Solar Flares over Time:Effects on Earth and Planets

Edward GuinanScott EngleJeff Gropp

Villanova UniversitySupported by NSF/RUI Grant AST 1009903NASA/Chandra Grant GO2-13020X and NASA/HST Grant HST-GO-13020.01A

IAUS 320.12.01Aug. 14, 2015

Talking Points

• Brief Summary of Sun-in-Time Program: Magnetic Evolution of the Sun - Coronal X-ray & Chromospheric UV emissions and Winds and Effects on planets/life.

• Extended to cooler stars- Living with a Red Dwarf Program

• Solar/ Stellar Flares (Superflares) over Space and Time

• Rotation-Age-Flare Relations for Sun and solar-type stars

• Effects of large Solar Flares on Earth

• Some Conclusions

Example of a Large Solar Flare Event

Nov 4, 2003 Solar Flare - Most Powerful Solar Flare observed with modern instruments –classified as X-28-45 - Observed with SOHO

Overall Energy Output ~1032 ergs

The “Sun in Time” Comprehensive multi-wavelength program to study the magnetic evolution of

the Sun (through G0-G5 V solar proxies) & Impacts of

X-UV -radiation Winds on Planetary Environments

Since 1990/ funded by NSF/NASA Grants

www.astronomy.villanova.edu/liv

ingwithareddwarf/opener.htm

Beyond Solar-typeStars - Red Dwarfs& Habitable Planets?

The original “Living With a Red Dwarf” Program logo

(1.10 Mo)1.08 Mo

1.04 Mo

(1.00 Mo)(0.98Mo)

“Sun in Time” Calibration of Rotation-Age

for G0-5 V Stars

Age-Rotation and Age-Log Lx

From Sun in Time Program

Values for 16 Cyg A & B from Davies et al. 2015 MNRAS

Cool Stars Rotation Over Time

Age (Gyr)

0 2 4 6 8 10 12

Ro

tati

on P

erio

d (

Day

s)

0

50

100

150

200

M2.5 - M5.5

M0 - M2

K0 - K5

G0 - G5

Rotation of main-seq. G, K, M Stars plotted vs. Age

Kapteyn Star

alpha Cen A,B,C

Brightness Variations of the Sun and Solar-Type Stars

over Time (Arising from Starspot Modulations)

"Sun in Time" Relative X-ray to Optical Irradiances

Age (Gyr)0 2 4 6

log

flu

x (

erg

s/s

ec/c

m2)

0

1

2

3ASCA (1-20Å)

ROSAT (20-100Å)

FUSE (920-1180Å)

Solar Luminosity

Fluxes are normalized to1AU distance and the radius

of a 1 solar mass star.

HardX-ray

SoftX-ray

FUV

PresentSun

Luminosity

LZAMS Sun

= 0.7 LPresent Sun

From Guinan et al. 2003; Ribas et al.2006

The Young Sun: A Summary of properties

X-Ray, Extreme

Ultraviolet: 300-

1000 times present

values

Visible

Wavelengths:

70% present

values

Far Ultraviolet,

Ultraviolet: 5-80

times present values

Solar Winds: 10-300?

times present values

(Wood et al. )

Flares: more frequent and energetic

E ~1031 - 1032 erg (~2-3 per day)

Etotal:1033-1035 erg ( ~16 superflares/10-yr) from this study

(Present observed flare upper limit: ~1032 ergs)Image courtesy: SOHO (ESA & NASA)

Also see Ayres (2015)

Super UV Flare

A Planet with a weak or non-existent magnetic

field will suffer the evaporation and possible

loss of its atmosphere by “sputtering” processes

associated with XUV radiation & winds.

From Griessmeier, Guinan et al. 2004, AA, 425, 753.

Effect of the intense solar wind of a young, active solar-type

star on the Magnetosphere of a nearby tidally locked planet

(X-UV/ Wind Flux data from Sun in Time program)

Strong Wind from young starWeaker Winds from an older Sun

To star->

Griessmeier et al. 2004

Fig. 3 Illustration of picked up planetary ions, directed

backwards to a planetary atmosphere, which is not protected

by a strong magnetic field. These ions can act together with

solar wind particles as sputter agents (courtesy of F. Leblanc)

From Lammer et al. 2008 , Space Sci. Rev –Atmospheric Escape and Evolution of

Terrestrial Planets and Satellites

during

Effects of young Sun’s Activity on

Mercury & Venus

Mercury: Given the closeness of Mercury to

the Sun (0.39 AU), the radiation and winds of

the young, active Sun ravaged the planet,

completely eliminating its atmosphere and

possibly even eroding away a significant

fraction of its mantle. This could have

resulted in a planet with a disproportionately

large iron core, relative to its overall size.

Tehrany et al.Mariner 10 images the barren Mercury

Magellan Radar Mosaic of Venus

Venus: Investigate evolution of the Venus’

atmosphere -D/H abundance indicates past

oceans- but all lost from Sun. Maybe the young

Sun’s enhanced activity played a major role?

It did! : H20 H + H + O (all lost quickly).

Result - Within the first ~½ Gyr, Venus lost all

of its water inventory

Messenger

at mercury

Evidence of Sputtered Sodium atoms blown off

Mercury by Solar winds and X-UV radiation

from the present (magnetically weak) Sun

THE YOUNG SUN WAS NOT KIND TO ITS NEAREST PLANET- MERCURY:

The Erosion and Sublimation Effects of the

Young Active Sun on Mercury’s Surface

Lammer, H., Tehrany, M.G.,

Hanslameier, A. & Kolb, C.

Astrobiology Institute

Graz, Austria

E.F. Guinan & I. Ribas

Villanova University

U. de Barcelona

Comparison of the neutral sodium observed during the 2nd and 3rd Mercury flybys to models. The color scale for the 3rd flyby has been stretched to show the distribution of sodium more clearly. As in previous flybys, the distinct north and south enhancements in the emission that result from material being sputtered from the surface at high latitudes on the dayside are seen.

One possible explanation is that Mercury’s lighter mantle/crust

was eroded away by the strong (if 500-1,000 times present value)

winds and the early Sun’s very high X-ray and ultraviolet fluxes.

But there are conflicting measures of the “solar wind in time”

But new data about high levels of super-flares and CMEs of the

young Sun could provide the energy to erode some of the mantle

Image credit: SOHO (ESA & NASA)

Loss of Water on Mars

from Effects of Young

Sun’s Strong X-ray – UV

Emissions and Winds (Lammer et al. 2003 & 2008)

Mars prior to 3.5 Billion Years Ago

Liquid iron core produced a magnetic field strong enough

to protect the young Martian atmosphere and surface water

from the nasty effects of the young Sun’s XUV& plasmas.

Mars after 3.5 Billion Years Ago years ago, Mars’ core solidified, shutting down the Martian magnetic dynamo.

Roughly 3.5 Billion

Without a magnetic field, the outer Martian atmosphere was subjected to the

ionizing effects and strong winds of the young sun, and began to erode.

At this time, water disassociates into 2H+O, where the lighter Hydrogen is lost to

the space while the heavier Oxygen combines with iron on its surface

Michael J. Dulude

Why we are here: Secret to the success for life on Earth - A Strong Magnetic Field & Magnetosphere -that shielded the early Earth from the young active Sun’s strong X-UV

and wind fluxes (and strong flares, & CME events.) This was not the

case for Venus and Mars!

http://en.wikipedia.org/wiki/File:Magnetosphere_rendition.jpg

Superflares (E>1033 ergs;>X-100) on

Solar-type Stars of Different

Rotations / Ages:

Solar Flares in Time

Sample of Solar X-ray GOES Data

Flares “rated” according to peak fluxX-100; E = 1033 erg

X-10 E = 1032 erg

Thermal

Plasma

Accelerated

Electrons

Accelerated

Ions

Composite Spectrum

from a Large Flare

RHESSI

12.4 A 1.2A

The ultra-high precision photometry now available from the Kepler Mission has made it possible to study starspot & flare properties, and rotations of solar-type stars. As discussed at previously at S320, superflares (E > 1033 erg (X-100) on hundreds of G,K,M stars have been found. See e.g. Shibayama et al. 2013; Maehara et al. 2015; Notsu et al. 2013/15; Saar et al. 2015

Typical Light Curves and superflares from high cadence Kepler Data are shown (from Maehara et al. 2015)

Shibayama et al. (2013) estimate that

superflares with an energies of 1034-1035 erg

occur once in 800-5,000 years in Sun-like

stars, i.e. main-sequence G2+/-2 stars with

rotational periods longer than 10 days (see

also Shibata et al. (2013). But for the Sun

and solar-age stars (P~ 20-27 d; Age ~ 3-6

Gyr), the probability is much less.

From Kepler data only two solar-age stars

(gauged from their slow rotations of 21.8-d

and 25.3-d, have been found to have

superflares. Nogami et al. 2014

Prot=21.8-d; Age~ 3-6 Gyr

Two Solar-Age Sun-like Superflare Stars

Prot = 25.3-d: ~4-6 Gyr

Light curves of typical superflares on solar-type stars from Kepler. The arrows indicate superflares reported in Maehara et al. (2012). From Notsu et al. (2013).

From Notsu,et al. 2015: Plot of Flare Energy as a function of sunspot/star spot coverage. Solar flares indicated by small dots. The data of superflares on solar-type stars (filled small squares) from Kepler photometry are shown.Open circle and triangle points on the filled squares represent the data points of the most energetic superflare event reported in Shibayama et al. (2013) of the 34 target superflare stars. Open triangles are superflare stars seen nearly pole-on so with small spot modulations & underestimated spot coverage.

Solar flares

AGE ~ 4____ 2__0.5 0.1 Gyr

Occurrence frequency distribution of superflares as a function of the rotation period. The vertical axis indicates the number of superflares per star and per year in each period bin. From Notsu et al. 2015

Solar-type (G) Stars Superflares: E > 1033erg (>X100)

Period (d)

The Solar Super-Flare (E >1033erg) Rates in TimeThese data indicate a probability of one super flare ~290 yrs. for the Sun

(For the Young Sun expect ~ 16 superflares/10 yrs (~480 superflares / 300 yrs)

X NGC 6866

X Saar et al. 2015 S320p.45

Flare Intensity Distribution

N(P) P-1.8

B. R. Dennis, Solar Physics, 1985

The frequency of super-duper10+34 erg = X-1000 level solarflares can be estimated from therelation given by Dennis (1985)and others that give N(P) P-1.8.

Thus the probability of a hugeX-1000 flare is 1/63 less likely thana X-100 flare. So that an X-1000 flare Is expected to occur once in ~18,300yrs. for the Sun or for solar-age stars.

Note that ~X-45 is the highest-everrecorded solar flare.

X-1000 Level Flare: Expected ~ 1/18,300 years for the Sun

From Maehara et al . 2015. Comparison between occurrence frequency super-flares on Sun-like stars & those of solar flares. Filled-circles indicates the occurrence frequency distribution of super-flares on Sun-like stars (G-type main sequence stars with Prot > 10 days &5800 (G2V) < Teff < 6300K (F9V) ) derived from short-cadence data. The average occurrence rate of superflares with the energy of 1033 erg which is equivalent to X100 solar flares is about once in ~500-600 yrs.

Solar Weather, Storms (Flares /CoronalMass Ejections...Effects on Earth

See SPACEWEATHER.COM

Missions making

Solar-related Measures

Effects of the Solar storm of August -September 1859 –The Carrington Flare: estimated ~X-45 Solar Flare

• Elias Loomis collected and published reports of the storm in the Amer. J. of Sci.

• Aurora were reported at New Orleans, Galveston, Key West, and Havana

• Telegraph operations in Europe and North America were severely impacted

• In some cases, telegraphs worked better using GIC currents alone, without batteries

Drawing by Carrington

Nov 4, 2003 Solar Flare - Most Powerful Solar Flare observed with modern instruments –classified as X-28-45 - Observed with SOHO

Overall Energy Output ~1032 ergs

Sample of Solar X-ray GOES Data

Flares “rated” according to peak fluxX-100; E = 1033 erg

X-10; E = 1032 erg

Solar weather and effects on Earth

The image sequence and graph above show the arrival of massive numbers of protons from the Bastille day solar flare. The top row of images show the crescent Earth onJuly 14, 2000, from the Visible Imaging System aboard the Polar spacecraft. The

oncoming wave of protons hitting the sensor caused the increasing amount of noise (white dots) in the image sequence. The graph below shows proton flux from the same time, measured by the High Energy Proton and Alpha Detector aboard GOES 8 (a NOAA weather satellite). The density of high-energy protons rose from less than 1 protons /cm2/s per steradian to over 9. This was just the beginning—on July 15 over 800 protons were counted per second. (Images courtesy International Solar-Terrestrial Physics, graph by Robert Simmon, based on data from the Space Physics Interactive Data Resource

Ozone can be depleted by the incomingFlare protons.P -> H2O -> OH + HOH -> O + H (frees up atomic Oxygen)

p -> N2 –> N + N (releases atomic N)N + O -> NO, NO2 etc. Nitric Oxides(called NOx)Destroy Ozone (see next slide)

http://www-istp.gsfc.nasa.gov/http://spidr.ngdc.noaa.gov/

Photo taken by Don Pettit, Expedition 6 Science Officer aboard the International Space

Station

AURORA AS SEEN From Space from the ISS- Aurorae are produced as solar

plasma (Winds) interacts and excites atoms

of Oxygen and Nitrogen in the Earth’s

Ionosphere

Some Specific Vulnerabilities

to Large Solar Flares/ CMEs

• Communications satellites

GPS/ cell phones. e.g.-The Halloween flare (October 2003) Interrupted Satellites &

Cell Phone Services

• Dangerous levels of radiation

/particle (H) fluxes to Astronauts in

space (e.g. Internat. Space Station

=ISS or future Mars Missions)

• Increased density/temperature of

ionosphere (increase drag on satellites/ radio communication)

• Large Flares can temporarily decrease

Ozone / produce Nitrates in Atm.

Flares and Astronaut Hazards

• Had the great storm of 1972 occurred during an Apollo flight, the crew would have received a huge and potentially dangerous dose of radiation

Effects of a X-100 Flare

In June 2013, a joint venture from

researchers at Lloyd's of London

and Atmospheric and Environmental

Research (AER) in the United States

used data from the Carrington Event

to estimate the current cost of a

similar event to the US alone at

$0.6–2.6 trillion.[2]

From Solar Storm Risk to the North

American Electric Grid Lloyd's 2013

https://en.wikipedia.org/wiki/Lloyd's_of_Londonhttps://en.wikipedia.org/wiki/Solar_storm_of_1859#cite_note-lloyds2013-2http://www.lloyds.com/~/media/lloyds/reports/emerging risk reports/solar storm risk to the north american electric grid.pdf

Conclusions• The Young Sun & solar-type stars, due to fast rotation & robust

dynamos, have very strong X-ray / UV emissions.

• Kepler data are yielding crucial information about the flaring

characteristics of the Sun & solar-type stars over time.

• These data show that the present Sun could have Superflares

(E>1033 erg) ~ 1/300-1/600 yrs. But the young Sun had very

frequent, super flares (1-2 per year).

• The flares on the young sun & solar-type stars could have major

effects on planetary atmospheres: Ionization, erosion and loss.

Flares pose very serious problems for habitability of close-in

Habitable Zone planets of red dwarf stars.

• Large flares from the present Sun are rare and pose mainly dangers

for astronauts but not to life on the Earth's surface. But could cause

considerable damage to unprotected technologies (satellites,

electric grids etc.) and resulting in huge loss financial losses.

Mahola