Transcript eta carinae – nature`s own hadron collider

ETA CARINAE – NATURE’S OWN HADRON COLLIDER
We still do not know one thousandth of one percent of what nature
has revealed to us.
- Albert Einstein -
ARTIST DRAWING
ETA CARINAE IS ONE OF THE MOST MASSIVE STARS KNOWN.
IT IS AROUND 100 SOLAR MASSES. THE UPPER LIMIT OF STAR SIZE
IS THOUGHT TO BE AROUND 150 SOLAR MASSES.
BECAUSE OF ITS SIZE, AND THE HIGH ENERGIES PRODUCED
BECAUSE OF GRAVITY, IT IS UNSTABLE.
IN AN EVENT THAT WAS OBSERVED IN 1843, IT SHED MASS
EQUIVALENT TO 10 SOLAR MASSES AND WAS THE SECOND
BRIGHTEST STAR NEXT TO SIRUS IN THE NIGHT SKY.
IT IS CURRENTLY SHEDDING AROUND 10-3 SOLAR MASSES EACH
YEAR. IN CONTRAST, OUR SUN SHEDS ONLY AROUND 10-14 SOLAR
MASSES PER YEAR.
AS A RESULT, ETA CARINAE HAS FORMED ITS OWN SURROUNDING
NEBULAE.
IT IS 5 MILLION TIMES AS BRIGHT AS OUR SUN.
THERE ARE MANY LARGE
CLOUDS OF GAS AND
DUST IN SPACE CALLED
NEBULAE.
NEBULAE ARE NURSERYS
FOR STAR FORMATION.
EVENTS IN SPACE CAN
CAUSE AN AREA OF GAS
AND DUST TO COMPRESS,
SUCH AS A GRAVITY
WAVE.
IF ONE AREA DEVELOPS
MORE MASS THAN
SURROUNDING AREAS,
THE INCREASE IN
GRAVITY CAN CAUSE
ADDITIONAL MASS TO
COLLECT, AND STAR
H-R DIAGRAM FOR CLASSIFICATION OF STARS
MAIN SEQUENCE STARS ARE STARS IN THEIR NORMAL LIFE
TIME.
INTERACTIVE GUIDE TO STELLAR EVOLUTION – CHANDRA
SITE
THE TYPE OF FUSION THAT CAN OCCUR IN A STAR
DEPENDS ON ITS CORE TEMPERATURE.
THE CORE TEMPERATURE, IN TURN, DEPENDS ON ITS
MASS.
SMALLER STARS ARE ONLY ABLE TO FUSE HYDROGEN TO
HELIUM.
AS THE MASS INCREASES, FUSION OF HEAVIER ELEMENTS
IS ABLE TO OCCUR.
THE HEAVIEST ELEMENT THAT CAN BE FORMED IN NORMAL
FUSION REACTIONS IN A STAR IS IRON.
ELEMENTS HEAVIER THAN IRON ARE FORMED WHEN
LARGE STARS GO SUPERNOVAE. THIS IS BECAUSE OF
THE BINDING ENERGY.
MASSES OF MOST STARS LIE WITHIN 0.3 TO 3 SOLAR
MASSES.
THE LARGEST STAR KNOWN IS R136A1 AT 265 SOLAR
MASSES.
THE THEORETICAL LOWER LIMIT IS 0.075 SOLAR
MASSES.
ANYTHING SMALLER THAN THIS WOULD NOT HAVE
ENOUGH GRAVITY TO GENERATE TEMPERATURES
NECESSARY FOR HYDROGEN FUSION.
THE HIGHER THE MASS, THE MORE GRAVITY, AND THE
HIGHER THE INTERIOR TEMPERATURE.
TEMPERATURE WILL AFFECT HOW LONG A STAR CAN
LIVE AND WHAT FUSION REACTIONS CAN OCCUR, E.G.,
WHAT ELEMENTS CAN BE FORMED.
A STAR WITH THE MASS OF THE SUN WILL LAST ABOUT 10
BILLION YEARS.
AT TWICE THE MASS OF THE SUN ABOUT 3 BILLION YEARS.
AT 10 SOLAR MASSES, LIFE WOULD BE MEASURED IN 10’S
OF MILLIONS OF YEARS.
STARS HAVING FRACTIONS OF THE SUN’S MASS COULD
LAST A TRILLION YEARS – LONGER THAN THE CURRENT
LIFE OF THE UNIVERSE.
BROWN DWARF STARS ARE
INTERMEDIATE BETWEEN
PLANETS AND STARS.
THEY EMIT A SMALL
AMOUNT OF LIGHT –
MOSTLY IN THE INFRARED
DUE TO A LIMITED AMOUNT
OF DEUTERIUM FUSION
AND THERMAL ENERGY
FROM SLOW
GRAVITATIONAL
CONTRACTION.
THE SIZE LIMIT RANGE IS
FROM ABOUT 0.075 SOLAR
MASSES TO 0.013 SOLAR
MASS (ABOUT 13 TIMES
THE SIZE OF JUPITER).
THE FIRST ONE
DISCOVERED WAS IN 1995.
INTERACTIVE GUIDE TO STELLAR EVOLUTION – CHANDRA
SITE
FOR A STAR THE SIZE OF THE SUN, WHEN ABOUT 10
PERCENT OF THE STAR’S MASS OF HYDROGEN HAS BEEN
CONSUMED, ITS STRUCTURE CHANGES.
THE INERT HELIUM ACCUMULATES IN THE CORE, AND
HYDROGEN FUSION MOVES TO LAYERS OUTSIDE OF THE
CORE.
THIS HEATS UP THE OUTER LAYERS AND CAUSES THEM TO
SWELL OUTWARD.
THE STAR BECOMES A RED GIANT. WHEN THIS HAPPENS
TO OUR SUN, THE OUTER LAYER WILL BE ABOUT WHERE
EARTH’S ORBIT IS NOW.
FOR STARS FROM ABOUT HALF TO 3 TIMES THE SIZE OF
THE SUN, AS MORE HELIUM IS PRODUCED, THE CORE
THE CORE TEMPERATURE RISES
TO AROUND 120,000,000o K, AND
HELIUM FUSION BEGINS,
MAKING ELEMENTS IN THE CNO
CYCLE.
THIS OCCURS MUCH FASTER
THAN THE HYDROGEN BURNING
PHASE – ABOUT 1/100TH OF THE
TIME.
THE END OF THIS PROCESS
WILL BE A SWOLLEN OUTER
SHELL WITH DIMENSIONS
ABOUT THE SIZE OF THE SOLAR
SYSTEM AND A CORE OF
CARBON ASH – WHITE DWARF.
THIS IS KNOWN AS A
PLANETARY NEBULA.
IN MORE MASSIVE STARS, THE FUSION CYCLES CAN
CONTINUE TO HEAVIER ELEMENTS AS THE CORE
TEMPERATURES REACH EVEN HIGHER VALUES.
BEYOND IRON, NO ENERGY IS RELEASED IN THE FUSION
REACTION, SO THERE IS NO THERMAL ENERGY TO BALANCE
THE GRAVITATIONAL ENERGY.
AT THIS POINT, THE STAR WILL COLLAPSE AND EXPERIENCE
A SUPERNOVA EXPLOSION.
ELEMENTS BEYOND IRON CAN BE PRODUCED IN THE
SUPERNOVA EXPLOSION.
MUCH GAS AND DUST WILL BE DISPERSED TO FORM A
NEBULA.
A CENTRAL CORE WILL REMAIN AS EITHER A NEUTRON
STAR OR A BLACK HOLE DEPENDING ON THE MASS OF THE
STAR.
CRAB NEBULA
CASSIOPEIA A
NASA FALSE COLOR IMAGE – IR IN RED, VISIBLE IN YELLOW, AND
X-RAY IN GREEN AND BLUE. STAR WENT SUPERNOVA ABOUT 325
YEARS AGO. LOCATED ABOUT 10,000 LIGHT YEARS AWAY.
A TYPICAL NEUTRON STAR WOULD HAVE A MASS OF
ABOUT 1.44 TO 2 TIMES THE MASS OF OUR SUN, BUT
WITH A DIAMETER OF ABOUT 12 KM.
OUR SUN HAS A DIAMETER OF 60,000 TIMES THAT.
MUCH BELOW 1.44 SOLAR MASSES AND A WHITE
DWARF WOULD BE CREATED.
ABOVE 10 SOLAR MASSES, AND A BLACK HOLE WOULD
EXIST.
WHITE DWARF STARS RADIATE BECAUSE OF STORED
THERMAL ENERGY. NO FUSION CAN TAKE PLACE.
OVER A VERY LONG PERIOD OF TIME, A WHITE DWARF
WILL LOSE THERMAL ENERGY THROUGH RADIATION
AND BECOME A BLACK DWARF.
THIS RADIATIVE COOLING WILL TAKE A VERY LONG TIME,
LONGER THAN THE AGE OF THE UNIVERSE, SO SCIENTISTS
THINK NO BLACK DWARF STARS EXIST.