phys.org
Scientists discover hidden galaxies behind the Milky Way
Hundreds of hidden nearby galaxies have been studied for the first time, shedding light on a mysterious gravitational anomaly dubbed the Great Attractor.

Despite being just 250 million light years from Earth—very close in astronomical terms—the new galaxies had been hidden from view until now by our own galaxy, the Milky Way.

Using CSIRO’s Parkes radio telescope equipped with an innovative receiver, an international team of scientists were able to see through the stars and dust of the Milky Way, into a previously unexplored region of space.

The discovery may help to explain the Great Attractor region, which appears to be drawing the Milky Way and hundreds of thousands of other galaxies towards it with a gravitational force equivalent to a million billion Suns.

Lead author Professor Lister Staveley-Smith, from The University of Western Australia node of the International Centre for Radio Astronomy Research (ICRAR), said the team found 883 galaxies, a third of which had never been seen before.

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NASA Astronomy Picture of the Day 2016 February 9 

The Rise and Fall of Supernova 2015F 

Sit back and watch a star explode. The actual supernova occurred back when dinosaurs roamed the Earth, but images of the spectacular event began arriving last year. Supernova 2015F was discovered in nearby spiral galaxy NGC 2442 by Berto Monard in 2015 March and was unusually bright – enough to be seen with only a small telescope. The pattern of brightness variation indicated a Type Ia supernova – a type of stellar explosion that results when an Earth-size white dwarf gains so much mass that its core crosses the threshold of nuclear fusion, possibly caused by a lower mass white-dwarf companion spiraling into it. Finding and tracking Type Ia supernovae are particularly important because their intrinsic brightness can be calibrated, making their apparent brightness a good measure of their distance – and hence useful toward calibrating the distance scale of the entire universe. 

The featured video tracked the stellar disruption from before explosion images arrived, as it brightened, and for several months as the fission-powered supernova glow faded. The remnants of SN2015F are now too dim to see without a large telescope.

I had my proudest moment of the year today during my cosmology lab. A friend of mine was struggling with getting good results for his model universe:

“Why is there a kink in my contours?”
“Are you kinkshaming the data?”

Everyone hated me while I just laughed on my own.

(Also we’re on week 4 of 9 and I preeetty much finished the project. My supervisor told me he was just trying to get me to waste time now while he thinks of other things I could do, because when I asked “what next?” he said “go home and gloat”. Well at least I’m still good at some stuff!)

Feb. 9, 1995, Bernard Harris and Michael Foale Ready For a Spacewalk

STS-63 astronauts Bernard A. Harris, Jr., payload commander (right), and C. Michael Foale, mission specialist (left), are ready to exit space shuttle Discovery’s airlock for a spacewalk on Feb. 9, 1995. The pair would test modifications to their spacesuits to keep spacewalkers warmer in the extreme cold of space. The astronauts were also scheduled to practice handling the approximately 2,500-pound (1,134-kilogram) SPARTAN spacecraft to rehearse space station assembly techniques, but this task was cut short by Mission Control after the men reported feeling very cold in their suits.

On this extravehicular activity (EVA), which lasted 4 hours and 38 minutes, Bernard Harris became the first African-American to walk in space.

Credit: NASA

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Is the multiverse a scientific theory?

“The thing is, the Multiverse is not a scientific theory on its own. Rather, it’s a theoretical consequence of the laws of physics as they’re best understood today. It’s perhaps even an inevitable consequence of those laws: if you have an inflationary Universe governed by quantum physics, this is something you’re pretty much bound to wind up with. But — much like String Theory — it has some big problems: it doesn’t predict anything we either have observed and can’t explain without it, and it doesn’t predict anything definitive we can go and look for.”

When people use the word theory colloquially, they use it to mean an “idea” or a “possibility” that could conceivably be at play. But a scientific theory has a much more stringent set of things it must accomplish: it must encompass all the successes of the previously leading theory, it must make successful predictions for phenomena that the leading theory cannot make, and it must predict additional, novel phenomena that can be either validated or refuted. So, is the Multiverse a scientific theory? It arises as a consequence of a scientific theory, but it fails on the grounds of making successful and novel predictions. While it might someday rise to the status of a scientific theory, it isn’t there today.

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NASA Astronomy Picture of the Day 2016 January 27 

An Airglow Fan from Lake to Sky 

Why would the sky look like a giant fan? Airglow. The featured intermittent green glow appeared to rise from a lake through the arch of our Milky Way Galaxy, as captured last summer next to Bryce Canyon in Utah, USA. The unusual pattern was created by atmospheric gravity waves, ripples of alternating air pressure that can grow with height as the air thins, in this case about 90 kilometers up. Unlike auroras powered by collisions with energetic charged particles and seen at high latitudes, airglow is due to chemiluminescence, the production of light in a chemical reaction. More typically seen near the horizon, airglow keeps the night sky from ever being completely dark.

Henry Wheaton - Norse Cosmos of the Nine Worlds, “Histoire des peuples du nord, et des Danois et des Normands”, 1844.

The cosmic geography in which the Norse deities dwell encompasses nine realms of interconnected realities that are often referred to as the Nine Worlds. These realms are all linked together by the various branches of the cosmic ash tree referred to in the myths as Yggdrasil. Asgard was connected to Midgard (the Earth) by a rainbow-hued bridge called Bifrost.  The Nine Worlds of the Norse cosmology are the following:

1.  Asgard - the realm inhabited by the great majority of the Norse deities, and ruled by Odin and Frigga. Most of the deities have their own palace, and it’s the original home of the war-loving Aesir tribe. Asgard is described in the myths as an amazing and majestic realm of towering spires and palaces of gold and silver situated within a remarkable city. It is surrounded by miles and miles of enchanted woodlands, rivers, and seas, which are populated by a large number of life forms, many of them analogous to Earth creatures, such as dogs, cats, and horses, and others unlike anything natural to the biological fauna of Earth, including dragons and various types of sea serpents. This realm is also the original home of the Aesir, one of the two tribes of deities who merged into a single tribe, the Asgardians. A special section of Asgard called Valhalla is inhabited by the souls of heroic and virtuous mortals who followed the Norse path, and these honored dead, known collectively as the Einerjar, are ruled by Odin and Freya (each of whom rules over half of these fallen heroes).    

2. Vanaheim - former home of the Vanir, a tribe of peaceful but powerful fertility deities, that went to war with the Aesir of Asgard and eventually achieved peace with them, merging and intermarrying with this other tribe, and making their home with them in Asgard.  Vanaheim, like Asgard, is a spectacular realm that is dotted with vast, unspoiled forests and bodies of water, all of which are inhabited by nature spirits and equivalents of Earth animals.      

3. Alfheim - the realm of the Light Elves, once ruled by the Norse god Frey in his youth (who since migrated to Asgard).  The light elves are the enchanted, shape-shifting beings of great magickal power who were known to the Celtic people as the faerie folk, or fays, and Alfheim is simply another word for the twilight realm known in Ireland and Scotland as Faerieland.       

4. Svartalfheim - the home of the Dark Elves, an offshoot species of the inhabitants of Alfheim, who have been known to people in the Western world as goblins, bogarts, and many other names.       

5. Midgard - this word, meaning “Middle Realm,” is the Asgardian name for the Earth dimension, which is the material manifested world of humanity that we mortals inhabit.  As we all know, our realm operates under a set of physical laws recognized by science, but the quantum nature of our reality enables mortals of varying skill to wield energies that can be drawn from the other, magickal realms comprising the Nine Worlds (and beyond).        

6. Jotunheim - the realm of the Jotun, or Giants, a third tribe of humanoid beings of great magickal power to rival the Aesir and Vanir who never made peace with either of these other two tribes, and are considered their sworn enemies. This realm is distinguished by an extremely cold, snow-capped tundra and huge mountain ranges.    

7. Nidavellir - rocky realm characterized by miles of caves whose whose lower levels are inhabited by the diminutive and elusive race of humanoid beings known as the Dwarves, where they maintain their forges that they sometimes use in the service of the deities, and occasionally for a few select mortals.    

8. Helheim (Hel) - this is the twilight realm of the common dead, the souls of those mortals and deities living under the purview of the Norse cosmology who were neither truly heroic nor truly evil, and are ruled by the death goddess Hela, where her great palace resides.  Helheim (not to be confused with the Hell of Biblical legend) is described as having a gray, barren, and bleak landscape.      

9. Niflheim - this frozen reality of endless snowscapes is the bitter realm of the dishonored - i.e., evil dead, the relatively small number of mortal souls of those people who were truly and remorselessly malicious or murderous while alive. It’s described in the legends as being an extremely cold, frozen landscape of endless night. The souls confined to that realm are subject to frequent hardships and tortures, and also fall under the rulership of the death goddess Hela. Niflheim is the former home of Ymir, the primal frost giant, and the birthplace of the later race of giants whom he spawned during the early history of the Nine Worlds. Niflheim may also be the same dimensional plane as the afterlife realm sometimes referred to as Winterland, where a small number of Wiccans fear that the most malign amongst their number may dwell at least temporarily following their mortal demise.        

Beatrice Tinsley, the (uncelebrated) cosmologist you should know

Beatrice Tinsley was born in England on 27 January 1941, when cosmologists were only just realising the enormous scale and structure of the universe. Tinsley’s name is not widely known but her work in cosmology and astrophysics made fundamental contributions to our understanding of how galaxies evolve.

Tinsley’s research changed the standard method for determining distances to far-away galaxies. This was significant in determining the size of the universe and its rate of expansion - leading ideas behind the development of the Big Bang theory.

She completed her Ph.D and wrote an “extraordinary and profound” dissertation on the evolution of galaxies in only two years. Despite her enormous intellect, she was initially overlooked in the male-dominated world of astronomy. She found resistance to her ideas from many senior scientists and struggled to have her work accepted.

She eventually made her way to Yale University and in 1978 became a professor of astronomy and the chairman of the Conference on Cosmology’s organizing committee. In the six years she was there, Tinsley published many scientific papers which cosmologists today have said make her world-leading in the field. But, aged 40, she died of cancer. She would have been 75 today. 

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Scientists Find Evidence for Ninth Planet in Solar System

A planet larger than Earth could be hiding in the cold, dark depths of the solar system. The presence of the planet, which would lie far beyond Pluto, is betrayed by the curious orbits of a handful of distant icy worlds.

A ninth large planet may lurk deep in the outer solar system. The planet, illustrated here, is far from the sun and thought to be gaseous like Uranus and Neptune, though smaller than both ice giants.

As described Wednesday in the Astronomical Journal, the gravitational signature of a large, lurking planet is written into the peculiar orbits of these farflung worlds. Called extreme Kuiper Belt Objects, the misbehaving bodies trace odd circles around the sun that have puzzled scientists for years.

It’s tantalizing evidence that a ninth large planet might live in the solar system, though the world hasn’t been detected yet.

Read more at National Geographic