solar data

Solar Physics and Sun-Solar Physics and Sun-Earth Connection Earth Connection

((introductionintroduction))Samuel DanagoulianSamuel DanagoulianNC A&T State UniversityNC A&T State University

Teacher’s Workshop, 1-27-05Teacher’s Workshop, 1-27-05

Solar DataSolar Data

Solar radius = 695,990 km = 432,470 mi = 109 Earth Solar radius = 695,990 km = 432,470 mi = 109 Earth radiiradii

Solar mass = 1.989 1030 kg = 4.376 1030 lb = Solar mass = 1.989 1030 kg = 4.376 1030 lb = 333,000 Earth masses333,000 Earth masses

Solar luminosity (energy output of the Sun) = 3.846 Solar luminosity (energy output of the Sun) = 3.846 10103333 erg/s erg/s

Surface temperature = 5770 K = 10,400 ºFSurface temperature = 5770 K = 10,400 ºF Surface density = 2.07 10Surface density = 2.07 10-7-7 g/cm g/cm33 = 1.6 10 = 1.6 10-4-4 Air density Air density Surface composition = 70% H, 28% He, 2% (C, N, Surface composition = 70% H, 28% He, 2% (C, N,

O, ...) by massO, ...) by mass

Solar Data (cont.)Solar Data (cont.)

Central temperature = 15,600,000 K = 28,000,000 Central temperature = 15,600,000 K = 28,000,000 ºFºF

Central density = 150 g/cm3 = 8 × Gold densityCentral density = 150 g/cm3 = 8 × Gold density Central composition = 35% H, 63% He, 2% (C, N, Central composition = 35% H, 63% He, 2% (C, N,

O, ...) by massO, ...) by mass Solar age = 4.57 10Solar age = 4.57 1099 yr yr Solar Rotation: period 27 days Solar Rotation: period 27 days Solar Cycles: ~11 yearsSolar Cycles: ~11 years, ~, ~22 years22 years

Solar StructureSolar Structure

15x106 K

6000 K

X-rays and UV, 1x106 K

Magnetic filed causes formation of Sunspots, flares, mass ejections

Introduction to Nuclear PhysicsIntroduction to Nuclear Physics Molecular force is Electromagnetic:Molecular force is Electromagnetic: (long range) (long range)

Atoms are held together by a dipole force which has an origin Atoms are held together by a dipole force which has an origin of Electro-Magnetismof Electro-Magnetism

AtomAtom == nucleus + (orbiting nucleus + (orbiting electronselectrons))

The force between nucleus and electrons has EM originThe force between nucleus and electrons has EM origin NucleusNucleus = few nucleons together = few nucleons together (protons(protons and and neutrons)neutrons)

The force between nucleons is STRONG (nuclear) which is The force between nucleons is STRONG (nuclear) which is present and attractive only at short distances. Between two present and attractive only at short distances. Between two protons, in addition, there is Electromagnetic force, which is protons, in addition, there is Electromagnetic force, which is repulsive. In order to create a stable nucleus, one needs to repulsive. In order to create a stable nucleus, one needs to dilute the charged nuclear matter dilute the charged nuclear matter (protons)(protons) with neutral with neutral particles particles (neutrons)(neutrons). STRONG force is 137 times stronger than . STRONG force is 137 times stronger than EM force.EM force.

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Particle ZooParticle ZooPARTICLESPARTICLES SIZESIZE MASSMASS(AMU)(AMU)

MoleculesMolecules 1010-8-8 m m AtomsAtoms 1010-11-11 m m 1-2601-260

• NucleusNucleus <10<10-14-14 m m 1-260 1-260 Heavy Particles (Heavy Particles (BARIONSBARIONS))

• Nucleons: (p, n), hyperons Nucleons: (p, n), hyperons 1010-15-15 m m 1 – 1.51 – 1.5 Light Particles (Light Particles (MESONSMESONS) ) <10<10-15-15 mm

• regular, strange, charm, top, bottomregular, strange, charm, top, bottom 0.14 – 100.14 – 10

-- -- QUARKSQUARKS ( (uu, , dd, , ss, , cc,, t t, , bb)) <10<10-18-18 mm 0.001 - 50.001 - 5 GAUGEGAUGE Particles Particles ((, W, W+-+-, Z, Z00, g), g) 0 - 1000 - 100 LEPTONSLEPTONS <10<10-18-18 mm

• Electron, mu, tau (Electron, mu, tau (ee,,)) 0.0005 - 20.0005 - 2

• Neutrino - electron, mu, tau ( Neutrino - electron, mu, tau ( e e , , , , ))0 (?)0 (?)

GAUGE GAUGE particles provide interaction between particles provide interaction between particles and quarksparticles and quarks

Nuclear Binding Energyhttp://hyperphysics.phy-astr.gsu.edu/hbase/nucene/nucbin.html

Solar EnergySolar Energy

Thermonuclear reactions, pp-chain (98% of energy)Thermonuclear reactions, pp-chain (98% of energy)

p+p p+p d+e d+e++++ee (neutrino energy is 0.42 (neutrino energy is 0.42 MeV)MeV)

p+ep+e- - ++ p p d+ d+ee (1.44 MeV)(1.44 MeV)

p+d p+d 33He+He+33He+He+33HeHe44He+2p He+2p 33He+pHe+p44He+eHe+e++++ee (18.8 MeV)(18.8 MeV)33He+He+44HeHe77Be+Be+

77Be+eBe+e-- 77Li+Li+(0.38, 0.86 MeV)(0.38, 0.86 MeV)77Li+ p Li+ p 88Be+Be+88BeBe2244HeHe

Solar StructureSolar Structure

15x106 K

6000 K

X-rays and UV, 1x106 K

Magnetic filed causes formation of Sunspots, flares, mass ejections

Modeling of Solar MechanismModeling of Solar Mechanism

Mechanical and thermal equilibriumMechanical and thermal equilibrium Pressure gradient balances gravitational forcePressure gradient balances gravitational force Solar energy radiation is balanced bySolar energy radiation is balanced by the thermonuclear the thermonuclear

energy of the coreenergy of the core Energy transportation from the core to the surface: Energy transportation from the core to the surface:

to the 1/3 of the radius from the surface, where the opacity is to the 1/3 of the radius from the surface, where the opacity is high (Radiative envelope); high (Radiative envelope);

Convective envelopeConvective envelope Radiation to the outer space through Photosphere and Radiation to the outer space through Photosphere and

ChromosphereChromosphere Numerical Integration of the process: the constraints:Numerical Integration of the process: the constraints:

Observed mass, radius, luminosity and ratio of chemical Observed mass, radius, luminosity and ratio of chemical abundances by mass. abundances by mass.

Solar Neutrino puzzle Chlorine experiment (Davis, 1964-1999) 615 tons Liquid

perchloroethylene (Homestake gold mine in South Dakota )37Cl+ 37Ar+e- (threshold=0.814 MeV)

Prediction from Solar Model Calculations: (7.6+-1.2) SNU

Experimental result: (2.56+-0.23) SNU Japanese Experiment (Kamioka mine, 1996) 680 tons of water.

Super-K: +e- +e- (threshold=5.5 MeV, e- cherenkov light in the water). Experimental result: low rate, flavour change

GALLEX, SAGE, GNO (1999, Gallium experiments) Experimental result: low rate

SNO (Sudbury Neutrino Observatory, heavy water experiment) Experimental result: neutrino flavour

change

SNO results confirmed Super-K results on e count rate.

There are three types of neutrinos: e and Neutrino oscillates from one flavour to another during it’s long journey to the Earth.

KamLAND experiment (2003, detection of neutrinos from the reactor): confirmed the results of SNO and calculated the parameter responsible for the mixing of flavors.

Solar Flares

http://science.nasa.gov/ssl/pad/solar/sunturn.htm

Coronal LoopsCoronal Loops

Coronal LoopsCoronal Loops

Coronal loops are found around sunspots and in active regions. Coronal loops are found around sunspots and in active regions.

These structures are associated with the closed magnetic field lines These structures are associated with the closed magnetic field lines

that connect magnetic regions on the solar surface. Many coronal that connect magnetic regions on the solar surface. Many coronal

loops last for days or weeks but most change quite rapidlyloops last for days or weeks but most change quite rapidly

Some loops, however, are associated with Some loops, however, are associated with solar flaressolar flares and are and are

visible for much shorter periods. These loops contain denser visible for much shorter periods. These loops contain denser

material than their surroundings. The material than their surroundings. The three-dimensional structurethree-dimensional structure

and the dynamics of these loops is an area of active research.and the dynamics of these loops is an area of active research.

Solar FlaresSolar FlaresSOHOSOHO

Solar Flares (cont)Solar Flares (cont)

Solar FlareSolar Flare

is defined as a sudden and intense is defined as a sudden and intense variation in solar brightness. The solar variation in solar brightness. The solar magnetic energy is suddenly released. magnetic energy is suddenly released. RadiationRadiation occurs in the entire occurs in the entire electromagnetic spectrumelectromagnetic spectrum, (radio waves to , (radio waves to X- and X- and -rays-rays). The first solar flare ). The first solar flare recorded in astronomical literature was on recorded in astronomical literature was on September 1, 1859. September 1, 1859.

Polar Plumes

SOHO

Polar PlumesPolar Plumes

Polar plumes are long thin streamers that Polar plumes are long thin streamers that project outward from the Sun's north and project outward from the Sun's north and south poles. These structures are south poles. These structures are associated with the "open" magnetic field associated with the "open" magnetic field lines at the Sun's poles. The plumes are lines at the Sun's poles. The plumes are formed by the action of the solar wind in formed by the action of the solar wind in much the same way as the peaks on the much the same way as the peaks on the helmet streamers.helmet streamers.

Solar Flares, Solar WindSolar Flares, Solar Wind

SOHOSOHO

Solar WindSolar Wind

Coronal HolesCoronal Holes

SOHOSOHO

Coronal HolesCoronal Holes

Coronal holes are regions where the corona is Coronal holes are regions where the corona is

dark. These features were discovered with X-ray dark. These features were discovered with X-ray

telescopes above the earth's atmosphere telescopes above the earth's atmosphere

observing the solar disc. Coronal holes are observing the solar disc. Coronal holes are

associated with "open" magnetic field lines and are associated with "open" magnetic field lines and are

often found at the Sun's poles. The high-speed often found at the Sun's poles. The high-speed

solar windsolar wind is known to originate in coronal holes. is known to originate in coronal holes.

Solar ActivitySolar Activity

Solar Activity and Geomagnetic stormSolar Activity and Geomagnetic storm

Aurora Aurora

AuroraAurora

Is caused by high energy particles (mainly Is caused by high energy particles (mainly

electrons) interacting with the Earth's atmosphere electrons) interacting with the Earth's atmosphere

over the North Pole. Due to the interaction of over the North Pole. Due to the interaction of

electrons with atoms of the air, an excitation of latter electrons with atoms of the air, an excitation of latter

takes place following by the emission of the light takes place following by the emission of the light

quanta which removes the excitation of the atom. quanta which removes the excitation of the atom.

AuroraAurora (cont.)(cont.)

This process is called scintillation of the air due to This process is called scintillation of the air due to

the passage of electrons through it. The spectrum the passage of electrons through it. The spectrum

of the light emission is in the UV-visible range, of the light emission is in the UV-visible range,

depending of the nature of the gas and maximum depending of the nature of the gas and maximum

energy of the particles. The intensity of the energy of the particles. The intensity of the

emission depends on the intensity of electrons. emission depends on the intensity of electrons.

Aurora from the spaceAurora from the space

Aurora (cont.)Aurora (cont.)

The effect of interaction of many electrons with The effect of interaction of many electrons with

atoms results in the Aurora that can be clearly atoms results in the Aurora that can be clearly

seen during some nights in the higher latitude seen during some nights in the higher latitude

close to the North Pole. Since electrons mainly close to the North Pole. Since electrons mainly

originate from the sun, the intensity depends originate from the sun, the intensity depends

greatly on the status of the solar activity. greatly on the status of the solar activity.


However, the energy of electrons is not enough However, the energy of electrons is not enough

high to excite the air atoms unless they are high to excite the air atoms unless they are

accelerated in the way to the earth's accelerated in the way to the earth's

atmosphere. The acceleration occurs during the atmosphere. The acceleration occurs during the

disturbance of the geomagnetic field of the disturbance of the geomagnetic field of the

Earth, during geomagnetic storm. Earth, during geomagnetic storm.


The idea is that the geomagnetic field is responding to The idea is that the geomagnetic field is responding to

a disturbance from the Sun due to magnetic a disturbance from the Sun due to magnetic

explosions on the Sun's corona and coronal mass explosions on the Sun's corona and coronal mass

ejection towards the Earth. The geomagnetic field of ejection towards the Earth. The geomagnetic field of

the Earth changes due to the flux of magnetic field, the Earth changes due to the flux of magnetic field,

releasing energy and thereby accelerating electrons releasing energy and thereby accelerating electrons

and other particles to high energies. and other particles to high energies.


These particles are bent in the These particles are bent in the

geomagnetic field to spiral geomagnetic field to spiral

along the magnetic field lines. along the magnetic field lines.

Some amount of particles end Some amount of particles end

up in the upper part of the up in the upper part of the

earth's atmosphere causing the earth's atmosphere causing the

auroral mechanism to begin. auroral mechanism to begin. http://www.oulu.fi/~spaceweb/textbook/auroras.htmlhttp://www.oulu.fi/~spaceweb/textbook/auroras.html

http://www.geo.mtu.edu/weather/aurora/images/aurora/http://www.geo.mtu.edu/weather/aurora/images/aurora/

jan.curtisjan.curtis

Happy New Year !

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