IRIS Glimpses an Elusive Region of the Sun

An innovative solar observatory is adding a key piece to the puzzle of the enigma that is our Sun.

Its two of key questions in heliophysics: why does our Sun have a corona? And why is the temperature of the corona actually higher than the surface of the Sun?

This week, researchers released results from the preliminary first six months of data from NASA’s Interface Region Imaging Spectrograph, known as IRIS. The findings were presented at the Fall American Geophysical Union Meeting this past Monday.

IRIS was launched on June 27th of this year on a Pegasus-XL rocket deployed from the belly of a Lockheed L-1011 aircraft flying out of Vandenberg Air Force Base. IRIS can focus in on a very specific interface region of the Sun sandwiched between the dazzling solar photosphere and the transition to the corona. To accomplish this, IRIS employs an ultraviolet slit spectrograph looking at ionized gas spectra.

IRIS in the clean room. The spacecraft is only about 2 metres in length, about the height of a person. (Credit: Lockheed Martin).
IRIS in the clean room. The spacecraft is only about 2 metres in length, about the height of a person. (Credit: Lockheed Martin).

“The quality of images and spectra we are receiving is amazing,” IRIS Principal Investigator Alan Title said in a recent press release from the NASA Goddard Space Flight Center. While other missions may take over a decade to go from the drawing board to the launch pad, IRIS was developed and deployed into Low Earth Orbit in just 44 months.

IRIS offers scientists a new tool to probe the Sun and a complimentary instrument to platforms such as Hinode, the Solar Heliospheric Observatory (SOHO) and NASA’s Solar Dynamics Observatory. In fact, IRIS has a better resolution than SDO’s AIA imagers or Hinode when it comes to this key solar interface region. IRIS has a 20x greater resolution in time, and 25x the spatial resolution of any former space-based UV spectrometer deployed.

“We are seeing rich and unprecedented images of violent events in which gases are accelerated to very high velocities while being rapidly heated to hundreds of thousands of degrees,” said Lockheed Martin science lead on the IRIS mission Bart De Pontieu. These observations are key to backing up theoretical models of solar dynamics as well as testing and formulating new ones of how our Sun works.

IRIS bridges this crucial gap between the photosphere and the lower chromosphere of the Sun. While the solar surface roils at relatively placid  6,000 degrees Celsius, temperatures rise into the range of 2-3 million degrees Celsius as you move up through the transition region and into the corona.

Two key solar phenomena that are of concern to solar researchers can be examined by IRIS in detail. One is the formation of prominences, which show up as long looping swirls of solar material rising up from the surface of the Sun. Prominences can be seen from backyard telescopes at hydrogen alpha wavelengths. IRIS can catch and track their early modeling with unprecedented resolution. Images released from IRIS show the fine structure of targeted prominences as they evolve and rise off the surface of the Sun. When a prominence and accompanying coronal mass ejection is launched in our direction, disruption of our local space environment caused by massive solar storm can result.

Slit jaw spectra images (the two strips to the left) and imaging a spicules 9to the right as seen by IRIS. (Credit: NASA/IRIS).
Slit jaw spectra images (the two strips to the left) and imaging of spicules (to the right) as seen by IRIS. (Credit: NASA/IRIS).

The second phenomenon targeted by IRIS is the formation of spicules, which are giant columns of gas rising from the photosphere. Although the spicules look like hair-fine structures through Earth-based solar telescopes, they can be several hundred kilometres wide and as long as the Earth. Short-lived, spicules race up from the surface of the Sun at up to 240,000 kilometres per hour and seem to play a key role in energy and heat transfer from the solar surface up through the atmosphere. IRIS is giving us a view of the evolution of spicules for the first time, and they’re proving to be even more complex than theory previously suggested.

“We see discrepancies between these observations and the models, and that is great news for advancing knowledge. By seeing something we don’t understand, we have a chance of learning something new,” Said University of Oslo astrophysicist Mats Carlsson.

Like SDO and SOHO, data and images from IRIS are free for the public to access online. Though the field of view for IRIS is a narrow 2’ to 4’ arc minutes on a side – the solar disk spans about 30’ as seen from the Earth – IRIS gives us a refined view of “where the action is.”

Where is IRIS looking? This snapshot gives some context of the IRIS field of view (green and red boxes) and black and white insets versus SDO's AIA full disk view of the Sun. (Credit: NASA/SDO/IRIS).
Where is IRIS looking? This snapshot gives some context of the IRIS field of view (green and red boxes) and black and white insets versus SDO’s AIA full disk view of the Sun. (Credit: NASA/SDO/IRIS).

And this all comes at an interesting time, as our nearest star crosses the sputtering solar maximum for Cycle #24.

The equivalent of 50 million CPU hours were utilized in constructing and modeling what IRIS sees. The reconstruction was an international effort, spanning the Partnership for Advanced Computing in Europe, the Norwegian supercomputing collaboration, and NASA’s Ames Research Center.

IRIS also faced the additional challenge of weathering a 2.5 week period of inactivity due to the U.S. government shutdown this fall. Potential impacts due to sequestration remain an issue, though small explorer missions such as IRIS demonstrate how we can do more with less.

“We’ve made a giant step forward in characterizing the heat transfer properties of this region between the visible surface and the corona, which is key to understanding how the outer atmosphere of the Sun exists, and is key to understanding the outer atmosphere that the Earth lies in,” said Alan Title, referring to the tenuous heliosphere of the Sun extending out through the solar system.

Understanding the inner working of our Sun is vital: no other astronomical body has as big an impact on life here on Earth.

IRIS is slated for a two-year mission, though as is the case with most space-based platforms, researchers will work to get every bit of usefulness out of the spacecraft that they can. And it’s already returning some first-rate science at a relatively low production cost. This is all knowledge that will help us as a civilization live with and understand our often tempestuous star.

 

Zombie ISON ‘Behaving Like A Comet’, Stunned Astronomers Say

Bright, brighter, brightest: these views of Comet ISON after its closest approach to the sun Nov. 28 show that a small part of the nucleus may have survived the comet's close encounter with the sun. Images from the Solar and Heliospheric Observatory. Credit: ESA/NASA/SOHO/GSFC

Talk about the Comeback Kid. After Comet C/2012 S1 ISON rounded the sun yesterday afternoon, professional astronomers around the world looked at the faded debris and concluded it was an “ex-comet.” NASA wrapped up an hours-long Google+ Hangout with that news. The European Space Agency declared it was dead on Twitter.

But the remnants — or whatever ISON is now — kept brightening and brightening and brightening in images from the NASA/European Space Agency Solar and Heliospheric Observatory. The pictures are still puzzling astronomers right now, almost a day after ISON’s closest encounter with the sun.

 

You can follow our liveblogged confusion yesterday, capped by a gobsmacking announcement from the Naval Research Laboratory’s Karl Battams, “We believe some small part of ISON’s nucleus has SURVIVED perihelion,” he said on Twitter. Since then, Battams wrote a detailed blog post, referring to images from the Large Angle and Spectrometric Coronagraph (LASCO) aboard SOHO:

“Matthew [Knight] and I are ripping our hair out right now as we know that so many people in the public, the media and in science teams want to know what’s happened. We’d love to know that too! Right now, here’s our working hypothesis: As comet ISON plunged towards to the Sun, it began to fall apart, losing not giant fragments but at least a lot of reasonably sized chunks. There’s evidence of very large dust in the form of that long thin tail we saw in the LASCO C2 images.

After its closest approach to to the sun on Nov. 28 (left), Comet ISON appeared a dim shadow of its former self (at right). "The comet may still be intact," NASA wrote on Nov. 29. Images from the Solar and Heliospheric Observatory. Credit: ESA/NASA/SOHO/Jhelioviewer
After its closest approach to to the sun on Nov. 28 (left), Comet ISON appeared a dim shadow of its former self (at right). “The comet may still be intact,” NASA wrote on Nov. 29. Images from the Solar and Heliospheric Observatory. Credit: ESA/NASA/SOHO/Jhelioviewer

Then, as ISON plunged through the corona, it continued to fall apart and vaporize, and lost its coma and tail completely just like Lovejoy did in 2011. (We have our theories as to why it didn’t show up in the SDO images but that’s not our story to tell – the SDO team will do that.) Then, what emerged from the Sun was a small but perhaps somewhat coherent nucleus, that has resumed emitting dust and gas for at least the time being. In essence, the tail is growing back, as Lovejoy’s did.

So while our theory certainly has holes, right now it does appear that a least some small fraction of ISON has remained in one piece and is actively releasing material. We have no idea how big this nucleus is, if there is indeed one. If there is a nucleus, it is still too soon to tell how long it will survive. If it does survive for more than a few days, it is too soon to tell if the comet will be visible in the night sky. If it is visible in the night sky, it is too soon to say how bright it will be…

This morning (EST), Battams succinctly summarized the latest images he saw: “Based on a few more hours of data, comet #ISON appears to be… well, behaving like a comet!”, he wrote on Twitter.

NASA issued a status update this morning saying it’s unclear if this leftover is debris or an actual nucleus, but added that “late-night analysis from scientists with NASA’s Comet ISON Observing Campaign suggest that there is at least a small nucleus intact.” NASA, as well as Battams, pointed out that comet has behaved unpredictably throughout the 15 months scientists and amateurs have been observing it.

Mike Hankey of Monkton, Maryland took this photo of Comet ISON in outburst this morning Nov. 14. The tail now shows multiple streamers. Click to enlarge. Credit: Mike Hankey
Mike Hankey of Monkton, Maryland took this photo of Comet ISON in outburst Nov. 14. The tail showed multiple streamers. Click to enlarge. Credit: Mike Hankey

Throughout the year that researchers have watched Comet ISON – and especially during its final approach to the sun – the comet brightened and dimmed in unexpected ways.  Such brightness changes usually occur in response to material boiling off the comet, and different material will do so at different temperatures thus providing clues as to what the comet is made of.  Analyzing this pattern will help scientists understand the composition of ISON, which contains material assembled during the very formation of the solar system some 4.5 billion years ago.

Slate Bad Astronomy blogger Phil Plait jokingly threw out phrases like “What the what?” on Twitter yesterday, but added in a late-night update: “If you haven’t figured this out yet: We are *loving* this. The Universe surprises us yet again! How awesome!” He continued with his astonishment in a blog post:

For those keeping score at home, it got bright, then it faded, then it got all smeared out, then it came around the Sun smeared out, and then it seemed to get its act together again. At this point, I refuse to make any further conclusions about this comet; it seems eager to confuse. I’ve been hearing from comet specialists who are just as baffled… which is fantastic! If we knew what was going on, there’d be nothing more to learn.

Science confusion: Comet ISON made its closest approach to the sun Nov. 28. Although it showed up again in images from the Solar and Heliospheric Observatory, scientists could not spot it using the ESA PROBA-2 spacecraft (view pictured). ISON's composition or proximity to the sun may have caused this. Credit: PROBA-2 Science Centre
Science confusion: Comet ISON made its closest approach to the sun Nov. 28. Although it showed up again in images from the Solar and Heliospheric Observatory, scientists could not spot it using the ESA PROBA-2 spacecraft (view pictured). ISON’s composition or proximity to the sun may have caused this. Credit: PROBA-2 Science Centre

In a series of Twitter posts this morning, the European Space Agency’s science feed offered this take from Gerhard Schwehm, ESA’s head of planetary science:

From my initial look at ISON in today’s SOHO images, it seems nucleus has mostly disintegrated. Will only know if part of ISON nucleus has survived by continuing observations and performing more analysis. Bright fan-shape implies lots of material was released and travelling along ISON orbit, not confined in a traditional tail. Would be interesting to learn more about composition of debris to help us piece together what’s happened, but we need more time.

Other spacecraft searching for ISON were not able to spot it. For ESA’s PROBA-2, it may have been because of its composition or proximity to the sun, but scientists are unsure. It was also invisible in NASA’s Solar Dynamics Observatory; “scientists are still looking at the data to figure out why,” an agency Twitter update stated this morning.

So to sum up: no one’s quite sure of what is happening now, or what is happening next, but we will keep you posted and let you know if and when you can see ISON again in your home telescopes.

One of the finest pictures to date of Comet ISON by ace astrophotographer Damian Peach taken on Oct. 27.
One of the finest pictures to date of Comet ISON by ace astrophotographer Damian Peach taken on Oct. 27.

NASA’s STEREO Spacecraft Spots Comets ISON and Encke

Comet ISON entered the STEREO scene with Encke on Nov. 21 (Credit: Karl Battams/NASA/STEREO/CIOC)

As comets ISON and Encke continue toward their respective rendezvous with the Sun, they have now both been captured on camera by NASA’s solar-observing STEREO spacecraft. The image above, taken on Nov. 21 (UT) with STEREO-A’s high-resolution HI-1 camera, shows ISON as it enters the field of view from the left. Encke is at center, while the planets Mercury and Earth (labeled) are bright enough to cause vertical disruptions in the imaging sensors. (The Sun is off frame to the right.)

As cool as this image is, it gets even better: there’s a video version. Check it out below:

Animation of STEREO-A images acquired on Nov. 20-21 (Karl Battams/NASA/STEREO/CIOC)
Animation of STEREO-A images acquired on Nov. 20-21 (Karl Battams/NASA/STEREO/CIOC)

The dark “clouds” coming from the right are density enhancements in the solar wind, causing all the ripples in comet Encke’s tail. (Source)

The position of NASA's STEREO spacecraft relative to Earth and the Sun on Nov. 22
The position of NASA’s STEREO spacecraft relative to Earth and the Sun on Nov. 22

It’s fascinating to watch how the solar wind shapes and affects the tail of comet Encke… as ISON moves further into view, I’m sure we’ll see similar disruptions in its tail as well. (And look what STEREO-A saw happen to Encke’s tail back in 2007!)

Encke reached the perihelion of its 3.3-year-long orbit on Nov. 21; newcomer ISON will arrive at its on Nov. 28. While it seems to be holding together quite well in these STEREO images, what happens when it comes within 730,000 miles of the Sun next week is still anybody’s guess.

Read more: Whoa, Take a Look at Comet ISON Now!

Bright Venus Takes Center Stage in November

(Credit: Brian McGaffney/Nutwood Observatory).

“What’s that bright object to the southwest at dusk?” We’ve already fielded more than a few such questions as Earth’s sister world shines in the dusk sky.  Venus just passed its maximum elongation 47 degrees east of the Sun on November 1st, and currently shines at a brilliant magnitude -4.46. This is almost 16 times brighter than the brightest star in the sky, -1.46th magnitude Sirius.

Venus and the waxing crescent Moon, looking to the west tonite at 30 minutes after sunset for latitude 30 degrees north. (Created using Stellarium).
Venus and the waxing crescent Moon, looking to the west tonite at 30 minutes after sunset for latitude 30 degrees north. (Created using Stellarium).

Just like the Moon, Venus goes through a full range of phases. Through the telescope, Venus currently presents a 26.7” diameter disk. That size will swell to almost 40” by month’s end, as Venus begins to approach the Earth and presents a noticeable crescent phase. We just passed dichotomy — the theoretical point where Venus presents a half-illuminated phase as seen from Earth — on October 31st, and Venus already shows a noticeable crescent:

Venus on the night of November 5th 2013, a quick stack of about 200 frames. (Photo by Author)
Venus on the night of November 5th 2013, a quick stack of about 200 frames. (Photo by Author)

Note that we say “theoretical” because there’s typically a discrepancy of a day or two between predicted and observed dichotomy. This is also known as Schröter’s Effect. One probable cause for this is the dazzling appearance of the disk of Venus. We typically use a variable polarizing filter to cut the glare of Venus down at the eyepiece.

You might also note that Venus currently occupies the “basement” of the zodiac in the constellation Sagittarius. In fact, the planet is currently as far south as it can go, sitting at a declination of -27° 14’ on this very evening. You have to go all the way back to 1930 to find a more southerly declination of Venus, just 12’ lower!

But you won’t have to wait much longer to break that record, as the chart below shows for the most southerly declinations of Venus for the next half century:

Year Date Declination
2013 November 6th -27° 09’
2021 “            “ -27° 14’
2029 “            “ -27° 18’
2037 “            “ -27° 23’
2045 “            “ -27° 29’
2053 “            “ -27° 34’
2061 “            “ -27° 39’

 

Note that each event occurs on November 6th, and they’re spaced 8 years apart. Apparitions of Venus closely duplicate their paths in the sky over an 8 year cycle. This is because the planet nearly completes 13 orbits of the Sun for our 8. Venus “catches up” to the Earth on its interior orbit once every 584 days to reach inferior conjunction. It usually passes above or below the Sun from our vantage point, though last year it transited, a feat that won’t be witnessed again until 2117 AD.

How far south can Venus go? Well, its orbit is tilted 3.4 degrees relative to the ecliptic. It can reach a southern declination of -28 05’, though you have to go way back to 1874 for its last occurrence!

Today is also a great time to try your hand at spotting Venus in the daytime, as a 3-day old waxing crescent Moon lies about eight degrees to its upper right:

A daytime Venus near the Moon transiting to the south at about 3:30PM EST today. A 5 degree wide Telrad "bullseye" is provided for scale. (Credit: Stellarium).
A daytime Venus near the Moon, transiting to the south at about 3:30PM EST today. A 5 degree wide Telrad “bullseye” is provided for scale. (Credit: Stellarium).

Note that seeing Venus in the daytime is surprisingly easy, once you known exactly where to look for it. Your best chances are around mid-afternoon at about 3PM local, when the daytime Moon and Venus lie highest in the southern sky. Did you know that Venus is actually intrinsically brighter per square arc second than the Moon? It’s true! The Moon actually has a very low reflective albedo of 12% — about the equivalent of fresh asphalt — while the cloud tops of Venus are more akin the fresh snow with an albedo of about 80%.

Its also worth checking out Venus and its local environs after nightfall as it passes near the Lagoon (M8) and the Trifid nebula (M8) on the night of November 6th. Continuing with its trek across the star rich plane of the heart of the Milky Way galaxy, Venus also passes near the globular cluster M22 on November 13th.

Venus also sits in the general of Pluto on November 15th, lying just 6.6 degrees south of it. Be sure to wave in the general direction of NASA’s New Horizons spacecraft bound for Pluto in July 2015 tonight as well, using the Moon and Venus for a guide:

The position of the Moon, Venus, Pluto, & New Horizons on the night of November 6th, 2013. (Created using Starry Night Education Software).
The position of the Moon, Venus, Pluto, & New Horizons at 14UT on November 7th, 2013. (Created using Starry Night Education Software).

Another shot at seeing Venus paired with the Moon occurs on December 5th.

Venus also presents a maximum area of illumination on December 6th, and will shine at its brightest on December 10th at magnitude -4.7. Can you catch it casting a shadow? The best time to search for this illusive phenomenon would be just before New Moon on December 2nd. A dark sky site away from any other sources of illumination, and a snow covered ground providing high contrast also helps. Fortunately, snow isn’t in short supply in the northern hemisphere in December!

Venus is currently the only naked eye planet in the November early evening sky. We always thought that it’s a bit of a cosmic irony that the nearest planet presents a dazzling, but featureless white disk as seen from Earth. Diligent amateurs have, however, been able to tease out cloud patterns on Venus using UV filters.

Another elusive phenomenon to watch for as Venus reaches a crescent phase is ashen light. Long reported by observers, a faint glow on the night side of Venus is something that persists, but shouldn’t be. A similar effect seen on the night side of the Moon known as Earthshine is easily explained by sunlight being reflected off of the Earth… but Venus has no moon. What gives? Frequent explanations over the years have been aurorae, electrical activity, airglow, or, more frequently cited, observer bias. The brain wants to see a filled in space, and promptly inserts it betwixt the dazzling horns of the planet.

Keep an eye on Venus as it reaches maximum brilliancy and heads towards inferior conjunction on January 11th, 2014, and a rare chance to see it on said date… more to come!

 

 

Watch Live: Sunday’s “Hybrid Solar Eclipse”

Totality! As seen during the November 13th, 2012 total solar eclipse. (Image credit: Narayan Mukkavilli, used with permission).

The chase is on. On Sunday, November 3rd, the shadow of the Moon will cross the Earth for one last time in 2013. We recently wrote about the prospects for viewing this “hybrid” annular-total solar eclipse as it crosses the Atlantic and central Africa. Viewers from northern South America across the U.S. Eastern Seaboard up into the Canadian Maritimes will also be treated to a brilliant rising partial eclipse over the Atlantic at sunrise. Tickets are already in hand for many, as umbraphiles wing their way (cue Indiana Jones music) to dusty and exotic far off locales to stand briefly in the shadow of our Moon…

But what if it’s cloudy?

Once the bane of eclipse-chasers, you can now thwart our sometimes murky atmosphere by catching the solar eclipse online.

I remember our first experience with eclipse-chasing on the internet, trying to catch an eclipse broadcast on ye ole dial up modem from an internet café (remember internet cafes?) way back in the late 90s. This was pre-You Tube, pre-UStream. Needless to say, the tenuous connection afforded nary a frozen glimpse of the partially eclipsed Sun, and crashed all together at the onset of totality.

Fast forward to 2013, when ginormous data packets routinely fly around the globe.

True, this eclipse presents a challenge, as it crosses some pretty wild and unconnected terrain. But one standby that we can expect is the good people at Slooh, who have dispatched a broadcast team to the African nations of Gabon and Kenya:

As of this writing, Slooh looks to be going live at around 11:45 UT on Sunday November 3rd. This is 6:45 AM EST, which takes into account our “falling back” one hour to UT -5 hours on Sunday morning. Astronomer Brian Cox will be broadcasting live from Kenya, and the broadcast starts just over two hours prior to the first landfall of totality at just before 14:00 UT. From Gabon, Maximum totality will be a brief 1 minute and 5 seconds, and will dwindle to an even briefer 14 seconds over Lake Turkana in Kenya before ending as a brilliant sunset eclipse over Somalia and Ethiopia. A backup broadcast of the partial phases of the eclipse is also planned from Slooh’s home base site in the Canary Islands.

Another fascinating potential broadcast may come our way from the BRCK organization basing their observations of the eclipse from the shores of Lake Turkana in Kenya.  Billed as “Your Backup Generator for the Internet,” BRCK’s mission is to bring broadband access internet to people in remote regions of the world. This weekend’s eclipse certainly qualifies. As of writing this on Halloween, October 31st, the BRCK team had gone into the field to “stress test” their webcasting capability onsite; follow them on Twitter as @brcknet for the latest updates. As of yet, there’s no embed for the broadcast, though we’ll be sure to drop it in if it surfaces!

There’s also some interesting science afoot during this eclipse as well. A recent press release out from Williams College notes that Field Memorial Professor of Astronomy and chair of the International Astronomical Union’s Working Group on Eclipses Jay Pasachoff will observe the eclipse, along with a student and tourist expedition from Gabon. A veteran eclipse chaser, Pasachoff will be working in concert with Dr. Vojtech Rusin of the Astronomical Institute of Slovakia, solar researchers Aris Voulgaris and Robert Lucas and William College students to study the ethereal solar corona.  Satellite-based coronagraphs, such as the one employed by SOHO, can create an “artificial eclipse” of the Sun to study the corona, but also face the challenge of scattered light via a phenomenon known as Fresnel-diffraction. Pasachoff and team hope to combine their observations with those being routinely carried out by NASA, the European Space Agency and the Royal Observatory in Belgium to characterize the solar corona and improve our understanding of the space weather environment. Pasachoff’s expedition is being assisted via support from the South African Astronomical Observatory, Nommo Astronomia, the Gabon Astronomy Society and the Gabon Space Agency. Veteran eclipse chaser and historian Michael Zeiler (@EclipseMaps) has also joined up with Pasachoff’s group in Gabon.

In space, the NASA/JAXA joint solar observing Hinode spacecraft and ESA’s Sun watching Proba-2 will also catch several partial eclipses from their respective perches in low Earth orbit. Expect to see these pics in the days following Sunday’s eclipse.

We’ll be dropping in more broadcasts as they come to our attention this weekend here at Universe Today. Planning an ad-hoc webcast of the eclipse? Let us know in the comments below! Even if it’s just a brief view of the rising partially eclipsed Sun from the beach, its worth the effort. Just remember that you’ll need a fairly long focal length (in the range of 200mm or longer) and a proper solar filter for the Sun to appear like anything more than a washed out dot in the broadcast. And always run a test of your rig beforehand!

Good luck, happy eclipse chasing, and don’t forget to send those eclipse pics to Universe Today!

 

Rare ‘Hybrid’ Solar Eclipse on November 3, 2013: How to See It

A partially eclipsed setting Sun as seen from Dallas, Texas on May 20th, 2012. This weekend's eclipse will offer U.S. East Coast residents a similar sunrise view. (Credit: Jason Major/Lights in the Dark).

It’s almost upon us. The final eclipse of 2013 occurs this coming weekend on Sunday, November 3rd. This will be the fifth eclipse overall, and the second solar eclipse of 2013. This will also be the only eclipse this year that features a glimpse of totality.

This eclipse is of the rare hybrid variety— that is, it will be an annular eclipse along the very first 15 seconds of its track before transitioning to a total as the Moon’s shadow sweeps just close enough to the Earth to cover the disk of the Sun along the remainder of its track.

An animation of the path of the November 3rd hybrid solar eclipse. (Credit: NASA/Goddard Space Flight Center).
An animation of the path of the November 3rd hybrid solar eclipse. (Credit: NASA/Goddard Space Flight Center).

How rare are hybrid solar eclipse? Of the 11,898 solar eclipses listed over a 5,000 year span from 1999 BC to 3000 AD in Fred Espenak’s Five Millennium Catalog of Solar Eclipses, only 569, or 4.8% are hybrids.

Who can see this eclipse?

People from northern South America, across the U.S. Eastern Seaboard and up through the Canadian Maritimes will see a brief partial solar eclipse finishing up around 30 minutes after local sunrise. The brief annular “ring of fire” portion of the eclipse begins at sunrise just ~1,000 kilometres east of Jacksonville, Florida, as it races eastward across the Atlantic. See our timeline, below.

Eclipse prospects for the US East Coast. (Courtesy of Michael Zeiler @EclipseMaps)
Eclipse prospects for the US East Coast. (Courtesy of Michael Zeiler @EclipseMaps)

Nearly all of Africa and the southern Mediterranean region including Spain will see partial phases of the eclipse, while greatest totality occurs just off of the coast of Liberia and heads for first landfall on the African continent over Wonga Wongue Reserve in Gabon. At this point, the duration of totality will already have shrunk back down to 1 minute and 7 seconds. The shadow of the Moon will then cross central Africa, headed for a short but brilliant sunset total eclipse over Uganda, Ethiopia, Kenya and Somalia.

The global path of this weekends eclipse-click to enlarge. (Credit: Michael Zeiler, @EclipseMaps).
The global path of this weekends eclipse-click to enlarge. (Credit: Michael Zeiler, @EclipseMaps).

This particular eclipse part of saros series 143 and is member 23 of the 72 eclipses in the cycle. The first eclipse in this saros occurred on March 7th, 1617, and the last one will occur on April 23rd, 2897.

Saros 143 also has a checkered place in  eclipse history. The last eclipse in this series crossed south eastern Asia on October 24th, 1995.

The first detailed picture of a solar eclipse was also taken of a saros 143 member on July 28, 1851. And one saros later, a total solar eclipse on August 7th, 1869 may have saved the butt of astronomer and explorer George Davidson while traversing the wilds of Alaska. And one more saros period later,  Dmitri Mendeleev (he of the modern periodic table) observed the total solar eclipse of August 19th, 1887 from a balloon.

A daguerreotype image of the 1851 eclipse captured by Berkowski of the  Royal Observatory in Königsberg, Prussia. (Public domain image).
A daguerreotype image of the 1851 eclipse captured by Berkowski of the Royal Observatory in Königsberg, Prussia. (Public domain image).

We’ve compiled a brief worldwide timeline for the November 3rd hybrid eclipse. Keep in mind, the shift back off of Daylight Saving Time occurs on the same morning as the eclipse for North America, putting the U.S. East Coast  once again back to -5 hours off of Universal Time (UT):

10:04 UT: The partial phases of the eclipse begin.

11:05:17 UT: annular phases of the eclipse begin.

11:05:36 UT: The eclipse transitions from an annular to a total along its track.

12:46: The point of greatest eclipse, occurring off of the SW coast of Liberia along the coast of Africa. The path will be 57 kilometres wide at this point with a maximum duration for totality at 1 minute & 40 seconds.

14:27 UT: The total phases of the eclipse end.

15:28 UT: Partial phases end.

Remember that solar safety is paramount while observing an eclipse during all partial phases. This is especially critical, as millions of viewers along the U.S. East Coast are poised to catch the eclipse at sunrise over the Atlantic on Sunday. Use only glasses designed specifically for eclipse viewing or welder’s glass #14. One project headed by Astronomers Without Borders is also working to provide eclipse glasses to schools in Africa.

Students in Tanzania demonstrating proper eclipse viewing safety. (Credit: Astronomers Without Borders).
Students in Tanzania demonstrating proper eclipse viewing safety. (Credit: Astronomers Without Borders).

Projecting the Sun onto a wall or a piece of paper is also a safe method to observe the eclipse. Construction of a Sun Gun, a pinhole projector, or even using a spaghetti strainer or colander to project the partially eclipsed sun are all fun projects to try.

Shooting pictures of the rising eclipse is also possible using a DSLR. To capture the disk of the Sun plus an outline of the foreground, you’ll want to use a combination of low ISO 100 and a fast shutter speed (1/4000 or faster) and a zoom lens of at least 200mm or greater. Keep in mind, DO NOT look at the Sun through the camera’s view finder— simply set the focus to infinity and aim via projection. It’s worth practicing your technique a morning or two prior to the main event!

As the partial phase of the eclipse progresses, keep an eye out for “tiny crescents” that may litter the ground. These are caused by gaps in things such as leaves, latticework, etc that may act as natural “pinhole projectors”. Those lucky enough to stand in the path of totality may snare a look at shadow bands sweeping across the landscape as totality approaches, as well as catch a brief glimpse of Baily’s Beads and the pearly white corona of the Sun.

Totality will last less than a minute across most of central Africa, giving viewers a very hurried view before partial phases commence once more. Venus will be easily visible at magnitude -4.4 just 47 degrees east of the Sun. Unfortunately, prospects aren’t great for air or seaborne viewers in the mid-Atlantic to catch sight of comet ISON during the frenzied moments of totality, which will sit 50 degrees from the Sun between magnitude +7 & +8.

The sky over Gabon during mid-eclipse. (Created by the author using Starry Nite).
The sky over Gabon during mid-eclipse. (Created by the author using Starry Nite).

Weather prospects are an all-important consideration when planning for an eclipse. Jay Anderson maintains an outstanding site with projections tailor-made for each eclipse. For the U.S. East Coast, clear skies right down to the crucial eastern horizon will be key!

A recent surge in piracy off of the West Coast of Africa may also factor into travel considerations for eclipse chasers. You can actually monitor such activities on the high seas now in near real time. Perhaps one could take a page from Mark Twain’s A Connecticut Yankee in King Arthur’s Court, and impress any would-be-brigands with the glory of an impending solar eclipse…

Unfortunately, the International Space Station will have an orbit nearly perpendicular to the Earth-Moon-Sun syzygy, and won’t lend itself to any great prospects of a transit during the partial phases of the eclipse. ESA’s Proba-2 and JAXA’s Hinode will, however, see several partial eclipses from orbit:

Sunspot activity has also been on the upswing as of late, making for a photogenic Sun heading into the partial phases of the eclipse. A well-placed, naked eye Coronal Mass Ejection on the solar limb also isn’t out of the question. Eclipse historian and expert Michael Zeiler notes that a CME last occurred during a total solar eclipse way back in 1860.

Sunspot activity as of October 28th... will it stay active until this weekend's eclipse? (Photo by author).
Sunspot activity as of October 28th… will it stay active until this weekend’s eclipse? (Photo by author).

Totality for this eclipse passes over some wild and largely wifi free areas; few plans to broadcast the eclipse live have surfaced thus far.

Slooh plans a broadcast, as did a proposed Indiegogo project whose current status is unclear. BRCK also plans to broadcast the eclipse live from the shores of Lake Turkana, Kenya.  Got plans to webcast even the partial phases of the eclipse? Let us know!

And speaking of eclipse chasing, we plan on heading to the Florida Space Coast Sunday morning at o’dark thirty to nab the partial sunrise eclipse over the Atlantic.

And as always, the question posed immediately after totality is: when’s the next one? Well, the next annular eclipse graces Australia on April 29th, 2014. The U.S. will also see a partial solar eclipse on October 23rd next year… but totality will not touch the surface of our fair planet until a high Arctic eclipse on March 20th, 2015.

Good luck, clear skies, and safe journeys to all who are chasing after this one near and far, and don’t forget to post those pics to Universe Today’s Flickr page!

-See more of Michael Zeiler’s work at Eclipse Maps.

-Simulations were created using Starry Night Education Software.

Huge Solar Sail Portion Unfurls In Crucial Ground Test

A view of the world's largest solar sail, Sunjammer. Credit: sunjammermission.com

We’re sure the people in that picture above must have had sweaty hands as they unfurled a huge solar sail in front of the camera. What you’re seeing there is a crucial ground test in which a quarter of Sunjammer — the largest solar sail ever expected to fly — was unfurled under Earth gravity conditions Monday (Sept. 30).

Sunjammer is expected to launch in January 2015, a slight delay from an earlier projection of November 2014. This test took place under even tougher conditions than the sail will face in space, as there will be no atmosphere and it will be operating in microgravity, officials said.

According to the team (which included prime contractor L’Garde Inc., NASA and Space Services Inc.), everything went well.

Sunjammer team members stand behind their solar sail. Credit: sunjammermission.com
Sunjammer team members stand behind their solar sail. Credit: sunjammermission.com

“If this test succeeded under these stressing conditions, we certainly anticipate it will work exceedingly well in space,” stated Nathan Barnes, L’Garde president.

Solar sails could one day be an alternative to conventional propellant-based spacecraft, providing that the spacecraft roam close enough to the sun to receive photonic pressure to do their maneuvers. There have been decades of development on the ground, but the first solar sail test took place in 2010 when Japan unfurled its IKAROS solar sail successfully.

Sunjammer, which would be NASA’s first solar sail in space, will look at solar activity. You can read more about the mission on its official website.

Source: Sunjammer

NASA Science Probe Blazes Spectacular Trail to the Moon from Virginia

This magnificent view of NASA’s LADEE lunar orbiter launched on Friday night Sept 6, on the maiden flight of the Minotaur V rocket from Virginia was captured by space photographer Ben Cooper perched atop Rockefeller Center in New York City. Credit: Ben Cooper/Launchphotography.com

This magnificent view of NASA’s LADEE lunar orbiter launched on Friday night Sept 6, on the maiden flight of the Minotaur V rocket from Virginia was captured by space photographer Ben Cooper perched atop Rockefeller Center in New York City. Credit: Ben Cooper/Launchphotography.com
Story updated[/caption]

WALLOPS ISLAND, VA – A NASA moon probe named LADEE thundered to space tonight, Sept. 6, blazing a spectacular trail to orbit from a beachside launch pad in Virginia that was easily visible to tens of millions of spectators along the eastern seaboard as a result of crystal clear skies and the night time liftoff – see magnificent photo shot from NYC above by Ben Cooper/Launchphotography.com.

The drama at the LADEE launch site on the eastern shore of Virginia at NASA’s Wallops Island facility was palpable due to the historic and experimental nature of the mission.

Hordes of tourists flooded into Virginia to be eyewitnesses to an unprecedented space spectacle that marked Americas ‘Return to the Moon’ and a chance to see the type of big and exciting rocket launches previously reserved for Florida and California.

Everyone I spoke too was absolutely overwhelmed with the amazing beauty of the Minotaur V blastoff carrying LADEE to orbit, whooping and hollering, far beyond our wildest expectations as the crackling fire pierced through the night and reverberated in our ears!

“It was a picture perfect launch,” said NASA Associate Administrator John Grunsfeld at a post launch media briefing at NASA Wallops.

“LADEE will help us unravel the mysteries of the lunar atmosphere.”

Blastoff of NASA’s dust exploring Lunar Atmosphere and Dust Environment Explorer (LADEE) Observatory marked the first space probe of any kind ever launched beyond Earth orbit from NASA Wallops, as well as being the first planetary science mission from Wallops.

LADEE's launch aboard a Minotaur V on Sept. 6, 2013. Credit: NASA Wallops/Chris Perry
LADEE’s launch aboard a Minotaur V on Sept. 6, 2013. Credit: NASA Wallops/Chris Perry

The Minotaur V rocket launched precisely on time at 11:27 p.m. EDT on the maiden flight of the powerful new Minotaur V rocket Launch Pad 0B on NASA’s Wallops Flight Facility.

“The spacecraft is healthy and power positive and separated from the fifth and last stage on time, approximately 23 minutes into the flight,” said Pete Worden to Universe Today after the liftoff. Worden is the Director of NASA’s Ames Research Center which designed and built LADEE using a revolutionary new design to reduce costs and increase science output.

Ignition of Minotaur V rocket launching NASA’s LADEE lunar orbiter on Sept. 6, at 11:27 p.m. EDT from NASA Wallops, Virginia, media viewing site 2 miles away. Credit: Ken Kremer/kenkremer.com
Ignition of Minotaur V rocket launching NASA’s LADEE lunar orbiter on Sept. 6, at 11:27 p.m. EDT from NASA Wallops, Virginia, media viewing site 2 miles away. Credit: Ken Kremer/kenkremer.com
Launch of NASA’s LADEE lunar orbiter on Friday night Sept. 6, at 11:27 p.m. EDT on the maiden flight of the Minotaur V rocket from NASA Wallops, Virginia, viewing site 2 miles away. Antares rocket launch pad at left.  Credit: Ken Kremer/kenkremer.com
Launch of NASA’s LADEE lunar orbiter on Friday night Sept. 6, at 11:27 p.m. EDT on the maiden flight of the Minotaur V rocket from NASA Wallops, Virginia, media viewing site 2 miles away. Antares rocket launch pad at left. Credit: Ken Kremer/kenkremer.com
Launch of NASA’s LADEE lunar orbiter on Friday night Sept. 6, at 11:27 p.m. EDT on the maiden flight of the Minotaur V rocket from NASA Wallops, Virginia, viewing site 2 miles away. Antares rocket launch pad at left.  Credit: Ken Kremer/kenkremer.com
Launch of NASA’s LADEE lunar orbiter on Friday night Sept. 6, at 11:27 p.m. EDT on the maiden flight of the Minotaur V rocket from NASA Wallops, Virginia, media viewing site 2 miles away. Antares rocket launch pad at left. Credit: Ken Kremer/kenkremer.com

The liftoff of LADEE (pronounced ‘laddie’ not ‘lady’) also marks the first launch of a five stage rocket and the first launch of a decommissioned Peacekeeper missile from Wallops. The Peacekeeper was a nuclear armed intercontinental ballistic missile ICBM built during the Cold War – now retired and refurbished by Orbital for peaceful uses.

The Minotaur V fifth stage boosted LADEE into a highly elliptical orbit. Over about the next 23 days, as LADEE orbits Earth 3.5 times, the Moon’s gravitational field will increase the apogee of its orbit. The spacecraft will fire its on-board braking thrusters to achieve lunar orbit.

Gantry doors open to expose Minotaur V rocket launching LADEE lunar orbiter to the Moon on Sept 6, 2013 from Launch Pad 0B at NASA Wallops Island.  Credit: Ken Kremer/kenkremer.com
Gantry doors open to expose Minotaur V rocket launching LADEE lunar orbiter to the Moon on Sept 6, 2013 from Launch Pad 0B at NASA Wallops Island. Credit: Ken Kremer/kenkremer.com

The mission will fly in a very low science orbit of about 50 kilometers altitude above the moon that will require considerable fuel to maintain. The science mission duration is approximately 100 days.

The 844 pound (383 kg) robot explorer is the size of a couch and was assembled at NASA’s Ames Research Center, Moffett Field, Calif., and is a cooperative project with NASA Goddard Spaceflight Center in Maryland.

It is equipped with a trio of science instruments whose purpose is to collect data that will inform scientists in unprecedented detail about the ultra thin lunar atmosphere, environmental influences on lunar dust and conditions near the surface.

The goal of the $280 Million mission is to gain a thorough understanding of long-standing unknowns about the tenuous atmosphere, dust and surface interactions that will help scientists understand other planetary bodies as well.

The LADEE satellite in lunar orbit.   The revolutionary modular science probe is equipped with a Lunar Laser Communication Demonstration (LLCD) that will attempt to show two-way laser communication beyond Earth is possible, expanding the possibility of transmitting huge amounts of data. This new ability could one day allow for 3-D High Definition video transmissions in deep space to become routine.  Credit: NASA
The LADEE satellite in lunar orbit. The revolutionary modular science probe is equipped with a Lunar Laser Communication Demonstration (LLCD) that will attempt to show two-way laser communication beyond Earth is possible, expanding the possibility of transmitting huge amounts of data. This new ability could one day allow for 3-D High Definition video transmissions in deep space to become routine. Credit: NASA

The couch sized probe is built on a revolutionary ‘modular common spacecraft bus’, or body, that could dramatically cut the cost of exploring space and also be utilized on space probes to explore a wide variety of inviting targets in the solar system. The overall mission cost is approximately $280 million.

“LADEE is the first in a new class of interplanetary exploration missions,” NASA Ames Director Worden told Universe Today. “It will study the pristine moon to study significant questions.”

“This is probably our last best chance to study the pristine Moon before there is a lot of human activity there changing things.”

The five stage Minotaur V rocket stands 80.6 feet (24.6 meters) tall, is 7.6 feet (2.3 m) in diameter and weighs 197,034 pounds (89,373 kilograms).

Gantry doors open to expose Minotaur V rocket launching LADEE lunar orbiter to the Moon on Sept 6, 2013 from Launch Pad 0B at NASA Wallops Island.  Credit: Ken Kremer/kenkremer.com
Gantry doors open to expose Minotaur V rocket launching LADEE lunar orbiter to the Moon on Sept 6, 2013 from Launch Pad 0B at NASA Wallops Island. Credit: Ken Kremer/kenkremer.com

The first three stages of the Minotaur V are based on the nuclear armed Peacekeeper ICBM intercontinental ballistic missile built during the Cold War – now retired and refurbished by Orbital Sciences for peaceful uses.

The upper 5th stage is a new addition and what makes this Minotaur a new rocket class. The additional thrust is what converts the Minotaur V into an interplanetary booster that enables shooting for the Moon.

“I dreamed all my life about launching a rocket to the moon. And now we are doing it,” Lou Amorosi, told Universe Today at the Minotuar launch pad. Amorosi is the Senior Vice President of Orbital’s Small Space Launch Vehicle business.

“This mission further demonstrates the capabilities of our well-established Minotaur rocket family and our commitment to providing reliable access to space,” Amorosi noted in a post launch statement.

Ken Kremer

…………….
Learn more about LADEE, Cygnus, Antares, MAVEN, Orion, Mars rovers and more at Ken’s upcoming presentations:

Sep 16/17: “LADEE Lunar & Antares/Cygnus ISS Rocket Launches from Virginia”; Rodeway Inn, Chincoteague, VA, 8 PM

Oct 3: “Curiosity, MAVEN and the Search for Life on Mars – (3-D)”, STAR Astronomy Club, Brookdale Community College & Monmouth Museum, Lincroft, NJ, 8 PM

Oct 8: “LADEE Lunar & Antares/Cygnus ISS Rocket Launches from Virginia”; Princeton University, Amateur Astronomers Assoc of Princeton (AAAP), Princeton, NJ, 8 PM

LADEE post launch news briefing at NASA Wallops, VA with  Air Force Col. Urban Gillespie, Minotaur mission director from the Space Development and Test Directorate, John Grunsfeld, Astronaut and    NASA Associate Administrator for Science, Pete Worden, Director of NASA’s Ames Research Center.   Credit: Ken Kremer/kenkremer.com
LADEE post launch news briefing at NASA Wallops, VA with Air Force Col. Urban Gillespie, Minotaur mission director from the Space Development and Test Directorate, John Grunsfeld, Astronaut and NASA Associate Administrator for Science, Pete Worden, Director of NASA’s Ames Research Center. Credit: Ken Kremer/kenkremer.com
Lou Amorosi, VP of Orbital Sciences Small Spacecraft Launch Vehicles and Ken Kremer of Universe Today with LADEE and Minotaur V rocket at Launch Pad.  Credit: Ken Kremer/kenkremer.com
Lou Amorosi, VP of Orbital Sciences Small Spacecraft Launch Vehicles and Ken Kremer of Universe Today with LADEE and Minotaur V rocket at Launch Pad 0B at NASA Wallops Island. Credit: Ken Kremer/kenkremer.com

LADEE_Poster_01

Double Vision: Scientists Spot An Elder ‘Twin’ To the Sun

The life-cycle of a Sun-like star from protostar (left side) to red giant (near the right side) to white dwarf (far right). Credit: ESO/M. Kornmesser

If you want a picture of how you’ll look in 30 years, youngsters are told, look at your parents. The same principle is true of astronomy, where scientists compare similar stars in different age groups to see how they progress.

We have a special interest in learning how the Sun will look in a few billion years because, you know, it’s the main source of energy and life on Earth. Newly discovered HIP 102152 could give us some clues. The star is four billion years older than the sun, but so close in composition that researchers consider it almost like a twin.

Telescopes have only been around for a few centuries, making it hard to project what happens during the billions upon billions of years for a star’s lifetime. We have about 400 years of observations on the sun, for example, which is a minute fraction of its 4.6 billion-year-old lifespan so far.

The Sun in H-Alpha, on 01-07-2013, using a Lunt Solar LS60Scope/LS50 Hydrogen Alpha Solar filter. Credit: John Chumack
Today, we take telescopic observations of the Sun for granted, but the technology only became available about 400 years ago. This picture shows the Sun in H-Alpha, on 01-07-2013, using a Lunt Solar LS60Scope/LS50 Hydrogen Alpha Solar filter. Credit: John Chumack

“It is very hard to study the history and future evolution of our star, but we can do this by hunting for rare stars that are almost exactly like our own, but at different stages of their lives,” stated the European Southern Observatory.

ESO’s Very Large Telescope — guided by a team led by the University of Sao Paulo’s Jorge Melendez — examined HIP 102152 with a spectrograph that broke up the light into various colors, revealing properties such as chemical composition. Around the same time, they scrutinized 18 Scorpii, also considered to be a twin but one that is younger than the sun (2.9 billion years old)

So what can we predict about the Sun’s future? One thing puzzling scientists has been the amount of lithium in our closest stellar companion. Although the Big Bang (the beginning of the universe) created hydrogen, helium and lithium, only the first two elements are abundant in the Sun.

Periodic Table of Elements
Periodic Table of Elements

HIP 102152, it turns out, also has low levels of lithium. Why isn’t clear yet, ESO notes, although “several processes have been proposed to transport lithium from the surface of a star into its deeper layers, where it is then destroyed.” Previous observations of young Sun-like stars also show higher levels of lithium, implying something changes between youth and middle age.

The elder twin to our Sun may host another discovery: there could be Earth-sized planets circling the star. Chemical properties of HIP 102152 show that it has few elements that you see in meteorites and rocky planets, implying the elements are “locked up” in bodies close to the star. “This is a strong hint that HIP 102152 may host terrestrial rocky planets,” ESO stated.

Better yet, separate observations showed that there are no giant planets close to the star — leaving room for Earth-sized planets to flourish.

The research is available in a recent edition of Astrophysical Letters.

Source: European Southern Observatory

Is the Sun More Active Than it Looks? An Innovative Method to Characterize the Solar Cycle

A solar cycle montage from August 1991 to September 2001 in X-rays courtesy of the Yohkoh Solar Observatory. (Credit: David Chenette, Joseph B. Gurman, Loren W. Acton, image in the public Domain).

The Sun has provided no shortage of mysteries thus far during solar cycle #24.

And perhaps the biggest news story that the Sun has generated recently is what it isn’t doing. As Universe Today recently reported, this cycle has been an especially weak one in terms of performance. The magnetic polarity flip signifying the peak of the solar maximum is just now upon us, as the current solar cycle #24 got off to a late start after a profound minimum in 2009…

Or is it?

Exciting new research out of the University of Michigan in Ann Arbor’s Department of Atmospheric, Oceanic and Space Sciences published in The Astrophysical Journal this past week suggests that we’re only looking at a portion of the puzzle when it comes to solar cycle activity.

Traditional models rely on the monthly averaged sunspot number. This number correlates a statistical estimation of the number of sunspots seen on the Earthward facing side of the Sun and has been in use since first proposed by Rudolf Wolf in 1848. That’s why you also hear the relative sunspot number sometimes referred to as the Wolf or Zürich Number.

But sunspot numbers may only tell one side of the story. In their recent paper titled Two Novel Parameters to Evaluate the Global Complexity of the Sun’s Magnetic Field and Track the Solar Cycle, researchers Liang Zhao, Enrico Landi and Sarah E. Gibson describe a fresh approach to model solar activity via looking at the 3-D dynamics heliospheric current sheet.

The spiralling curve of the heliospheric current sheet through the inner solar system. (Graphic credit: NASA).
The spiraling curve of the heliospheric current sheet through the inner solar system. (Graphic credit: NASA).

The heliospheric current sheet (or HCS) is the boundary of the Sun’s magnetic field separating the northern and southern polarity regions which extends out into the solar system. During the solar minimum, the sheet is almost flat and skirt-like. But during solar maximum, it’s tilted, wavy and complex.

Two variables, known as SD & SL were used by researchers in the study to produce a measurement that can characterize the 3-D complexity of the HCS.  “SD is the standard deviation of the latitudes of the HCS’s position on each of the Carrington maps of the solar surface, which basically tells us how far away the HCS is distributed from the equator. And SL is the integral of the slope of HCS on that map, which can tell us how wavy the HCS is on each of the map,” Liang Zhao told Universe Today.

Ground and space-based observations of the Sun’s magnetic field exploit a phenomenon known as the Zeeman Effect, which was first demonstrated during solar observations conducted by George Ellery Hale using his new fangled invention of the spectrohelioscope in 1908. For the recent study, researchers used data covering a period from 1975 through 2013 to characterize the HCS data available online from the Wilcox Solar Observatory.

SD and SL perameters juxtaposed against the tradional monthly sunspot number.
SD and SL parameters juxtaposed against the traditional monthly sunspot number (SSN). Note the smooth fit until the end of solar cycle #23 around 2003. (Credit: Liang Zhao/The Astrophysical Journal).

Comparing the HCS value against previous sunspot cycles yields some intriguing results. In particular, comparing the SD and SL values with the monthly sunspot  number provide a “good fit” for the previous three solar cycles— right up until cycle #24.

“Looking at the HCS, we can see that the Sun began to act strange as early as 2003,” Zhao said. “This current cycle as characterized by the monthly sunspot number started a year late, but in terms of HCS values, the maximum of cycle #24 occurred right on time, with a first peak in late 2011.”

“Scientists believe there will be two peaks in the sunspot number in this solar maximum as in the previous maximum (in ~2000 and ~2002),” Zhao continued, “since the Sun’s magnetic fields in the north and south hemispheres look asymmetric, and the north evolved faster than the south recently. But so far as I can see, the highest value of monthly-averaged sunspot number in this cycle 24 is still the one in the November 2011. So we can say the first peak of cycle 24 could be in November of 2011, since it is the highest monthly sunspot number so far in this cycle. If there is a second peak, we will see it sooner or later.”

The paper also notes that although cycle 24 is especially weak when compared to recent cycles, its range of activity is not unique when compared with solar cycles over the past 260 years.

HCS curves plotted on the surface of the Sun.
HCS curves plotted on the surface of the Sun. Comparisons are made for the solar maximum on October 2000 (CR 1968), descending phase on April 2005 (2029), solar minimum on September 2009 (CR 2087), and ascending phase on March 2010 (CR2094). CR=Carrington Rotation. (Credit: Liang Zhao, The Astrophysical Journal).

The HCS value characterizes the Sun over one complete Carrington Rotation of 27 days. This is an averaged value for the rotation of the Sun, as the poles rotate slower than the equatorial regions.

The approximately 22 year span of time that it takes for the poles to reverse back to the same polarity again is equal to two average 11 year sunspot cycles. The Sun’s magnetic field has been exceptionally asymmetric during this cycle, and as of this writing, the Sun has already finished its reversal of the north pole first.

This sort of asymmetry during an imminent pole reversal was first recorded during solar cycle 19, which spanned 1954-1964. Solar cycles are numbered starting from observations which began in 1749, just four decades after the end of the 70-year Maunder Minimum.

“This is an exciting time to study the magnetic field of the Sun, as we may be witnessing a return to a less-active type of cycle, more like those of 100 years ago,” NCAR/HAO senior scientist and co-author Sarah Gibson said.

A massive sunspot group that rotated into view in early July, 2013... one of the largest seen for solar cycle #24 thus far. (Credit: NASA/SDO).
A massive sunspot group that rotated into view in early July, 2013, one of the largest seen for solar cycle #24 thus far. (Credit: NASA/SDO).

But this time, an armada of space and ground-based observatories will scrutinize our host star like never before. The SOlar Heliospheric Observatory (SOHO) has already followed the Sun through the equivalent of one complete solar cycle— and it has now been joined in space by STEREO A & B, JAXA’s Hinode, ESA’s Proba-2 and NASA’s Solar Dynamics Observatory. NASA’s Interface Region Imaging Spectrograph (IRIS) was also launched earlier this year and has just recently opened for business.

Will there be a second peak following the magnetic polarity reversal of the Sun’s south pole, or is Cycle #24 about to “leave the building?” And will Cycle #25 be absent all together, as some researchers suggest? What role does the solar cycle play in the complex climate change puzzle? These next few years will prove to be exciting ones for solar science, as the predictive significance of HCS SD & SL values are put to the test… and that’s what good science is all about!

-Read the abstract with a link to the full paper in The Astrophysical Journal by University of Michigan researchers here.