Summer Stars (i)
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Look up at the summer night sky. You see stars, of course. There are bright stars like Vega and Arcturus, middling stars like Polaris (the North Star) and Mizar (the star in the “bend” of the Big Dipper’s handle), and faint stars like Rho Leo (an unremarkable star in the constellation of Leo, the lion) and Alcor (the dim companion of Mizar). When we look at these stars, what are we seeing? How do we know what the stars are? You have probably heard that the sun is a star, but are all these stars suns?

Some of the stars of the summer sky as represented by the Stellarium planetarium app.

Some of the stars of the summer sky as represented by the Stellarium planetarium app.

I have previously discussed in this blog how a person with excellent vision will see stars as small, round dots of differing apparent sizes, or magnitudes. Magnitude means bigness, as this old discussion of the scale of magnitudes indicates:

The fixed Stars appear to be of different Bignesses.... Hence arise the Distribution of Stars, according to their Order and Dignity, into Classes; the first Class... are called Stars of the first Magnitude; those that are next to them, are Stars of the second Magnitude... and so forth, ‘till we come to the Stars of the sixth Magnitude, which comprehend the smallest Stars that can be discerned with the bare Eye....

The idea of magnitude as bigness also shows clearly in this old discussion of the changing magnitude of a “new star” or “nova”:

...from the sixteenth to the twenty-seventh of the same month... it changed bigness several times, it was sometimes larger than the biggest of those two stars, sometimes smaller than the least of them, and sometimes of a middle size between them. On the twenty-eighth of the same month it was become as large as the star in the beak of the Swan, and it appeared larger from the thirtieth of April to the sixth of May. On the fifteenth it was grown smaller; on the sixteenth it was of a middle size between the two, and from this time it continually diminished till the seventeenth of August, when it was scarce visible to the naked eye.

More stars of the summer sky. Note how Stellarium represents the stars as dots of differing sizes. Stellarium's web pages states that Stellarium “shows a realistic sky... just like what you see with the naked eye....”

More stars of the summer sky.  Note how Stellarium represents the stars as dots of differing sizes.  The web page for Stellarium states that Stellarium “shows a realistic sky... just like what you see with the naked eye....”

This system of classifying stars by their apparent sizes dates back to the ancient Greek astronomer Hipparchus, nearly two centuries before Christ. However, following the development of the telescope in the early seventeenth century, astronomers came to realize that the apparent sizes of stars are spurious: Arcturus looks larger than Rho Leo not because of its physical size, but because of its light output and how that light interacts with the eye.

This is perhaps better understood by imagining that one night you and a friend experiment with two identical small LED flashlights, one of which has a weak battery, and the other of which has a very strong battery. Your friend walks two hundred paces directly away from you, then stops, turns on the lights, and aims them both back toward you. The brighter light will appear larger to you than the fainter light, even though both are the same physical size. Try it and see. When it comes to point-like light sources, be they distant flashlights or distant stars, the apparent size you see resides not in the lights but in your eyes.

Thus in the nineteenth century astronomers reworked the magnitude scale so that it wasn’t about size. They came to understand that the light that reaches Earth from a first magnitude star is about 100 times more intense than the light that reaches Earth from a sixth magnitude star. The intensity is measured in power per unit of area—Watts per square centimeter or W/cm2. The magnitude scale is related to light intensity through a factor of 2.5; the light from a (very faint) fifth magnitude star is 2.5 times more intense than the light from a (barely discernable to the eye) sixth magnitude star. A fourth magnitude star (still pretty faint) has 2.5 times the light intensity of that fifth magnitude star and 2.5x2.5=6.25 times the light intensity from the sixth magnitude star. Thus a bright first magnitude star is 2.5x2.5x2.5x2.5x2.5=100* times brighter in terms of intensity than that barely discernable sixth magnitude star.

Why this system? Because the original magnitude scale was based on what the eye sees, and the eye works on a multiplicative scale, not a simple additive one. To see this for yourself, gather up about ten birthday cake candles and turn out all the lights in the room. Look around; it’s dark in the room! Now light one candle. Note how one candle changes things a lot; with one candle you can really see. Now light a second candle, so that two candles are burning. Note how the second candle does make the room brighter, but the change it causes is not as dramatic as the change caused by the first. The third candle causes even less change, the fourth less still, and by the time you go from nine candles to ten you hardly notice the difference. Your eye is not attuned to additive increases in light; each additional candle does not seem to increase the illumination of the room equally, even though each is adding an equal amount of light power. No, your eye is attuned to multiplicative increases in light.

Understanding the multiplicative nature of the magnitude scale makes it easier to determine what we are seeing when we look at the stars, and how we know what the stars are. We will learn more about magnitude next week.


*OK, for those of you who multiplied this out and found out that the result is not 100 but 97.66... well, actually the multiplying factor in the magnitude scale is not exactly 2.5, but 2.5118864.... This number is called “Pogson’s ratio,” after N. R. Pogson, the British astronomer who proposed this system in 1856.

 

Supercivilizations
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We live in a truly vast universe with 100 billion galaxies (give or take a few), each of which houses 10-100 billion stars (give or take a few).

IF there are other forms of intelligent life out there, then it seems reasonable that, like us, they will also suffer energy crises. As on Earth, they may consider using solar energy to supply their world's energy needs.

At some point they may find that building solar panels on their alien roofs supplies woefully little energy in return. If so, then they may think bigger and decide to harness the energy from their entire sun.

How? Perhaps some civilizations will be just powerful enough to disassemble some nearby orbiting moon to use as raw material to build solar energy panels that surround their star. Such a complete solar energy structure is called a "Dyson sphere," named after physicist Freeman Dyson at the Institute for Advanced Study in Princeton who first came up with this concept.

Were a civilization to choose to build a Dyson sphere, then an observer far away looking at such a star with a telescope (say on Earth), we would not see that star anymore. The star would be covered up by all those panels, and would seemingly 'disappear.'

Interestingly, it is well known that solar panels also radiate in the mid-infrared. Astronomers could still hope to detect the presence of a Dyson sphere by its mid-infrared heat.

Now imagine an alien civilization that has still bigger energy demands and decides that harnessing all the light from one star is not just not enough for them. Instead, they would encase the entire galaxy with its billions of stars in a gigantic Dyson sphere (or equivalently, encase every one of its stars in Dyson spheres). Again, this civilization would be detectable despite its invisibility in the optical colors by looking for its radiation in the mid-infrared.

Recently astronomers have undertaken a search of 100,000 galaxies for any signatures of such civilizations. They found none. That possibly means that "Star Trek" dramas may not literally be playing out in nearby galaxies as we speak. At the same time, Professor Dyson comments that an all-encompassing Dyson sphere is not the only way for a significantly advanced civilization to signal its presence. Perhaps advanced alien civilizations may not all feel the need to be quite so energy-hungry? What would/will we do?

Get ready the Perseids are coming
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Perseids drawing

Perseids 2010 using , Pastel ,Conte and a White Gel Pen on Black Mounting Board. A composite sketch created in my garden between July 28th and August 10th 2010.

About 30 years ago we had a holiday in a remote location in the West of Ireland. The house was high on a grassy ridge on Bolus Head looking over St Finian’s Bay in Co Kerry. From this vantage point the 350 million year old Skellig Rocks rose like stegosaurus plates from the Atlantic Ocean. They were 16 kilometres out to sea but their jagged presence dominated the view to the South. It was early August and when darkness fell the predictable blinking of a distant lighthouse was the only manmade object discernible at sea level in the blackness.

One moonless evening, the sky was crystal clear, the summer triangle was dramatically intersected by our galaxy's river of stars, so much more touchable than the suburban view. I lay on the sun dried grass looking for Perseids, one, two, three, four, five, six, plus several in the corner of my eye within a few minutes. Time to take action, I went into the house and dragged out several mattresses, and encouraged (made) my family and our guests come outside, lie down and look up. I have a vague memory of sofa cushions being shoved through windows at one point to help the nest-building.

As usual they thought I was mad, but soon they were seeing one of the year’s wonders in perhaps the darkest place on our island. We watched for satellites and my mattress guests (two families, four adults, four children) had never seen them either, so in between meteors we looked at these metal objects orbiting about 200 miles up.

A perfect viewing spot, we watched on a slight incline toward Perseus in North East, but the meteors came from what seemed like every direction. We watched many meteors sizzling into our atmosphere in dots and dashes with long gaps and differing lengths. The Perseids are the result of tiny cast - off particles from Comet Swift Tuttle, shed as it passed through our solar system on its 130 year orbit of our sun. Once a year the Earth’s journey round our sun brings our atmosphere and these remnants into contact with each other .These particles hit the atmosphere at huge speeds and burn up thereby offering the observer natural fireworks. Ancient elements revealed by their colours as they vaporise in front of our eyes.

I will never forget the perfection of the viewing, the WOW’s,the laughter and the joy of my family seeing this shower for the first time ever.This area of Kerry has become Ireland's first International Dark Sky Reserve. The close by village of Ballinskelligs now hosts the annual Skellig Star Party .

Over the years since I have watched the Perseids from a deck chair in my garden, some escape the eye under hazy lights in suburbia. It is always the most exciting shower of the year and rarely disappoints. If you are lucky to have clear skies between mid July and mid August, no equipment is needed, just you and your eyeballs. If you want to fill out an observing sheet to record, the colour, length, duration, direction, location, hourly rate of your Perseids then they are easy to find online.

Post midnight is the best time to view. The Earth has left the Belt of Venus long behind and has rolled toward the night were other suns populate the soft deep cloak of space. The Perseids bring nano seconds, and multi seconds of wispy joy to all who take the time to look up from mattresses or other comfy viewing places.

Occasionally I record the Perseids in a drawing, yes a drawing built up over several weeks . The way I went about this was to observe each meteor and record not only its magnitude, length et cetera but to also draw a representation of it on black card. I made notes on one sheet and drew on the card, so afterwards I could photograph the drawing and drop in the numbers to relate to my recorded data.

The Perseid Meteor Shower 2016 Facts
The Perseid Meteor Shower peaks on the night of August 12th 2016 but any clear evening up to and a few nights after should produce some meteors. Look to the NE after midnight, look under the big W of Cassiopeia and that is the location of Perseus.Earth will pass through the path of Comet Swift-Tuttle from July 17 to Aug 24.The waxing gibbous moon may be an issue this year but when it sets, the sky will deliver Persieds for your delight.

Meteor Colours
As a tiny meteor enters the Earth’s atmosphere heat and light energy is created. A meteor’s composition ignites and interacts with Earths atmosphere and causes different colours. Meteors made of sodium produce orange/yellow light, iron will produce yellow, magnesium creates bluish/green, calcium makes violet and silicate meteors produce fiery red colours.

Belt of Venus
Look to the eastern horizon on a clear evening after sunset, when no clouds obstruct your view. You will see a pinkish glow or antitwilight arch or belt of colour that extends about 10 – 20 degrees above the horizon. Often the glow is separated from the horizon by a dark blue layer. This blue layer is the shadow of the Earth. The rose-pink colour is due to scattering of reddened light from the setting sun. These coloured bands are known as The Belt of Venus.

Sketch details
Cassiopeia (top right) - Perseus (Middle)- Capella (lower left) in Auriga and as many stars as I could see in between from my suburban view.

My town street lights are partly screened by tall trees, the view to the N / NE and over head was dark. The Double Cluster was visible naked eye and M 31 was there with averted gaze. The Milky Way had visible knotted areas overhead on August 9th and 10th, unusual for Bray.

Some stars are sketched brighter than they appear to stand out for the photograph of the sketch
which was too big to scan. I was sitting in my garden looking up over the pergola. On part cloudy
evenings, I put several chairs around the garden and moved to view different areas of the sky when
clear sections appeared. Each hour on the hour I took a break for tea, kept the lights off in
the house to try to keep my dark adaption. The meteors are as close to what I saw in length and colour as is possible to sketch.
Kerry International Dark Sky Reserve
Skellig Star Party 2016

Hunting for Supernova: Why is Humanity Wired to Explore?
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Have you ever had the desire to discover something of significance? If so, welcome to the human race! For varying reasons, the human person is wired to explore and discover. Some forms of exploration can be rather basic, such as the desire to find food and water for survival. Some forms can be self-seeking, such as the acquisition of wealth found in a hidden treasure. Some discoveries are timeless, such as finding love with another person. While other explorations speak to adventure, such as studying creation to understand our place in the universe. Despite the many reasons why we explore our world, it is plain to see that exploration is a natural part of the human experience.

Click on the image to learn more about Pan-Starrs.

Click on the image to learn more about Pan-Starrs.

Over the past two weeks, I have enjoyed a small taste of the explore's heart. Bob Trembly and Brenda Frye have recently offered wonderful reflections on citizen science programs. These programs allow science enthusiasts the opportunity to work side by side with professionals in numerous fields to help advance our scientific knowledge of the world. I have recently participated in a citizen science program that looks for supernovae. Darryl Wright and his team leads this program, using the Panoramic Survey Telescope & Rapid Response System (known as Pan-Starrs) on Mount Haleakala in Hawaii. My job as a citizen scientist is to sift through the images that Pan-Starrs' computer identifies as potential supernovae. Often times Pan-Starrs falsely identifies asteroids, camera glitches, and off center images as supernovae. Citizen science volunteers help identify these different image types, submitting the best supernova candidates to the Pan-Starrs team.

After all the images are reviewed multiple times by volunteers, the Pan-Starrs team submit the best supernova candidates to the Transit Name Server (the official registry of supernova candidates)One of the exciting incentives for citizen science volunteers participating in this program is if a potential supernova is submitted by the Pan-Starrs team to the Transit Name Server, the first three volunteers that submit the image will be named as collaborators in the discovery. Personally, it was exciting to see my username (bigpapaj) on two of these submissions. Though it may mean little to most people, one of my dreams since childhood was to contribute something, no matter how small, to the advancement of science. It was a humbling moment to think that this moment may have come.

These are images of one of the supernova candidates I submitted to the Pan-Starrs team.

Image One: Spiral Galaxy from a few years back.

Image One: Spiral galaxy from a few years back.

Image Two: Spiral Galaxy with Supernova Candidate.

Image Two: Recent image of the same spiral galaxy with supernova candidate.

 

 

 

 

 

 

 

 

 

For reasons of wanting to write this post and trying to learn more about the process of confirming a supernova, I contacted Darryl Wright. I asked his permission to use the above images for this post (which he granted since these images are now public) and asked how a supernova candidate becomes a confirmed supernova? Dr. Wright explained that all the submissions they make cannot be confirmed as supernova based on the images alone. Many things can literally drift into the image, making it hard to determine whether or not what is observed is a real supernova.

The only way to confirm a supernova is by studying its light spectra. Pan-Starrs and other groups that hunt for supernovae make their findings public so other groups that do spectra work (like PESSTO) might decide to study their submissions. Given the expense of time involved in doing spectra research, only a small number of supernova submissions are selected for this verification, leaving most candidates unconfirmed.

From the confirmed supernovae, an even smaller group are then selected for full scientific research. Those that are chosen for full research are supernovae that are different in kind from those that have already been studied. Each supernova contains a wealth of information that help scientists understand the nature of these celestial explosions. The reason why supernovae are so important is that their explosions create the heavier elements needed for life to develop in our universe. From this standpoint, supernovae literally "seed" planets with these heavy elements. The better we understand supernovae, the better we can understand this seeding process and how the elements needed for life on our planet came about.

When I understood what goes into confirming a supernova, I began to realize that my small contribution to science might be a lot smaller than I first thought. Nevertheless, supernova hunting has become a fun hobby and I thank Dr. Wright for putting this program together and for the support he provides to his volunteers.

It's amazing to think that a small, white dot on a black and white photograph can lead to understanding how the physical stuff we need to exist came about. It reminds me that even small discoveries are not that small, since they help provide a better understanding of our world and feed the natural curiosity we all have to explore. When we allow our inner desire to explore to take flight, we quickly find ourselves looking for more than our material origins, but also our spiritual origins.

Though scientific study and philosophical/theological questions about meaning and purpose are two different types of questions, we can see a bridge emerge between the two that is our desire to explore and discover. We need to explore our world to understand its material qualities. We also need to explore meaning and purpose to understand who we are in God's eyes. Both explorations point to the question in the title of this post: Why is humanity wired to explore? The answer to this question is rather simple: There are things in this world worth discovering and the Source of this world wants to be known.

As we begin this week, I would invite you to prayerfully reflect upon this question: What are the things God has inspired you to explore? Whether your desire is to understand the world we live in and/or explore questions of meaning and purpose, realize that both types of questions ultimately point to a common origin. Our exploration of this world and our lives prepares us for life's final exploration in which we will pass through the womb of death from this life to the next. It is through this journey that we will discover the answer to one of the most fundamental questions of life: Who am I in God's eyes? May all of us discover today the beginnings of the answer to this question that affirms that all of us, to quote Pope Francis, are sinners who have been looked upon by God with love and mercy.

* The Pan-Starrs Project is hosted by Zooniverse.

Dawn Probe to Remain in Ceres Orbit
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NASA's Dawn spacecraft has completed its primary mission - to explore the two most massive bodies in the main asteroid belt: asteroid 4 Vesta, and dwarf planet Ceres. After a recent mission extension, Dawn will continue studying Ceres - essentially becoming a long-term reconnaissance orbiter.

One of the advantages of long-term observations is seeing changes that occur over time, as with the seasonally recurring slope lineae on Mars, and fresh impact craters on both the Moon and Mars. There was a brief period of confusion on various social media sites, as rumors that Dawn was possibly going to leave Ceres and fly-by asteroid 145 Adeona, but Jim Green, NASA’s Director of Planetary Science, noted that long-term monitoring of Ceres had more of a potential for significant scientific discoveries than a flyby of Adeona.

Dawn Mission infographic

NASA's Dawn mission exceeded all expectations during its primary mission to Vesta and Ceres. Credit: NASA/JPL-Caltech

Scientists have found permanently shadowed craters on Ceres; if the temperature in these creates remains below -151°C (-240°F), these craters can collect ice. These so-called "cold traps" could have been doing this for billions of years. Scientists will monitor these craters as part of Dawn's extended mission.

Shadowed Craters on Ceres

"Cold trap" craters may have been collecting ice for billions of years. Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

High abundances of carbonates in Occator crater (red in the image below) may be the result of  hydrothermal activity within Ceres. The bright patches in Occator represent the highest concentration of carbonate minerals ever seen outside of the Earth.

Image credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA/ASI/INAF

The Dawn feed on Twitter is continuously posting spectacular new images from Ceres:

Wothin Zadeni Crater

A moody scene within Zadeni Crater on Ceres. Image Credit: NASA/JPL-Caltech/UCLA/MPS/DLR/IDA

Dawn currently orbits Ceres at an altitude of 385 km (240 mi).

Position of Dawn spacecraft on July 24, 2016 at 9:19 AM EST. Credit: NASA Eyes on the Solar System / Bob Trembley

Position of Dawn spacecraft on July 24, 2016 at 9:19 AM EST. Credit: NASA Eyes on the Solar System / Bob Trembley

Position of dwarf planet Ceres on July 24, 2016. Credit: NASA Eyes on the Solar System / Bob Trembley

Position of dwarf planet Ceres on July 24, 2016. Credit: NASA Eyes on the Solar System / Bob Trembley

Across the Universe: Three Lunatic Answers
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This column first ran in The Tablet in July 2009

July 20 – the 21st, in Rome – marks the anniversary of the landing of the Apollo 11 astronauts to the Moon. Here are a few lunar topics probably not covered by most folks remembering that event...

Pope Paul VI seeing the moon through the finder of our Schmidt telescope, July 21 [Rome time], 1969

Pope Paul VI seeing the moon through the finder of our Schmidt telescope, July 21 [Rome time], 1969

I saw a photo of Pope Paul VI looking at the Apollo 11 Moon landing through a telescope. Why didn’t he watch it on TV like everyone else? For the Moon landings, world leaders were invited to address the astronauts on a world-wide television link-up, and the Pope read his greetings (in front of a TV) from the Vatican Observatory dome in Castel Gandolfo (in the gardens near the Pope's summer palace). In fact, the system of geosynchronous satellites to send TV pictures live around the world was still pretty new; those of us of a certain age can remember the Beatles introducing All You Need is Love on one of the first Europe/North America TV link-ups, in 1967.

Pope Paul watched the moon landing on TV from our telescope dome, then addressed the astronauts from there

Pope Paul watched the moon landing on TV from our telescope dome, then addressed the astronauts from there

Afterwards, the Pope looked at the Moon through the small finder scope attached to that telescope; that’s the picture all the papers ran. The big telescope itself was actually a camera designed to photograph the sky, with no eyepiece to look through. The Pope’s view of the Moon through the finder scope was delightful, no doubt, but there was no way that even the biggest telescope on Earth could have seen the astronauts themselves. Interestingly, NASA has an orbiter around the Moon now that has imaged the Apollo sites; the landers are still there!

Is there religion on the Moon? Theological discussions of God’s imminence and transcendence aside, the Apollo astronaut Buzz Aldrin did bring with him the communion species from his Presbyterian church near the NASA center in Houston.

This is the chalice that Buzz Aldrin took with him to the Moon

This is the chalice that Buzz Aldrin took with him to the Moon

There are lots of interesting religious questions that come up when you leave Earth and travel to another planet. The Jewish and Islamic calendars are based in part on where the Moon is in the sky; what do you do when it’s not in the sky, but under your feet? It’s easier for Christians; one principle of Pope Gregory XIII’s reform of the calendar in 1582 was to set the date of Easter and other religious holidays not by the position of the Moon but by a mathematical formula anyone can use, anywhere in the world (or off it). It only roughly approximates the “first Sunday after the first full Moon of Spring.”

The Jesuit who helped explain this formula, Christopher Clavius, has a crater named for him on the Moon. So do 35 other Jesuits. How did that happen? The men who made the telescopic map defining the nomenclature we use today were themselves Jesuits. (And they named the Moon’s most prominent crater for Copernicus – this, in Rome, less than 20 years after the Galileo trial.)

Did we really go to the Moon, or was it all faked? I have touched the rocks. I have looked at them through petrographic microscopes, and measured their properties in my lab. They are distinctly different from any Earth rocks, different enough to insure that they are not from this planet. And, for all our work over the last 40 years, we still can’t quite agree about how they were made. If they were faked, whoever did it was cleverer than any of the geologists who have worked on them ever since.

When my colleague Dan Britt got some Apollo samples to measure, he let me hold one...

When my colleague Dan Britt got some Apollo samples to measure, he let me hold one...

That puts me in a privileged position, I know. I believe in the Moon landings because I have seen; most people have to be blessed with believing even though they haven’t seen the direct evidence like I have. Perhaps St. Thomas (the one who doubted) was the first scientist… not because he refused to believe without evidence – a lot of people are quick to doubt – but because when he finally did touch the evidence for himself, he was able to alter his understanding.

Also in Across the Universe

  1. Across the Universe: What’s in a Name?
  2. Across the Universe: Fools from the East
  3. Across the Universe: Hunches
  4. Across the Universe: Desert or a dessert?
  5. Across the Universe: Stardust messages
  6. Across the Universe: The best way to travel
  7. Across the Universe: Original Proof
  8. Across the Universe: Pearls among Swine
  9. Across the Universe: One Fix Leads to Another
  10. Across the Universe: Limits to Understanding
  11. Across the Universe: Words, Words, Worlds: Have We Found Planet X?
  12. Across the Universe: The Glory of a Giant
  13. Across the Universe: Fire and Ice
  14. Across the Universe: Science as Story
  15. Across the Universe: Recognition
  16. Across the Universe: Tending Towards Paganism
  17. Across the Universe: The Ethics of Extraterrestrials
  18. Across the Universe: Orbiting a New Sun
  19. Across the Universe: Seeing the Light
  20. Across the Universe: DIY Religion
  21. Across the Universe: Truth, Beauty, and a Good Lawyer
  22. Across the Universe: Techie Dreams
  23. Across the Universe: By Paper, to the Stars
  24. Across the Universe: Transit of Venus
  25. Across the Universe: Ordinary Time
  26. Across the Universe: Deep Impact
  27. Across the Universe: New Worlds
  28. Across the Universe: Tom Swift and his Helium Pycnometer
  29. Across the Universe: Tradition… and Pluto
  30. Across the Universe: Bucks or Buck Rogers?
  31. Across the Universe: Key to the Sea and Sky
  32. Across the Universe: Off The Beach
  33. Across the Universe: All of the Above
  34. From the Tablet: Tales of Earthlings
  35. Across the Universe: Heavenly peace?
  36. Across the Universe: Help My Unbelief
  37. Across the Universe: Stories of Another World
  38. Across the Universe: Planetary Counsels
  39. Across the Universe: Words that Change Reality
  40. Across the Universe: New Heavens, New Earth
  41. Across the Universe: Souvenirs from Space
  42. Across the Universe: For the love of the stars…
  43. Across the Universe: Spicy planet stories
  44. Across the Universe: Asking the right questions
  45. Across the Universe: Everything You Know Is Wrong
  46. Across the Universe: Errata
  47. Across the Universe: Clouds of Unknowing
  48. Across the Universe: Being Asked the Right Questions
  49. Across the Universe: Recognizing the Star
  50. Across the Universe: Heavenly Visitors
  51. Across the Universe: Christmas Presence
  52. Across the Universe: When Reason Itself Becomes Flesh
  53. Across the Universe: Spinning our Hopes
  54. Across the Universe: Relish the Red Planet
  55. Across the Universe: Obedience
  56. Across the Universe: Traveling Light
  57. Across the Universe: The Still Voice in the Chaos
  58. Across the Universe: Europa
  59. Across the Universe: Defamiliarization
  60. Across the Universe: Forbidden Transitions
  61. Across the Universe: Genre and Truth
  62. Across the Universe: False Economies
  63. Across the Universe: Reflections on a Mirror
  64. Across the Universe: Japan
  65. From the Tablet: Why is Easter So Early This Year?
  66. Across the Universe: Oops!
  67. Across the Universe: Dramatic Science
  68. Across the Universe: Me and My Shadows
  69. Across the Universe: Touch the Sky
  70. Across the Universe: Treasure from Heaven
  71. Across the Universe: Gift of Tongues
  72. Across the Universe: Maverick Genius
  73. Across the Universe: Awareness
  74. Across the Universe: Friends in high places
  75. Across the Universe: A Moving Experience
  76. Across the Universe: Grain of truth
  77. Across the Universe: Clerical Work
  78. Across the Universe: Teaching new stars
  79. Across the Universe: Science for the Masses
  80. Across the Universe: Changelings
  81. Across the Universe: Three Lunatic Answers

View the entire series

Solar Sketching in h-alpha – Prominences dancing on the limb
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Proms-Drawing-WEB

Click on the image to see the sequence of my prom drawings that created the animated gif. See all the movement at the end of this page

Astronomical sketching is not just about drawing pictures it is  about learning. This kind of  sketching is about observing very closely the subject at the far end of your telescope. Sketching at the eyepiece is challenging but  rewarding,  however solar sketching in hydrogen alpha  (h-alpha) is for me the ultimate challenge.  As I have mentioned in another post on sketching  a person does not have to be good at drawing  to produce a  sketch  or learn about a target.

A persons first efforts are not going to be very accurate, whether the target is an apple or the sun. Some increment of wisdom will come with every endeavour . Improvement comes with effort, trial and error over time .

Unlike astrophotography, the sketcher processes the dynamics of the subject in his or her head not in software, however the brain may be a hardware of sorts if one considers all it does for us . The sketcher seizes the moment or the hours on the spot. The sun is so complex ,an ever-changing vista of vigorous motion the action of which appears to be still. In my 40mm Personal Solar Telescope (PST) using an 8mm eyepiece the sun appears to almost fill my field of view . A tiny sphere with enormous and powerful action playing out before my eye. Miniscule filaments belie their size as thousands of miles of plasma behave like ropes twisting wildly in an unimaginable stellar environment.

My first adventures with the sun involved drawing prominences on the solar limb. The movements of these eruptions are not immediately visible because of the 93 million miles between my pupil and our star. The 8mm eyepiece gives me the best view of detail in the prominences and allows me to sketch accurately. This eyepiece coupled with a continuing a fine balancing act between focusing and tuning enables me to see the shapes the gasses make as they move. It allows me to observe  their anchor points and sometimes their disconnecting events as they leave the sun.

Because the seeing conditions can change very often during an observation it is important to adjust the focus regularly. Tuning also needs altering during the sessions in order to keep the action sharp and see the best image possible. With a h- alpha telescope one can see some detail on and around sunspots, the umbra's, penumbra's and the shape of the spots themselves. Active regions are very detailed , fibrils, plage, and flares all combine with the dark sunspots to make these areas a challenge to capture. Prominences on the limb and filaments against the disc can lure your eye into a task that can be forever daunting. So that is most likely why I began my solar sketching with just prominences off the limb as it seemed to be the easier choice as opposed to trying to capture the entire commotion on the disc.

I remember being both amused and delighted when I found out that particular shaped prominences have specific names such as broccoli proms and hedgerow proms. Prominences can also look like trees with many branches. They can present as complex loops within loops as the electrified plasma follows and reveals the invisible magnetic field lines which are present but hidden to our eyes.

In order to show movement over time with proms on the solar limb it is necessary to draw a sequence of sketches over the course of several hours. As you can see in the drawings above there is a sequence of sketches between 10:50 UT and 19:50 UT May 15th 2008 . Conte sticks on black card give the best edge for drawing these , however I have also used ink on white paper with a fine brush from time to time. This sequence was animated via Photoshop by a friend using my still photographs of the proms . You can see the proms over time moving and swaying like trees in a storm. Another method to produce a relatively fluid sequence set is to use one of the many free gif makers online . iMovies on a Mac can also create mini films if you use a tight transition.

Animated Gif of all Deirdre's the prom sketches above. Gif made in Photoshop by Sally Russell

Radio Eyes on the Sky
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Historically radio astronomy held a rather modest place. Around 40-50 years ago it was thought that only a few objects in space would emit radio waves strong enough to be detected by receivers on Earth, thereby making it not profitable to build radio telescopes at all. This conclusion was incorrect not because astronomers made mistakes with computing the numbers, but because the majority of sources had not yet been discovered. Now we know that all galaxies emit radio waves at some level, and that certain types of galaxies are powerful sources, the so-called radio galaxies. The strong radio emission is thought to be produced as a result of the violent process of material in-falling into the center onto supermassive black holes. Even apart from the fascinating radio galaxies, radio astronomy is interesting because this particular color of light has the longest wavelengths, from millimeters to kilometers in size. The great benefit of such long wavelengths is that other telescopes that … Continue reading

From the Cabinet of Physics: Conveying Heat across Space
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Today’s demonstration from the Cabinet of Physics appears at first to be about optics but, in a surprising twist (SPOILER ALERT), turns out to be about heat. A curved mirror, a paraboloid, reflects the light of a candle flame to another curved mirror some distance away. The candle sits at the focal point of the first mirror. The second mirror brings the light to its own focal point; hold a white card at this precise spot, and you’ll see an image of the candle flame. Now the candle is replaced by a collection of burning lumps of charcoal. Across the room, a piece of tinder is placed at the focus of the second mirror. To the eye, the coals seem much dimmer than the candle flame. The mirrors are gathering not only the visible light, but also the more copious invisible infrared light emitted by the coals. The unseen radiant heat is energetic enough to ignite the tinder. Soon it … Continue reading

Across the Universe: Changelings
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This column first ran in The Tablet in July 2010 In 1803, a team of French scientists investigated a fall of meteorites near the town of L’Aigle, and concluded that they were indeed samples from outside of Earth. It was a revolution comparable to Copernicus’: the Earth we live on does not exist isolated from all the other planets. Well, at least, not isolated from the asteroids, whose chips may come to us in the form of meteorites or, more often, as harmless showers of meteors. Surely the real planets, orbiting in simple, stable paths far from Earth, don’t touch us. But about sixty years ago, we finally realized that some bits of outer space bigger than dust or rocks manage to hit us, exploding on impact with the energy of nuclear bombs, leaving giant craters. Thirty years ago, we came to admit that one that hit 65 million years ago was big enough to wipe out the dinosaurs. (About that … Continue reading

The Modern Solar System, the Diversity of Worlds, and William Whewell (II)
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Last week I introduced readers to a newly published paper by Michael J. Crowe entitled “William Whewell, the Plurality of Worlds, and the Modern Solar System.” Crowe is the Rev. John Cavanaugh, C.S.C., Professor Emeritus in the Program of Liberal Studies and the Graduate Program in History and Philosophy of Science at the University of Notre Dame, and one of a relatively small number of scholars who study the history of human thought concerning intelligent life on other worlds, and Crowe suggests that Whewell (1794–1866), Master of Trinity College of Cambridge University, was the first person to envision the modern solar system.  As noted last week, from Copernicus up through the early nineteenth century astronomers assumed that intelligent life was abundant outside of Earth—and in particular, abundant within the solar system.  To use the language of the times, they believed in a “Plurality of Worlds” like Earth. Of course today we know that the solar system is not full of worlds … Continue reading

Patience, Patience, Patience: Why Haven’t We Heard Much From Jupiter?
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Any international trip involves overcoming a universal problem: Jet lag. Having traveled from the United States to Rome on a few occasions, I find the best approach to overcoming jet lag is to stay busy until evening on the day you arrive. After arriving at Fiumicino airport, I jump on the train, check into my hotel, get back on the train or bus, visit St. Peter’s Basilica, and then just walk for the rest of the day, camera in hand, doing my best impression of an over-zealous American tourist in Vatican Square. When night comes, I am exhausted, but always ready to face the new day in the morning. These first moments of arrival are an essential part of a successful trip to Rome, but often are not the most memorable. The memorable moments come with time, exploration, and surprises that didn’t make the initial itinerary. I think many of us, myself included, have adapted this “let’s get busy right away” … Continue reading