Sun | Science Of Cycles News and Research

BREAKING NEWS: New Findings Illustrate Secondary Extended Solar Cycles Far Greater Danger than Previously Known

Based on a new study, space scientists at the University of Reading are predicting we are witness to the beginning of a longer-term solar cycle, which will exceed the better-known 11 year and 22 year cycles. Each cycle consist of a ‘solar minimum’ and ‘solar maximum’ measured by the number of sunspots during these periods – and the waxing and waning of charged particles produced by solar flares, coronal mass ejections, coronal holes, and charged filaments.

This research is produced by Dr Mathew Owens, from the University of Reading’s Meteorology department, and Co-author Professor Mike Lockwood FRS, University of Reading. Their paper was published in the journal ‘Scientific Reports’. “The magnetic activity of the Sun ebbs and flows in predictable cycles, but there is also evidence that it is due to plummet, possibly by the largest amount for 300 years”; said Owens.

As the Sun becomes less active, sunspots and coronal ejections will become less frequent. As this trend continues over time, the escalating reduction in solar wind has a direct causal effect on the layers of the Sun’s atmosphere. The most significant effect will be on the ‘heliosphere’ – which like Earth’s magnetic field, shields the Earth dangerous charged particles and radiation.

**I am working on the completion of this study – hope to have it published tomorrow. STAY TUNED…..

ALMA Starts Observing the Sun – VIDEO

Astronomers have harnessed ALMA‘s capabilities to image the millimeter-wavelength light emitted by the Sun’s chromosphere – the region that lies just above the photosphere, which forms the visible surface of the Sun. The solar campaign team, an international group of astronomers with members from Europe, North America and East Asia, produced the images as a demonstration of ALMA’s ability to study solar activity at longer wavelengths of light than are typically available to solar observatories on Earth. Atacama Large Millimeter/submillimeter Array (ALMA)

Astronomers have studied the Sun and probed its dynamic surface and energetic atmosphere in many ways through the centuries. But, to achieve a fuller understanding, astronomers need to study it across the entire electromagnetic spectrum, including the millimeter and submillimeter portion that ALMA can observe.

Since the Sun is many billions of times brighter than the faint objects ALMA typically observes, the ALMA antennas were specially designed to allow them to image the Sun in exquisite detail using the technique of radio interferometry – and avoid damage from the intense heat of the focused sunlight. The result of this work is a series of images that demonstrate ALMA’s unique vision and ability to study our Sun.The data from the solar observing campaign are being released this week to the worldwide astronomical community for further study and analysis.

The team observed an enormous sunspot at wavelengths of 1.25 millimeters and 3 millimeters using two of ALMA’s receiver bands. The images reveal differences in temperature between parts of the Sun’s chromosphere. Understanding the heating and dynamics of the chromosphere are key areas of research that will be addressed in the future using ALMA.Sunspots are transient features that occur in regions where the Sun’s magnetic field is extremely concentrated and powerful. They are lower in temperature than the surrounding regions, which is why they appear relatively dark.

The difference in appearance between the two images is due to the different wavelengths of emitted light being observed. Observations at shorter wavelengths are able to probe deeper into the Sun, meaning the 1.25 millimeter images show a layer of the chromosphere that is deeper, and therefore closer to the photosphere, than those made at a wavelength of 3 millimeters.

ALMA is the first facility where ESO is a partner that allows astronomers to study the nearest star, our own Sun. All other existing and past ESO facilities need to be protected from the intense solar radiation to avoid damage. The new ALMA capabilities will expand the ESO community to include solar astronomers.

Interplay of Magnetic Fields and Gravitation in Star Development

Space bears witness to a constant stream of star births. Whole star clusters are often formed at the same time – and within a comparatively short period. Amelia Stutz and Andrew Gould from the Max Planck Institute for Astronomy in Heidelberg have proposed a new mechanism to explain this quick formation.

Star formation is basically a simple process: You take a very cold cloud consisting of hydrogen gas and a sprinkling of dust and leave the system to get on with it. Then, within the space of a few million years, the sufficiently cold regions will collapse under their own gravity and form new stars.

Reality is a bit more complicated. A particular feature is that there seem to be two types of star formation. In conventional, smaller molecular clouds, only one or a few stars form – until the gas has dispersed over a period of three million years or so. Larger clouds survive around ten times longer. Whole star clusters are born simultaneously in these clouds and very massive Suns are formed.

Why is it that so many stars are created during these approximately 30 million years? In astronomical terms, this period is quite short. Most attempts at an explanation are based on a kind of chain reaction in which the formation of the first stars in the cloud triggers the formation of further stars. Supernova explosions of the most massive (and therefore shortest-lived) stars which have just formed could be one explanation, as their shock waves compress the cloud material and thus create the seeds for new stars.

Amelia Stutz and Andrew Gould from the Max Planck Institute for Astronomy in Heidelberg are pursuing a different approach and bringing gravity and magnetic fields into play. To test their idea, they undertook a detailed investigation of the Orion nebula, 1300 light years away. The bright red gas cloud with the complex pattern is one of the best-known celestial objects.

The starting point for Stutz and Gould’s considerations are maps of the mass distribution in a structure known as an “integral-shaped filament” because of its form – it resembles that of a curved integral sign – and which includes the Orion nebula in the central section of the filament.

The Heidelberg-based researchers also drew on studies of the magnetic fields in and around this object.

The data show that magnetic fields and gravitation have approximately the same effect on the filament. Taking this as their basis, the two astronomers developed a scenario in which the filament is a flexible structure undulating to and fro. The usual models of star formation, on the other hand, are based on gas clouds which collapse under their own gravitation.

Important proof for the new idea is the distribution of protostars and infant Suns in and around the filament. Protostars are the precursors of Suns: they contract even further until their nuclei have reached densities and temperatures which are high enough for nuclear fusion reactions to start in a big way. This is the point at which a star is born.

Protostars are light enough to be dragged along when the filament undulates backwards and forwards. Infant stars, in contrast, are much more compact and are simply left behind by the filament or launched into the surrounding space as if fired from a slingshot. The model can thus explain what the observation data actually show: protostars are to be found only along the dense spine of the filament; infant stars, on the other hand, are found mainly outside the filament.

This scenario has the potential for a new mechanism which could explain the formation of whole star clusters on (in astronomical terms) short timescales. The observed positions of the star clusters suggest that the integral-shaped filament originally extended much further towards the north than it does today. Over millions of years, one star cluster after another seems to have formed, starting from the north. And each finished star cluster has scattered the gas-dust mixture surrounding it as time has passed.

This is why we now see three star clusters in and around the filament: the oldest cluster is furthest away from the northern tip of the filament; the second one is closer and is still surrounded by filament remnants; the third one, in the center of the integral-shaped filament, is just in the process of growing.

The interaction of magnetic fields and gravity allows certain types of instabilities, some of which are familiar from plasma physics, and which could lead to the formation of one star cluster after another. This hypothesis is based on observational data for the integral-shaped filament. It is not a mature model for a new mode of star formation, however. Theoreticians have first to carry out appropriate simulations and astronomers have to make further observations.

Only when this preparatory work is complete will it be clear whether the molecular cloud in Orion represents a special case. Or whether the birth of star clusters in a medley of magnetically trapped filaments is the usual route to forming whole clusters of new stars in space within a short period.

Strong Magnetic Fields Discovered in Majority of Stars

An international group of astronomers led by the University of Sydney has discovered strong magnetic fields are common in stars, not rare as previously thought, which will dramatically impact our understanding of how stars evolve.

Using data from NASA’s Kepler mission, the team found that stars only slightly more massive than the Sun have internal magnetic fields up to 10 million times that of the Earth, with important implications for evolution and the ultimate fate of stars.

“This is tremendously exciting, and totally unexpected,” said lead researcher, astrophysicist Associate Professor Dennis Stello from the University of Sydney.

“Because only 5 percent of stars were previously thought to host strong magnetic fields, current models of how stars evolve lack magnetic fields as a fundamental ingredient,” Associate Professor Stello said. “Such fields have simply been regarded insignificant for our general understanding of stellar evolution. “Our result clearly shows this assumption needs to be revisited.”

The research is based on previous work led by the Californian Institute of Technology (Caltech) and including Associate Professor Stello, which found that measurements of stellar oscillations, or sound waves, inside stars could be used to infer the presence of strong magnetic fields. The findings are published today in the journal Nature.

This latest research used that result to look at a large number of evolved versions of our Sun observed by Kepler. More than 700 of these so-called red giants were found to show the signature of strong magnetic fields, with some of the oscillations suppressed by the force of the fields.

“Because our sample is so big we have been able to dig deeper into the analysis and can conclude that strong magnetic fields are very common among stars that have masses of about 1.5-2.0 times that of the Sun,” Associate Professor Stello explained.

“In the past we could only measure what happens on the surfaces of stars, with the results interpreted as showing magnetic fields were rare.”

Using a new technique called asteroseismology, which can ‘pierce through the surface’ of a star, astronomers can now see the presence of a very strong magnetic field near the stellar core, which hosts the central engine of the star’s nuclear burning. This is significant because magnetic fields can alter the physical processes that take place in the core, including internal rotation rates, which affects how stars grow old.

Most stars like the Sun oscillate continuously because of sound waves bouncing back-and-forth inside them. “Their interior is essentially ringing like a bell.” Associate Professor Stello said. “And like a bell, or a musical instrument, the sound they produce can reveal their physical properties.”

The team measured tiny brightness variations of stars caused by the ringing sound and found certain oscillation frequencies were missing in 60 percent of the stars because they were suppressed by strong magnetic fields in the stellar cores.

The results will enable scientists to test more directly theories of how magnetic fields form and evolve – a process known as magnetic dynamos – inside stars. This could potentially lead to a better general understanding of magnetic dynamos, including the dynamo controlling the Sun’s 22-year magnetic cycle, which is known to affect communication systems and cloud cover on Earth.

“Now it is time for the theoreticians to investigate why these magnetic fields are so common,” Associate Professor Stello concluded.