Space and astronomy news
The Sun looks like a harmless burning ball of fire in the sky: warm, life-giving and forever unchanging. But we know better, don’t we. It’s really a massive ball of churning hydrogen plasma, encased in twisting magnetic field lines, speckled with sunspots, and constantly disgorging vast plumes of radiation and charged particles. The Sun is very active indeed.
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What has been billed as the largest sunspot observed in several years has now rotated around to stare straight at Earth. How large is it? Active Region 1339 and the group of sunspots adjacent to it extends more than 100,000 km from end to end and each of the several dark cores is larger than Earth. The now very active Sun has already blasted out several medium- to large-sized solar flares and has the potential to hurl out more.
And the Sun is now dotted with several smaller sunspots as well. Above is an amazing image of all this activity, as captured by astrophotographer Alan Friedman. “This has been a glorious week for solar observers!” Friedman said. “Led by large sunspot region AR1339, the sun’s disk is alive with activity… the most dynamic show in many years.”
Take a look below for an incredible closeup of AR1339 taken by Friedman, as well as a movie from the Solar Dynamics Observatory showing the sunspots rotating into view.
Click on the image for a larger version on Friedman’s website, AvertedImagination.com
From all this activity, there may be a good chance for viewing aurorae. On November 9 at around 1330 UT, a magnetic filament in the vicinity of sunspot complex 1342-1343 erupted, producing a M1-class solar flare and hurling a CME into space, which will probably deliver a glancing blow to Earth’s magnetic field on Nov 11 or 12, according to SpaceWeather.com
And here’s an image from astrophotographer Raymond Gilchrist showing a labeled version of all the current sunspots: 1338, 1339, 1340, 1341, 1342, 1343, 1344.
Raymond used a Baader Solar Continuum Filter and Thousand Oaks Full Solar Filter with a Skywatcher 120mm S/T Refractor,
with a Canon 350D, 1/15th Sec Exp. at ISO400. You can see more of his images at his Flickr page.
One of the largest sunspots in years is now visible, rotating around into view on the Sun’s limb on November 3, 2011. And it’s a feisty one, too. The Solar Dynamics Observatory team called Active Region 1339 a “Bad Boy,” as at 20:27 UTC, a solar flare peaked at X1.9. X-class flares are massive, and can be major events that can trigger planet-wide radio blackouts and long-lasting radiation storms. This region is not facing Earth — yet. But we’ll be keeping on eye on it as it turns toward an Earth-facing direction.
See a full-Sun image from SDO below.
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This sunspot is huge, measuring some 40,000 km wide and at over 80,000 in length. Spaceweather.com said two or three of the sunspot’s dark cores are wider than Earth itself.
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Just in time for Halloween, the Sun has been putting on some spectacular shows recently, including this ghostly-looking prominence captured by amateur astronomer Monty Leventhal from Australia. He estimates this giant pillar shot up over 158,000 km (98,000 miles) from the Sun’s surface! Monty took the image on October 26, 2011 using a Meade SC 10 inch telescope, with a Hydrogen Alpha filter and a Canon 300D camera.
Monty Leventhal is a noted amateur astronomer in Australia and his work has been recognized with several awards including a medal in the General Division of the Order of Australia, “For service to science through volunteer roles at the Sydney Observatory,” and also the Steavensen Award from the British Astronomical Association for his careful and conscientious observations of the Sun for almost two decades. Congratulations to Monty and we thank him for sharing his observations with Universe Today.
This video created with data from the Solar Dynamics Observatory is just absolutely and astoundingly beautiful, showing magnetic loops on the Sun earlier today (October 22, 2011). Via @TheSunToday Twitter feed, just watch how the magnetic loops jump, shimmer and coil back into the Sun, following a long duration M1 flare at about 1100 UTC.
This beautiful time-lapse video was created by photographer Joe Capra during his 17-day solo trek around Iceland in June 2011. A “photographer’s paradise”, summer in Iceland never gets fully dark as the Sun sets around midnight and rises three hours later. The stars don’t even reappear until August!
Continue reading “Iceland’s Midnight Sun: a Time-Lapse Treat!”
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The Sun is big. And comparatively, Earth is a tiny Lilliputian. We’ve all seen images comparing the size of Earth to the Sun, but here are two images from October 10, 2011 that really bring home the size-scale of features on the Sun when compared to the size of Earth. Amateur astronomer Ron Cottrell from Oro Valley, Arizona took these images of two different features on the the Sun yesterday, overlaying the size of the Earth for reference. Both are viewed in Hydrogen- Alpha light, and the first is a fiery-looking huge prominence from the northwest limb of the Sun. Yikes!
Below, see a comparison of Earth to a current sunspot:
This is sunspot 1312 which has a classic sunspot shape with a core a that’s larger than the Earth.
Ron used a 40mm Coronado telescope and a webcam to capture the images. He explains the colors of the Sun in Hydrogen-Alpha, and in particular why the prominence appears fiery red:
“The red color of the prominence is very close to the color collected in the image. The yellow disk is enhanced. I actually capture the disk image in black and white and add the color. I can choose any color. The final image is a composite of two separate images. Prominences are, in general, much fainter than the bright disk. Therefore, the prominence image is captured at a slower shutter speed, e.g. 1/25 sec, compared to the disk image captured at 1/100 sec. The two images are combined in PhotoShop.”
You can see more of Ron’s handiwork on his Flickr page.
And speaking of the Sun, activity on our closest star has been ramping up and last week a series of active regions were lined up one after the other across the upper half of the Sun. Interestingly, the Solar Dynamics Observatory was able to capture how these regions twisted and interacted with each other. The video shows activity from Sept. 28 – Oct. 2, 2011, as seen in extreme UV light. The magnetically intense active regions sported coils of arcing loops and numerous times these magnetic field lines above them can be seen connecting with the active region next door. Towards the end of the clip, a leading active region blasted out a coronal mass ejection, quickly succeeded by a blast from another active region. The disruption of the magnetic field from one likely triggered the second, a phenomenon that has been observed before by SDO.
This amazing video from the SOHO mission (Solar and Heliospheric Observatory) shows a sun-diving comet hitting the solar surface on October 1, 2011 and unexpectedly a huge explosion occurs shortly after. Are the two events related? Probably not, but solar scientists don’t know for sure. The region where the CME originated was on the opposite side of the Sun from the comet hit, so that is very great distance. Scientists say there is no known mechanism for comets to trigger a CME.
SpaceWeather.com reports that before 2011 most solar physicists would have discounted these two events as being related, but earlier this year, the Solar Dynamics Observatory (SDO) watched another sungrazer comet disintegrate in the Sun’s atmosphere, and it appeared to interact with plasma and magnetic fields in its surroundings as it fell apart. Could a puny comet cause a magnetic instability that might propagate and blossom into a impressive CME? Most likely this is just a coincidence, but this is definitely an event in which solar scientists are taking a closer look. The comet, named SOHO-2143, was just discovered on Sept. 30 by an amateur astronomer.
See below for SDO’s look at two solar flares which also occurred on October 1, showing how events on the Sun can be related.
Continue reading “Did a Comet Hit Cause an Explosion on the Sun?”
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A highly active region on the Sun threatens to deliver powerful geomagnetic storms over the week ahead. Highly energetic solar eruptions are likely heading in our direction to give Earth’s magnetic field a significant glancing blow!
Over the past few days the new sunspot AR1302 has been incredibly active, hurling massive X-class solar flares into space and it will soon face Earth.
The massive sunspot, many times larger than the Earth (see images below) is expected to increase in size and energy, and is expected to release powerful solar flares, sparking strong geomagnetic storms.
What does this mean for the Earth and it inhabitants?
The Earth experiences material ejected from the Sun on a daily basis and we are protected by the Earth’s own magnetic field. This is normal and has been happening since the birth of the solar system. But occasionally the Sun erupts and sends vast quantities of solar material our direction in the form of Coronal Mass Ejections (CME’s).
This can trigger very powerful geomagnetic storms, which can damage satellites in orbit and cause problems for communications and power networks. One positive outcome, though, is amazing displays of aurorae at the poles (Northern and Southern Lights).
Sunspot 1302 is expected to eject material towards Earth over the next few days, so look for news of strong geomagnetic activity and displays of aurorae.
Several observers are reporting that AR1302 is easily visible on the Sun at sunset or sunrise. Never ever look at the sun with your eyes, or any other optical aid! This will damage your eyesight permanently! The Sun should only be viewed using specialist equipment.
For further updates see Spaceweather.com and NASA’ Heliophysics Science Division
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Did you know that you can see the Moon during the day?
Many people only notice our Moon at night, when there is considerably more contrast between the Moon and the night sky. Being the second brightest object in the sky (after the Sun, of course) and with Venus visible during the day to trained eyes, it’s no real surprise that the Moon is visible during the day.
Why then, do so many people act surprised when they notice the Moon during the day? What makes it possible for the Moon to be visible during the day?
Understanding how and when you can spot the Moon is a matter of knowing the different lunar phases, specifically the relationship between the Sun, Earth and the Moon during each phase. The image below shows the simple geometry responsible for each of the Moon’s distinct phases.
In the diagram it’s pretty easy to see that when Earth is between the Sun and the Moon, we see a full moon. When the Moon is between Earth and the Sun, we see a new Moon. The other phases are simply transitions from new to full and from full back to new.
Based on the orbital geometry of the Moon, there will certainly be times where the Sun will partially illuminate the Moon, during the day and at night. What makes the lunar cycle even more interesting is that the moon rises about an hour later each day, and yet invariably, a full moon rises near dusk and sets near sunrise. The reverse is true in that a new moon rises near sunrise and sets near dusk.
Looking at the above diagram though, a question comes to mind…
Why don’t we have a lunar eclipse during each full moon, or a solar eclipse each new moon?
I’ll explain the conditions needed for a solar or lunar eclipse in an upcoming article.
In the meantime enjoy the transition from waning gibbous to waning crescent over the next week and get your telescopes out during the weekend of the 25th. The Moon will almost be at its new phase.
If you’d like to learn more about moon phases and when the moon will be visible in your area, the US Naval observatory has a great calculator at: http://aa.usno.navy.mil/data/docs/RS_OneYear.php