EXTRASOLAR PLANETARY SYSTEMSDETECTION METHODS, RESULTS

AND PERSPECTIVES

MICHAŁ RÓŻYCZKANICOLAUS COPERNICUS ASTRONOMICAL CENTER

1ST PLANETS SHOOL, HEIDELBERG, OCT. 8TH, 2003

AN EASY INTRODUCTION FOR EVERYBODY

• The first discoveries

• Observing planet formation

• Detecting „mature” planets

• Statistics of extrasolar systems

• Future space missions

THE FIRST

DISCOVERIES

ALEXWOLSZCZAN

2 PLANETS (NOW 3)1600 LIGHT YEARS FROM THE SUN

CONSTELLATION VIRGO

1ST EXTRASOLAR PLANETARY SYSTEM

ANNOUNCED IN JANUARY 1992

SU

N

MERCURYVENUS

EARTH

DISTANCE (EARTH = 1)

PS

R

1257+

12

A B C

SU

N

MERCURYVENUS

EARTH

DISTANCE (EARTH = 1)

PS

R

1257+

12

A B C

THE FIRST

EXTRASOLAR SYSTEM:

CERTAINLY

GLORIOUS...

... BUT RATHER

UNFRIENDLYSURPRISING

... BUT

PROMISING

MICHEL MAYOR DIDIER QUELOZ

STAR 51 PEGASI40 LIGHT YEARS FROM THE SUN

CONSTELLATION PEGASUS

1ST PLANET AT A SOLAR-LIKE STAR

ANNOUNCED IN OCTOBER 1995

LONG BEFORE THAT STARBIRTH-PROCESSESHAVE BEEN STUDIED,

YIELDING CLUES ABOUT

PLANET FORMATION

OBSERVING

PLANET FORMATION(INDIRECTLY)

50 000 LIGHT YEARS

25 000 LIGHT YEARS

1011 STARS

MILKY WAY – STARS ONLY

MILKY WAY – VISIBLE LIGHT

MILKY WAY - INFRARED

3-6×109 M

CO, 2.64 mm

INFRARED

300 l.y.

CO

3×105 M

mostly H2

ORION STAR-FORMING REGION

ORION NEBULA

VISIBLE

2.5 l.y.

INFRARED

ORIONNEBULA

AGE:A FEW MILLION YEARS

150 objectsR = 50 -1000 AU

M > 600 M

(H2 emission; absorption of visible light emitted by the nebula )

M > 2000 M

Concave Disk

AGE:108 years

dust mass: 0.1 M gas mass: 100 M

Infrared 1,2 resolution 0,12’’ 50 AU

Pictoris 63

l.y. 1.7 M

STARS ARE BORN

WITH

CIRCUMSTELLAR DISCS

THE DISCS DISPERSE WITHIN

~ 107 YEARS

DETAILS OF

STAR AND DISC FORMATION

UNKNOWN

DETAILS OF

DISC DISPERSAL

UNKNOWN

RESIDUAL DISCS

SEEM TO CONTAINMORE

THAN JUST DUST

WARP

A PLANET?

Pictoris

HOLE

WARP

OUTER PLANET?

INNER PLANET(S)?

FOMALHAUT

25 l.y. 2.8 M

AGE:108 years

dust mass: 0.1 M

HOLE

OUTER PLANET

INDIRECT EVIDENCE:

RESIDUAL DISCS

CONTAINPLANETSPLANETS

DETECTING

MATURE PLANETS

JUPITER SHINES WEAKER THAN THE SUN:

1 000 000 000 TIMES (visible light)

50 000 TIMES (infrared)

5 000 TIMES (mm and sub-mm)

JUPITEROBSERVED FROM THE NEAREST

STAR

0.1” DISTANT FROM THE SUN

„DROWNED” IN SUNSHINE !!

PSF, SEEING, ZODIACAL LIGHT, BACKGROUD SKY

REMNANT DISK

AND YETWITHIN THE LAST 8 YEARS

MORE THAN 110

EXTRASOLAR PLANETS

HAVE BEEN FOUND

HOW ??

POPULARVIEW

POPULARVIEW

REALITY

X = CENTER OF MASS

SYSTEM VIEWEDPOLE-ON (RARE)

REALITY

SYSTEM VIEWEDOBLIQUELY(MORE COMMON)

...BUT

THE PLANET CANNOT BE SEEN

MOTIONS OF THE STAR

BETRAYITS PRESENCE !

X

EARTH

X

JUPITER

150 000 000 km

30 km/s

450 km

9 cm/s

780 000 000 km

13 km/s

750 000 km

13 m/s

2010

2000

2005

1995

1990

2015

2020

0.002”

MOTIONS OF THE SUN VIEWED FROM A STAR 30 LIGHT YEARS AWAY

0.002’’ IS THE ANGULAR SIZE OF A MAN ON THE MOON OR A STANDARD NEWSPAPER FONT 300 KM AWAY

STELLARWOBBLE

RECEDING:

REDDER

APPROACHING:

BLUER

1 Angstrom = 10-8 cm

PLANET DETECTION DUE TO STELLAR WOBBLE

-50

-100

0

100

50

m/s

0 321 days

K

P ito the observer

normal to the orbit

V

K = Vsin i

PLANET DETECTION DUE TO STELLAR WOBBLE

K = V sin i

MK /(sin i VPL)MPL sin i = MK / VPL

KNOWN:

COMPUTED:

3. MASS OF THE STAR *2. AMPLITUDE OF VELOCITY VARIATIONS

1. ORBITAL PERIOD

1. MASS OF THE PLANET (LOWER LIMIT)2. ORBITAL RADIUS

ANOTHEREFFECT:

TRANSIT

PLANET IN FRONTOF THE STAR

TIMEBR

IGH

TN

ES

S

TRANSIT

1%

LIGHTCURVE

ANDRZEJ UDALSKI MACIEJ KONACKI

STAR OGLE-TR-56~5000 LIGHT YEARS FROM THE SUN

CONSTELLATION SAGITTARIUS

FIRST DETECTION OF A PLANETVIA THE TRANSIT PHENOMENON

ANNOUNCED IN 2002/2003

KNOWN:

COMPUTED:1. MASS OF THE PLANET (LOWER LIMIT)

2. RADIUS AND SHAPE OF THE ORBIT

4. LIGHT CURVE

1. ORBITAL PERIOD2. AMPLITUDE OF VELOCITY VARIATIONS

3. MASS OF THE STAR

3. RADIUS OF THE PLANET

COMPUTED:1. MASS OF THE PLANET

2. RADIUS AND SHAPE OF THE ORBIT

BASIC STATISTICS

OF EXTRASOLAR

PLANETS

data from February 2001

semimajor axis (AU)

excen

tric

ity e

e=(a2-b2)1/2/a

b a

ASTRONOMICAL UNITS

AS

TR

ON

OM

ICA

L U

NIT

S

EARTH’S ORBIT

COMPOSITE EXTRASOLAR SYSTEM -1

AS

TR

ON

OM

ICA

L

UN

ITS

ASTRONOMICAL UNITS

EARTH’S ORBIT

COMPOSITE EXTRASOLAR SYSTEM -2

MERCURY’S ORBIT

„JUPITERS”

DEEP INSIDE MERCURY’S ORBIT !!!

Planetary system of And

Solar system

0.06 AU4.5 days0.75 MJ

2.5 AU3.5 years

4 MJ

0.85 AU242 days

2 MJ

0.39 AU89 days

0.73 AU228 days

1 AU1 year 1.54 AU

1.9 years

Source: Harvard-Smithsonian CfA

EXPECTED:

NEARLY CIRCULARNEARLY CIRCULAR ORBITS ORBITS

BIG PLANETS BIG PLANETS FAR AWAY FROM THE STARFAR AWAY FROM THE STAR

NONO PLANETS BIGGER THAN JUPITER PLANETS BIGGER THAN JUPITER

DISCOVERED:

STRONGLY ELONGATEDSTRONGLY ELONGATED ORBITS ORBITS

BIG PLANETS BIG PLANETS VERY CLOSE TOVERY CLOSE TO THE STARTHE STAR

MANYMANY PLANETS BIGGER THAN JUPITER PLANETS BIGGER THAN JUPITER

CONCLUSION

SOME PLANETARY SYSTEMS SOME PLANETARY SYSTEMS

HAVE FORMED AND/OR EVOLVED HAVE FORMED AND/OR EVOLVED

ENTIRELY DIFFERENTLY ENTIRELY DIFFERENTLY

THAN THE SOLAR SYSTEMTHAN THE SOLAR SYSTEM

QUESTIONS:

WHO WE ARE: WHO WE ARE:

COSMIC STANDARDCOSMIC STANDARD

OR COSMIC EXCEPTION?OR COSMIC EXCEPTION?

ARE THERE ARE THERE ANY EARTH-LIKEANY EARTH-LIKE

PLANETS PLANETS AT DISTANT STARS?AT DISTANT STARS?

Distribution of masses of known extrasolar planets. About 1000 stars have been surveyed: a nearly complete sample of solar-type stars within 30 pc.Occurrence varies inversely with mass.

PLANETS AND METALLICITY

FUTURE

SPACE MISSIONS

RELATED

TO EXTRASOLAR

PLANETS

SIRTF

INFRARED

PROTOSTARSPTOTPLANETARY DISCS

LAUNCH:AUGUST 25TH

This engineering image is a quick look at the sky through the Infrared Array Camera (IRAC), one of three scientific instruments aboard SIRTF.

The instrument was powered on for a brief electronics checkout, and some imagesof the sky were taken to test whether the IRAC detectors were functioning.

The 5 arcmin x 5 arcmin image was taken in a low Galactic latitude region in the constellation Perseus.

3.09.2003

COROT, KEPLER, EDDINGTON

LAUNCH IN 3-5 YEARS

TRANSITS SEARCH FOR EARTH-LIKE PLANTES

SIM

WOBBLE DUE TO EARTH-LIKE PLANTES

LAUNCH IN ~6 YEARS

ORBITAL PERIOD (YEARS)

0.001 0.01 0.1 1 10 100

10

1

0.1

0.010.1

110

1001000

Solar System

ST

EL

LA

R M

AS

S (

M)

A

M

KG

F

B

Kepler search space

habitable zone

MainSequence

STELLAR RADIUS ORBITAL RADIUS (AU )

DARWIN

LAUNCH IN MIN. 11 YEARS

DIRECT OBSERVATIONS OF EARTH-LIKE PLANETS

INTEN

SIT

Y

× 1/10 000 cm

The 2001 decadal review of astronomy and astrophysics, prepared by the U.S. National Research Council, stated that:

the discovery of life on another planet is potentially one of the most important scientific advances of this centuryit would have enormous philosophical implications

IN MORE PRACTICAL TERMS:

PLANETS

ATTRACT

MONEY

ASTRONOMICAL UNIT

1AU = 150 000 000 km= 8.3 light minutes

LIGHT YEAR

1l.y. = 63 115 AU = 1013 km