long, tubular purplish part of the aurora. They called it "proton arc" but it attracted the attention of aurora researcher Prof. Eric Donovan with the University of Calgary. He saw their photos but knew proton arcs aren't visible so it had to be something else.


Ratzlaff told CBC-TV he came up with the name "Steve" after watching the movie "Over the Hedge" in which animals are scared of an unknown something on the other side of a hedge, and decide to call it Steve. The name has stuck. (Guess it's a good idea he wasn't watching Shrek.)

Donovan was able to go back and match the chasers' photos of Steve to when a satellite from the European Space Agency's "swarm" project flew through that spot and were able to detail changes in the electric fields.

Comment: Another incredible image of 'Steve' as a purple auroral arc was captured in the sky of Alberta on September 27, 2017 by Alan Dyer.

'Steve' purple arc over Alberta
© Alan Dyer
"The Steve arc appeared for only about 20 minutes, starting at 10:45 pm MDT, during a lull in the main display," says Dyer, who captured the arc in a 6-shot, 360o panorama.

A surprisingly strong G3-class geomagnetic storm meant the Northern Lights spilled over the Canadian border into more than half a dozen US states.


Cloud Grey

Huge 'alien ship' cloud appears over Maracaibo, Venezuela

Huge 'alien ship' cloud over Maracaibo, Venezuela
© Met Uy Station bcpHuge 'alien ship' cloud over Maracaibo, Venezuela
A huge 'alien ship' shaped cloud formed over the city of Maracaibo in Venezuela on Monday, September 25 prompting social networks like Twitter to go viral with announcements of the 'end of the world', as reported in Perú.com.

The article went on to explain that the phenomenon was caused by cloud iridescence (also called "fire rainbows" or "rainbow clouds"), whereby the sun's light is refracted by water droplets and ice crystals in the cloud. An iridescent cumulonimbus cloud was seen over Singapore in April this year.


Cassiopaea

Shedding more light on the 1572 supernova in Cassiopeia

Tycho Brahe star shines in gamma rays
© CC BY 2.0/NASA Goddard Space Flight Center/Tycho BraheTycho Brahe star shines in gamma rays.
Russian astronomer Marat Gilfanov managed to shed light on the origin of the world-famous supernova that flared up in the sky in 1572 and drastically changed scientists' perspective of astronomy at the time.

"The explosion of the [Tycho Brahe] supernova in the constellation of Cassiopeia in 1572 showed the whole world that the sky is not perennial as Aristotle wrote, and that the universe is constantly evolving," Russian astronomer Marat Gilfanov and his foreign colleagues said in a study published by the journal Nature Astronomy.

To understand the essence of the study, a small introduction to the nature of supernova might be needed.

Ice Cube

Megacryometeor? Huge ice block hits garden in Renfrewshire, Scotland

Ice block in Scottish garden
© Lyndsey Helliwell/SWNS.comEleanor Stephen said: 'I was sitting at my desk and heard this big boom. I thought it was an explosion and I felt the house shake'
A family had a lucky escape when huge block of ice fell from the sky and crashed into their garden.

The Helliwell family were left with a huge crater in their grass after the rock fell this morning.

The impact left a dent of 4ft 7in by 3ft 11in in the middle of their lawn and bits of ice scattered across the grass.

There has been no explanation for the freak incident but experts suspect the ice may have formed on the body of a passing aircraft.

Family friend Eleanor Stephen, 41, was at the Helliwell's home in Busby, Renfrewshire, when the ice struck.

She said: 'I was sitting at my desk and heard this big boom. I thought it was an explosion and I felt the house shake.

'When I went downstairs the dog was acting strangely. I looked out of the window and saw a hole with white stuff in it. It was splashed all over the grass.

Comment: See also: Icy 'Window Fallers' or Frozen Harbingers of Change? The Peculiar Phenomenon of Megacryometeor


Comet 2

Death from the clouds - Toxic Comets

Cumulus Congestus
© Flickr/Kevin Dooley
Although molecular Nitrogen represents 78.09% of the air we breath this doesn't mean all substances containing Nitrogen are nice and nurturing.

In reality Nitrogen is a very curious substance that can also be very nasty.

The combination of Nitrogen and Carbon in the form of Cyanogen is very toxic.
Cyanogen is the chemical compound with the formula (CN)2.

It is a colorless, toxic gas with a pungent odor.
cyanogen
© Malaga Bay
Like other cyanides, cyanogen is very toxic, as it readily undergoes reduction to cyanide, which poisons the cytochrome c oxidase complex, thus interrupting the mitochondrial electron transfer chain.
...
Inhalation of 900 ppm over a period of 10 minutes is considered lethal.

https://en.wikipedia.org/wiki/Cyanogen
Comet Composition
© Wikipedia
Comets are very toxic because they produce cyanogen.

Info

Doubt cast on what causes the northern lights

Northern Lights
© David Phan, CC by 2.0UAlberta physicists have shown that the mechanism thought to be the cause of the northern lights fly in the face of what is has been commonly accepted in the world of space science.
What scientists thought caused certain classes of northern lights is not what causes certain classes of northern lights.

In a landmark study that has toppled what scientists know about the night sky, UAlberta physicists Robert Rankin and Dmytro Sydorenko found that the ionospheric feedback instability (IFI)-the mechanism thought to be the cause of certain types of northern lights-not only doesn't cause northern lights, it may not even exist at all.

"These findings fly in the face of what is now commonly accepted in the world of space science," said Rankin. "Our research shows that conditions necessary for the ionospheric feedback instability to occur are very unlikely, meaning it cannot be the cause of something as regular as the Aurora Borealis."