Alchemy of The HeavensAlchemy of The Heavens

Lecture Eight, Feb. 3, 2003Lecture Eight, Feb. 3, 2003

View, low in View, low in the East, the East, early in the early in the morning of morning of July 5, 1054 July 5, 1054 shows the shows the Crab Crab SupernovaSupernova

Columbia’s Final FlightColumbia’s Final Flight

8:53 a.m. Shuttle had just8:53 a.m. Shuttle had just completed a roll reversal,completed a roll reversal, a procedure to bleeda procedure to bleed energy before landing.energy before landing. Four left wing temperatureFour left wing temperature sensor readings in thesensor readings in the hydraulic systemhydraulic system suddenly were lost.suddenly were lost. 8:56 a.m. Sensors in8:56 a.m. Sensors in main left wheel well failed,main left wheel well failed, and tire temperaturesand tire temperatures were not available. Shuttlewere not available. Shuttle was performing wellwas performing well otherwise.otherwise.

8:58 a.m. Three left wing temperature 8:58 a.m. Three left wing temperature sensor readings are lost. Because sensor readings are lost. Because sensors are independent and not sensors are independent and not linked to a common avionics box, linked to a common avionics box, Mission ControlMission Controlbecomes concerned.becomes concerned.

8:59 a.m. Eight tire temperature and 8:59 a.m. Eight tire temperature and pressure readings are lost. An on pressure readings are lost. An on board alert message is sent to the board alert message is sent to the crew. In their last transmission, crew crew. In their last transmission, crew members said they had received the members said they had received the alert.alert.

9 a.m. All communication with the 9 a.m. All communication with the shuttle is lost.shuttle is lost.

Alchemy of The HeavensAlchemy of The Heavens

• How did God make the chemical How did God make the chemical elements?elements?

• Chemical element has atomic number Z Chemical element has atomic number Z (number of electrons orbiting nucleus).(number of electrons orbiting nucleus).

• Chemical reactionsChemical reactions do not change the # do not change the # or type of atomic nuclei. Many or type of atomic nuclei. Many alchemists tried and failed to convert alchemists tried and failed to convert Lead (Z=82) into Gold (Z=79).Lead (Z=82) into Gold (Z=79).

Big Bang NucleosynthesisBig Bang Nucleosynthesis

• Nucleosynthesis: origin of the atomic nuclei, (which Nucleosynthesis: origin of the atomic nuclei, (which capture electrons to form chemical elements).capture electrons to form chemical elements).

• Nuclei are made of protons and neutrons. These Nuclei are made of protons and neutrons. These particles have similar mass but only protons have an particles have similar mass but only protons have an electric charge.electric charge.

• Protons and neutrons are each made of three Protons and neutrons are each made of three quarks.quarks.

• By about 3 min. after Big Bang all of the neutrons By about 3 min. after Big Bang all of the neutrons are bound into are bound into 44He nuclei which have two protons He nuclei which have two protons (Helium has Z=2) and 2 neutrons.(Helium has Z=2) and 2 neutrons.

• Remaining protons are free to form Hydrogen (Z=1).Remaining protons are free to form Hydrogen (Z=1).• Thus Universe was about 25% He and 75% H and Thus Universe was about 25% He and 75% H and

little heavier elements (those with Z>2).little heavier elements (those with Z>2).

Early StarsEarly Stars

• First generation stars were First generation stars were made out of only H and He.made out of only H and He.

• Even if they had planets Even if they had planets there was no Si (Z=14) for there was no Si (Z=14) for rocks, no O (Z=8) for Hrocks, no O (Z=8) for H22O O and no C (Z=6) for life. and no C (Z=6) for life. Planets would be gas balls Planets would be gas balls like our gas giants.like our gas giants.

• Need to make these Need to make these elements with elements with nuclear nuclear reactionsreactions in first in first generation stars.generation stars.

There could not be rocky There could not be rocky planets like Jupiter’s Moons planets like Jupiter’s Moons (above) but only gas balls like (above) but only gas balls like Jupiter (below).Jupiter (below).

Nuclear ReactionsNuclear Reactions

• Can make new nuclei.Can make new nuclei.• However, nuclei are normally kept However, nuclei are normally kept

apart by strong electric repulsion.apart by strong electric repulsion.• Need great heat and or density to Need great heat and or density to

overcome this repulsion and allow overcome this repulsion and allow nuclear rxns.nuclear rxns.

• These extreme conditions are reached These extreme conditions are reached in the center of normal stars.in the center of normal stars.

How to get new elements How to get new elements out?out?

• Problem, nuclear rxns, in general, Problem, nuclear rxns, in general, only take place deep within a star. only take place deep within a star. Thus the new elements are locked Thus the new elements are locked deep in the stars core.deep in the stars core.

• How to get the elements out to form How to get the elements out to form rocky planets and life?rocky planets and life?

• Answer: Wait for the star to die.Answer: Wait for the star to die.

Life of a StarLife of a Star

• Birth: collapse of gas cloud forms protostar.Birth: collapse of gas cloud forms protostar.• Main sequenceMain sequence: center of star becomes hot : center of star becomes hot

enough to burn Hydrogen into Helium. Our enough to burn Hydrogen into Helium. Our Sun will be on main sequence for 10 billion Sun will be on main sequence for 10 billion years.years.

• Red GiantRed Giant: Outer part of star expands and : Outer part of star expands and cools. Core contracts and starts to burn He cools. Core contracts and starts to burn He into Carbon and other heavier elements.into Carbon and other heavier elements.

• Star dies: either as a planetary nebula (low Star dies: either as a planetary nebula (low mass star) or as a mass star) or as a supernovasupernova (high mass star). (high mass star).

Planetary NebulaPlanetary Nebula

• Stars with mass less then about 8 Stars with mass less then about 8 times the mass of the Sun die as times the mass of the Sun die as planetary nebula.planetary nebula.

• Intense stellar wind ejects lots of gas Intense stellar wind ejects lots of gas from surface of red giant. Note, Sun from surface of red giant. Note, Sun has solar wind which is stream of has solar wind which is stream of particles from surface.particles from surface.

• Note, planetary nebula name has Note, planetary nebula name has nothing to do with planets.nothing to do with planets.

Planetary Nebula M27Planetary Nebula M27

Image by J. Image by J. NewtonNewton

Jack Newton’s HouseJack Newton’s House

Furniture salesman and amateur astronomerFurniture salesman and amateur astronomer

The Universe From My The Universe From My DrivewayDriveway• On the course web site On the course web site

I have added some I have added some images taken with a images taken with a small 8” telescope and small 8” telescope and a sensitive CCD a sensitive CCD camera.camera.

• http://physics.indiana.ehttp://physics.indiana.edu/~lifedu/~life and click on driveway and click on driveway universe.universe.

• One evening during the One evening during the class, those interested class, those interested can observe with me.can observe with me.

SupernovaSupernova

• Stars with more then 8 solar masses die in Stars with more then 8 solar masses die in gigantic explosions called supernovae. Note, gigantic explosions called supernovae. Note, plural of supernova is supernovae.plural of supernova is supernovae.

• A single star that explodes as a supernova A single star that explodes as a supernova can outshine an entire galaxy (billions of can outshine an entire galaxy (billions of stars).stars).

• Hard to imagine the violence of the explosion.Hard to imagine the violence of the explosion.• Core of star imploded to form neutron star or Core of star imploded to form neutron star or

black hole.black hole.• Outer part of star ejected into space with new Outer part of star ejected into space with new

chemical elements.chemical elements.

Supernova viewed from my Supernova viewed from my drivewaydriveway

SN1998S in Ngc 3877, April 2, 1998 (8” SCT homemade CCD)

A Supernova is very brightA Supernova is very bright

• Note, foreground stars are typically Note, foreground stars are typically 100s of light years away.100s of light years away.

• Galaxy and supernova are ~100 Galaxy and supernova are ~100 millionmillion light years away. light years away.

• That one can see it at all implies the That one can see it at all implies the explosion is very bright. explosion is very bright.

Supernova SimulationSupernova Simulation

• Computer simulation Computer simulation by Adam Burrows of a by Adam Burrows of a supernova in a binary supernova in a binary star system (two stars star system (two stars orbiting each other).orbiting each other).

• You are looking at the You are looking at the 22ndnd star which is many star which is many times larger then the times larger then the Earth. The exploding Earth. The exploding star is just off the top star is just off the top of the screen.of the screen.

• Real Video of Burrows Real Video of Burrows Simulation Simulation

The Crab SupernovaThe Crab Supernova

Simulation of view early in the morning, July 5, Simulation of view early in the morning, July 5, 10541054

MoonMoon

SupernovSupernovaa

Native American Paintings of Native American Paintings of CrabCrab

• Well recorded in China, Korea and Middle East but not in Europe (middle ages).Well recorded in China, Korea and Middle East but not in Europe (middle ages).

Crab Nebula TodayCrab Nebula Today

• Exploding star has Exploding star has thrown material out thrown material out into space at about into space at about 1/300 speed of 1/300 speed of light.light.

• In 1000 years In 1000 years nebula is now about nebula is now about 3 light years across.3 light years across.

• Nebula enriches Nebula enriches interstellar medium interstellar medium with chemical with chemical elements. elements.

Vela: 10000 year old SN Vela: 10000 year old SN RemnantRemnant

Vela Vela PulsarPulsar

Crab pulsarCrab pulsar

• Hubble space Hubble space telescope image (in telescope image (in visible light) of visible light) of neutron star (base neutron star (base of arrow) at heart of of arrow) at heart of Crab nebula.Crab nebula.

• Neutron star spins Neutron star spins 30 times a second 30 times a second and emits pulses of and emits pulses of radio waves radio waves pulsar.pulsar.

Neutron StarNeutron Star

• Collapsed object 1.5 Collapsed object 1.5 times mass of Sun but times mass of Sun but only about 10 miles only about 10 miles across. It is one across. It is one gigantic atomic gigantic atomic nucleus!nucleus!

• Squeeze all of the Squeeze all of the empty space out of an empty space out of an atom. Squeeze atom. Squeeze electrons onto protons electrons onto protons to form neutrons.to form neutrons.

• Gives neutron star. Gives neutron star. Densest form of matter Densest form of matter before black hole.before black hole.

SupernovaeSupernovae

• Gigantic stellar explosions.Gigantic stellar explosions.• Eject new chemical elements into space.Eject new chemical elements into space.• Make neutron stars and black holes.Make neutron stars and black holes.• Accelerate cosmic rays (energetic particles Accelerate cosmic rays (energetic particles

constantly hitting Earth’s atmosphere from constantly hitting Earth’s atmosphere from space).space).

• Shock waves can help gas clouds to Shock waves can help gas clouds to collapse and form new stars.collapse and form new stars.

• Deadly to life (within say ~1-300 light Deadly to life (within say ~1-300 light years???)years???)

22ndnd Generation Stars Generation Stars

• 22ndnd generation stars, made from the collapse of generation stars, made from the collapse of a gas cloud enriched in chemical elements, a gas cloud enriched in chemical elements, can have rocky planets and perhaps life.can have rocky planets and perhaps life.

• Sun formed 4.6 Billion years ago.Sun formed 4.6 Billion years ago.• Needed 1Needed 1stst generation stars to be formed, live, generation stars to be formed, live,

and die all before 4.6 Billion years ago. and die all before 4.6 Billion years ago. • These provided the Carbon, Oxygen, Nitrogen These provided the Carbon, Oxygen, Nitrogen

… of which we are made.… of which we are made.• We are literally “star dust”. All of the atoms in We are literally “star dust”. All of the atoms in

our body were made in other stars. our body were made in other stars.

For next timeFor next time

• Read chap. 4 of Jakosky about the Read chap. 4 of Jakosky about the earliest life and read “Vital Dust", earliest life and read “Vital Dust", pages 1-23 in course packet about pages 1-23 in course packet about origin of life.origin of life.

• Next lecture, Wend Feb 5, 2003, Next lecture, Wend Feb 5, 2003, “Formation of Earth”.“Formation of Earth”.