Download Flare Luminosity and the Relation to the Solar Wind and the Current

Flare Luminosity and the
Relation to the Solar Wind
and the Current Solar
Minimum Conditions
Roderick Gray
Research Advisor:
Dr. Kelly Korreck
Abstract
The Sun is an active and energetic star. From time to time,
based on favorable magnetic structures, the Sun gives off bursts
of energy in the form of particles and light. The light is
commonly referred to as a solar flare, which is of great interest
both scientifically as well as due to its relation to space weather.
This project examined the luminosity in flares between Hinode's
XRT, GOES and STEREO data to gain an understanding as to
the energy budget of the flare as well as to the flare class that
has already been used as a standard in space weather
prediction. This is an important step to understanding the
energy of the flare as well as the future of space weather
prediction. It will be applicable to the soon to be launched SDOAIA instrument which will observe the whole Sun full time.
Sun’s Magnetic Field Lines
Solar Flares Facts
Solar flare is an explosive release of
energy that appear as a sudden, short
lived brightening of an area in the
chromosphere
A more powerful flare can produce a
coronal mass ejection but coronal mass
ejection can also happen without the
presence of a flare
High Energy Flares can cause
disturbances at Earth such as auroral
displays, ground level particle events,
electrical transmission power outages,
and upper atmospheric altercations aswell
Soft X-Rays Classification
B Class
C Class
M Class
X Class
10-4(erg cm-2 s-1 )
10-3 (erg cm-2 s-1 )
10-2 (erg cm-2 s-1 )
10-1 (erg cm-2 s-1 )
10-7 (W m-2)
10-6(W m-2)
10-5 (W m-2)
10-4 (W m-2)
Integrated total output of soft x-rays
detected from the sun in the
wavelength passband 1-8 A
Space Weather Effects of Solar
Flare Protons
The Solar Wind
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The solar wind is a stream of particles that
blows from the corona expanding into the
interplanetary space, carrying a ceaseless
flow of electrons, ions, and magnetic fields,
after hitting the weakly ionized interstellar
gaseous medium around 160 AU it is
believed to begin to terminate
At Earth’s orbit about 1 AU the solar wind
velocity usually ranges between 300-1400
km/s, the most probable value of solar wind
is about 500 km/s which correlates to about
a 4-day particle flight from the Sun to the
Earth
Active regions have been identified as a
potential source for the solar wind, it also
emit X-rays, which are produced during
magnetic reconnection events in the solar
corona
There is a given linear relationship between XRay luminosity and the magnetic flux from the
sun, which is describe by the equation:
Lx∝Φ1.13
Hinode X-RAY TELESCOPE
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The Hinode X-Ray Telescope (XRT) is a highresolution grazing-incidence telescope, which
is a successor to the highly successful Yohkoh
Soft X-Ray Telescope (SXT).[1]
A primary purpose of the Hinode XRT is to
observe the generation, transport, and
emergence of solar magnetic fields, as well
as the ultimate dissipation of magnetic
energy in forms such as flares and picoflares, coronal heating, and coronal mass
ejections [1]
Hinode consists of a set of three
instruments: Solar Optical Telescope(SOT),
Extreme ultraviolet Imaging Spectrometer
(EIS), and X-RAY Telescope (XRT)
instruments, of which XRT was used to
calculate the Luminosity for the the active
regions in the experiment
SOHO’s MDI
 The magnetic flux in the active
region was determined by using
magnetograms from SOHO’s
MDI instrument
 The magnetic flux was
calculated by the magentogram
closest to the time of the flare as
reported by GOES
 The magnetic flux recorded in
Maxwells was obtained by
summing up a 512”X512” region
of the magnetogram
corresponding to the the field of
view in XRT, in order to relate
this quantity to the luminosity
and solar wind power[2]
Ace Satellite
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The Advanced Composition Explorer
(ACE) spacecraft carries six highresolution sensors and three
monitoring instruments that samples
low energy particles of solar origin and
high energy galactic particles
ACE has a prime view of the solar
wind, interplanetary magnetic field
and higher energy particles
accelerated by the Sun, as well as
particles accelerated in the
heliosphere
The ACE SWPAM (Solar Wind Electron,
Proton, and Alpha Monitor)
instrument was used to measure solar
wind speed and density []
Connection between Flux and
Luminosity

We use the formula provided by work from
Schawdron, McComas & DeForest to find a
connection between this unsigned magnetic
flux and the Stereo EUV Data & X-Ray
Luminosity

It describes the maximum power available
for the solar wind since the available power
can be reduced by chromospheric losses

Assuming that the injected electromagnetic
energy-per-particle which powers the solar
wind is constant, also the equation is
observed by the constant magnetic
reorganization of the low corona,
suggesting that the upwelling energy flux at
the solar wind source is proportional to the
magnetic flux
Stereo EUV Data
 STEREO is a 2 year mission of nearly
identical spaced based observatories
which can study the nature of the sun,
more specifically coronal mass
ejections at two different wavelengths
 The corresponding flares are then
done found in the Stereo 171 A &
195A, within 30 minutes before and
after for a 512X512 image and also
2048X2048
 The Total Data Number is then
averaged, and converted to
Luminosity by using the formula:
DN AVG X (E)X 2*p*r2/ EFA
Magnetic Flux vs Luminosity
=XRT
=171
Luminosity (erg s-1)
=195
Magnetic Flux (Mx)
Luminosity and Power of Solar
Wind vs Magnetic Flux
=XRT
Luminosity (erg s-1)
=171
=195
Referencs:

"Hinode is a Japanese mission developed and launched by ISAS/JAXA, with NAOJ as
domestic partner and NASA and STFC (UK) as international partners. It is operated by
these agencies in co-operation with ESA and the NSC (Norway).”[1]

Korreck et al (in preparation ApJ)[2]
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http://www.srl.caltech.edu/ACE/[3]