The Lives of the Stars Are Our Lives

8/8/2019 The Lives of the Stars Are Our Lives

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The Lives of the Stars are Our Lives


by Michael Erlewine

Over the centuries, astrologers havetaken note of a handful of fixed starsand a few other celestial objects. In the20th Century, the advent of more andmore powerful telescopes, made it clearthat there are literally billions of objects

out there, each with some kind ofsignificance. There is no way each ofthese objects could be individuallystudied and their influences (or lackthereof) noted.

In fact, many astrologers find the recentadvances in astronomy andastrophysics over the last 40 yearscomplex and difficult to understand. Andyet it could be important for us to graspthe significance of what is being

discovered out there in deep space. Inthis article, we will attempt to provideastrologers with a key to unlocking themysteries of modern astrophysicalinquiry.

I have been repeatedly asked to explainwhat all this deep-space astrology

(stars, black holes, etc.) means. Myanswer is that it is far easier for you tolearn to read and interpret the results ofscientific astronomers than to look forsomeone to explain the endless series

of newly discovered stellar objects toyou, one by one. It should be enough tobe told that everything out there has todo with the life and death of stars, justas down here we are concerned withour own life and death. That note plusthe age-old maxim "As Above, SoBelow," should do it for you. Learn toread science in terms of your own selfand life. It is not hard and it opens upthe world of scientific writing to you,

from that moment forward. You don'tneed an interpreter. You are theinterpreter.

Any investigation of our universebecomes the story of the stars. Asidefrom dust and gas, space contains stars.Even such exotic objects as pulsars,neutron stars and black holes are butthe end stages in the lives of stars.Almost all of the information assembledthrough various branches of

astronomical observation, be it visual,infrared, ultraviolet, x-ray or Gamma-raymay best be examined in terms of thefollowing question: What stage in the lifehistory of a star do they describe?Therefore, a grasp of the basic stages inthe life history of a star provides theessential framework for astrophysicalinquiry.

It is difficult, perhaps impossible, toconsider the various stages of a star'slife and the sequence of these stages,without being struck by the resemblanceto our own life story. Here is our own lifestory acted out on a grand scale beforeour very eyes.

It is now considered fact that thebirthplace of stars is the womb of vast


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nebular clouds of dust and gasdistributed throughout space. In theserelatively cool and dark clouds, proto-stars (new stars) form through a processof gravitational condensation or

contraction. It is imagined that perhapssome outside force, maybe in the formof gravitational energy from a passingstellar object, causes a dust cloud tobegin the contraction process. Thesehuge clouds are known to be of variousdensities. They contain spots where thegas and dust is somewhat denser thanin the surrounding regions of the cloud.These denser areas attract still morematerial toward themselves until a huge

amount of matter, many times the sizeof our solar system, is formed. Thecontraction process becomes critical --nothing within the protostar can standup to the crushing weight of gas anddust that continues to accumulate. Acrisis is reached.

Through a friction-like process, the ever-increasing pressure and density insidethe proto-star causes the temperature torise in the star's center or core until a

thermonuclear reaction is initiated at 10million degrees. Such a reactionreleases enormous radiant energy thatpulses out from within and holds back orstops the contraction process. A star isborn!

From this point forward, the life story ofa particular star is dependent upon themass of the original protostar. Thecollapse of the protostar takes arelatively short portion of the star's life,and once the thermonuclear ignitiontakes place, the star's surfacetemperature rises rapidly, and thenlevels off, and the star settles down toabout ten billion years of being a star inthe common sense of the word. It isimportant, at this point, to examine the

struggle going on within the stellarinterior.

Once born, the star must live and die,much like us. The death of stars isinevitable and the life process is often

conceived as one of thwarting or puttingoff of this inescapable death and thusprolonging life. The most fascinatingaspect of a star's life is the intensestruggle between the forces of gravityand contraction on one hand (so calledouter forces) and the internal forces ofradiation pressure on the other. As longas there is radiation coming from within,the forces of gravitational contractionare resisted or balanced, and stellar life

as we observe it continues. The starshines. In fact, the entire life of the starcan be conceived of in terms of acontinuous conversion process. FigureB shows how these two archetypicalforces form the stellar shell, which iswell below the actual surface of the staritself. The thickness of this shell as wellas its position near to or far from theinner stellar core suffers continualchange and adjustment throughout the

life of the star.The incredible weight of the many layersof gas first initiates and than continuesto contain and maintain the radiantprocess -- a cosmic crucible. Thispressure and the inevitable collapse thatmust occur is forestalled and put off byan incredible series of adjustments andchanges going on within the core of thestar. First of all, hydrogen burning(initiated at the birth of the star)continues for around ten billion years.This constitutes a healthy chunk of thestellar lifetime. Our sun is about halfwaythrough this stage at present, and wecan expect the sun to continue as it istoday for another five billion years or so.The exhaustion of hydrogen signals theonset of drastic changes in the life of the


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star and brings on the next stage of thatlife.

The radiant pressure of burningHydrogen within was all that held backthe initial contraction of the protostar,

and when this is gone, the star's corecontinues to contract. It then has nomaterial strong enough to stop thiscontraction and the core again shrinks,causing increased pressure, density andtemperature. When the temperature atthe center of the star reaches l00 milliondegrees, the nuclei of helium atoms(products of the Hydrogen burningstage) are violently fused together toform carbon. The fusion of this helium

burning at the stellar core againproduces a furious outpouring of radiantenergy, and this energy release insidethe star's core (as the star contracts)pushes the surface far out into space inall directions. The sudden expansioncreates an enormous star with adiameter of a quarter of a billion milesand a low surface temperature between3,000-4,000 degrees -- a red giant.

In about five billion years, the core ofour sun will collapse while its surfaceexpands. This expansion will swallowthe earth and our planet will vanish in apuff of smoke. Figure C. shows a redgiant. The red stars like Antares andArcturus are examples of this stage andthis kind of star.

This helium burning stage (red giant)continues for several hundred millionyears before exhaustion. With the

helium gone, the contraction processagain resumes and still greatertemperatures, densities, and pressuresresult. At this point, the size or mass ofthe star begins to dictate the final courseof the life. For very massive stars, theignition of such thermonuclear reactionsas carbon, oxygen, and silicon fusion

may take place, creating all of theheavier elements. These later stages instellar evolution produce stars that arevery unstable. These stars can vary orpulsate in size and luminosity. In certain

cases this can lead to a total stellardetonation, a supernova.

A star may end its life in one of severalways. When all the possible nuclearfuels have been exhausted, allconversions or adjustments made, theinexorable force of gravity (the grave)asserts itself and the remaining stellarmaterial becomes a white dwarf. As thestar continues to contract, having nointernal radiation pressure left, the

pressures and densities reach suchstrength that the very atoms are torn topieces and the result is a sea ofelectrons in which are scattered atomicnuclei. This mass of electrons issqueezed until there is no possible roomfor contraction. The resulting whitedwarf begins the long process of coolingoff.

Becoming a white dwarf is only possiblefor stars with a mass of less than 1.25solar masses. If the dying star has amass that is greater than this limit, theelectron pressure cannot withstand thegravitational pressure and thecontraction continues. This critical limitof l.25 solar masses is termed theChandrasekhar Limit after the famousIndian scientist by that name.

To avoid this further contraction, it isbelieved that many stars unload or blow

off enough excess mass to get withinthe Chandrasekhar Limit. The nova isan example of an attempt of this kind. Inrecent years it has become clear thatnot all stars are successful in discardingtheir excess mass, and for them a verydifferent state results than what we findin the white dwarf. We have seen that


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the electron pressure is not strongenough to halt the contraction processand the star gets smaller and tighter.The pressure and density increase untilthe electrons are squeezed into the

nuclei of the atoms out of which the staris made. At this point the negativelycharged electrons combine with thepositively charged protons and theresulting neutron force is strong enoughto again halt the contraction processand we have another type of stellarcorpse: a neutron star.

We have one further kind of `dead' star.There is a limit to the size of star thatcan become a neutron star. Beyond a

limit in mass of 2.25 solar masses, thedegenerate neutron pressure cannotwithstand the forces of gravity. If thedying star is not able to eject enoughmatter through a nova or supernovaexplosion and the remaining stellar corecontains more than three solar masses,it cannot become a white dwarf or aneutron star. In this case there are noforces strong enough to hold up the starand the stellar core continues to shrink

infinitely! The gravitational fieldsurrounding the star gets so strong thatspace-time begins to warp and when thestar has collapsed to only a few miles indiameter, space-time folds in upon itselfand the star vanishes from the physicaluniverse. What remains is termed ablack hole.

It should be clear at this point that all ofthe many kinds of stars and objects inspace could be ordered in terms of theevolutionary stage they represent in thelife of the star. Just as each of us facewhat has been called the "personalequation" in our lives, so each star's lifeis made possible by the opposinginternal and external forces. In the end,it appears, the forces of gravitydominate the internal process of

adjustment and conversion that is takingplace, just as in our own lives the agingof our personal bodies is a fact. And yetfresh stars are forming and being born,even now. The process of life or self is

somehow larger than the physical endsto the personal life of a star or a manand our larger life is a whole orcontinuum and continuing process thatwe are just beginning to appreciate.Some of the ideas that are emerging inregard to the black hole phenomenonare most profound and perhaps are theclosest indicators we have of how theeternal process of our life, in fact,functions.

In conclusion, a very useful way toapproach the fixed stars, as we pointedout above, is to determine what stage instellar evolution a particular star may be.Is the star a young, energetic newlyformed star in the blue part of thespectrum or an old dying (red colored)star? Are we talking about a white dwarfor a super dense neutron star? I havefound this approach to the endlessmillions of stars to much more helpful

than ascribing particular characteristicsto existing stars and objects, most ofwhich are too new to have any history inastrology anyway. As mentioned earlier,learn to read the writings of sciencefrom a personal or astrologicalperspective. It is very instructive.

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The Lives of the Stars Are Our Lives