Neutron stars, the remains of massive stars that have imploded and gone supernova at the end of their life, can still create massive flares. These incredible bursts of energy release X-rays that propagate through space. It is a complex process to simulate but astronomers have turned to a supercomputer to help. Modelling the twisting magnetic fields, the interaction with gas and dust, the surface of flaring neutron stars has been revealed in incredible 3D.
The US Government budget announcement in March left NASA with two billion dollars less than it asked for. The weeks that followed have left NASA with some difficult decisions forcing cuts across the agency. There will be a number of cuts across the agency but one recent decision came as quite a shock to the scientific community. NASA have just announced they are no longer going to support the Chandra X-Ray Observatory which has been operational since 1999 and made countless discoveries.
Any astronomical instrument dubbed “Lobster Eyes” is bound to grab attention. It’s actually unlike scientists to give anything creative names, take the big red coloured storm on Jupiter which resembles a spot…aka the Great Red Spot! Lobster Eyes is the name adtoped by the X-ray telescope that just been launched from China and will scan the sky looking for X-rays coming from high-energy transients.
Simulation of glowing gas around a spinningblack hole. Credit: Chris White, Princeton University
Pick any object in the Universe, and it is probably spinning. Asteroids tumble end over end, planets and moons rotate on their axes, and even black holes spin. And for everything that spins, there is a maximum rate at which it can rotate. The black hole in our galaxy is spinning at nearly that maximum rate.
One of the miracles of modern astronomy is the ability to ‘see’ wavelengths of light that human eyes can’t. Last week, astronomers put that superpower to good use and released five new images showcasing the universe in every wavelength from X-ray to infrared.
Combining data from both Earth- and ground-based telescopes, the five images reveal a diverse set of astronomical phenomena, including the galactic centre, the death throes of stars, and distant galaxies traversing the cosmos.
What’s better than two gigantic galaxies swirling into one another until they collide? How about three galaxies swirling into one another until they collide – and they all have supermassive black holes at their core to boot! Recently, a team led by Dr. Adi Foord of Stanford combed through data from the WISE mission and the Sloan Digital Sky Survey to search for instances of three galaxies colliding with one another. In all that data, they managed to find 7 separate systems that met those criteria.
Canadian astronaut Chris Hadfield on an EVA, or spacewalk, during STS 100. Image Credit: NASA/CSA
Earth is a radiation cocoon. Inside that cocoon, the atmosphere and the magnetosphere keep us mostly safe from the Sun’s radiaition. Some ultraviolet light gets through, and can damage us. But reasonable precautions like simply minimizing exposure can keep the Sun’s radiation at bay.
But space is a different matter altogether. Among the many hazards it poses to astronauts, ever-present radiation is one that needs a solution.
Now a team of researchers have developed a new biomaterial to protect astronauts.
This visualization uses data from simulations of orbital motions of gas swirling around at about 30% of the speed of light on a circular orbit around the black hole. Credit: ESO/Gravity Consortium/L. Calçada
It’s relatively easy for galaxies to make stars. Start out with a bunch of random blobs of gas and dust. Typically those blobs will be pretty warm. To turn them into stars, you have to cool them off. By dumping all their heat in the form of radiation, they can compress. Dump more heat, compress more. Repeat for a million years or so.
Eventually pieces of the gas cloud shrink and shrink, compressing themselves into a tight little knots. If the densities inside those knots get high enough, they trigger nuclear fusion and voila: stars are born.
On June 5th, 2012, the NASA/JAXA Hinode mission captured these stunning views of the transit of Venus. Credit: JAXA/NASA/Lockheed Martin
Venus and Mercury have been observed transiting the Sun many times over the past few centuries. When these planets are seen passing between the Sun and the Earth, opportunities exist for some great viewing, not to mention serious research. And whereas Mercury makes transits with greater frequency (three times since 2000), a transit of Venus is something of a rare treat.
In June of 2012, Venus made its most recent transit – an event which will not happen again until 2117. Luckily, during this latest event, scientists made some very interesting observations which revealed X-ray and ultraviolet emissions coming from the dark side of Venus. This finding could tell us much about Venus’ magnetic environment, and also help in the study of exoplanets as well.
For the sake of their study (titled “X-raying the Dark Side of Venus“) the team of scientists – led by Masoud Afshari of the University of Palermo and the National Institute of Astrophysics (INAF) – examined data obtained by the x-ray telescope aboard the Hinode (Solar-B) mission, which had been used to observe the Sun and Venus during the 2012 transit.
Artist’s impression of the Hinode (Solar-B) spacecraft in orbit. Credit: NASA/GSFC/C. Meaney
In a previous study, scientists from the University of Palermo used this data to get truly accurate estimates of Venus’ diameter in the X-ray band. What they observed was that in the visible, UV, and soft X-ray bands, Venus’ optical radius (taking into account its atmosphere) was 80 km larger than its solid body radius. But when observing it in the extreme ultraviolet (EUV) and soft X-ray band, the radius increased by another 70 km.
To determine the cause of this, Afshari and his team combined updated information from Hinode’s x-ray telescope with data obtained by the Atmospheric Imaging Assembly on the Solar Dynamics Observatory (SDO). From this, they concluded that the EUV and X-ray emissions were not the result of a fault within the telescope, and were in fact coming from the dark side of Venus itself.
They also compared the data to observations made by the Chandra X-ray Observatory of Venus in 2001 and again in 2006-7m which showed similar emissions coming from the sunlit side of Venus. In all cases, it seemed clear that Venus had unexplained source of non-visible light coming from its atmosphere, a phenomena which could not be chalked up to scattering caused by the instruments themselves.
Comparing all these observations, the team came up with an interesting conclusion. As they state in their study:
“The effect we are observing could be due to scattering or re-emission occurring in the shadow or wake of Venus. One possibility is due to the very long magnetotail of Venus, ablated by the solar wind and known to reach Earth’s orbit… The emission we observe would be the reemitted radiation integrated along the magnetotail.”
Collected images of Venus 2012 transit of the Sun, taken in June of 2012 by NASA’s Solar Dynamics Observatory (SDO). Credit: NASA/SDO, AIA
In other words, they postulate that the radiation observed emanating from Venus could be due to solar radiation interacting with Venus’ magnetic field and being scattered along its tail. This would explain why from various studies, the radiation appeared to be coming from Venus’ itself, thus extending and adding optical thickness to its atmosphere.
If true, this finding would not only help us to learn more about Venus’ magnetic environment and assist our exploration of the planet, it would also improve our understanding of exoplanets. For example, many Jupiter-sized planets have been observed orbiting close to their suns (i.e. “Hot Jupiters“). By studying their tails, astronomers may come to learn much about these planets’ magnetic fields (and whether or not they have one).
Afshari and his colleagues hope to conduct future studies to learn more about this phenomenon. And as more exoplanet-hunting missions (like TESS and the James Webb Telescope) get underway, these newfound observations of Venus will likely be put to good use – determining the magnetic environment of distant planets.
Our Sun regularly pelts the Earth with all kinds of radiation and charged particles. Just how bad can these solar storms get?
In today’s episode, we’re going to remind you how looking outside of the snow globe can inspire your next existential crisis.
You guys remember the Sun right? Look how happy that little fella is. The Sun is our friend! Life started because of the Sun! Oooh, look, the Sun has a baby face! It’s a beautiful, ball of warmth and goodness, lighting up our skies and bringing happiness into our hearts.
It’s a round yellow circle in crayon. Very stable and firmly edged. Occasionally drawn with a orange lion’s mane for coronal effects. Nothing to be afraid, right?
Wake up sheeple. It’s time to pull back the curtain of the marketing world, big crayon fridge art and the children’s television conspiracy of our brightly glowing neighborhood monstrosity. That thing is more dangerous than you can ever imagine.
You know the Sun is a nuclear reaction right next door. Like it’s right there. RIGHT THERE! It’s a mass of incandescent gas, with a boiling bubbling surface of super-heated hydrogen. It’s filled with a deep yellow rage, expressed every few days by lashing out millions of kilometers into space with fiery death tendrils and blasts of super radiation.
The magnetic field lines on the Sun snap and reconnect, releasing a massive amount of radiation and creating solar flares. Solar plasma constrained in the magnetic loop is instantly released, smashed together and potentially generating x-ray radiation.
“Big deal. I get x-rayed all the time.” you might think. We the mighty humans have mastered the X-ray spectrum! Not so fast puny mortal. Just a single x-ray class flare can blast out more juice than 100 billion nuclear explosions.
In this image, the Solar Dynamics Observatory (SDO) captured an X1.2 class solar flare, peaking on May 15, 2013. Credit: NASA/SDO
Then it’s just a quick 8 minute trip to your house, where the radiation hits us with no warning. Solar flares can lead to coronal mass ejections, and they can happen other times too, where huge bubbles of gas are ejected from the Sun and blasted into space. This cosmic goo can take a few hours to get to us, and are also excellent set-ups for nocturnal emission and dutch oven jokes.
Astronomers measure the impact of a solar storm on the Earth using a parameter called DST, or “disturbance storm time”. We measure the amount that the Earth’s protective magnetosphere flexes during a solar storm event. The bigger the negative number, the worse it is.
If we can see an aurora, a geomagnetic storms in the high altitudes, it measures about -50 nanoteslas. The worst storm in the modern era, the one that overloaded our power grid in 1989, measured about -600 nanoteslas.
The most potent solar storm we have on record was so powerful that people saw the Northern Lights as far south as Cuba. Telegraph lines sparked with electricity and telegraph towers caught on fire. This was in 1859 and was clearly named by Syfy’s steampunk division. This was known as the Carrington Event, and estimated in the -800 to -1750 nanotesla range.
A spectacular green and red aurora photographed early this morning March 17, 2015, from Donnelly Creek, Alaska. Credit: Sebastian Saarloos
So, how powerful do these things need to be to cook out our meat parts? The good news is contrary to my earlier fear mongering, the most powerful flare our Sun can generate is harmless to life on Earth.
Don’t let your guard down, the Sun is still horribly dangerous. It’ll bake us alive faster than you can say “Hansel und Gretel”. Assuming you can drag that phrase out over a billion years. As far as flares go, and so long as we stay right here, we’ll be fine. We might even see a nice aurora in the sky.
For those of you who use technology on a regular basis, you might not be so lucky. Powerful solar storms can overload power grids and fry satellites. If the Carrington Event happened now, we’d have a lot of power go out, and a small orbital scrapyard of dead satellites.
Astronauts outside the Earth, perhaps bouncing around on the Moon, or traveling to Mars would be in a universe of trouble without a good method of shielding.
The solar flares that the Sun can produce is minuscule compared to other stars out there. In 2014, NASA’s Swift satellite witnessed a flare that generated more than 10,000 times more energy than the most powerful solar flare ever seen.
Solar flare on the surface of the Sun. Image credit: NASA
For a brief moment, the surface of the red dwarf star DG Canum Venaticorum lit up hotter than 200 million degrees Celsius. That’s 12 times hotter than the center of the Sun. A blast that powerful would have scoured all life from the face of the Earth. Except the future colony of tardigrade descendants. Remember, the water bears are always watching.
Young red dwarf stars are renowned for these powerful flares, and this is one of the reasons astronomers think they’re not great candidates for life. It would be hard to survive blast after blast of radiation from these unruly stars. Alternately, planets around these stars are could be living terrariums inspired by the Gamma World RPG.
Breathe easy and don’t worry. Perhaps the Sun is our friend, and it truly does have our best interests at heart.
It’s not a big fan of our technology, though, and it’s ready to battle alongside us when the robot revolution begins. Oh, also, wear sunscreen, as the Sun’s brand of love isn’t all that different from Doctor Manhattan.
Have you ever seen an aurora display? Tell us a cool story in the comments below.
