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In this glorious new era of planet hunting, astronomers have been discovering all sorts of freakish & unexpected worlds. To date scientists have confirmed over 4300 exoplanets (and they have partial data or leads on thousands of others). Among the 4300 known planets there are some true odd balls–a carbon planet nine times the size of Earth made of diamond, a super ghost planet twice the volume of Jupiter with half the mass, “hot Jupiter” worlds which are bigger than Jupiter but closer to their suns than Mercury. Today scientists have announced a whole new superlative: they discovered the oldest known planet, a world which dates back to the roaring infancy of the galaxy. This world goes by the name TOI-561b and, before our sun spun into existence, it was already older than the sun is now.
To put this in proper context, we need some astronomical ages (which are highly revealing in their own right). Here is a useful table of the known ages of various galaxies, stars, and, uh, everything. These dates are in Earth years (in case you are reading this elsewhere, I guess) as of AD 2021. The dates may be subject to some revision, although we keep zeroing in with greater and greater precision so I do not anticipate any large shifts:
| Age of Universe | 13.77 Billion Years |
| Age of Milky Way Galaxy | 13.4 Billion Years |
| Age of TOI-561b | 10 Billion Years |
| Age of Sun | 4.6 Billion Years |
| Age of Planet Earth | 4.543 billion years |
| Age of Cher | 74 Years |
The exoplanet TOI-561b is located in the thick disk of the Milky Way. The planet is close to its home star which it orbits twice an Earth Day (ergo, a TOI-561b year lasts about twelve hours). Because TOI-561b is so close to its star, it is hot, the surface temperature is reckoned to be about 2,000 Kelvin (3,140 degrees Fahrenheit). The rocky world has a volume 50 percent larger than Earth and a mass three times as great. The density of TOI-561b, however, is much less than that of Earth and this is because the planet is largely lacking in metals. The reason for this absence is disconcerting: TOI-561b formed before many stars had exploded, back in a time when metal was rare in the universe. There may not be many planets older than TOI-561b anywhere because there was nothing to make planets out of in the time before it formed. A generation or two of stars needed to live and die before such elements existed!
Thinking of how different things were when Cher was young is hard for me! (I like Cher and I put her up there because she is still a dynamic star). Thinking of what things were like when TOI-561b formed out of the first matter more complex than hydrogen and lithium and whatnot is practically inconceivable! It must have been quite a view though: hovering above a glowing brand-new galaxy sparkling with supernovae. I wonder if there was ever any sort of (non metallic) life there before its star became old and giant and hot.
Today is Nunavut Day! Long ago, on July 9th of the far distant year of…uh…1993 the Parliament of Canada established the territory of Nunavut, which was carved out of the catch-all Northwest Territories (a vast expanse of tundra, wilderness, and ice at the northern end of the Americas). Nunavut includes most of the Canadian Arctic Archipelago as well an innumerable northern islands–including some which are quite huge. The region has an area of 2,038,722 square km (787,155 sq mi) meaning it is the same size as Japan, South Korea, Italy, France, the UK, and Germany combined, however Nunavut is rather more sparsely populated than these locations and has a total population of less than 40,000 humans (whereas the collective population of Japan, South Korea, Italy, France, the UK, and Germany totals approximately half a billion people).
But we are not here to quibble about a variation of a few zeroes in population size. The important thing about Nunavut is its rich cultural heritage! This is reflected in the flag of Nunavut, which is what I really want to talk about in this blog post.
Here it is! This flag was crafted in 1999 by an unholy process involving 800 hand drawn submissions from across Canada, a committee of Inuit elders and artists, and Queen Elizabeth II. This improbable group collaborated to make a vividly unique and colorful banner. The red device in the middle of the flag is an inuksuk, a ceremonial land marker from Inuit culture, and the blue star is Niqirtsuituq, the North star. According to Wikipedia “The colours blue and gold were selected to represent the “riches of land, sea, and sky”, while red is used to represent Canada as a whole.” Apparently there is no explanation for the white (although a traveler in Nunavut at any time other than mid-July would probably not need an explanation for that particular color).
Although the flag is unique in its appearance and imagery, it has been criticized by vexillologists for having too many colors, having two bright colors as a background, and for the placement of the star. Seemingly vexillologists are as vexatious as their name makes them sound. Join me in the future to criticize their flag! In the meantime enjoy Nunavut Day and try to imagine the serene coolness of that vast northern land.
My office has moved to Midtown (across from Grand Central…more about that later), but I think I like the concrete canyons of Downtown better. The streets down by Wall Street feel like I always imagined New York felt like when I was little (although so do the brownstone streets of Brooklyn). Downtown also has unique holiday decorations–those jagged star/explosions. Whenever I see them, I imagine Batman has just punched the lamppost and an audible “Bap” or “Kapow” is forthcoming. I guess they are supposed to betoken universal peace or some such thing, but it sure looks like Batman went on a rampage. Indeed, the whole downtown area sort of has the brooding gritty melancholy of Gotham…especially on foggy or wintry days.
Two years ago, the world astronomy community first directly detected gravitational waves when two black holes collided. The ability to “listen” to gravitational wave noises has now come in extremely handy as the international astronomy community witnessed (or “detected”?) a new category of astronomical event—the “kilonova”! This August (2017) astronomers around the world observed two neutron stars in a nearby galaxy collide in a high energy event which distorted spacetime and was detected via both the media of electromagnetic radiation and gravitational waves.
Neutron stars have 10 to 20% more mass than the sun—but all packed into a ball with 15 kilometers of diameter—about the size of a city. It has been postulated that two of these super dense monstrosities can spin into each other in a bizarre high energy event, but such a thing was never properly detected and observed…until August 17. You can listen to it here!
These events actually happened 130 million years ago during the early Cretaceous, but it took the gravitational waves and electromagnetic radiation 130 million years to cross from the nearby galaxy where they were observed (this galaxy is located in the southern constellation of Hydra).
The idea that most (or all?) of the universe’s extremely dense metals such as gold and platinum came from neutron stars is a fairly recent concept. It was largely theoretical and seemed a trifle…preposterous (since neutron stars are not exactly everywhere to fall into each other) yet the recent kilonova has proven the concept and has provided a bonanza of information for astronomers. Of course it has provided a literal bonanza too—the universe now has the equivalent of several earths worth of newly created gold and platinum. Admittedly that vast treasure trove is 130 million light years away in the southern sky—yet that still seems closer than the Federal Reserve Depository or some Swiss vault.
What could we talk about today other than NASA’s stunning announcement of a “nearby” star system with seven Earthlike planets? Three of these rocky worlds are comfortably in the so-called habitable zone where liquid water exists and earthlike life could be possible. The star is TRAPPIST-1, a small-batch artisanal microstar with only a tenth the mass of the sun. It glistens a salmon hue and is half the temperature of the sun (and emits far less energy). Fortunately, all of its planets are much closer to the pink dwarf than Earth is to the sun, and so the middle worlds could be surprisingly clement. These planets are close to each other and sometimes appear in each other’s skies larger than the moon looks to us! The coral sun would be dimmer… but 3 times larger in the sky! It is a pretty compelling picture! Imagine sauntering along the foamy beaches of one of these worlds and looking up into a pool-table sky filled with Earth sized worlds and a cozy Tiffany lamp in the sky emitting titian-tinted light.
I am leaving out the details we know about the seven worlds because we don’t know much other than approximate mass (approximately earthsized!) and the ludicrously short length of their years. Since the inner three worlds are tidally locked they may have extreme weather or bizarre endless nights or be hot like Venus (or bare like Mercury).
Trappist1 is 40 light-years (235 trillion miles) from Earth in the constellation Aquarius. It seems like an excellent candidate for one of those near-light speed microdarts that Steven Hawking and that weird Russian billionaire have been talking about (while we tinker with our spaceark and debate manifest destiny and space ethics). However, before we mount any interstellar expeditions to Trappist1 (an anchoritic-sounding name which I just cannot get over) we will be learning real things about these planets from the James Webb space telescope when it launches in 2018–assuming we don’t abandon that mission to gaze at our navels and pray to imaginary gods and build dumb-ass walls.
Today’s announcement is arguably the most astonishing thing I have heard from the astronomy community in my lifetime (and we have learned about treasure star collisions and super-dense micro galaxies and Hanny’s Voorwerp). Ferrebeekeeper will keep you posted on news as it comes trickling out, but in the meantime let’s all pause for a moment and think about that alien beach with a giant balmy peach sun…. Ahh! I know where I want to escape to next February!
Aww…look: a baby planet! This is the youngest known exoplanet—a mere 5 to 10 million years old. It orbits its star every 5 days—a ridiculously short year which puts even Mercury’s 88 day orbit to shame (although, to be fair, the planet is 10 times closer to its star than Mercury is to the sun). The newly discovered world is approximately 500 light years from Earth. Researchers discovered the world with the Kepler space telescope (which continues to disgorge a treasure trove of data, even after its primary mission has ended because of mechanical failure).
The planet is thought to be about the size of Neptune. Since its star, K2-33, is only 10 million years old, the planet is assumed to be younger than that…though who knows. The strange nature of this system may cause scientists to rethink and refine their models of planetary formation. It isn’t the sort of thing they expected (though these super-hot giant planets right next to their stars seem to be more common than anyone would have guessed).
Orpheus (Jean Delville, 1893, oil on canvas)
The constellation Lyra was named after the haunting lyre of Orpheus. After the great musician was killed by maenads, his severed head and his lyre were thrown into the river and then drifted down to the sea. Zeus sent his eagle to pick up the lyre and carry it up into the night sky as an eternal reminder for human creative professionals about the nature of their discipline. The myth of this constellation is entirely different in China—as we have seen—yet it too revolves around star-crossed lovers sundered by circumstance.
The Constellation Lyra
Meanwhile…the robot observatory Kepler has been scanning the heavens for the subtle signs of exoplanets since 2009. The spacecraft malfunctioned in 2013, and engineers are still arguing about how best to salvage or repurpose it (or whether such a thing is even possible), but the vast treasure troves of data collected by Kepler are still yielding stunning discoveries. One of those discoveries just came to light this past week. In the constellation Lyra, there is an orange star 117 light years away from earth. The star is only 3/4th the size of the sun, but it is much older—dating back to 11.2 billion years ago (the sun, by comparison, is 4.567 billion years old). The universe itself is 13.8 billion years old—so the orange star has been burning through most of the history of creation. Because the orange star is smaller than the sun it has a much longer lifespan and will probably continue to fuse atoms together for another 20 billion years (whereas the dear sun, alas, will use up its fuel in another 4 or 5 billion years).
An artist’s conception of 444 Kepler and its planetary system
This is already heady stuff to think about, but not unprecedented. What is news is that Kepler discovered five small, rocky planets orbiting this ancient star—by far the oldest planets ever discovered. The planets are tiny—smaller than Earth and closer to 444 Kepler than Mercury is to our sun. In light of this discovery, the ancient orange star in Lyra has been designated as 444 Kepler.
The Lament of Orpheus (Alexandre Séon, 1896, oil on canvas)
444 Kepler is from one of the first broods of stars to exist. The fact that it has planets at all is something of a surprise. Astronomers are working to explain the genesis of such early planets. Of course this discovery raises other questions as well, about whether life could be much older than imagined. However to such questions there are still no answers. From the heavenly lyre of Orpheus, as from the rest of the firmament we have still heard nothing but silence.
This strange object which resembles a bottle gourd is actually a depiction of the largest yellow star known to science. HR5171A is located 11,700 light years from Earth in the heart of Centaurus (a southern constellation). Actually the image above is two stars: HR5171A is part of a binary system and its companion star is so close that the topology of the hypergiant is affected. The smaller companion is not visible. To quote Universe Today, “what we see is not the companion itself, but the regions gravitationally controlled and filled by the wind from the hypergiant.” It is uncanny how the giant star looks like a 1930s cartoon character’s head! The combined system has a total mass 39 times that of our own sun, but their volume is vastly larger—nearly 1,300 times greater that that of the sun (and the luminosity of the star is a million times greater). Although HR5171A is much less large than the true giants (like the astonishing Eta Carinae which has 120 solar masses), its ultimate fate is still not happy. Yellow hypergiant stars are passing through a transitional phase on the way to going supernova (so enjoy it now, while you can).
Between giant planets and small stars exists a bizarre class of heavenly objects known as brown dwarfs. Brown dwarfs are not massive enough to fuse hydrogen elements together as do main sequence stars like the sun, however brown dwarfs larger than 13 Jovian masses are believed to fuse deuterium atoms and large brown dwarfs (65 Jovian masses and up) are believed to fuse lithium. Since brown dwarfs can be very much like planets or like stars, there is a specific definition to describe the objects: a brown dwarf must have experienced some sort of nuclear fusion as a result of mass and temperature, however it cannot have fused all of its lithium (or it is considered a star or stellar fragment). A stellar physicist reading this blog might object that medium and large stars have some lithium present in their outer atmosphere, or that a very young white dwarf could still have some unused lithium present, or even that an old heavy brown dwarf could have fused all of its lithium. That physicist would be correct: she deserves some cookies and a pat on the head for poking holes in unnecessarily simple definitions.
Various Classifications of Brown Dwarfs
Brown dwarfs were theorized to exist in the 1960s, but no astronomer managed to discover one until 1988 when a team of University of California astronomers who were studying white dwarfs found a bizarrely cool red spectral signature for a faint companion to the star GD 165. Since then many brown dwarfs have been discovered and sorted into the major types M, L, T, and Y. They occupy a strange ambiguous area at the bottom of the Hertzsprung-Russell diagram—objects which are luminous and massive in comparison to everything else but tiny and dim compared to real stars.
There are some planets which are known to orbit brown dwarfs and there also brown dwarfs known to orbit true stars. It is beginning to seem that there a great many brown dwarfs out there: perhaps they are as numerous as true stars (or maybe they are even more common than that). Since they are hard to detect, scientists do not have a very accurate assay of their frequency in the universe. The question bears somewhat on our understanding of the universe–since a great deal of matter is not accounted for.
An artist’s conception of a brown dwarf seem from a closely orbiting planet
My mind keeps returning to the fact that some brown dwarfs have planetary systems. Imagine these melancholic twilight ice worlds forever orbiting a dim glow which will never blaze into a true sun. It is a melancholy picture, but not without a certain beauty.
A Brown Dwarf with Planet and Moon (painting by Lynette Cook from fineartamerica.com)
An astronomy story has made big news headlines this week. Usually most people are not unduly interested in the happenings in the heavens (either because such events are difficult to comprehend, or because they are regarded as remote to human interests), however this story does directly involve matters which humans take great interest in. 
Scientists and theorists working for the Harvard-Smithsonian Center for Astrophysicists have announced a spectacular new theory concerning the origin of gold (and other heavy elements like platinum and uranium): the cosmologists believe that the heaviest natural elements are created when two neutron stars collide or when a neutron star collides with a black hole (here is an easy summary of neutron stars, extremely tiny supernova remnants with a mass greater than the sun). Elements as complicated as iron are manufactured by normal stars in the course of their lifetime, however the creation of heavier elements is more mysterious. Until now, chemists and physicists had imagined that gold, platinum, uranium, and what have you, come from supernovae—however computer models of various types of supernova events did not supporting that conjecture. The scientists at the Harvard-Smithsonian Center for Astrophysicists based their hypothesis partly on the massive gamma radiation burst detected on June 3rd, 2013 from 3.9 billion light years away in a galaxy located in the constellation Leo. Gamma ray bursts tend to be associated with hypernovae/supernovae caused by the collapse of super-giant stars, but the June 3rd burst was different. In certain rare circumstances, two neutron stars are in a binary system together. Over time, the orbits decay and the stars come together in a cataclysmic event which releases energy tantamount to that of a supernova. Based on the unusual exotic energy signatures of the June 3rd gamma ray burst, it seems that scientists caught a rare peek at such an event.
Neutron Star Collision
I will confess that I am having trouble imagining two objects the size of small cities (yet each with a mass greater than the sun) slamming into each other at astronomical speeds. Apparently such events only happen every 100,000 years or so in a galaxy the size of the Milky Way. When the neutron stars come together, a black hole is ripped in the fabric of spacetime. Huge parts of the neutron stars fall into the black hole and vanish from this universe, but other portions of the neutron stars (which, as the name hints, are made up largely of neutrons) are jettisoned into space. Edo Berger, one of the astrophysicists who authored the new theory described the process with an earthy metaphor, saying, “several exciting things happen very quickly…. Most of the material collapses to form a black hole. Some of it is spewed into space. That material is rich in neutrons, which drives the formation of heavier and heavier elements, the way mud piles up on an off-road vehicle.” 
The gold, platinum, and heavy elements are created in astonishing mass (like many earths made entirely of gold). The elements are diffused through the cosmos and become part of newly forming star systems. Gold is strange stuff anyway. The gold present on Earth during its nebular formation is believed to have sunk deep into the center of planet’s molten core where it is inaccessible. All the gold that rappers and kings wear (and that Ron Paul and draugers hoard) first began falling to Earth 200 million years after the planet’s final formation on asteroids. The great gold strikes are well named: gold on the surface of Earth is there because of meteor strikes (although billions of years of geology have buried and twisted and hidden these cosmic remnants).
Yeehaw! There’s asteroid fragments!
