May 30, 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...]

AstroEvent: Will Anyone Welcome the New Saros?

A Remote partial for the hardcore…(Credit: Eclipse Predictions by Fred Espenak, NASA/GSFC).

This week, we’d like to turn your attention to a unique event that no one but a few penguins may witness. July 1st kicks off the month with a partial eclipse of the Sun, the second solar in the past month and the third eclipse overall. The penumbra of the Moon will barely kiss the Earth from 07:53 to 9:22UT and greatest eclipse is a paltry 9.7% around 8:39UT. [Read more...]

AstroEvent: Can You Spy the Zodiacal Light?

The Zodiacal Light as seen from Paranal. (Credit: ESO/Y. Beletsky).

This week’s astronomy challenge is seasonal for mid-latitude observers. Around the time of the equinox, the ecliptic meets the horizon at a favorable angle and a unique phenomenon may become apparent: the zodiacal light. This diffuse band of light can be briefly seen after sunset or before sunrise from a moderately dark location. [Read more...]

14.02.11: Sol Unleashes A Powerful Radio Flare.

An SDO spectrum composite of the sun as of Monday, February 14th.  (Credit: NASA/SDO).

Our nearest star unleashed the most powerful solar flare of 2011 thus far yesterday, and amateur and professionals alike were on hand to bear witness to the event. On Sunday, February 13th at approximately 1738 Universal Time, NASA’s Solar Dynamics Observatory detected the burst emanating from the large Earthward facing sunspot group 1158. Likewise, radio amateur astronomers detected a large simultaneous spike in the 19 to 21 MHz frequency range. [Read more...]

Astro-Event: A Difficult Occultation.

Looking west from Tampa, Fl at about 5:40PM EST. (Created in Starry Night). 

   This week, interesting planetary goings-on are afoot low in the western dusk skies, if you have the patience to observe them. On the evening of Monday, December 6th, visual athletes will want to try and spot an extremely thin crescent Moon occult a fading planet Mars. [Read more...]

Astro Event of the Week: The Heliacal Rising of Sirius.

Sirius Rising as seen from Astroguyz HQ on August 1st, at Lat. 28 North...Radio Telescopes pending! (Created in Starry night).

Sirius Rising as seen from Astroguyz HQ on August 1st, at Lat. 28 North...Radio Telescopes pending! (Created in Starry night).

 

   August is traditionally a real roaster for the northern hemisphere. This month usually sees the onset of what’s known as the Dog Days of summer… but did you know that this term has an actual astronomical tie-in? We’re talking about the dawn appearance of the Dog Star, Sirius.  The ancient Egyptians knew this star as the dog-headed god Anubis, and the first sightings of Sirius preceded that most important of calendar dates in their world; the flooding of the life-giving Nile. [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!

26.05.10: SDO and the Coronal Rain.

Coronal Rain as imaged by SDO. (Credit: NASA/SDO).

Coronal Rain as imaged by SDO. (Credit: NASA/SDO).

  

   NASA’s Solar Dynamics Observatory continues to astound. Launched earlier this year, SDO is already providing insight into key solar mysteries. One long standing mystery has been the action of what’s termed “coronal rain.” This long documented phenomenon is caused by super heated blobs of plasma in-falling back to the fiery surface of the Sun. But until now, no one could adequately model the slowing down of this sinking material. It was as if an unidentified medium existed, “cushioning” the fall of the coronal rain. In a recent news conference, SDO scientists revealed a key culprit; an underlying area of hot gas. What makes SDO standout from previous solar observatories is its acute temperature sensing technology. Utilizing its ultraviolet Atmospheric Imaging Assembly (AIA), SDO can probe the outer layers of the Sun’s atmosphere as never before. The picture emerging is of relatively cool (60,000 K) plasma falling through hotter material standing between 1,000,000 K and 2,200,000 K.

All of this portends to a future understanding of our Sun in intimate detail. As Solar Cycle #24 gets underway, Platforms like SDO will study our nearest star in unprecedented resolution. As Dick Fisher, head of NASA’s Heliophysics Division stated; “I’ve never seen images like this…” Keep em’ coming!

28.04.10-Green Light Given for the Advanced Technology Solar Telescope.

 

ATST: An Artist's Conception. (Credit: NSF/ATST/AURA/Tom Kekona).

ATST: An Artist's Conception. (Credit: NSF/ATST/AURA/Tom Kekona).

 

   Move over, SDO: the Association of Universities for Research in Astronomy is going to kick the telescope envy game up  a notch.  The National Science Foundation gave the go ahead earlier this year to break ground on the Advanced Technology Solar Telescope (ATST), a 4-meter Sun dedicated platform to be built atop Haleakala Mountain on the big island of Hawaii. When completed in 2017, ATST will be the largest solar telescope in existence. From this pristine site, the ATST will deliver resolution in the order of 0.1” arc seconds and have imaging capabilities spanning the ultraviolet to infrared spectrum. Originally in jeopardy of ever reaching construction, a deposit of $146 million courtesy of the American Recovery and Reinvestment Act breathed new life into ATST.  8-year costs are expected to extend to about $298 million dollars total. ATST will join a growing battery of telescopes atop windswept Haleakala, including the Mees Solar observatory, the USAF Advanced-Electro-Optical System, and the Faulkes Telescope North. Environmentalists oppose the construction of the telescope, as they have for most of the instruments constructed on the big island of Hawaii. It is interesting to note, however, that where observatories are built land is usually preserved, as these instruments tend to need remote undeveloped wilderness to operate. In fact, the foot print of telescopes on the environment is pretty small compared with the average strip mall… perhaps a dual use/protection agreement would be equitable to all parties concerned? Whatever is the case, the future looks bright (pun intended) as both NASA and the NSF received boosts to pursue solar physics over the next decade.

25.04.10-First Extra-solar Magnetic Loop Recorded.

 

(Credit: Peterson, NRAO/NSF).

(Credit: Peterson, NRAO/NSF).

Artist’s conception of the radio flare superimposed over the Algol system.

   Radio-Interferometry has really shown its stuff as of late. Recently, astronomers have used a collaboration of radio telescopes based planet-wide to study a familiar variable star; Algol in the constellation Perseus. Known since Arabic times as “The Demon Star,” Algol is an eclipsing binary, where two stars are locked in a 5.8 million mile embrace and “eclipse” each other from our vantage point. This explanation has been known since 1889, but radio astronomers have added another unique feature to the pair; a long pair of magnetic loops connecting the two stars. “This is the first time we’ve seen a feature like this in the magnetic field of any star other than the Sun,” stated William Peterson of the University of Iowa. The scopes linked included the NSF’s Very Long Baseline Array, Green Bank, and the Effelsburg Radio telescope based in Germany.  Collectively, the setup is known as the High Sensitivity Array. Algol is about 93 light years distant, and is a variable star that can be easily monitored by even beginning amateurs with the naked eye.

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?

Astro-Event:The Vernal Equinox.

Clouds & Sky 110

Watch for that rising/setting equinox Sun! (Credit: Art Explosion).

     Batten down the hatches; spring is here in a most astronomical way. The vernal equinox occurs this Saturday, March 20th at 17:32 Universal Time; expect uniform amounts of sunshine and darkness worldwide as well as a Sun rising directly due east and setting due west. The spring equinox is also used in the reckoning of Easter; this year’s Paschal or Easter Full Moon falls on March 29th and the proceeding Sunday and Easter falls on April 4th. This year, Eastern Orthodox Easter also falls on the same date; The Orthodox church uses the older Julian calendar and hence the two don’t always coincide. In fact, this year’s date is the earliest that an Eastern Orthodox Easter can fall. [Read more...]

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...]

Event of the Week: Happy Winter Solstice!

Time again to reset those sundials... (Photo by Author).

Time again to reset those sundials... (Photo by Author).

Brace yourselves; the Winter Solstice is upon us this week. This is the point at which the Sun reaches its lowest southerly declination and begins its long march northward. This makes for shortened days and long nights in the northern hemisphere and the reverse in the southern. Of course, its not the Sun that’s moving, but the Earth with its 23 degree 26′ minute tilt that causes this variation. Several cultures mark this celestial turn of events, not the least of which is modern day Christmas, which is fixed on December 25th, the solstice date on the old Roman Calendar. Modern reform by Pope Gregory gave us an offset solstice that falls on or around the 21st each year, and will eventually move by one day every 3,000 years. The solstice is always a good time to check out any local chance alignments at sun rise or sunset, as well as note the length of shadows cast at local noon. The precise timing of the winter solstice this year is Monday, December 21st at 5:47 PM Universal Time. Merry Saturnalia/Christmas!

This week’s astro-term is the Chandler Wobble. This is one of the many complex movements of our planet that causes the complex motions of the Earth’s axis to shift slowly. But unlike larger effects such as our friend, the precession of the equinoxes, the Chandler Wobble is much more subtle. First discovered by Seth Carlo Chandler in 1891, this movement amounts to 0.7 arc seconds or about 15 meters of axial shift over a period of about 433 days. This wobble is caused by the “sloshing” motion of Earth’s fluid core and even the drag created by the friction of our oceans. Think of the Earth as a sort of egg with a liquid center dragging us about  as we orbit about the Sun. This amount can vary (it was greatest in 1910) and is enough that modern off the shelf GPS devices can measure it and must take it into account. It can also cause the poles, equator and lines of longitude and latitude to change perceptibly. Along with the drag created by our Moon and Sun, the Chandler Wobble is also responsible for variations in Delta T, causing an occasional tweaking of our clocks by the addition or subtraction of an occasional second!

17.10.09: Pondering the Possible Fate of the Earth.


Colossus-The Forbin Project: a Sci-Fi classic that kicked off the talks!

What’s the future of humanity and life on Earth? Will we have a good multi-billion year run until our Sun swells into a red giant boiling away our atmosphere, or will we first do the job of snuffing ourselves out? Earlier this year, some of the leading thinkers of our time gathered near Harvard University at the Arrow Theater to discuss just these weighty concepts. Dubbed Crossroads: The Future of Human Life in the Universe, each talk in the series was 30 minutes long and solicited an avalanche of enthusiastic questions. Some of the highlights:

-Gerrit Verschuur discussed the Drake equation and just how prevalent any interstellar neighbors might be; at a guesstimated 2,500 light years, we may be pretty, well, spaced out!

-Maira Zuber discussed the future of space travel in the solar system and the difficulties of overcoming probably the biggest engineering problem; prolonged radiation exposure.

-Astronomers Dimitar Sasselov, David Charbonneau, and paleontologist Peter Ward of Rare Earth fame discussed the slew of recent exoplanet findings and the quest for the true coin of the realm; Earth-like worlds around other stars. Most interestingly, the idea was proposed that a “super-Earth” may be more conducive to the development of life, and our own planet may represent the bottom rung of habitability; indeed, as Ward notes, “Rare does not mean unique!” Another interesting proposal by Ward is what he termed the Medea Hypothesis, a sort of anti-Gaia Hypothesis, were the Earthly biosphere may actually occasionally become detrimental to life, and thus fuel mass extinctions. The name comes from perhaps the worst Mom in mythological history!

-Finally, big time elder thinker Freeman Dyson of Princeton urges that our very search methods for life might be flawed, and that we should be looking for “what is detectable, rather than only whats probable.” he also proposed missions targeting such possible abodes for life such as Europa, the icy large moon of Jupiter.

Whatever the future of humanity is, one gets the impression from the visionary speakers presented that it is NOT endless consumerism. The message in the history of life on Earth is clear; evolve or die. No one will save us but ourselves, and the future is collectively ours to choose!

16.10.09:A Moscow UFO?

Invaders over Moscow? (Credit: YouTube still).

Invaders over Moscow? (Credit: YouTube still).

What is it? Earlier this week, the above image and obligatory YouTube video flew around ye ‘ole Internet, purportedly showing an “Independence Day”-like spacecraft seemingly descending through the clouds over Moscow. The video was shaky, and the perspective of the light poles moving in the foreground all lent themselves to an eerie look and feel…a classic UFO, right?

Semi-unfortunately, this phenomena has a slightly more prosaic explanation, although its still pretty cool. Many naysayers are simply claiming that the video was “Photo-shopped” although we here at Astroguyz HQ don’t necessarily believe so. The patterns look to be consistent with low altitude, mammatus-type clouds. Of course, the hoaxer might have been a meteorologist…what your looking at is known as a parahelic arc, a breed of sun-dog shining through low-altitude clouds seen under somewhat unusual conditions. Many folks on the ‘Net have stated that the glowing ring is the cloud, but if you look closely, the entire sky is overcast. Meteorologists confirm that a converging front was over Moscow at the time, and that the sun was indeed at a low angle, i.e. prime sun-dog conditions. To explore near-sky phenomena complete with explanations, I refer you to Les Cowley’s excellent site on Atmospheric Optics. Stare at the sky long enough, and you’ll see all sorts of bizarre things. Incidentally, pilots are much more familiar with this sort of reflection phenomenon, as they frequently fly above low cloud banks. I would suspect that there is also an inversion source, like say, a heat belching factory right below the halo. Alas, no ET…but isn’t UFO debunking fun?

21.9.9: The Autumnal Equinox.

A celestial alignment; in a neigborhood near you? (Credit: Art Explosion).

A celestial alignment; coming to a neighborhood near you? (Credit: Art Explosion).

Can you feel it? The brunt of northern hemisphere summer is about over, giving  way to our favorite season here at Astroguyz; Fall. It’s not just our collective imagination; this Tuesday marks the Autumnal Equinox, or the spring (vernal) Equinox for those down under. This marks the mid way point for the Sun’s apparent journey form north to south, and the beginning of spring and fall, respectively. Of course, we’re the ones in motion!To be technical, this is the point that the Sun rests at 180 degrees along the ecliptic, and at a right ascension of 12 hours and a declination of exactly 0. This occurs this year at precisely 21:18 hours Universal Time on Tuesday, September 22nd. The Sun will rise exactly due east from your locale and set due west, our personal favorite observation to make on this day (weather willing) to site any potential local “Stonehenge” alignments. [Read more...]