sun Archives

August 31, 2024August 31, 2024 by Laurence Tognetti

Coronal Loops-Digital Art Combination Captures Power of the Sun, Rendered by Andrew McCarthy

A composite image comprised of the Sun's surface, corona, and digitally-added coronal loops rendered by Andrew McCarthy. (Credit: Andrew McCarthy)

Our Sun is one of the most fascinating objects in the universe and photographing it with specialized equipment to capture its splendor and beauty has become increasingly more common around the world. This is most evident with the work obtained by renowned astrophotographer, Andrew McCarthy (@AJamesMcCarthy), who owns Cosmic Background Studios in Florence, Arizona.

On July 27, 2024, McCarthy posted an image of the Sun on X (formerly known as Twitter) taken with his specialized equipment designed to safely photograph our life-giving star, which revealed active coronal loops and plasma within the solar chromosphere that are some of the many intriguing features of the Sun. However, McCarthy is quick to mention in his post that this image isn’t entirely genuine, but a combination of several attributes.

July 31, 2024July 31, 2024 by Laurence Tognetti

Why is the Sun’s Corona So Hot? One Hypothesis Down, Many to Go

Illustration of NASA’s Parker Solar Probe flying through a magnetic switchback from the Sun, with scientists still debating the origin of switchbacks within the Sun. (Credit: Adriana Manrique Gutierrez/NASA’s Goddard Space Flight Center)

The temperature of the Sun’s corona is a minimum of 100 times hotter than the Sun’s surface, despite the corona being far less dense and extending millions of miles from the Sun’s surface, as well. But why is this? Now, a recent study published in The Astrophysical Journal could eliminate a longstanding hypothesis regarding the processes responsible for the corona’s extreme heat, which could help them better understand the Sun’s internal processes. This study holds the potential to help scientists gain greater insight into the formation and evolution of our Sun, which could lead to better understanding stars throughout the universe, as well.

July 27, 2024July 27, 2024 by Mark Thompson

Kepler Sketched the Sun in 1607. Astronomers Pinpointed the Solar Cycle

The earliest datable sunspot drawings based on Johannes Kepler's solar observations with camera obscura in May 1607.

Johannes Kepler is probably most well known for developing the laws of planetary motion. He was also a keen solar observer and in 1607 made some wonderful observations of our nearest star using a camera obscura. His drawings were wonderfully precise and enabled astronomers to pinpoint where the Sun was in its 11-year cycle. Having taken into account Kepler’s location and the location of sunspots, a team of researchers have identified the Sun was nearing the end of solar cycle-13.

July 12, 2024July 12, 2024 by Laurence Tognetti

Solar Flares and Solar Magnetic Reconnection Get New Spotlight in Two Blazing Studies

Image of a solar flare (bright flash) obtained by NASA’s Solar Dynamics Observatory on Oct. 2, 2014, with a burst of solar material erupting being observed just to the right of the solar flare. (Credit: NASA/SDO)

Two recent studies published in The Astrophysical Journal discuss findings regarding solar flare properties and a new classification index and the Sun’s magnetic field, specifically what’s called solar magnetic reconnection. These studies hold the potential to help researchers better understand the internal processes of the Sun, specifically pertaining to solar flare activity and space weather. Here, Universe Today discusses these two studies with both lead authors regarding the motivation behind the studies, significant results, and implications on our understanding regarding solar flares and space weather.

June 28, 2024June 28, 2024 by Carolyn Collins Petersen

Seeing Both Sides of the Sun at the Same Time

Solar Orbiter's view of a solar outburst from AR3664 on May 21st, 2024. The views are in two different wavelengths of ultraviolet light. Courtesy: ESA & NASA/Solar Orbiter/EUI Team

As everybody who saw May’s spectacular auroral displays knows, the Sun is in its most active period in 11 years. The active region sunspot group that unleased the giant X-class flare rotated around the Sun, away from our direct view. But, that isn’t keeping the Solar Orbiter from spotting what’s happening with it and other active regions as they travel around on the Sun.

June 25, 2024June 25, 2024 by Evan Gough

Do We Now Have an Accurate Map of Nearby Stars?

This image shows the bright stars within 15 parsecs of the Sun. If red dwarfs and brown dwarfs were included, there would be far more stars. But those stars are difficult to spot. Have we found all of them yet? Image Credit: By Andrew Z. Colvin - Own work, CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=14359465

If the Sun has a stellar neighbourhood, it can be usefully defined as a 20 parsec (65 light-years) sphere centred on our star. Astronomers have been actively cataloguing the stellar population in the neighbourhood for decades, but it hasn’t been easy since many stars are small and dim.

Even with all of the challenges inherent in the effort, astronomers have made steady progress. Do we now have a complete catalogue?

June 11, 2024June 11, 2024 by Evan Gough

Was Earth’s Climate Affected by Interstellar Clouds?

About two million years ago, the Solar System may have passed through a dense cloud of hydrogen and radioactive material. It compressed the heliosphere, the protective cocoon the Sun provides for Earth and the other planets. It's shown here as the dark gray bubble over the backdrop of interstellar space. This could have exposed Earth to high levels of radiation and influenced the climate, and possible human evolution. Photo courtesy of Opher, et al., Nature Astronomy

Scientists scour the Earth and the sky for clues to our planet’s climate history. Powerful and sustained volcanic eruptions can alter the climate for long periods of time, and the Sun’s output can shift Earth’s climate over millions of years.

But what about interstellar hydrogen clouds? Can these regions of gas and dust change Earth’s climate when the planet encounters them?

May 28, 2024May 28, 2024 by Carolyn Collins Petersen

The Sun’s Magnetic Field Might Only Be Skin Deep

A new study suggests sunspots and solar flares could be generated my a magnetic field within the Sun's outermost layers. This shows the Sun's magnetic fields overlaying an image from the Solar Dynamics Observatory. NASA/SDO/AIA/LMSAL

It’s coming back! Sunspot AR3664 gave us an amazing display of northern lights in mid-May and it’s now rotating back into view. That means another great display if this sunspot continues to flare out. It’s all part of solar maximum—the peak of an 11-year cycle of solar active and quiet times. This cycle is the result of something inside the Sun—the solar dynamo. A team of scientists suggests that this big generator lies not far beneath the solar surface. It creates a magnetic field and spurs flares and sunspots.

May 20, 2024May 20, 2024 by Matt Williams

That Recent Solar Storm Was Detected Almost Three Kilometers Under the Ocean

Aurora at Cassidy Point, Northwest Territories, Canada CREDIT: mericsso

On May 10th, 2024, people across North America were treated to a rare celestial event: an aurora visible from the Eastern Seabord to the Southern United States. This particular sighting of the Northern Lights (aka. Aurora Borealis) coincided with the most extreme geomagnetic storm since 2003 and the 27th strongest solar flare ever recorded. This led to the dazzling display that was visible to residents all across North America but was also detected by some of Ocean Networks Canada‘s (ONC) undersea sensors at depths of almost three kilometers.

May 16, 2024May 16, 2024 by Mark Thompson

The Sun Hurls its Most Powerful Flare in a Decades

The Sun has been vying for attention these last couple of weeks. First with the appearance of a fabulous complex sunspot region and then with a plethora of solar flares. On the 14th May, yet another was released, this time an X8.7 class flare from the same complex sunspot regions. It was significantly more powerful than the flare that set off the aurora displays which enchanted much of the planet but alas it was not pointing toward the Earth ( 🙁 sad emoji face.) Even though it was not directed at us, it could still disrupt communications and electronics but is a reminder that the Sun, whilst is on its way to solar maximum still has lots to give.