September 26, 2017

Review: The Sun’s Heartbeat by Bob Berman.

Out from Little-Brown!

Think you know our nearest star? Think again… no other astronomical object influences our often mundane daily lives like our Sun. Think about it; the fuel in our cars, the energy in that Twinkie you had for “breakfast” (admit it) and the very power in the electrons that propel this blog can all be traced back the fusion force coming from our nearest star. As Bob Berman points out in his latest book, The Sun’s Heartbeat, and Other Stories from the Life of the Star that Powers out Planet, all Earthbound energy with the exception of nuclear fission can be traced back to our Sun. Fans of Astronomy magazine (which JUST finally joined the ranks of the digital, winning back at least one more subscriber!) will be familiar with Mr. Berman’s Dave Barry-meets-Carl Sagan style of writing from his monthly column. [Read more...]

17.06.10: Living with Solar Cycle #24.

The beginnings of solar activity earlier this year. (Photo by Author).

The beginnings of solar activity earlier this year. (Photo by Author).

 

     As our local star gets underway into solar cycle #24, all eyes, orbiting and ground based, are keeping a close watch. The very concept of space weather is coming very much into vogue, and the activity over the next several year span may test the underpinnings of our technological civilization like never before. This past June 8th, scientists, authorities and civic planners met in Washington D.C. at the Space Weather Enterprise Forum at the National Press Club to discuss what if anything can be done to protect ourselves from the tempestuous throes of the Sun. This next cycle got off to a sputtering start but is forecast to be a rough one; keep in mind, while the solar cycle lasts 11 years, technology as per Moore’s law has been doubling exponentially once every 18 months. Ask yourself, what would you have read this on 11 years ago? And a really nasty flare such as the Carrington event in 1859 would do more than simply put your cell on the fritz; increasingly, everything from emergency services to navigation to commerce depends on technology. Heck, knocking out the power grid on a humid summers’ day might spell death for hundreds… with this apocalyptic setting in mind, the National Academy of Sciences built a report two years ago entitled Severe Space Weather Events- Societal and Economic Impacts, which outlined the possibilities of a really massive solar flare and efforts to minimize its impact. This year’s meeting marks the fourth symposium on the subject. It been suggested by the study that a century class storm could have the impact of Katrina twenty fold, but it is also true that there is simply no precedent for such an event. On the frontlines of the space weather wars are Richard Fisher, head of NASA’s Heliophysics Division, and Thomas Bogdan, director for the NOAA’s Space Weather Prediction Center. Along with ground based networks such as GONG (The Global Oscillation Network Group), three key elements stand at the ready in their Sun monitoring arsenal;

The Solar Dynamics Observatory (SDO). It’s no coincidence that NASA’s premiere solar observing platform took to orbit at the start of the solar cycle; SDO will be able to monitor solar activity with unprecedented detail and resolution.

STEREO: The Solar Terrestrial RElations Observatory, STEREO is actually a pair of satellites, one Earth-leading and one Earth-trailing. This will allow us to peer around the backside of the Sun to see if anything nasty is rotating our way.

But one of the most vital instruments may be the one you’ve never heard of; ACE, or the Advanced Composition Explorer. ACE was launched in 1997 and samples the near Earth solar environment from its upwind position and gives scientists a 30 minute warning before an event begins interacting with our planet.

So what can be done if the big one is on the way? In many instances, equipment can be saved simply by disconnecting transformers or placing satellites in safe mode…but one thing is for certain, we can no longer afford to think that our daily lives are somehow separate from the space environment. Like it or not, we are now a space faring culture, with all that entails. Be grateful that NASA and the NOAA are on continued solar vigil!

23.04.10-SDO Unveiled.

(Credit: NASA/SDO).

(Credit: NASA/SDO).

An SDO Original!

    Cool images Alert: NASA’s recently launched Solar Dynamics Observatory (SDO) has released some fairly mind-blowing pics and videos this week. The video below is but a small sampling of the capabilities showcased by this Sun-monitoring spacecraft. “We’ve seen prominences before, but not like this!” states Alan Title of Lockheed Martin. SDO was launched on February 11th, 2010 and studies the Sun from a polar inclined geosynchronous orbit. Equipped with high definition cameras and a 4096x 4096 –pixel array, you haven’t seen the Sun the way SDO has revealed it. Part of NASA’s Living With a Star program, SDO will provide a continuum in solar astronomy started by the ESA’s SOHO satellite in the 1990’s. One can only hope that SDO’s data will be as easily accessible and provide real time access to the public as SOHO has done. Not only will SDO have the capability to monitor the Sun in ultraviolet and extreme ultraviolet, but it also possesses an Atmospheric Imaging Assembly (AIA) and a Helioseismic and Magnetic Imager. But beyond pretty pictures, SDO also promises to give us a unique insight into the inner workings of our Sun. And with sunspot cycle #24 just gearing up, this capability may have come none too soon!

15.04.10- Do We Know the Future of our Sun?

(Credit: Oliver Beatson).

(Credit: Oliver Beatson).

  You Are Here!

    Our modern understanding of stellar evolution states that our Sun is a middle-aged main sequence star, destined to bellow up into a Red Giant in a few billion years and eventually wind up as a degenerate white dwarf embedded in a shroud of a planetary nebula. Looking out at the stars in various stages of evolution in our galaxy, we see systems that have done just that. These Red Giants often exhibit a rhythmic oscillation as their atmospheres swell and contract, but about one third also display a longer five year variation that scientists do not completely understand. Now, a study conducted by the European Southern Observatories’ Very Large Telescope (VLT) is looking into this mystery by studying 58 sun-like stars towards their elderly Red Giant stage located in the Large Magellanic Cloud. Known since the 1930’s, this mystery has baffled astronomers. “Astronomers are left in the dark, and for once, we do not enjoy it,” stated Christine Nicholls of Australia’s Mount Stromlo Observatory. Some of the long term pulsations could be explained by the presence of an unseen binary companion, but not all. This phenomenon is of special interest to astrophysicists because our own Sun may one day throw similar temper tantrums. Could stellar evolution be in need of tweaking?

AstroEvent: A Very Looong Annular Eclipse!

Animation of the Annular Eclipse on January 15th, 2010.

Animation of the Annular Eclipse on January 15th, 2010. (Credit: NASA/A.T. Sinclair).

          One of the more unique celestial events on the calendar for 2010 occurs on Friday, January 15th; an annular eclipse of the Sun, and the longest for the millennium! An annular solar eclipse occurs when the moon is at or near apogee (its most distant point from the Earth) and/or the Earth is at or near perihelion (its closest approach to the Sun)… these happened on January 17th and January 2nd respectively, setting us up for a visually large Sun and correspondingly small Moon, small enough that it won’t completely cover the Sun’s disk.   The maximum possible duration for an annular eclipse is 12 minutes and 24 seconds and the actual maximum for this eclipse is 11 minutes and 7.7 seconds, which occurs off of the southwestern coast of the Indian subcontinent. [Read more...]

Top Astronomy Events for 2010.

(Photo credit: Art Explosion).

(Photo credit: Art Explosion).

Ah, it’s that most hallowed time of year yet again; a time to look ahead at what astro- wonders await in 2010. Here’s a quick month-by-month rundown of the curious, unique and bizarre coming to a sky near you. Like last year, rather than bore you with a laundry list of every obscure wide conjunction and moon phase, we distilled ‘em down to the best of the best. [Read more...]

05.11.09:A Low Pass of Enceladus.

The alien surface of Enceladus as seen during the Nov. 2nd pass. (Credit: NASA/JPL).

The alien surface of Enceladus as seen during the Nov. 2nd pass. (Credit: NASA/JPL).

Cassini has completed another close reconnaissance pass of one of Saturn’s most intriguing moons; Enceladus. On November 2nd at 7:40 AM UTC, Cassini passed 62 miles above the icy surface of the south polar region, completing a carefully timed plunge through one of its liquid plumes. This was one of its most comprehensive passes of the moon out of the seven completed so far, enabling the spacecraft to utilize its array of infrared and ultraviolet detectors to analyze speed and particle size. Cassini itself is whizzing along at 5 miles per second. Sodium, water, and carbon dioxide have been detected in the out-gassing, tantalizing evidence that more complex organic chemistry may exist below the surface. Enceladus is heated from tidal flexing caused by Saturn’s gravity squeezing it like a rubber ball. Along with Jupiter’s moon, Europa, Enceladus has been proposed as deserving of future scrutiny as a possible abode of life. Enceladus is a tiny world, about 310 miles in diameter, or about 15% the diameter of our Moon. Two subsurface oceans in one solar system also poses the intriguing question; are environments like Enceladus and Europa more common throughout the universe than Earth? Cassini has phoned home after the recent pass and is reported in good health. Scientists are currently poring over the results; watch for another pass of Enceladus on April 28th of next year. What ever the outcome, Enceladus is proving to be a dynamic place, worthy of future study!

29.10.09:Is Solar Activity on the Upswing?

Sunspot group #1029. (Credit: Global Osillation Network Group).

Sunspot group #1029. (Credit: Global Oscillation Network Group).

Our characteristically dormant Sun has shown signs of awakening from it’s year plus long slumber this week. Specifically, a new sunspot group has formed on the Earthward facing side, and is now rotating towards the limb. This is definitely part of the new solar cycle #24, as characterized by its reversed polarity. Thus far, this solar cycle has been off to a sputtering start, at best. All amateur scopes, be they hydrogen Alpha, Calcium K, or safely filtered white light are encouraged to watch as this “monster” sunspot rotates around this Sun’s limb. The group already shows the envelopment of a fine dark umbra embedded in a pale penumbra, and will hopefully throw some looping prominences up through the chromosphere as it rotates from view. If you do not have optical means, you can still follow the action via SpaceWeather (the link above) or the Solar Heliocentric Observatories’ (SOHO) website! Enjoy!

17.9.9: A Farside Sunspot Group?

STEREO-B UV light image showing possible active area at the 7 o'clock position. (Credit: NASA/STEREO).

STEREO-B UV light image showing possible active area at the 7 o'clock position. (Credit: NASA/STEREO).

Activity on the Sun may be finally picking up. Specifically, a new sunspot group has been “seen” up forming on the farside of the Sun. That’s right; astronomers can now model the goings-on within the Sun with such precession, thanks largely to satellites like SOHO and the GONG network, that we can now predict with some confidence whats going on on the side of the Sun turned away from us! This is mostly due to a growing sub-branch of astronomy known as helioseismology. The Sun itself rotates at about once every 25 days, although this varies by latitude because the Sun is essentially a big rotating gas ball. The twin Stereo spacecraft are also slowly inching their way out into leading and trailing orbit(s), providing us with a good “peak” around the limb. If you own a solar scope, the next week or so might be good cause for increased monitoring; the new solar cycle #24 might just be ready to put on its first show!

Review: The Sun Kings by Stuart Clark

 

We here at Astroguyz love a good read about the “secret history” of astronomy… sure, everybody knows the exploits of Galileo and Copernicus, but how many have heard of the trials of 18th century British astronomer Richard Carrington? The Sun KingsThe Unexpected Tragedy of Richard Carrington and the Tale of How Modern Astronomy Began, by Stuart Clark  and out now by Princeton University Press is the fascinating tale of how the science of astrophysics and space weather truly began, and of how astronomers went from passively observing to truly analyzing data gleened from the universe around us. A truly rare and engaging breed of science history book, we were almost sad to finish it. It stands probably as the best read we’ve had since The Search for Planet Vulcan, and tells how these old-time astronomers operated.

The tale opens with the now infamous Halloween flares of 2003, some of the most powerful of the previous solar cycle. This represented the first time that some of our most cherished solar watch dogs, such as SOHO and the GONG  network were on hand to witness the full fury of the Sun. The shock was even felt by our vanguards elsewhere is the solar system, such as the Ulysses, Voyager 2, and Mars Odyssey spacecraft, even burning out the radiation detectors on the latter!

But as with much in science, our interpretation and understanding took a long and torturous road. The book then whisks the reader back to late 18th century England, a time when William Herschel proposed an astonishing idea; that the observed 11 year sunspot cycle was linked to Earthly agriculture and commerce. Specifically, he noted that the price of wheat tended to fluctuate in a corresponding period, with prices at their highest and supplies at their scarcest during the solar minimum and the opposite occurring at the solar max. Of course, this was seen as the delusion of an aging astronomer and roundly dismissed by his peers. Herschel had discovered Uranus and the infrared part of the spectrum, but this third contribution was largely overlooked.

Enter Richard Carrington. He stands as the kind of guy you’d always root for, an astronomer of ambition and insight whose personal life was marred by tragedy. He’s is now remembered mostly for being on hand and having the prescience to accurately record what he saw, but also made the right connections to what was going on around the environs of the Earth in late 1859.  It was interesting to note that during the height of the electromagnetic turbulence, a telegraph operator in Portland, Maine noted that his transmission system worked better utilizing solely the charge on the line, with the batteries disconnected!

Carrington’s prime ambition was to observe the Sun through the span of one complete solar cycle, but like many of us, his plan to pursue astronomy was continuously be-deviled by the pursuit of funding and that whole “personal life” thing.  Perhaps he needed a blog…

First, the death of his father left him running the family brewery. Not that the title of “Gentleman/ Brewer/ Astronomer” is a bad byline… but his romantic exploits turned sour as well, when his marriage to an under class woman turned into a love triangle that pulls him into trial and scandal. The whole affair reads like a bad Jane Austin novel… unfortunately,  the innocent Carrington took his life by overdose of chloral of hydrate mixed with alcohol shortly after the death of his wife Rosa.

As sad a fate as Carrington’s life was, his insight sparked a vigilant monitoring of the Sun. In fact, in the late 19th century, the riddle of the Sun was the topic in astronomy, as scientists turned a battery of new toys on our nearest star, such as the spectroheliograph and that new fangled device, the camera.

Hereto unknown elements such as helium  were first discovered in the atmosphere of the Sun. But the source of its enormous energy output had to remain and mystery until Einstein revealed the miracle of fusion in the early 20th century.

Enter Edward Walter Maunder, in many ways the intellectual predecessor to Carrington. From his early childhood, Maunder had been transfixed by the Sun, spying a naked eye sunspot as a boy through a low heavy fog. It must have been an astonishing sight to the young Carrington, who went on to lead an expedition to India in 1898 to photograph the elusive solar corona.

Images taken by his wife Annie, an expert astronomer in her own right,  later confirmed the connection between the tenuous streamers seen and sunspot activity. Here finally lay the mechanism by which the Sun could reach out and touch the Earth.

But its for another fascinating theory that Maunder is now known. He noted during his historical research that large spans of spotless periods corresponded with eras of dramatic global climatic cooling; a famous stretch from 1645 to 1715 now bears his name as the Maunder Minimum. During this period, the Thames river froze annually, harvests were meager, and several “years without a summer” were recorded. At first, even Maunder himself was skeptical; he believed the apparent lack of sunspots could easily be explained away by the gaps in the chronological record. However, Maunder’s research was revived by Dr. Jack Eddy in the 1970′s, who also combed through Chinese records of naked eye sunspot observations. Today, the existence of the Maunder Minimum remains hotly contested, as does the Sun’s role and measure of effect in climate change.

Of course, today it is tempting and sometimes even fashionable to link the solar cycle to everything from fluctuations in the stock market to  the cycle of global conflict over resources to the prevalence of bikinis on your local beach, and the list of dubious links could provide headlines for your favorite search engine for years to come. But Hershel was in fact finally vindicated; in 2003, Israeli scientists proved that the link between wheat prices and the solar cycle in the 17th century was real. Similar assertions for top vintage wine years beg for a similar study. Wherever you stand on the global warming issue, few can deny that the shenanigans of our Sun  are tied up in the cosmic riddle.

The author ends on an interesting coda; in 2004, large gamma-ray burst tore through our solar system two days after Christmas.  This was powerful enough to effect our upper atmosphere for several hours, and was even recorded reflecting off of our own Moon! The source; a magnetar, a bizarre sort of pulsar just recently identified, about 50,000 light years distant. This event shows the emerging realization that not only are we at the mercy of our local Sun’s whim, but that there are much meaner beasties out there that can and do reach out and touch us. We owe the beginnings of this understanding to Carrington and his ilk, who proved, often amid controversy, that we are not immune or aloof from our cosmic environs. Read The Sun Kings and marvel at this largely unknown but fascinating chapter in astronomical history!

 

Remembering the Super Flare of 1859.

This coming Tuesday marks the 150th anniversary of a unique astronomical event that has repercussions even today. On the morning of September 1st, 1859, Astronomer Richard Carrington found his routine of carefully drawing and recording the transit times of sunspot groups disrupted by an odd phenomenon emerging on the face of the Sun. The day dawned unusually sunny over his private observatory in Redhill, England, and 33 year old Carrington had taken to his usual daily task of sketching sunspot groups projected onto a screen in a darkened room. The scope used was a 2-meter long brass refractor, (scopes were often measured by focal length instead of aperture in those days) and it yielded an 11-inch diameter projected image of the Sun. the Sun itself had been extremely active most of the year, and there was plenty to draw.

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AstroEvent of the Week: 6.7.09: Can you spot the Penumbral?

 

 

This week, I give you what is surely the meekest of all eclipses; a very shallow penumbral eclipse. At about 5:38 Eastern Standard time on the morning of Tuesday, July 7th, the northern edge of the Moon will find itself not quite a quarter submerged in the Earth’s penumbra, the light outer part of the planet’s shadow. The geometry for most of the continental United States is not good, as the Moon will be setting in the brightening dawn twilight. So why should you care to wake up early for an almost non-eclipse? [Read more...]

Event of the Week: 29.06.09: The Deepening Solar Minimum.

Something mildly bizarre is happening on our nearest star, the Sun. Or should we say, a lack there of… This weeks astro-event is a sort of non-event, but one of the big mysteries of 2009; where exactly are the sunspots? Turning that newly constructed white-light filter we built last week on our mild-mannered star shows a definite lack of activity in the solar photosphere. This isn’t entirely abnormal, as the Sun is just coming off of a solar minimum that occurs every 11 years. What is unusual is the length of this minimum; we’ve had over 600+ spotless days since 2004, a quarter of which have been in 2009 alone. A typical minimum consists of an average of 485 days. You have to go way back to 1913 to find such comparable a lull! Two tiny sunspots appeared last week, which prompted the discussion as to whether the latent solar cycle #24 is finally amping up or not. Both spots belong to the new cycle, their reversed polarity giving them away. Using the technique of helioseismology, Frank Hill and Rachel Howe at Tucson’s National Solar Observatory have discovered that the Sun’s internal dynamo isn’t dead, just sleeping. They predict that the subsurface tachocline should begin intersecting the surface at the junction of 22 degrees latitude by the end of 2009, and activity should resume. It’ll be a wait and see mystery that will only deepen if the spots don’t return to roost; and does this portend a stronger than usual maximum around the solar bend? Stay tuned!

This week’s astro-term of the week is Sporer’s Law. First worked out by astronomer Gustav Sporer, this law simply states that sunspots form at higher latitudes at the beginning of a solar cycle, and then gradually progress downward to lower latitudes in both hemispheres as the cycle progresses. We never see spots above 45 degrees of latitude, and astronomers aren’t quite sure why. The link between the solar cycle and the climate isn’t yet fully understood. Could a spotless Sun mimic or mask the effects of global warming? Both Earth and space bound telescopes are keeping a constant watch on our Sun. Cries of another Maunder minimum, a time from 1645 to 1715 that was marked by harsh winters and almost no sunspots were seen, may be a bit premature… cycle #24 were art thou?

A Home-made Solar Filter for Cheap.

Solar observing is just plain cool. While some celestial objects such as the Andromeda Galaxy will look exactly the same on the day you die as when you were born, the face of the Sun can change day to day, or even minute to minute. As we are currently in the depths of a solar minimum, now is the time to construct a white-light filter and prepare for those sunspots and faculae that will start to creep across the face of our nearest star in the next few years.

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May 2009 News & Notes.

And the Winner is: It’s official; after much debating and furious blog commenting, the newly discovered moon of the Plutoid Orcus (remember, the anti-Pluto?) is… drum roll… Vanth! Loyal followers of this space and Astronomy Picture of the Day will remember a few weeks ago, when astronomer Mike Brown put out a call to name the tiny object and give a good reason why.

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A Peek at the Structure of the Sun.

(Blogger’s Note: This paper is a Bloggified version of an essay I submitted last year in a quest for my science teaching degree…it has been re-edited to fit this format.)

The Sun is often touted to introductory astronomy students as our nearest star. Of course, its proximity gives us an unprecedented opportunity to study the behavior of a star up close. But how do we really know what we know? Our friendly neighborhood Sun powers life here on Earth. A stable G2V type star, it fuses hydrogen into helium, while releasing copious amounts of energy in the process. [Read more...]

Astro Event of the Week: January 26th-February 1st, 2009; An Annular Eclipse.

This week’s event is a rare annular eclipse of the Sun. The first eclipse of the year, this one traverses Borneo, Sumatra and the Mid-Indian Ocean. Folks from India and Southeast Asia to South Africa, Antarctica, and Australia will see varying degrees of partiality.

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To the Ends of the Earth: Chasing Eclipses.

An obsession exists in the netherworlds of astronomy, and its bite is just as addictive as any; that of the secret world of total solar eclipse chasing. Not cure has yet been devised. No support group exists. (Although it might be fun to imagine such a beast in an alternate reality; “sure, I couldn’t afford that 2nd mortgage, but I told myself it was to complete saros 92…and I didn’t have a problem!)

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