Showing posts with label Hinode. Show all posts
Showing posts with label Hinode. Show all posts

Wednesday, October 22, 2014

NASA SDO: Electromagnetic 'Twisted rope' clue to dangerous solar storms

Model of the magnetic field in the region where occurred a major flare on December 13th 2006. 

This model has been obtained using magnetic field data obtained at the surface of the Sun by the satellite HINODE and the high resolution model MESHMHD few hours before the eruption. 

It shows that a magnetic rope (grey) is maintained in equilibrium by overlaying arcades (orange). 

Credit: Tahar Amari /Centre de physique théorique.CNRS-Ecole Polytechnique.FRANCE.

A "twisted rope" of magnetically-charged energy precedes solar storms that have the potential to damage satellites and electricity grids, French scientists said on Wednesday.

A cord of magnetic flux emerges on the Sun's surface, grows and is squeezed upwards, and the following day, the star unleashes a blast of radiation, high-energy particles and magnetised plasma.

Solar outbursts are considered a rare but increasingly worrisome risk for satellites, global positioning systems (GPS) and power grids on which modern life depends.

Reporting in the journal Nature, a team led by Tahar Amari of France's National Centre for Scientific Research (CNRS) looked at a solar storm that brewed in December 2006 and happened to be observed by a Japanese scientific satellite.

"We were able to identify the source of the eruption four days before it developed," Amari said to reporters.

"The magnetic field builds up in the shape of a twisted rope. The ends of the rope are anchored in sunspots," he said, referring to notoriously magnetised features on the solar surface.

Experts say solar storms can cause widespread breakdowns, disabling everything from power and radio to GPS geo-location and water supplies which rely on electrical pumps.

View of typical solar eruption using data from the NASA Solar Dynamic Observatory space mission. 

The Earth has been shown to show the gigantic size of the phenomena 

Credit: Tahar Amari /Centre de physique théorique.CNRS-Ecole Polytechnique.FRANCE

They begin with an explosion on the Sun's surface, known as a solar flare, sending X-rays and extreme ultra-violet radiation towards Earth at light speed.

Hours later, energetic particles follow and these electrons and protons can electrify satellites and damage their electronics.

Next are coronal mass ejections (CME), billion-tonne clouds of magnetised plasma that take a day or more to cross the Sun-Earth gap.

A solar storm in 1859 caused an electrical surge on telegraph lines that prompted some offices to catch fire and operators to receive shocks. A 1989 event caused power outages for five million people in the Canadian province of Quebec.

A 2009 report by a panel of scientists assembled by NASA warned that a catastrophic solar storm could cost the United States alone up to two trillion dollars (1.6 trillion euros) in repairs in the first year, and it could take up to 10 years to fully recover.

Predicting when these events will take place, and if Earth lies in their path, has been thwart with problems.

Eruption of the magnetic rope in the dynamic model METEOSOL after its departure from equilibrium 

Credit: Tahar Amari /Centre de physique théorique.CNRS-Ecole Polytechnique.FRANCE

On July 23, 2012, Earth narrowly missed the biggest storm in 150 years, an event big enough to "knock modern civilisation back to the 18th century," yet few humans were even aware of the peril, NASA said last July.

At present, Earth gets a few hours' warning of a solar eruption thanks to the eyes of orbiting US satellites.

But, said Amari, warning time should eventually improve.

"The work will help us fine tune knowledge about impending solar eruptions," he said.

"Using real-time magnetic data and mathematical models, it will eventually be possible to predict space weather."

More information: Characterizing and predicting the magnetic environment leading to solar eruptions, Nature, dx.doi.org/10.1038/nature13815

Tuesday, September 30, 2014

NASA SDO: Sounding rocket has 6 mins to study Solar Heating

A view of the sun from Sept. 24, 2014 from NASA's Solar Dynamics Observatory shows bright spots representing magnetically active regions in the lower right quadrant of the sun. 

The VAULT2.0 mission will focus on this area to better understand what heats the solar atmosphere. 

Credit: NASA/SDO

On Sept. 30, 2014, a sounding rocket will fly up into the sky,  past Earth's atmosphere that obscures certain wavelengths of light from the sun, for a 15-minute journey to study what heats up the sun's atmosphere.

This is the fourth flight for the Very high Angular Resolution Ultraviolet Telescope (VAULT), will launch from the White Sands Missile Range near Las Cruces, New Mexico.

The instrument, now called VAULT 2.0, has been refurbished with new electronics and an imaging detector to capture images more frequently than before.

While in space, VAULT 2.0 will observe light emitted from hydrogen atoms at temperatures of 18,000 to 180,000 degrees Fahrenheit.

"That's the temperature range where the action is," said Angelos Vourlidas, the principal investigator for VAULT 2.0 at the Naval Research Laboratory in Washington, D.C.

"These are the temperatures where the heating of the sun's atmosphere, the corona, really takes place."

Understanding how the corona heats remains one of the great, unanswered questions on the sun.

The solar surface itself is only about 10,500 F, but further up in the atmosphere, the temperatures rise to million of degrees Fahrenheit, the opposite of what one typically expects when moving away from a heat source.

Something heats up that corona, and VAULT 2.0 will be watching.

The sounding rocket will fly up to about 180 miles in the air, just below the height where the International Space Station travels. It will fly in an arc, taking 15 minutes from launch to landing back on the ground.

This allows for just six minutes of actual observations while it is above the atmosphere, during which VAULT 2.0 will capture an image every six to eight seconds.

Vourlidas plans to focus the telescope on active regions at the center of the sun, areas of intense and complex magnetic activity, to understand the heating process there.

NASA's Interface Region Imaging Spectrograph (IRIS)
During the VAULT 2.0 launch, three other observatories will watch the same area: NASA's Interface Region Imaging Spectrograph (IRIS), the joint Japanese Exploration Agency (JAXA) and NASA's Hinode, and NASA's Solar Dynamics Observatory (SDO).

IRIS focuses on solar material slightly hotter than does VAULT 2.0, while Hinode can see solar material both cooler and much hotter.

The temperatures also loosely correlate to heights in the atmosphere with the cooler temperatures at the bottom, and the hotter temperatures higher up.

SDO will observe the larger scale structure of the solar atmosphere as well as the underlying magnetic field.

"Together the three telescopes will be looking at a sandwich of solar material," said Vourlidas.

"We'll be looking at the layers from near the surface all the way up into the corona, the layers where the bulk of coronal heating is believed to happen."

VAULT's launch time is planned for 1:47 p.m. EDT on Sept. 30. Launch timing will depend on good weather conditions as well as optimum times for coordinating with Hinode satellite and IRIS spacecraft.

Thursday, March 6, 2014

JAXA Hinode SOT Solar Image: Sunspot Activity - Active Region 11967

Active Region 11967 consisted of a major sunspot that released numerous solar flares in early 2014. 

Above is an image taken by the Solar Optical Telescope (SOT) aboard Hinode in the Calcium II H line on Feb. 7, 2014 at 16:09 UT. 

Below is a wider view of Active Region 11967 as seen by SDO on Feb.12, 2014, at 01:35 UT. 

By studying the sun's magnetic field, scientists hope to shed new light on explosive solar activity that can interfere with satellite communications and electric power transmission grids on Earth and threaten astronauts on the way to or working on the surface of the moon. 

Solar Optical Telescope (SOT)
In particular they want to learn if they can identify the magnetic field configurations that lead to these explosive energy releases and use this information to predict when these events may occur. 

The Honide mission is led by the Japan Aerospace Exploration Agency (JAXA), and is a collaboration between the space agencies of Japan, the United States, the United Kingdom and Europe. 

NASA helped in the development, funding and assembly of the spacecraft's three science instruments. 

Hinode is part of the Solar Terrestrial Probes (STP) Program within the Heliophysics Division of NASA's Science Mission Directorate in Washington, which are also responsible for the Solar Dynamcis Observatory (SDO). 

Image credit: NASA/JAXA/Lockheed Martin

Friday, August 17, 2012

Observing Sunrise: Solar scientists review Hinode findings

Japan has a long tradition in solar physics and in 2006 launched one of the major space observatories – Hinode, which means 'sunrise' in Japanese.

For almost six years this satellite has been constantly monitoring our local star with a suite of three telescopes: the Solar Optical Telescope, X-ray Telescope and Extreme Ultraviolet Imaging Spectrometer (EIS).

Solar Optical Telecope
Together, they enable the study of how magnetic energy is generated and released in the atmosphere of our Sun.

This week in St. Andrews over 150 scientists from around the world gathered for the "Hinode 6" conference to celebrate what has been learnt using the Hinode satellite.

Although launched and led by Japan, the satellite has major contributions from the UK, the USA and Norway.

Extreme Ultraviolet Imaging Spectrometer (EIS)
Unexpectedly, St. Andrews has a connection to Hinode’s modern observing methods that dates back to the late 1600s.

The Scottish mathematician James Gregory upon walking along the beach in St. Andrews, Scotland, picked up a feather and wondered what would happen if a beam of light were shone through it.

Isaac Newton was conducting similar experiments with glass prisms in Cambridge.

Back in his lab, Gregory saw that the feather split the light into its component colours in a process now known as diffraction – a simple technique that is used today in many solar telescopes as it allows us to measure the properties of sunlight and in turn learn about the star that emitted it.

The Solar Science department at UCL led the development of the EIS telescope - a modern equivalent to the bird’s feather - which splits the ultraviolet light emitted from atmospheric gases into the component colours.

A major topic for discussion at the conference has been how magnetic fields that emanate up from the Sun’s surface into the atmosphere, create structures that glow in ultraviolet and X-rays and produce activity such as solar flares and coronal mass ejections (CME).

A large X-class flare captured by the X-ray telescope on Hinode. Image credit: JAXA/Hinode

High-speed gas flows associated to solar flares have been observed, helping scientists understand the processes that convert energy stored in the magnetic fields into energy of gas motions.

Computer models have been combined with observations to understand how currents surge along the magnetic structures, supported by the charged particles of the atmospheric gases, heating the atmospheric gases to very high temperatures.

Read the full article here at SEN: Solar scientists review Hinode findings