The scale of things

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^ ALMA | In Search of Our Cosmic Origins

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Could There be 100 Billion Potentially Habitable Planets in the Galaxy?
Universe Today, Nancy Atkinson | 15MAR13


^ A visualization of the “unseen” red dwarfs in the night sky. Credit: D. Aguilar & C. Pulliam (CfA)

As we’ve reported recently, the likelihood of findings habitable Earth-sized worlds just seems to keep getting better and better. But now the latest calculations from a new paper out this week are almost mind-bending. Using what the authors call a “very careful extrapolation” of the rate of small planets observed around M dwarf stars by the Kepler spacecraft, they estimate there could be upwards of 100 billion Earth-sized worlds in the habitable zones [HZs] of M dwarf or red dwarf stars in our galaxy. And since the population of these stars themselves are estimated to be around 100 billion in the Milky Way, that’s – on average – an Earth-sized world for every red dwarf star in our galaxy.

Whoa.

And since our solar system is surrounded by red dwarfs – very cool, very dim stars not visible to the naked eye (less than a thousandth the brightness of the Sun) — these worlds could be close by, perhaps as close as 7 light-years away.

With the help of astronomer Darin Ragozzine, a postdoctoral associate at the University of Florida who works with the Kepler mission (see our Hangout interview with him last year), let’s take a look back at the recent findings that brought about this latest stunning projection.

Back in February, we reported on the findings from Courtney Dressing and Dave Charbonneau from the Center for Astrophysics that said about 6% of red dwarf stars could host Earth-size habitable planets. But since then, Dressing and Charbonneau realized they had a bug in their code and they have revised the frequency to 15%, not 6%. That more than doubles the estimates.

Then, just this week we reported how Ravi Kopparapu from at Penn State University and the Virtual Planetary Lab at University of Washington suggested that the habitable zone around planets should be redefined, based on new, more precise data that puts the habitable zones farther away from the stars than previously thought. Applying the new habitable zone to red dwarfs pushes the fraction of red dwarfs having habitable planets closer to 50%.


^ The graphic shows optimistic and conservative habitable zone boundaries around cool, low mass stars. The numbers indicate the names of known Kepler planet candidates. Yellow color represents candidates with less than 1.4 times Earth-radius. Green color represents planet candidates between 1.4 and 2 Earth radius. Credit: Penn State.

But now, the new paper submitted to arXiv this week, “The Radius Distribution of Small Planets Around Cool Stars” by Tim Morton and Jonathan Swift (a grad student and postdoc from Caltech’s ExoLab) finds there is an additional correction to the numbers by Dressing and Charbonneau numbers.

“This is basically due to the fact that there are more small planets than we thought because Kepler isn’t yet sensitive to a large number that take longer to orbit,” Ragozzine told Universe Today. “Accounting for this effect and enhancing the calculation using some nice new statistical techniques, they estimate that the Dressing and Charbonneau numbers are actually too small by a factor of 2. This puts the number at 30% in the old habitable zone, and now up to about 100% in the new habitable zone.”

Now, it is important to point out a few things about this.

As Morton noted in an email to Universe Today, it’s important to realize that this is not yet a direct measurement of the habitable zone rate, “but it is what I would classify as a very careful extrapolation of the rate of small planets we have observed at shorter periods around M dwarfs.”

And as Ragozzine and Morton confirmed for us, all of these numbers are based on Kepler results only, and so far, while there confirmed planets around M dwarfs, there are none confirmed so far in the habitable zone.

“They do not use any results from Radial Velocity (HARPS, etc.),” Ragozzine said. “As such, these are all candidates and not planets. That is, the numbers are based on an assumption that most/all of the Kepler candidates are true planets. There are varying opinions about what the false positive rate would be, especially for this particular subset of stars, but there’s no question that the numbers may go down because some of these candidates turn out to be something else other than HZ Earth-size planets.”

Other caveats need to be considered, as well.

“Everyone needs to be careful about what “100%” means,” Ragozzine said. “It does not mean that every M dwarf has a HZ Earth-size planet. It means that, on average, there is 1 HZ-Earth size planet for every M dwarf. The difference comes from the fact that these small stars tend to have planets that come in packs of 3-5. If, on average, the number of planets per star is one, and the typical M star has 5 planets, then only 20% of M stars have planetary systems.”

The point is subtle but important. For example, if you want to plan new telescope missions to observe these planets, understanding their distribution is critical, Ragozzine said.

“I’m very interested in understanding what kinds of planetary systems host these planets as this opens a number of interesting scientific questions. Discerning their frequency and distribution are both valuable.”

Additionally, the new definition of the habitable zone from Kopparapu et al. makes a big difference.

As Ragozzine points out:


“This is really starting to point out that the definition of the HZ is based on mostly theoretical arguments that are hard to rigorously justify,” Ragozzine said. “For example, a recent paper came out showing that atmospheric pressure makes a big difference but there’s no way to estimate what the pressure will be on a distant world. (Even in the best cases, we can barely tell that the whole planet isn’t one giant puffy atmosphere.) Work by Kopparapu and others is clearly necessary and, from an astrobiological point of view, we have no choice but to use the best theory and assumptions available. Still, some of us in the field are starting to become really wary of the “H-word” (as Mike Brown calls it), wondering if it is just too speculative. Incidentally, I much, much prefer that these worlds be referred to as potentially habitable, since that’s really what we’re trying to say.”

However, Morten told Universe Today that he feels the biggest difference in their work was the careful extrapolation from short period planets to longer periods. “This is why we get occurrence rates for the smaller planets that are twice as large as Dressing or Kopparapu,” he said via email.

He also thinks the most interesting thing in their paper is not just the overall occurrence rate or the HZ occurrence rate even, but the fact that, for the first time, they’ve identified some interesting structure in the distribution of exoplanet radii.

“For example, we show that it appears that planets of roughly 1 Earth radius are actually the most common size of planet around these cool stars,” Morton said. “This makes some intuitive sense given the rocky bodies in our Solar System—there are two planets about the size of Earth, making it the most common size of small planet in our system too! Also, we find that there are lots and lots of planets around M dwarfs that are just beyond the detection threshold of current ground-based transiting surveys—this means that as more sensitive instruments and surveys are designed, we will just keep finding more and more of these exciting planets!”

But Ragozzine told us that even with all aforementioned caveats, the exciting thing is that the main gist of these new numbers probably won’t change much.

“No one is expecting that the answer will be different by more than a factor of a few – i.e., the true range is almost certainly between 30-300% and very likely between 70-130%,” Ragozzine said. “As the Kepler candidate list improves in quantity (due to new data), purity, and uniformity, the main goal will be to justify these statements and to significantly reduce that range.”

Another fun aspect is that this new work is being done by the young generation of astronomers, grad students and postdocs.

“I’m sure this group and others will continue producing great things… the exciting scientific results are just beginning!” Ragozzine said.

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Light Echoes from V838 Mon
Image Credit: NASA, ESA, H. E. Bond (STScI)

Explanation: What caused this outburst of V838 Mon? For reasons unknown, star V838 Mon's outer surface suddenly greatly expanded with the result that it became the brightest star in the entire Milky Way Galaxy in January 2002. Then, just as suddenly, it faded. A stellar flash like this had never been seen before -- supernovas and novas expel matter out into space. Although the V838 Mon flash appears to expel material into space, what is seen in the above image from the Hubble Space Telescope is actually an outwardly moving light echo of the bright flash. In a light echo, light from the flash is reflected by successively more distant rings in the complex array of ambient interstellar dust that already surrounded the star. V838 Mon lies about 20,000 light years away toward the constellation of the unicorn (Monoceros), while the light echo above spans about six light years in diameter.

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M42: Inside the Orion Nebula
Image Credit & Copyright: Reinhold Wittich

Explanation: The Great Nebula in Orion, an immense, nearby starbirth region, is probably the most famous of all astronomical nebulas. Here, glowing gas surrounds hot young stars at the edge of an immense interstellar molecular cloud only 1500 light-years away. In the above deep image in assigned colors highlighted by emission in oxygen and hydrogen, wisps and sheets of dust and gas are particularly evident. The Great Nebula in Orion can be found with the unaided eye near the easily identifiable belt of three stars in the popular constellation Orion. In addition to housing a bright open cluster of stars known as the Trapezium, the Orion Nebula contains many stellar nurseries. These nurseries contain much hydrogen gas, hot young stars, proplyds, and stellar jets spewing material at high speeds. Also known as M42, the Orion Nebula spans about 40 light years and is located in the same spiral arm of our Galaxy as the Sun.

Vernal Equinox: This day and night are equal over all planet Earth.

[JackRiddler]

So beautiful, Allegro. I always visit when you post here. You should know it's appreciated.

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^ Thank you, Jack. I’ve been OBSESSED lately with an idea of the amount of space, evidently expanding, within which myriad objects (and dusts and gases and everything else) are moving and thrashing about faster than what’s imaginable. I think that one idea keeps fascinating me so that I’m inundating myself with listening to and reading abstracts and papers about sonifications. I can’t seem to get enough. Frankly, I’m near exhaustion! Am I in school, or what?

On Monday last, I had had a really adventurous morning answering phone calls, each of which I had assumed were to be pretty uncomfortable for all parties concerned. I had enjoyed myself, actually, and as it turned out, all parties were working old presumptions. The conversations were untypically sincere and reconciliatory. I was flabbergasted. Then, to change course for a while, I thought to bring something to RI, and I read the article below that includes a marvelous timelapse that surprised me at its listen so that I wept a bit. I was flabbergasted, again. No one warned me about the music I’d be hearing . A very pleasant surprise, really.

The music for the timelapse is the final three+ minutes from a piece called “Saturn” that’s included with six other movements in an orchestral suite titled, “The Planets Op. 32” by composer, Gustav Holst. (Obviously, Pluto wasn’t included by the finish of the symphony in 1916.) “Saturn” could be a type of music that sometimes prompts a feeling in that area just below the diaphragm, and pushes upward into the area of the throat, and maybe further upward into tears. The last few seconds of the piece might blend one’s senses into the quiet, when one is so inclined.

Here are notes that describe metaphorically the amiable resolutions during phone calls noted above.

SATURN, the bringer of old age. Unlike the previous movements, which are static in the sense that each depicts various aspects of a single trait, this one moves through a series of ‘events’ that bring the music to conclusions not envisioned at the beginning. There is a profound hollowness and sense of defeat in the harmony of the opening chords, and an even deeper despair in the motif sounded beneath them by the double basses. But the elderly voice of wisdom is soon heard in the B-minor theme for the trombones, and at the end the mood is one of acceptance, reconciliation and consequent serenity.

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Beautiful Pan-STARRS Time-Lapse Video | Phil Plait
Bad Astronomy | Monday, March 18, 2013


^ Comet Pan-STARRS sets, as seen from the top of Gaislachkogel Mountain in Ötztal, Austria. Image credit: Christoph Malin

Comet Pan-STARRS is still going strong in the western skies for folks north of the Earth’s equator. It’s been cloudy here in Boulder (of course, because I just got a fancy new camera, sigh) so I haven’t seen it in a few days, though I’m hopeful for tonight.

But even if it starts to pour rain I can console myself that others are getting a spectacular view of it…even if they have to work for it. Astrophotographer Christoph Malin decided the only way to escape the clouds was to go above them, climbing 3000+ meters (9800 feet) to the top of Gaislachkogel Mountain in Ötztal, Austria. It was a brisk -20° C there, but he thinks it was worth it. He took enough pictures to create a fantastic time-lapse video of the comet:



I think it was worth it, too.

< In 2006, Hubble caught Comet LINEAR disintegrating as it approached the Sun. Click to enhalleynate. Image credit: NASA, ESA, H. Weaver (JHU/APL), M. Mutchler and Z. Levay (STScI)

Incidentally, SpaceWeather.com is reporting the comet may be fragmenting. This happens sometimes with comets; they are essentially collections of rocks, pebbles, and dust held together by ice. That ice (ammonia, water, carbon dioxide, and more) turns into gas as the comet warms near the Sun, releasing the material that becomes the tail. Larger chunks can dislodge in an event called calving. Sometimes the comet even disintegrates completely! We’ll have to see what happens with Pan-STARRS over the next few weeks. One calving does not a disintegration make, but it does show the comet is active and—like almost all its brethren—still able to give us a surprise or two.

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LOFAR Captures Giant Galaxy
Universe Today, Tammy Plotner | March 19, 2013


^ Overlay of the new GRG (blue-white colors) on an optical image from the Digitized Sky survey. The inset shows the central galaxy triplet (image from Sloan Digital Sky Survey). The image is about 2 Mpc across.

Our Universe is full of surprises. Sometimes those surprises come in packages so overwhelmingly huge that it’s almost impossible for us to comprehend the size. Thus is the case of a newly discovered “giant galaxy”. It’s a galaxy which extends millions of light years across intergalactic space, covering an area as much as a half degree of sky. It’s a new class of monster – one called a Giant Radio Galaxy.

Thanks to the work of an international team of astronomers made up of about fifty members from various institutes and led by ASTRON astronomer, Dr. George Heald, there’s a new discovery which can be credited to the powerful International LOFAR Telescope (ILT). During a perpetual all-sky radio survey – the Multi-frequency Snapshot Sky Survey (MSSS) – the team captured some images which revealed a new radio source. This wasn’t just a weak signal that showed a new blotch. It was a source the size of the full Moon projected on the sky! The huge new radio emission appears to have originated up to hundreds of million of years ago from a single member of a interacting triple galaxy system and spread itself across a vast expanse of space.

Cataloged as UGC 09555, the parent galaxy system is located some 750 million light years from our solar system. Its central galaxy had been studied before and was known to have a flat radio spectrum – a signature of giant radio galaxies. Astronomers speculate when the trio interacted, material was released – spreading out over millions of light years and releasing very low radio frequencies. It’s a source that’s either very powerful, or it’s very old.

Enter LOFAR and the MSSS Survey…

As part of a well orchestrated attempt to image the expanse of the northern night sky at frequencies between 30 and 150 MHz, the radio researchers have taken a initial “shallow scan” image set. This new survey will allow astronomers to fashion an all-sky model which will eventually assist with much deeper observations. Thanks to LOFAR’s extreme sensitivity, ability to operate at low frequencies and suitability to observe old sources, the survey was able to reveal this gargantuan galaxy. Picture its size again in your mind. This Giant Radio Galaxy covers as much sky as the Moon, yet it’s 750 million light years away! As the MSSS Survey continues to scan the skies, who knows what may yet be discovered?

With capabilities as sensitive as some of the world’s greatest radio telescopes, such as the Very Large Array (VLA) in the USA, ASTRON’s Westerbork Synthesis Radio Telescope (WSRT), and the Giant Metrewave Radio Telescope (GMRT) in India, LOFAR will take discoveries such as Giant Radio Galaxies to the next level. It will reveal objects missed by previous surveys and the broad bandwidth coverage may show us even more cosmic wonders.

Really big ones…

Original News Source: Netherlands Institute for Radio Astronomy News Release.

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Super-fast Duo: Black Hole and Star Break Speed Records
Universe Today, Nancy Atkinson | March 20, 2013

A group of telescopes and astronomers have worked together to help identify a star and a black hole that orbit each other at the dizzying rate of once every 2.4 hours, smashing the previous record by nearly an hour.

The black hole is called MAXI J1659-152, is at least three times more massive than the Sun, while its red dwarf companion star has a mass only 20% that of the Sun. The pair is separated by roughly a million kilometers.

The duo was discovered on September 25, 2010 by NASA’s Swift space telescope and were initially thought to be a gamma-ray burst. Later that day, Japan’s MAXI telescope on the International Space Station found a bright X-ray source at the same place.

More observations from ground and space telescopes, including ESA’s XMM-Newton, revealed that the X-rays come from a black hole feeding off material ripped from a tiny companion.

Several regularly-spaced dips in the emission were seen in an uninterrupted 14.5 hour observation with XMM-Newton, caused by the uneven rim of the black hole’s accretion disc briefly obscuring the X-rays as the system rotates, its disc almost edge-on along XMM-Newton’s line of sight.

From these dips, an orbital period of just 2.4 hours was measured, setting a new record for black hole X-ray binary systems. The previous record-holder, Swift J1753.5–0127, has a period of 3.2 hours.

The black hole and the star orbit their common center of mass. Because the star is the lighter object, it lies further from this point and has to travel around its larger orbit at a breakneck speed of two million kilometres per hour – it is the fastest moving star ever seen in an X-ray binary system. On the other hand, the black hole orbits at ‘only’ 150 000 km/h.

“The companion star revolves around the common center of mass at a dizzying rate, almost 20 times faster than Earth orbits the Sun. You really wouldn’t like to be on such a merry-go-round in this Galactic fair!” says lead author Erik Kuulkers of ESA’s European Space Astronomy Centre in Spain.

His team also saw that they lie high above the Galactic plane, out of the main disc of our spiral Galaxy, an unusual characteristic shared only by two other black-hole binary systems, including Swift J1753.5–0127.

“These high galactic latitude locations and short orbital periods are signatures of a potential new class of binary system, objects that may have been kicked out of the Galactic plane during the explosive formation of the black hole itself,” says Dr Kuulkers.

Returning to MAXI J1659-152, the quick response of XMM-Newton was key in being able to measure the remarkably short orbital period of the system.

“Observations started at tea-time, just five hours after we received the request to begin taking measurements, and continued until breakfast the next day. Without this rapid response it would not have been possible to discover the fastest rotation yet known for any binary system with a black hole,” adds Norbert Schartel, ESA’s XMM-Newton project scientist.

Source: ESA

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Grand Spiral Galaxy Graced By Faded Supernova
Universe Today, Tammy Plotner | March 20, 2013

One of the most lovely deep space objects to observe is the grand-design spiral galaxy and there are few so grand as NGC 1637. Located in the constellation of Eridanus and positioned approximately 35 million light years away, this twisted beauty was home to a radical supernova event just 14 years ago. Now astronomers are taking a close look at the resultant damage caused by the stellar explosion and giving us some pretty incredible views of the galaxy as well.

When viewing NGC 1637, it seems as if the galaxy itself is evenly distributed, but take a closer look. In this image you will notice the spiral arm to the top left is much more openly constructed and stretches out a bit further than the more concentrated and stubby spiral arm to its opposite side. You will also notice the more compact arm has the appearance of being cut through its mid-section. In whole, this particular appearance is what astronomers refer to as a “lopsided spiral galaxy”.

Now, let’s talk about what happened to disturb the peace…

In 1999, high atop Mt. Hamilton and near San Jose, California, the Lick Observatory was busy utilizing a telescope which specialized in searching for supernova events. Low and behold, they discovered one… a very bright one located in NGC 1637. Like all astronomical observations, the call went out immediately to other observatories to confirm their find and to gather support data. As with most dramatic events, SN 1999em was quickly and thoroughly researched by telescopes around the world – its magnitude carefully recorded and the resultant fading meticulously accounted for as the years have passed.

Better to burn out than to fade away? There are very few things in our natural world which can match the violent beauty of a supernova event. When a star ends its life in this way, it goes out with a bang, not a whimper. For their cosmic finale, they briefly outshine the combined light of all the stars contained within the host galaxy. Like snowflakes, each supernova is unique and the cataclysmic star within NGC 1637 was eight times more massive than our Sun.


^ This video sequence starts with a view of the bright constellation of Orion (The Hunter). As we zoom in, we focus on an adjacent region of the constellation of Eridanus (The River) and a faint glow appears. This is the spiral galaxy NGC 1637, which appears in all its glory in the final view from ESO’s Very Large Telescope. In 1999 scientists discovered a Type II supernova in this galaxy and followed its slow fading over the following years. Credit: ESO/Nick Risinger

Go ahead. Take another look. During the confirmation observing runs, astronomers also imaged SN 1999em with the VLT and this data was combined with the Lick Observatory information to give us the spectacular view above. Caught in the spiral arm are young stars singing the blues amidst ethereal gas clouds and veiling dust lanes. NGC 1637 isn’t alone, either… You’ll see line of sight stars and even more galaxies in the background.

No rust here…

Original Story Source: ESO News Release.

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Well, wouldn’t you know. We live in a lopsided Universe, and it’s older than we thought. It’s information like the following that helps me keep my feet solidly planted while my head bobbles . Tip: keep breathing!

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The Universe Is 13.82 Billion Years Old | Phil Plait
Bad Astronomy | Thursday, March 21, 2013, at 2:46 PM


^ Baby picture of the Universe. Click to expand. Image credit: ESA–Planck Collaboration

The Universe is a wee bit older than we thought. Not only that, but turns out the ingredients are a little bit different, too. And not only that, but the way they’re mixed isn’t quite what we expected, either. And not only that, but there are hints and whispers of something much grander going on as well.

So what’s going on?

The European Space Agency’s Planck mission is what’s going on. Planck has been scanning the entire sky, over and over, peering at the radio and microwaves pouring out of the Universe. Some of this light comes from stars, some from cold clumps of dust, some from exploding stars and galaxies. But a portion of it comes from farther away…much farther away. Billions of light years, in fact, all the way from the edge of the observable Universe.

This light was first emitted when the Universe was very young, about 380,000 years old. It was blindingly bright, but in its eons-long travel to us has dimmed and reddened. Fighting the expansion of the Universe itself, the light has had its wavelength stretched out until it gets to us in the form of microwaves. Planck gathered that light for over 15 months, using instruments far more sensitive than ever before.


^ Drawing of the Planck
spacecraft. Image credit:
ESA/NASA/JPL-CaltechThe light from the early Universe shows it’s not smooth. If you crank the contrast way up you see slightly brighter and slightly dimmer spots. These correspond to changes in temperature of the Universe on a scale of 1 part in 100,000. That’s incredibly small, but has profound implications. We think those fluctuations were imprinted on the Universe when it was only a trillionth of a trillionth of a second old, and they grew with the Universe as it expanded. They were also the seeds of the galaxies and the clusters and galaxies we see today.

What started out as quantum fluctuations when the Universe was smaller than a proton have now grown to be the largest structures in the cosmos, hundreds of millions of light years across. Let that settle in your brain a moment.

And those fluctuations are the key to Planck’s observations. By looking at those small changes in light we can find out a lot about the Universe. Scientists spent years looking at the Planck data, analyzing it. And what they found is pretty amazing:


⋅ The Universe is 13.82 billion years old.
⋅ The Universe is expanding a bit slower than we expected.
⋅ The Universe is 4.9 percent normal matter, 26.8 percent dark matter, and 68.3 percent dark energy.
⋅ The Universe is lopsided. Just a bit, just a hint, but that has profound implications.

What does all this mean? Let’s take a quick look, one at a time, at these results.

The Universe is 13.82 billion years old.

The age of the Universe is a little bit higher than we expected. A few years ago, the WMAP spacecraft looked at the Universe much as Planck has, and for the time got the best determination of the cosmic age: 13.73 +/- 0.12 billion years old.

Planck has found that the Universe is nearly 100 million years older than that: 13.82 billion years.

At first glance you might think this is a really different number. But look again. The uncertainty in the WMAP age is 120 million years. That means the best estimate is 13.73 billion years, but it could easily be 13.85 or 13.61. Anything in that range is essentially indistinguishable in the WMAP data, and 13.73 is just in the middle of that range.

And that range includes 13.82 billion years. It’s at the high end, but that’s not a big deal. It’s completely consistent with the older estimate, but Planck’s measurements are considered to be more accurate. It will become the new benchmark for astronomers.

The Universe is expanding a bit slower than we expected.

The Universe is expanding, and has been ever since the moment it was born. We can measure the speed of this expansion in various ways; for example, looking at distant exploding stars. We can measure how fast they are moving away from us, swept along with the expansion of space, by seeing how much their light is redshifted (I have details about how this works in an earlier post on redshifts and the expansion of the Universe). We can measure their distance, too, using various methods including how bright they appear to be, and with both their speed and distance we can calculate how fast the Universe is expanding.

The farther away you go, the faster the Universe expands, and what Planck found is that the Universe is getting bigger at a rate of 67.3 kilometers per second per megaparsec. A megaparsec is a unit of distance equal to 3.26 million light years (which is convenient to astronomers). That means that if you look at a galaxy one megaparsec away, it appears to be moving away from you at 67.3 km/sec. A galaxy two megaparsecs away would recede at twice that speed, 134.6 km/sec, and so on.

This is called the Hubble constant. Various methods have been used to measure it for the past century, and some of the best found it to be about 74.2 km/s/Mpc. Planck’s measurement is smaller, so the Universe appears to be expanding a little more slowly than we thought, which is why the age is a bit higher than measured before, too.

Part of the reason the number is smaller from Planck is that it’s looking at light that is very old, and came from very far away, so they extrapolate forward in time to see how fast the Universe is growing. Other measurements use light from objects that are closer, and scientists extrapolated backwards.

Since the two numbers are different, this may mean the Hubble constant has changed over time, though that’s way too preliminary to tell. I’ll just note it here as an interesting development. The Hubble constant is notoriously difficult to measure, and I imagine astronomers will be arguing about it for some time yet to come.

The Universe is 4.9 percent normal matter, 26.8 percent dark matter, and 68.3 percent dark energy.

I love this bit. The amount of the fluctuations in the light from the early Universe as well as how they are distributed can be used to figure out what the Universe is made of. The ingredients and amounts of the universal constituents are:


⋅ 4.9 percent normal matter
⋅ 26.8 percent dark matter
⋅ 68.3 percent dark energy


^ Planck’s map of the location of all the matter in the Universe. The strip across the middle is due to bright light from our galaxy which interfered with the much fainter background, and had to be subtracted away. Click to ensaganate. Image credit: ESA/NASA/JPL-Caltech

Normal matter is what we call protons, neutrons, electrons; basically everything you see when you look around. Stars, cashews, dryer lint, and books are all made of normal matter. So are you.

Dark matter is a substance we know exists, but it’s invisible. We see its effects through its gravity, which profoundly alters how galaxies rotate and clusters of galaxies behave. There’s more than five times as much of it as there is normal matter.

Dark energy was only discovered in 1998. It’s very mysterious, but acts like a pressure, increasing the expansion rate of the Universe. We know very little about it other than the fact that it exists, and it’s a bigger component of the universal budget than normal and dark matter combined.

The best estimates for these numbers before Planck were a bit different: 4.6, 24, and 71.4 percent, respectively. That’s neat: there’s less dark energy than we thought, so the Universe is made up a little bit less of that weird stuff, if that makes you feel better. But there’s still a lot of it!

The good news is that having better numbers for all these means astronomers can tune their models a little bit better, and we can understand things a little better. Different models of how the Universe behaves predict different ratios for these ingredients, so getting them focused a bit better means we can see which models work better. We’re learning!

The Universe is lopsided. Just a bit, just a hint, but that has profound implications.

Of all the results announced so far, this may be the most provocative. We expect the Universe to be pretty smooth on large scales. Those early fluctuations should be random, so when you look around at this ancient light, the pattern should be pretty random.

And it is! The distribution of the fluctuations is quite random. It may look to your eye to have patterns, but our brains are miserable at seeing true randomness; we impose order on it. You have to use computers, math, and statistics to measure the distribution to test for true randomness, and the Universe passes the test.

Kindof. The distribution is random, but the amplitudes of the fluctuations are not. Amplitude is how bright they are; like the height of a wave. It’s hard to see by eye, but in the big map made by Planck, the fluctuations are a wee bit brighter than they should be on one side, and a wee bit dimmer on the other. It’s an incredibly small effect, but appears to be real. It was seen in WMAP data and confirmed by Planck.

A simple model of the Universe says that shouldn’t happen. The Universe is lopsided on a vast scale! What can this mean?


^ A map of the lopsided Universe. This shows the difference between a smooth mathematical fit to the background light of the cosmos versus what is actually seen - these leftover fluctuations are just a hair bigger than we expected, but that makes all the difference in the Universe. Click to anomalate. Image credit: ESA and the Planck Collaboration

Right now, we don’t know, and there are far more ideas for why this would happen than we have data to test for. It could mean dark energy is changing over time, for example. Another idea, and one that is terribly exciting, is that we’re seeing some pattern imprinted on the Universe from before the Big Bang. I know, that sounds crazy, but it’s not completely crazy. My friend and cosmologist Sean Carroll has some detail on this.

We may be seeing something so big in extent it’s happening over scales we literally cannot see. It’s like having a house built on a slight incline. Standing in one room you might not notice it, but measuring the elevation in a room on one side of the house versus one all the way on the other side might show the discrepancy. And even then, it only gives you a taste of how big that hill might be.

We’re seeing that on a cosmic scale. The Universe itself appears to be slightly canted, and we only get a hint of it when we take the measure the entire Universe.

Everything

I am entirely and thoroughly delighted by these new results.

As a scientist, of course, I like it when we get better measurements, more detail, refined numbers. That’s how we test models, and it helps us understand our ideas better.

But I’m human, and a big part of my brain is still reeling from the fact that we can accurately measure the age of the Universe at all. We can figure out what’s in it, even when most of it is something we cannot see. We can determine not only that it’s expanding, but how quickly.

And best of all, we see that the Universe is doing things we still don’t understand. It’s showing us that there is still more out there, things occurring on so vast a canvas that it both crushes utterly our sense of scale and expands ferociously our imagination.

Every day, we get better at learning what the Universe is doing. And the work continues to find out how. It may even lead us to the answer of the ultimate question of all: why?

If that answer exists (if the question even makes sense), and we can understand it, then we are making our first steps toward it right now.

I still hear some people say that science takes the wonder out of life. Those people are utterly and completely wrong.

Science takes us to the wonder.

[Allegro]

Over the years, I hadn’t seen that many pictures of Orion Nebula, but I had stared at them—they were captivating. Now I’m seeing pictures of Orion nearly every day.

In a certain way, Rigorous Intuition has been my Orion. I remember that, while registering for RI over three years ago, I’d imagine just to the right of Orion would be a place I’d call my home-office-man-cave. Although I had lurked RI since late 2004, I felt excited and anxious like a babe taking his first steps into RI, a place that would challenge my thinking, and writing of course, for topics I had barely considered except while lurking.

There are places sought that provide time for creative thought and personal expression for thousands of people like me who put their lives on hold to care for a mature family member. Mom is doing remarkably well—no diseases, good bones; convivial, humorous, talkative, walks almost anywhere at a moment’s notice; plays piano and sometimes sings soprano as I do baritone—it’s her memories that not entirely disappear. Normal social and professional lives of familial care givers can be indefinitely waived as I chose fifty-two months ago. All’s well, and so am I—beautifully and graciously grounded with the piano nearby.

Thank You to Jeff, and thanks to thinkers and writers who’ve moved on and to those who’ve stayed put, and thanks to those who from other places encourage by listening to a thinker’s distinctive experiences and wiggly speculations. Rigorous Intuition thankfully remains my Orion.

Allegro

[Allegro]

Highlights mine in the following.

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The Cold Fire of Orion | Phil Plait
Bad Astronomy | Monday, March 25, 2013, at 8:00 AM

The Orion Nebula (also called M42) is one of the most recognizable objects in the entire sky. The middle “star” in Orion’s dagger hanging below his belt, this cloud of gas and dust is so bright that even from more than 13 quadrillion kilometers (8 thousand trillion miles) away it’s easily visible to the naked eye.

It’s a vast sprawling complex of interstellar material, lit by the fierce energy of stars born within. It’s amazing through a small telescope, stunning through a big one, and gorgeous in pictures…but then adjectives seem a little dingy and small when trying to describe the view in the infrared:


^ NASA’s WISE view of the famous Orion Nebula. Click to mightyhunternate. Image credit: NASA/JPL-Caltech/UCLA

Jaw-dropping? Mind-blowing? I can’t come up with a hyphen-dashing word appropriate for this. It’s chillingly beautiful.

And I do mean chilling. This is the view from NASA’s Wide-field Infrared Survey Explorer (WISE), one of my all-time favorite space astronomy missions. It scanned the sky continuously, able to see objects in one go that most telescopes would need huge mosaics to encompass completely. Its detectors were designed to see in the infrared, where extremely cold objects emit light.

In this false-color picture, blue is actually light at a wavelength of 3.4 microns (about five times longer than you can see with your eye, and mostly coming from stars), green is 12 microns, and red is 22 microns. The coolest material you see is dust, complex organic molecules called PAHS, for polycyclic aromatic hydrocarbons—pretty much just soot. Dust is created in the atmospheres of stars when they are born and when they die, and it’s common in giant clouds where stars are being born.

The Orion Nebula (and the Flame Nebula, located just above M42 in the WISE shot) is the closest big stellar nursery. Amazingly, the visible part of the nebula is just one small part of it! The entire complex is what’s called a giant molecular cloud, a fog of gas and dust that is so thick it’s completely opaque and invisible to the eye. It’s outline becomes more apparent in the infrared, and you can start to get a sense of the three-dimensional structure.

The nebula itself is actually caused by several extremely massive stars that have formed near the edge of the cloud. Once the stars formed, their fierce heat and strong winds herniated the cloud, blowing out a cavity in the cloud’s side, letting their light out. The glow in pictures is due to both thin gas fluorescing like a neon sign as well as the dust itself lit directly by the stars.

When I picture it in my head, I actually visualize it like the Death Star, if it were cloaked and all you could see was the dish from the planet-killing main weapon. But then, I’m a dork.


^ The constellation of Orion over El Castillo, the Temple of Kukulkan, in Chichen Itza, Mexico. You can see the nebula to the right of the three belt stars, and even make out it’s not a star. Click to ennebulenate. Image credit: Stéphane Guisard

Still, the incredible beauty of this region is undeniable. I was looking at it through my own small telescope just the other day, the wisps of gas visible, as well as the four stars of the Trapezium, the incredibly massive and hot stars illuminating essentially that whole region. The gorgeous and delicate view was amazing, and only heightened by my knowledge that nearly every single star I could see would someday explode as a tremendous supernova, releasing energies so vast and terrible our puny minds can’t grasp them except as numbers and physical equations.

Someday, perhaps in a million years, perhaps less, this incredible region will undergo a sudden and extraordinarily violent change. It will still be beautiful, but in a different way, I suppose. And what a boon it will be to science, to see supernovae from only 1300 light years away! They will shine as brightly as the Moon, casting shadows on the ground for weeks as they flare and finally dim. What a sight that will be!

There is beauty in pictures like this, but there is also such beauty in knowledge. Knowing is always better, and always adds depth and meaning to art, especially the scientific kind.

[Allegro]

Highlights mine.

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Astrophoto: Beautiful New Look at the Orion Nebula
Universe Today, Nancy Atkinson | March 27, 2013


^ M 42 in Orion using the “Hubble Palette.” Images by Gary Gonnella, image editing by Paul M. Hutchinson.

The enormous cloud of dust and gas that makes up the Orion Nebula is featured in this beautiful astrophoto. This image was a joint effort, with images taken by Gary Gonnella – a regular on our Virtual Star Parties – and image editing by Paul Hutchinson. Paul used the “Hubble Palette” – named for the Hubble Space Telescope and its capability of imaging in very narrow wavelengths of light using various filters. This enables astrophotographs to reveal details of objects in space that can’t be seen by the human eye. Here, the filters used produced different colors: were Hydrogen Alpha=Green, S=Red, O=Blue. Paul said he combined two exposures, a 1 minute and 10 second exposure, to reduce the blow-out in the bright center of the nebula. The results are striking!

Compare this great image to another image of the Orion Nebula, recently taken by the WISE telescope (Wide-field Infrared Survey Explorer), below. Colors in this image represents specific infrared wavelengths. Blue represents light emitted at 3.4-micron wavelengths and cyan (blue-green) represents 4.6 microns, both of which come mainly from hot stars. Relatively cooler objects, such as the dust of the nebulae, appear green and red. Green represents 12-micron light and red represents 22-micron light.


^ The Orion Nebula as seen by the WISE telescope. Image Credit: NASA/JPL-Caltech/UCLA

The Orion nebula is part of the larger Orion molecular cloud complex, which also includes the Flame nebula. This region is actively making new stars.

[Allegro]

Highlights mine.

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Solar System Antiquities Abound in Saturn’s Rings
Universe Today, Nancy Atkinson | March 28, 2013


^ The Cassini spacecraft observes three of Saturn’s moons set against the darkened night side of the planet. Credit: NASA/JPL/Space Science Institute

Anyone looking for miscellanies from the early days of the Solar System can likely find them all in one place: the Saturn system. A new analysis of data from the Cassini spacecraft suggests that Saturn’s moons and rings are “antiquities” from around the time of our Solar System’s very beginnings.

“Studying the Saturnian system helps us understand the chemical and physical evolution of our entire solar system,” said Cassini scientist Gianrico Filacchione, from Italy’s National Institute for Astrophysics. “We know now that understanding this evolution requires not just studying a single moon or ring, but piecing together the relationships intertwining these bodies.”

The rings, moons, moonlets, and other debris date back more than 4 billion years. They are from around the time that the planetary bodies in our neighborhood began to form out of the protoplanetary nebula, the cloud of material still orbiting the sun after its ignition as a star.

Data from Cassini’s visual and infrared mapping spectrometer (VIMS) have revealed how water ice and also colors — which are the signs of non-water and organic materials — are distributed throughout the Saturnian system. The spectrometer’s data in the visible part of the light spectrum show that coloring on the rings and moons generally is only skin-deep.

Using its infrared range, VIMS also detected abundant water ice – too much to have been deposited by comets or other recent means. So the authors deduce that the water ices must have formed around the time of the birth of the solar system, because Saturn orbits the sun beyond the so-called “snow line.” Out beyond the snow line, in the outer solar system where Saturn resides, the environment is conducive to preserving water ice, like a deep freezer. Inside the solar system’s “snow line,” the environment is much closer to the sun’s warm glow, and ices and other volatiles dissipate more easily.


^ The effects of the small moon Prometheus loom large on two of Saturn’s rings in this image taken a short time before Saturn’s August 2009 equinox. Credit: NASA

The colored patina on the ring particles and moons roughly corresponds to their location in the Saturn system. For Saturn’s inner ring particles and moons, water-ice spray from the geyser moon Enceladus has a whitewashing effect.

Farther out, the scientists found that the surfaces of Saturn’s moons generally were redder the farther they orbited from Saturn. Phoebe, one of Saturn’s outer moons and an object thought to originate in the far-off Kuiper Belt, seems to be shedding reddish dust that eventually rouges the surface of nearby moons, such as Hyperion and Iapetus.

A rain of meteoroids from outside the system appears to have turned some parts of the main ring system — notably the part of the main rings known as the B ring — a subtle reddish hue. Scientists think the reddish color could be oxidized iron — rust — or polycyclic aromatic hydrocarbons, which could be progenitors of more complex organic molecules.

One of the big surprises from this research was the similar reddish coloring of the potato-shaped moon Prometheus and nearby ring particles. Other moons in the area were more whitish.

“The similar reddish tint suggests that Prometheus is constructed from material in Saturn’s rings,” said co-author Bonnie Buratti, a VIMS team member based at NASA’s Jet Propulsion Laboratory, Pasadena, Calif. “Scientists had been wondering whether ring particles could have stuck together to form moons — since the dominant theory was that the rings basically came from satellites being broken up. The coloring gives us some solid proof that it can work the other way around, too.”

“Observing the rings and moons with Cassini gives us an amazing bird’s-eye view of the intricate processes at work in the Saturn system, and perhaps in the evolution of planetary systems as well,” said Linda Spilker, Cassini project scientist, based at JPL. “What an object looks like and how it evolves depends a lot on location, location, location.”

Filacchione’s paper has been published in the Astrophysical Journal.

Source: JPL

[Allegro]

Not too often is the astronomer, Sir William Herschel, born 1738, mentioned as a music composer of some twenty-four orchestral works. The first movement from Sinfonia n. 12, marked Allegro, is heard in the video to the left.

Hershel discovered Uranus, and its two major moons, Titania and Oberon as well as two moons of Saturn; and he discovered infrared radiation. See Herschel’s Wiki page.

Highlights mine, below.

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Hubble Uncovers Hidden Mysteries in Messier 77
Universe Today, Tammy Plotner | March 28, 2013


^ The NASA/ESA Hubble Space Telescope has captured this vivid image of spiral galaxy Messier 77 — a galaxy in the constellation of Cetus, some 45 million light-years away from us. The streaks of red and blue in the image highlight pockets of star formation along the pinwheeling arms, with dark dust lanes stretching across the galaxy’s starry centre. The galaxy belongs to a class of galaxies known as Seyfert galaxies, which have highly ionised gas surrounding an intensely active centre. Credit: NASA, ESA & A. van der Hoeven

Discovered on October 29, 1780 by Pierre Mechain, this active Seyfert galaxy is magnificent to behold in amateur equipment and even more so in NASA/ESA Hubble Space Telescope photographs. Located in the constellation of Cetus and positioned about 45 million light years away, this spiral galaxy has a claim to fame not only for being strong in star formation, but as one of the most studied galaxies of its type. Cutting across its face are red hued pockets of gas where new suns are being born and dark dustlanes twist around its powerful nucleus.

When Mechain first observed this incredible visage, he mistook it for a nebula and Messier looked at it, but did not record it. (However, do not fault Messier for lack of interest at this time. His wife and newly born son had just died and he was mourning.) In 1783, Sir William Herschel saw it as an “Ill defined star surrounded by nebulousity.” but would change his tune some 8 years later when he reported: “A kind of much magnified stellar cluster; it contains some bright stars in the centre.” His son, John Herschel, would go on to catalog it – not being very descriptive either.


^ This video zooms in on spiral galaxy Messier 77. The sequence begins with a view of the night sky near the constellation of Cetus. It then zooms through observations from the Digitized Sky Survey 2, and ends with a view of the galaxy obtained by Hubble. Credit:NASA, ESA, Digitized Sky Survey 2. Acknowledgement: A. van der Hoeven

At almost double the size of the Milky Way, we now know it is a barred spiral galaxy. According to spectral analysis, Messier 77 has very broad emission lines, indicating that giant gas clouds are rapidly moving out of this galaxy’s core, at several hundreds of kilometers per second. This makes M77 a Seyfert Type II galaxy – one with an expanding core of starbirth. In itself, that’s quite unique considering the amount of energy needed to expand at that rate and further investigations found a 12 light-year diameter, point-like radio source at its core enveloped in a 100 light year swath of interstellar matter. A miniature quasar? Perhaps… But whatever it is has a measurement of 15 million solar masses!

Deep at its heart, Messier 77 is beating out huge amounts of radiation – radiation suspected to be from an intensely active black hole. Here the “galaxy stuff” is constantly being drawn towards the center, heating and lighting up the frequencies. Just this area alone can shine tens of thousands of times brighter than most galaxies… but is there anything else hiding there?

“Active galactic nuclei (AGNs) display many energetic phenomena—broad emission lines, X-rays, relativistic jets, radio lobes – originating from matter falling onto a supermassive black hole. It is widely accepted that orientation effects play a major role in explaining the observational appearance of AGNs.” says W. Jaffe (et al). “Seen from certain directions, circum-nuclear dust clouds would block our view of the central powerhouse. Indirect evidence suggests that the dust clouds form a parsec-sized torus-shaped distribution. This explanation, however, remains unproved, as even the largest telescopes have not been able to resolve the dust structures.”

Before you leave, look again. Clustered about Messier 77′s spiral arms are deep red pockets – a sign of newly forming stars. Inside the ruby regions, neophyte stars are ionising the gas. The dust lanes also appear crimson as well – a phenomenon called “reddening” – where the dust absorbs the blue light and highlights the ruddy color. A version of this image won second place in the Hubble’s Hidden Treasures Image Processing Competition, entered by contestant Andre van der Hoeven.

Twistin’ the night away…