SIGNS IN THE HEAVENS: Crater 2 - Humongous Galaxy Orbiting Our Own JUST APPEARED OUT OF NOWHERE?!

Milky Way. ESO / Serge Brunier, Frederic Tapissier via NASA

April 25, 2016 - SPACE - Researchers scanning the skies just got a big surprise. They spotted a humongous galaxy orbiting our own, where none had been seen before. It appeared, seemingly, out of nowhere.

So, just how did the newly-discovered Crater 2 manage to pull off this feat, like a deer leaping from the interstellar bushes to stare us down through our collective headlights?

Although the appearance may seem sudden, the fact is that Crater 2 has been there all along. We just missed it.

Now that we know it’s there, though, there are a few other humiliating details that astronomers discovered.

First of all, we can’t blame the galaxy’s size for its relative obscurity. Crater 2 is so enormous that researchers have already pegged it as the fourth largest galaxy orbiting our own.

We can’t blame its distance, either. Crater 2's orbit around the Milky Way puts it right in our neighborhood.

That said, how did we still not know it was there? A new paper out in Monthly Notices of the Royal Astronomical Society from researchers at the University of Cambridge has an answer for us. It turns out that, despite being large and close, Crater 2 is also a pretty dark galaxy.

In fact, it’s one of the dimmest galaxies ever spotted in the universe. That, along with some much brighter neighbors, let the galaxy that researchers have nicknamed “the feeble giant” escape detection until now.

Now that we have seen Crater 2, however, the discovery raises questions about what else is out there.

Researchers are already talking about mounting a search for similarly large, dark galaxies around us. It’s a good reminder that there’s still so much about space that we don’t know.
- Gizmodo.

ELECTRIC UNIVERSE: High-Energy Particles - Magnetic Jet Shows How Stars Begin Their Final Transformation; Crucial Step In Explaining How Some Of The Most Beautiful Objects In Space Are Formed!

September 17, 2013 - SPACE - An international team of astronomers have for the first time found a jet of high-energy particles emanating from a dying star. The discovery, by a collaboration of scientists from Sweden, Germany and Australia, is a crucial step in explaining how some of the most beautiful objects in space are formed -- and what happens when stars like the sun reach the end of their lives.

Two older objects, the Calabash nebula (a proto-planetary nebula) and M 2-9 (a young planetary nebula)
show how IRAS 15445-5449 (left panel) may evolve in the future. The white bar indicates 0.5 light year.
(Credit: E. Lagadec/ESO/A. Pérez Sánchez; NASA/ESA & Valentin Bujarrabal; B. Balick,
V. Icke, G. Mellema and NASA/ESA)

The researchers publish their results in the journal Monthly Notices of the Royal Astronomical Society.

At the end of their lives, stars like the sun transform into some of the most beautiful objects in space: amazing symmetric clouds of gas called planetary nebulae. But how planetary nebulae get their strange shapes has long been a mystery to astronomers.

Scientists at Chalmers University of Technology in Sweden have together with colleagues from Germany and Australia discovered what could be the key to the answer: a high-speed, magnetic jet from a dying star.

Using the CSIRO Australia Telescope Compact Array, an array of six 22-metre radio telescopes in New South Wales, Australia, they studied a star at the end of its life. The star, known as IRAS 15445−5449, is in the process of becoming a planetary nebula, and lies 23,000 light years away in the southern constellation Triangulum Australe (the Southern Triangle).

"In our data we found the clear signature of a narrow and extremely energetic jet of a type which has never been seen before in an old, sun-like star," says Andrés Pérez Sánchez, graduate student in astronomy at Bonn University, who led the study.

The strength of the radio waves of different frequencies from the star match the expected signature for a jet of high-energy particles which are, thanks to strong magnetic fields, accelerated up to speeds close to the speed of light. Similar jets have been seen in many other types of astronomical object, from newborn stars to supermassive black holes.

"What we're seeing is a powerful jet of particles spiralling through a strong magnetic field," says Wouter Vlemmings, astronomer at Onsala Space Observatory, Chalmers. "Its brightness indicates that it's in the process of creating a symmetric nebula around the star."

Right now the star is going through a short but dramatic phase in its development, the scientists believe.

"The radio signal from the jet varies in a way that means that it may only last a few decades. Over the course of just a few hundred years the jet can determine how the nebula will look when it finally gets lit up by the star," says team member Jessica Chapman, astronomer at CSIRO in Sydney, Australia.

The scientists don't yet know enough, though, to say whether our sun will create a jet when it dies. "The star may have an unseen companion -- another star or large planet -- that helps create the jet. With the help of other front-line radio telescopes, like ALMA, and future facilities like the Square Kilometre Array (SKA), we'll be able to find out just which stars create jets like this one, and how they do it," says Andrés Pérez Sánchez. - Space Daily.

FIRE IN THE SKY: "Lazarus Comets" - "Dead" Comets Closer To Earth Than Previously Thought, Return To Life After Million Of Years!

August 04, 2013 - SPACE - Millions of years ago the the main belt of asteroids between the orbits of Mars and Jupiter was populated by thousands of active comets. This population aged and the activity subsided. What we see today is the residual activity of that past. Twelve of those rocks are true comets that were rejuvenated after their minimum distance from the Sun was reduced a little. The little extra energy they received from the Sun was then sufficient to revive them from the graveyard. "These objects are the 'Lazarus comets', returning to life after being dormant for thousands or even millions of years," says astronomer Prof. Ignacio Ferrin. "Potentially any one of the many thousands of their quiet neighbors could do the same thing."

"We found a graveyard of comets," said Ferrín. "Imagine all these asteroids going around the Sun for aeons, with no hint of activity. We have found that some of these are not dead rocks after all, but are dormant comets that may yet come back to life if the energy that they receive from the Sun increases by a few per cent."

The researchers, led by Anitoquia's Ignacio Ferrin, describe how some of these objects, inactive for millions of years, have returned to life. The team publish their results in the Oxford University Press journal Monthly Notices of the Royal Astronomical Society.

Comets are amongst the smallest objects in the Solar System, typically a few km across and composed of a mixture of rock and ices. If they come close to the Sun, then some of the ices turn to gas, before being swept back by the light of the Sun and the solar wind to form a characteristic tail of gas and dust.

Most observed comets have highly elliptical orbits, meaning that they only rarely approach the Sun. Some of these so-called long period comets take thousands of years to complete each orbit around our nearest star. There is also a population of about 500 short period comets, created when long period comets pass near Jupiter and are deflected in orbits that last anything between 3 and 200 years. Although uncommon events, comets also collide with Earth from time to time and may have helped bring water to our planet.

The new work looked at a third and distinct region of the Solar System, the main belt of asteroids between the orbits of Mars and Jupiter shown below. This volume of space contains more than 1 million objects ranging in size from 1 m to 800 km. The traditional explanation for asteroids is that they are the building blocks of a planet that never formed, as the movement of the pieces was disrupted by the strong gravitational field of Jupiter.

In the last decade 12 active comets have been discovered in the asteroid main belt region. This was something of a surprise and the Medellin team set out to investigate their origin. The team, made up of Prof. Ferrin and his colleagues Profs. Jorge Zuluaga and Pablo Cuartas, now think they have an explanation.

Surprisingly, this "rebirth" can occur fairly easily, as the orbits of many objects in the asteroid belt are nudged by the gravity of Jupiter. The shape of their orbits can then change, leading to a decrease in the minimum distance between the object and the Sun (perihelion) and a slight increase in average temperature. - Daily Galaxy.

SIGNS IN THE HEAVENS: Extremely Rare Triple Quasar Found - For Only The Second Time In History!

March 13, 2013 - SPACE -For only the second time in history, a team of scientists have discovered an extremely rare triple quasar system.

For only the second time in history, a team of scientists including Michele Fumagalli from the Carnegie Institution for Science in the United States have discovered an extremely rare triple quasar system. Their work is published in the Oxford University Press journal Monthly Notices of the Royal Astronomical Society.

Quasars are extremely bright and powerful sources of energy that sit in the centre of a galaxy, surrounding a black hole. In systems with multiple quasars, the bodies are held together by gravity and are believed to be the product of galaxies colliding.

It is very difficult to observe triplet quasar systems, because of observational limits that prevent researchers from differentiating multiple nearby bodies from one another at astronomical distances. Moreover, such phenomena are presumed to be very rare.

An infrared image of the triple quasar system QQQ J1519+0627, made using the 3.5-m aperture telescope of the Calar Alto Observatory. The three quasars are labelled A, B and C. Credit: Emanuele Paolo Farina.

The team led by Emanuele Farina of the University of Insubria in Como, Italy, combined observations from the New Technology Telescope of the European Southern Observatory at La Silla, Chile and from the Calar Alto Observatory in Spain with advanced modelling. This enabled them to find the triplet quasar, called QQQ J1519+0627.

The light from the three quasars has travelled 9 billion light years to reach us, which means the light was emitted when the universe was only a third of its current age.

Advanced analysis confirmed that what the team found was indeed three distinct sources of quasar energy and that the phenomenon is extremely rare.

Two members of the triplet are closer to each other than the third. This means that the system could have been formed by interaction between the two adjacent quasars, but was probably not triggered by interaction with the more-distant third quasar.

Furthermore, no evidence was seen of any ultra-luminous infrared galaxies (galaxies with very strong emission in infrared light), which is where quasars are commonly found. As a result, the team proposes that this triplet quasar system is part of some larger structure that is still undergoing formation.

“Honing our observational and modelling skills and finding this rare phenomenon will help us understand how cosmic structures assemble in our universe and the basic processes by which massive galaxies form,” Fumagalli said.

“Further study will help us figure out exactly how these quasars came to be and how rare their formation is,” Farina added.

Via Royal Astronomical Society

- Earth Sky.

FIRE IN THE SKY: "Unusual" Daytime Fireball Over Chelmsford in the United Kingdom is a Burning Mystery!

November 17, 2012 - UNITED KINGDOM - These photographs apparently show a large fireball in the skies above Chelmsford.  The pictures are just two of a series taken by Eleanor Collop, 13, and her 17-year-old sister Leanne, after they spotted the 'meteor' from outside their home on the Beechenlea Estate.  The burning object was seen high in the sky last Friday at 4pm and appeared to fall to earth, leaving the sisters to wonder whether they had just witnessed a plane crash. 

Debris: This piece detached
from the fireball, Eleanor said.
© This Is Total Essex.

Eleanor, a student at Hylands School, said: "I haven't seen anything like that before - it was so bright."  She spotted the object - with a distinctive fiery core and long, forked tail - as she got ready for her after-school paper-round.  "I was just taking my trolley from the garage when I caught sight of it," said Eleanor.  "At first I thought it was a plane but it got brighter and brighter.  "I shouted for my sister and then we called our dad, who told us to take a picture."  The fireball - thought to be caused by debris burning up in the earth's atmosphere - spent five minutes visible in the Chelmsford sky before it disappeared behind some houses.  "I'm not sure what it was but it was bright and it definitely looked like it was burning," added Eleanor, who used a normal ten-megapixel camera to capture the images. 

The event stunned the family so much that Eleanor's mother, Martine, called the police to ask if anyone else in Essex had seen a burning meteor.  "I just can't believe Eleanor and Leanne were the only two people to see it," she said.  An expert from the Royal Astronomical Society said it was "unusual" to see a meteor during the day.  Dr Robert Massey said: "On the face of it, the streaks look a lot like aircraft contrails illuminated by the setting sun.  "That said, there are occasional meteors that are bright enough to be seen in daylight - in this case the sun didn't set until around 4.15pm.  "So, without having seen it in motion, this may be an image of a larger-than-average piece of debris burning up in the Earth's atmosphere," he added.  "This happens all the time and are normally seen at night as shooting stars, most of which are relatively small.  "But it's unusual to see an event during the day." - Total Essex.