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A Composite Image of M104–The Sombrero Galaxy–taken from the Hubble Space Teelscope in Summer of 2003 (click on the image for a full-sized version)
Today I am posting some pictures of what I think is the most beautiful deep space object. The Sombrero Galaxy (M104) is a nearby galaxy which is visible edge-on in the constellation of Virgo. Actually, calling it an object might be a bit misleading since M104 consists of more than 400 billion stars–not to mention numerous associated globular clusters, innumerable planets, immense clouds of gas & gas, and a supermassive black hole which lies in the center. The black hole in the center of M104 isn’t a mild mannered & quiescent black hole like the one in the center of the Milky Way either. Based on the speed of revolution of the stars near the middle of M104, astronomers calculate that the central black hole has a billion times the mass of the sun.
An Infrared false-color image of the Sombrero Galaxy
In cosmic terms, the Sombrero galaxy is nearby—which is to say it is merely 28-odd million light years away. The galaxy was discovered in the late eighteenth century by Pierre Méchain . Other prominent 18th century astronomers subsequently observed and studied M104, including Charles Messier (which is the reason the galaxy is included in the “Messier” catalog and has a M-designation) and the redoubtable William Herschel who noted a “dark-stratum” bounding the luminous central bulge. We now know that this ring around M104 is a toroid dust lane of vast proportions which halos the galaxy. Astronomers initially thought that the Sombrero Galaxy was an unbarred spiral galaxy, but thanks to observations from NASA’s Spitzer space telescope (an infrared scope orbiting Earth), the scientific community has revised their estimation of its size upward. It lies somewhere between a spiral galaxy and an elliptical galaxy. In other words, when you look at the Sombrero Galaxy, you are looking at something vast beyond human comprehension—a galaxy bigger than our own filled with who knows what things we will never know. And yet if you expand the Hubble photo at the top of this post, you will see that all of the little stars shining around M104 are other galaxies farther away.
Olé!
The constellation Sagittarius (from “Urania’s Mirror” a set of constellation cards published in England circa 1825)
My apologies for the blogging break last week. Usually I try to write a new post every weekday, but last week was a blogging holiday. To reinvigorate things after the lost week, let’s turn to a big subject—in fact a super-massive subject! Long ago, Ferrebeekeeper featured a post about Eta Carinae, a blue hypergiant with a hundred times the mass of the sun (which is itself a million times more massive than Earth). Stars like Eta Carinae are rarely formed and short lived—there are probably less than a dozen in our galaxy. However compared to the most massive object in the galaxy, Eta Carinae is puny and common. Twenty six thousand light years away from the solar system there exists a truly monstrous space object!
In 1974, Astronomers discovered an astronomical feature which was emitting exotic radio waves in the Sagittarius constellation. The scientists named the feature “Sagittarius A” and set out to determine what it was. Part of the feature seems to be the remnants of a star which had gone supernova. A second part of the feature is a cloud of ionized gas surrounded by an even larger torus of molecular gas. In the middle of Sagittarius A is something which is emitting most of the high energy electromagnetic radiation visible to radio telescopes. The cloud of ionized gas seems to be emptying into it and nearby stars orbit it with greater velocity than stars move anywhere else in the galaxy (in fact the object affects the proper motion of thousands of nearby stars). And yet the space object at the center of Sagittarius A has a diameter of only 44 million kilometers–a bit less than the distance between the middle of the sun and Mercury at its perihelion (when the rocky planet is closest to the sun). By calculating the proper motion of thousands of nearby stars, scientists determined that the mysterious object at the center of Sagittarius A (which they took to calling Sagitarrius A*) has mass of 4.31 million suns (i.e. solar masses). Whatever lies at the center of Sagittarius A–which I probably should have mentioned, is also the center of the Milky Way Galaxy–is smaller in volume than a large star, but has a mass which exceeds by many orders of magnitude even exotic hypergiants like Eta Carina.
Of course the only kinds of discrete objects which we know (or even hypothesize) to be capable of attaining such mass are black holes. It is believed that most (indeed probably all) galaxies have super-massive black hole at their centers. Smaller galaxies have small super massive black holes (forgive the oxymoron) but large galaxies have immense central black holes which can equal billions of solar masses. Radio astronomers have observed plumes of exotic electromagnetic radiation coming from the center of other galaxies, and they wondered where the Milky Way’s galactic center was located. It seems that a supernova near the galactic center blew away a great deal of the dust and gas on which the black hole would otherwise “feed” thereby making the galactic center of the Milky Way less energetic than the active center of farther (e.g. older) galaxies.
Artist’s Conception of Galactic Center
The super massive black holes which lie at the center of galaxies may be a result of the accretion of matter around stellar-sized black holes (which could grow quickly in matter-rich galactic cores) but most astrophysicists believe they are instead a primordial feature of the Big Bang around which galaxies themselves coalesced. The ultimate nature of super massive black holes remains unknown and seems to be tied to the nature and shape of our universe.
The Black Dragon Gong Gong and the Serpent Goddess Nüwa
In Chinese mythology, Gong Gong was a tempestuous and unhappy water spirit of great strength. He is usually portrayed as a raging black dragon or as a seething water monster. In an earlier post concerning the Black Mansion—the Chinese underworld—I described how rigorously regimented the Chinese spirit world is (on earth, in heaven, and in hell). Gong Gong was a spirit who was not happy with the rigid hierarchical order of things. Despite his raw power, his job in the courts of heaven was to run trivial errands and fill out tedious paperwork. Growing sick of what he perceived as menial chores, Gong Gong rebelled against the Jade Emperor. In order to usurp control of heaven, he unleashed terrible floods and allied with a wicked nine-headed demon named Xiang Yao.
Gong Gong hurls himself into Mount Buzhou
Together Gong Gong and Xiang Yao brought about great destruction in the world. The tumult they unleashed killed countless people. But, despite the suffering they caused, the two could not defeat the powers of heaven. They were opposed by Zhu Rong, the god of fire and ruler of the south who fought with a great sword from the back of his tiger. Unable to withstand Zhu Rong’s ferocity, the monsters were about to be defeated outright. Infuriated and unwilling to accept such shame, Gong Gong hurled himself into Mount Buzhou, a mythical mountain which was one of the principal supports of heaven. Part of the mountain collapsed and a terrible hole appeared in the sky. The suffering caused by Gong Gong’s earlier actions was nothing compared to the catastrophe caused by this collapse. Flood and fire swept earth. Terrible creatures from beyond came through the rip in existence and ravaged the planet. Famine and horror stalked the world and it seemed as though all living things were doomed.
Nüwa Repairs the Breach in Heaven
With the other gods helpless, the creator goddess Nüwa again stepped forward. She cut the legs off a great turtle and propped the sky back on its axis. Then she gathered precious stones from a river and cast the breath of her magic into them. With these multicolored stones she repaired the vault of heaven. In some versions of the story she slew the black dragon Gong Gong whereas in other versions he sneaked away and still remains at large somewhere in the world. Whatever the case, Nüwa’s repairs were not perfect. The sun and moon now flow across the heavens from east to west and the stars were thrown from their position to drift with the seasons. Even the North star was jarred from true north.
Nüwa Repairs the Breach in Heaven (a modern interpretation)
Strangely enough my favorite Chinese novel (maybe my favorite novel from anywhere) originates from this tumultuous myth. The Story of the Stone was written by Cao Xueqin in the eighteenth century as the Qing dynasty first began to relentlessly unwind. It is the story of a great princely house slowly losing its vigor and declining from within. In a bigger sense it is the story of mortal kind and the ineluctable flux of our little lives. There are thirty major characters and over four hundred minor characters in a drama that spans the epic breadth of Chinese history and culture (and takes up thousands of pages). The portrayal of all levels of Chinese society is magnificent…but just beyond the petty intrigues, squabbles, affairs, and misunderstandings that make up the complex plot of The Story of the Stone are hints at an enigmatic divine order underpinning the cosmos. From time to time, a strange beggar covered with sores and limping on an iron crutch shows up with magic medicines. The female lead is hauntingly familiar with an otherworldy beauty to her mien. And the protagonist of the story, Jia Baoyu, is a fey aristocratic adolescent who was born with a magic piece of jade in his mouth. Although it doesn’t come up often in the novel and it is not obvious to the characters, the hero is the stone. He was one of the gemstones given magical life by Nüwa in order to repair the breach in heaven–but he was not used because of a flaw. Frustrated by life at the edge of heaven, he incarnates as a mortal and the book is the story of his human life…indeed of all human life. I won’t say more about The Story of the Stone other than to apologize for not explaining how impossibly brilliant and ineffable the work is. I must also offer an attendant caveat: this is the consummate literary masterpiece of China and, as such, it is overwhelmingly and heartbreakingly sad.
The Penguin version as elegantly translated by David Hawke
