The Sun, showing several sunspots/active regions. This image was made at 3:43 PM EDT/7:43 PM UTC on September 10, 2021 using the photographer’s personal reflecting telescope with safe solar filter, and DSLR camera body. Credit: James Guilford
After a long period of quiet during our Sun’s fairly predictable 11-year activity cycle, things have been happening. What was a bright, clear disk has become speckled with sunspots of late. The increased activity brings with it the chance of Earth-directed coronal mass ejections, or CMEs, which result in solar storms when they collide with our home planet’s magnetic field. Auroras, or “northern lights” for us, are one potential result of solar storms. The less pleasant effects can include disruption of radio communications and satellite operation, all the way to electrical grid failures at the extreme!
Several recent CMEs have missed Earth but one is headed in our direction as this blog entry is being written. According to SpaceWeather.com, “{A} CME is on the way following an explosion in the magnetic canopy of sunspot AR2864 on Sept. 8th. NOAA analysts believe Earth could experience a glancing blow or near miss late on Sept. 11th.” Those favored with clear skies and a good view to the north may want to be on the lookout for aurora, but the odds aren’t favorable … this time!
Here are two photos of Sun, shot by Stephens’ Director James Guilford, at 3:43 PM EDT (7:43 PM UTC). The first image shows the full solar disk. Notice not only the dark sunspots but also the lighter-colored “splotches” of additional active solar regions, most visible near the edges of the disk.
The second image is cropped to show the major concentration of the day’s sunspots with their official numerical designations. Both images have been color tinted.
A tightly-cropped portion of the day’s full-disk image shows three sunspot groups: AR 2866, AR 2868, and AR 2869. Sunspots only appear to be dark because they are significantly “cooler” than the surrounding solar atmosphere; they are actually quite hot. Sun’s shining photosphere has a temperature of 5,800 degrees Kelvin while sunspots have temperatures of around 3,800ºK (6,380℉). Nearly all of the dark features seen here are larger than planet Earth. Credit: James Guilford
The galaxy Centaurus A, which lies over 12 million light-years away in the direction of the southern-hemisphere constellation Centaurus (The Centaur), is the leading light of this striking image. This image provides a spectacular view of the luminous glow of stars and dark tendrils of dust that hide the bright center of the galaxy. This dust is the result of a past galactic collision, in which a giant elliptical galaxy merged with a smaller spiral galaxy. As well as large amounts of gas and dust, Centaurus A’s dust lane contains widespread star formation, as indicated by the red clouds of hydrogen and by the large numbers of faint blue stars visible at each end of the dust lane.
This image, taken with the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner, shows wide (left) and close-up (right) views of the moon-forming disc surrounding PDS 70c, a young Jupiter-like planet nearly 400 light-years away. The close-up view shows PDS 70c and its circumplanetary disc center-front, with the larger circumstellar ring-like disc taking up most of the right-hand side of the image. The star PDS 70 is at the center of the wide-view image on the left. Two planets have been found in the system, PDS 70c and PDS 70b, the latter not being visible in this image. They have carved a cavity in the circumstellar disc as they gobbled up material from the disc itself, growing in size. In this process, PDS 70c acquired its own circumplanetary disc, which contributes to the growth of the planet and where moons can form. This circumplanetary disc is as large as the Sun-Earth distance and has enough mass to form up to three satellites the size of the Moon. Credit:ALMA (ESO/NAOJ/NRAO)/Benisty et al.
These images, taken with the SPHERE instrument on ESO’s Very Large Telescope, show the surface of the red supergiant star Betelgeuse during its unprecedented dimming, which happened in late 2019 and early 2020. The image on the far left, taken in January 2019, shows the star at its normal brightness, while the remaining images, from December 2019, January 2020 and March 2020, were all taken when the star’s brightness had noticeably dropped, especially in its southern region. The brightness returned to normal in April 2020.
June 16, 2021 — When Betelgeuse, a bright orange star in the constellation of Orion, became visibly darker in late 2019 and early 2020, the astronomy community was puzzled. A team of astronomers have now published new images of the star’s surface, taken using the European Southern Observatory’s Very Large Telescope (ESO’s VLT), that clearly show how its brightness changed. The new research reveals that the star was partially concealed by a cloud of dust, a discovery that solves the mystery of the “Great Dimming” of Betelgeuse.
Betelgeuse’s dip in brightness — a change noticeable even to the naked eye — led Miguel Montargès and his team to point ESO’s VLT towards the star in late 2019. An image from December 2019, when compared to an earlier image taken in January of the same year, showed that the stellar surface was significantly darker, especially in the southern region. But the astronomers weren’t sure why.
The team continued observing the star during its Great Dimming, capturing two other never-before-seen images in January 2020 and March 2020. By April 2020, the star had returned to its normal brightness.
“For once, we were seeing the appearance of a star changing in real time on a scale of weeks,” says Montargès, from the Observatoire de Paris, France, and KU Leuven, Belgium. The images now published are the only ones we have that show Betelgeuse’s surface changing in brightness over time.
In their new study, published today in Nature, the team revealed that the mysterious dimming was caused by a dusty veil shading the star, which in turn was the result of a drop in temperature on Betelgeuse’s stellar surface.
Betelgeuse’s surface regularly changes as giant bubbles of gas move, shrink and swell within the star. The team concludes that some time before the Great Dimming, the star ejected a large gas bubble that moved away from it. When a patch of the surface cooled down shortly after, that temperature decrease was enough for the gas to condense into solid dust.
“We have directly witnessed the formation of so-called stardust,” says Montargès, whose study provides evidence that dust formation can occur very quickly and close to a star’s surface. “The dust expelled from cool evolved stars, such as the ejection we’ve just witnessed, could go on to become the building blocks of terrestrial planets and life,” adds Emily Cannon, from KU Leuven, who was also involved in the study.
An annular eclipse of the sun will take place June 10 and it will be underway at sunrise. Unfortunately, even with clear skies we will not see the “ring of fire” that is the namesake look of this type of eclipse. In fact, no place in the United States will see the complete circle, or annulus, of Sun around Moon. So don’t feel left out.
In our area, sunrise will be at 5:55 AM (EDT) with the eclipse already at its maximum for us. The eclipse ends at 6:35 AM as Moon completes its passage across Sun.
A total eclipse of the sun takes place when Earth’s Moon, at normal orbital distances, covers the solar disk completely and blocks all but the glowing corona from view. An annular eclipse takes place when Moon is at higher points in its orbit when it passes between Earth and Sun, too distant and small to form a perfect cover, allowing a brilliant ring of our star to shine.
What we may see at dawn and diminishing thereafter, is a partial solar eclipse — looking a bit like the chomping character from the classic PAC-MAN video game. Much of the solar disk will be visible but the curved edge of Moon will take a bite out of one side.
How can you watch the eclipse? With great care!
Partial Eclipse of the Sun, August 21, 2017 — this image rotated to resemble what viewers might see at dawn, June 10, 2021. Photo by James Guilford
How can you watch the eclipse? With great care! At no time during our partial solar eclipse will it be safe to watch the event without vision protection. If you have eclipse glasses from a recent solar eclipse, those should be just fine — just make sure there are no pinholes or other damage to the plastic film “lenses”! You can check for damage by holding the eclipse viewer at arm’s length and looking at a bright lightbulb. If you see any dots of light through the viewer film, throw those glasses out!
Do NOT look at the sun through sunglasses, even multiple sets of sunglasses, or photo negatives, Compact Discs, or anything other than certified eclipse viewing equipment! Pinhole and other projection techniques can be used safely since the viewer is looking at a projection and not the sun itself. Five Ways to View the Solar Eclipse
“The Sun can be viewed safely with the naked eye only during the few brief seconds or minutes of a total solar eclipse. Partial eclipses, annular eclipses, and the partial phases of total eclipses are never safe to watch without taking special precautions. Even when 99% of the Sun’s surface is obscured during the partial phases of a total eclipse, the remaining photospheric crescent is intensely bright and cannot be viewed safely without eye protection [Chou, 1981; Marsh, 1982]. Do not attempt to observe the partial or annular phases of any eclipse with the naked eye. Failure to use appropriate filtration may result in permanent eye damage or blindness!” — NASA: Eye Safety During Solar Eclipses
This map shows where the May 26, 2021 lunar eclipse is visible. Contours mark the edge of the region where the eclipse will be visible at the times when the Moon enters or leaves the umbra (the part of the Earth’s shadow where the Sun is completely hidden) and penumbra (the part where the Sun is only partially blocked). Credit: NASA’s Scientific Visualization Studio.
They say timing is everything and, with eclipses, that is certainly true. Unfortunately, timing will not be in our favor for viewing the Wednesday, May 26 total lunar eclipse. Earth’s Moon will be dipping very close to the horizon as morning twilight brightens hiding the most colorful portion of the event — totality — when Moon turns shades of copper and red. The subtle penumbral eclipse as Moon enters Earth’s outer shadow and will likely be even harder to see than usual. The partial phase of the eclipse begins as Moon enters the dark inner portion of the shadow cone and is easily spotted under other circumstances. Even the partial eclipse begins so late with Moon so close to the horizon that only a lucky few Ohioans will see any part of it.
Penumbral Eclipse begins
May 26 at 4:47 a.m.
Partial Eclipse begins
May 26 at 5:45 a.m.
Total Eclipse begins
May 26 at 7:11 a.m.
Maximum Eclipse
May 26 at 7:18 a.m.
Eclipse Timings — Eastern Daylight Time — Northeastern Ohio
The good news? Lunar eclipses can occur only at the time of a Full Moon and this event features a perigee Moon — our natural satellite at a particularly low portion of its orbit around Earth — appearing just a bit bigger and brighter than average. “Low”, in this case means 221,880 miles out. So, if skies allow, get out and enjoy the big, brilliant Full Moon tonight — it’s a natural wonder in its own right.
Visibility of the total phase in the contiguous U.S., at 11:11 UTC. Totality can be seen everywhere in the Pacific and Mountain time zones, along with Texas, Oklahoma, western Kansas, Hawaii and Alaska.
Still want to watch the eclipse, even though we can’t see it from here? Just do an online search for live eclipse viewing opportunities or tune in to your favorite morning TV news show; they’ll be broadcasting from the West Coast or Hawaii where the eclipse can be properly seen!
Don’t despair, dear moonwatcher! Come this November 19, in the wee hours of the morning, we will be in an excellent position to see a nearly total lunar eclipse from our own backyards! More on that at a later time!
In celebration of the 31st anniversary of the launch of the NASA/ESA Hubble Space Telescope, astronomers aimed the celebrated observatory at one of the brightest stars seen in our galaxy to capture its beauty. The giant star featured in this latest Hubble Space Telescope anniversary image is waging a tug-of-war between gravity and radiation to avoid self-destruction. The star, called AG Carinae, is surrounded by an expanding shell of gas and dust. The nebula is about five light-years wide, which equals the distance from here to our nearest star, Alpha Centauri.Credit: NASA, ESA and STScI
The giant star featured in this latest Hubble Space Telescope anniversary image is waging a tug-of-war between gravity and radiation to avoid self-destruction. The star, called AG Carinae, is surrounded by an expanding shell of gas and dust — a nebula — that is shaped by the powerful winds of the star. The nebula is about five light-years wide, which equals the distance from here to our nearest star (beyond our own Sun), Alpha Centauri.
The huge structure was created from one or more giant eruptions several thousand years ago. The star’s outer layers were blown into space, the expelled material amounting to roughly 10 times the mass of our Sun. These outbursts are typical in the life of a rare breed of star called a Luminous Blue Variable (LBV), a brief unstable phase in the short life of an ultra-bright, glamorous star that lives fast and dies young. These stars are among the most massive and brightest stars known. They live for only a few million years, compared to the roughly 10-billion-year lifetime of our own Sun. AG Carinae is a few million years old and resides 20 000 light-years away inside our Milky Way galaxy. The star’s expected lifetime is between 5 million and 6 million years.
LBVs have a dual personality. They appear to spend years in semi-quiescent bliss and then they erupt in a petulant outburst, during which their luminosity increases — sometimes by several orders of magnitude. These behemoths are stars in the extreme, far different from normal stars like our Sun. In fact AG Carinae is estimated to be up to 70 times more massive than our Sun and shines with the blinding brilliance of 1 million suns.
Shown in this screen grab from a video, the small “Ingenuity” rotorcraft made history, hovering above Jezero Crater, demonstrating that powered, controlled flight on another planet is possible. The video including this image was captured by the Perseverance rover parked nearby. Image Credit: NASA/JPL
April 19, 2021 — NASA’s Ingenuity Mars Helicopter became the first aircraft in history to make a powered, controlled flight on another planet. The Ingenuity team at the agency’s Jet Propulsion Laboratory in Southern California confirmed the flight succeeded after receiving data from the helicopter via NASA’s Perseverance Mars rover at 6:46 a.m. EDT (3:46 a.m. PDT).
A tight crop from a video frame showing the Ingenuity Mars Helicopter during its historic first flight on Mars. The video including this image was captured by the Perseverance rover parked nearby. Image Credit: NASA/JPL
The solar-powered helicopter first became airborne at 3:34 a.m. EDT (12:34 a.m. PDT) – 12:33 Local Mean Solar Time (Mars time) – a time the Ingenuity team determined would have optimal energy and flight conditions. Altimeter data indicate Ingenuity climbed to its prescribed maximum altitude of 10 feet (3 meters) and maintained a stable hover for 30 seconds. It then descended, touching back down on the surface of Mars after logging a total of 39.1 seconds of flight.
NASA’s Ingenuity Mars helicopter is seen in a close-up taken by Mastcam-Z, a pair of zoomable cameras aboard the Perseverance rover. This image was taken on April 5, 2021, the 45th Martian day, or sol, of the mission. Credits: NASA/JPL-Caltech/ASU
UPDATE: Based on data from the Ingenuity Mars helicopter that arrived late Friday night, NASA has chosen to reschedule the Ingenuity Mars Helicopter’s first experimental flight to no earlier than April 14. CLICK HERE for the full story.
A livestream confirming Ingenuity’s first flight is targeted to begin around 3:30 a.m. EDT Monday, April 12, on NASA Television, the NASA app, and the agency’s website, and will livestream on multiple agency social media platforms, including the JPL YouTube and Facebook channels. When it happens it will be the first flight of an aircraft operated on another planet.
This image shows the polarized view of the black hole in M87. The lines mark the orientation of polarization, which is related to the magnetic field around the shadow of the black hole. Credit: EHT Collaboration
March 24 — The Event Horizon Telescope (EHT) collaboration, who produced the first ever image of a black hole, has today revealed a new view of the massive object at the center of the Messier 87 (M87) galaxy: how it looks in polarized light. This is the first time astronomers have been able to measure polarization, a signature of magnetic fields, this close to the edge of a black hole. The observations are key to explaining how the M87 galaxy, located 55 million light-years away, is able to launch energetic jets from its core.
“We are now seeing the next crucial piece of evidence to understand how magnetic fields behave around black holes, and how activity in this very compact region of space can drive powerful jets that extend far beyond the galaxy,” says Monika Mościbrodzka, Coordinator of the EHT Polarimetry Working Group and Assistant Professor at Radboud University in the Netherlands.
On 10 April 2019, scientists released the first ever image of a black hole, revealing a bright ring-like structure with a dark central region — the black hole’s shadow. Since then, the EHT collaboration has delved deeper into the data on the supermassive object at the heart of the M87 galaxy collected in 2017. They have discovered that a significant fraction of the light around the M87 black hole is polarized.
“This work is a major milestone: the polarization of light carries information that allows us to better understand the physics behind the image we saw in April 2019, which was not possible before,” explains Iván Martí-Vidal, also Coordinator of the EHT Polarimetry Working Group and GenT Distinguished Researcher at the University of Valencia, Spain. He adds that “unveiling this new polarized-light image required years of work due to the complex techniques involved in obtaining and analyzing the data.”
Light becomes polarized when it goes through certain filters, like the lenses of polarized sunglasses, or when it is emitted in hot regions of space where magnetic fields are present. In the same way that polarized sunglasses help us see better by reducing reflections and glare from bright surfaces, astronomers can sharpen their view of the region around the black hole by looking at how the light originating from it is polarized. Specifically, polarization allows astronomers to map the magnetic field lines present at the inner edge of the black hole.
“The newly published polarized images are key to understanding how the magnetic field allows the black hole to ‘eat’ matter and launch powerful jets,” says EHT collaboration member Andrew Chael, a NASA Hubble Fellow at the Princeton Center for Theoretical Science and the Princeton Gravity Initiative in the US.
The bright jets of energy and matter that emerge from M87’s core and extend at least 5000 light-years from its center are one of the galaxy’s most mysterious and energetic features. Most matter lying close to the edge of a black hole falls in. However, some of the surrounding particles escape moments before capture and are blown far out into space in the form of jets.
This chart shows the position of giant galaxy Messier 87 in the constellation of Virgo (The Virgin). The map shows most of the stars visible to the unaided eye under good conditions.
Astronomers have relied on different models of how matter behaves near the black hole to better understand this process. But they still don’t know exactly how jets larger than the galaxy are launched from its central region, which is comparable in size to the Solar System, nor how exactly matter falls into the black hole. With the new EHT image of the black hole and its shadow in polarized light, astronomers managed for the first time to look into the region just outside the black hole where this interplay between matter flowing in and being ejected out is happening.
The observations provide new information about the structure of the magnetic fields just outside the black hole. The team found that only theoretical models featuring strongly magnetized gas can explain what they are seeing at the event horizon.
“The observations suggest that the magnetic fields at the black hole’s edge are strong enough to push back on the hot gas and help it resist gravity’s pull. Only the gas that slips through the field can spiral inwards to the event horizon,” explains Jason Dexter, Assistant Professor at the University of Colorado Boulder, US, and Coordinator of the EHT Theory Working Group.
To observe the heart of the M87 galaxy, the collaboration linked eight telescopes around the world — including the northern Chile-based Atacama Large Millimeter/submillimeter Array (ALMA) and the Atacama Pathfinder EXperiment (APEX), in which the European Southern Observatory (ESO) is a partner — to create a virtual Earth-sized telescope, the EHT. The impressive resolution obtained with the EHT is equivalent to that needed to measure the length of a credit card on the surface of the Moon.
“With ALMA and APEX, which through their southern location enhance the image quality by adding geographical spread to the EHT network, European scientists were able to play a central role in the research,” says Ciska Kemper, European ALMA Program Scientist at ESO. “With its 66 antennas, ALMA dominates the overall signal collection in polarized light, while APEX has been essential for the calibration of the image.”
“ALMA data were also crucial to calibrate, image and interpret the EHT observations, providing tight constraints on the theoretical models that explain how matter behaves near the black hole event horizon,” adds Ciriaco Goddi, a scientist at Radboud University and Leiden Observatory, the Netherlands, who led an accompanying study that relied only on ALMA observations.
The EHT setup allowed the team to directly observe the black hole shadow and the ring of light around it, with the new polarized-light image clearly showing that the ring is magnetized. The results are published today in two separate papers in The Astrophysical Journal Letters by the EHT collaboration. The research involved over 300 researchers from multiple organizations and universities worldwide.
“The EHT is making rapid advancements, with technological upgrades being done to the network and new observatories being added. We expect future EHT observations to reveal more accurately the magnetic field structure around the black hole and to tell us more about the physics of the hot gas in this region,” concludes EHT collaboration member Jongho Park, an East Asian Core Observatories Association Fellow at the Academia Sinica Institute of Astronomy and Astrophysics in Taipei.
Stephens Memorial Observatory 