The slides in this collection are all related and should be useful in preparing a presentation on SI

1
The slides in this collection are all related and
should be useful in preparing a presentation on
SIM PlanetQuest. Note, however, that there is
some redundancy in the collection to allow users
to choose slides best suited to their needs.
2
Studying Planets Challenges to Overcome
Planets are faint - Much smaller than stars -
emit only the stars reflected light - high
sensitivity of large telescopes is
needed Planets are close to their much brighter
star - looking for a firefly in the bright beam
of a light house - high angular resolution is
needed to separate the planet from the star
3
Planetary Systems Questions

• Statistics of planetary systems
• How common are planetary systems?
• Are certain star types favored?
• What is the distribution of planetary systems in
  the Galaxy?
• Characterizing planetary systems
• What are the orbit radii?
• Are the orbits circular or eccentric?
• Are multiple-planet systems common?
• For multiple planet systems
• What is the typical mass distribution of planets
  in a system?
• What is the typical radius distribution?
• Are the orbits co-planar?
• Must have astrometry to answer this
• Are the planets stable?

4
Planet Detection - Search Regimes for SIM

• Jupiter-mass planets
• Signature is 5 ?as at 1 kpc
• Very large number of available targets
• Intermediate mass range 2 - 20 Earth masses
• Massive terrestrial planets
• Detectable to many 10s of pc
• SIM can survey a large number of stars for
  planets less massive than Jupiter
• Earth-like planets
• The most challenging science for SIM
• 1 Earth mass at 1 AU - 0.3 ?as signature at 10
  pc
• Earths detectable only out to a few pc
• Orbit parameters only for the closest systems

5
To find life on other planets, first we need to
find planets
Intensive telescope search (1930) - based on
incorrect prediction!
Predicted by Newtonian Mechanics (1846)
Telescope (1781)
Naked Eye planets
6
Astrometric Planet Detection What do we derive
from SIM measurements?
Astrometry can measure all of the orbital
parameters of all planets. Orbit parameter
Planet Property Mass
Atmosphere? Semi-major axis
Temperature Eccentricity Variation
of temp Orbit Inclination Coplanar
planets? Period
Suns reflex motion (Jupiter) 500 µas Suns
motion from the Earth 0.3 µas
7
A star will wobble because it orbits a common
center of mass with its companion planets
There is more wobble when the companion planet is
massive and close to the central star.
Groundbased observers measure the Doppler shift.
SIM will measure the positional wobble. Doppler
shift or a well-determined stellar mass is
necessary to determine the true orbit(s) and
planet mass(es).
8
Many exoplanets have been found by measuring
the Doppler shift of starlight
First discovery of a planet around a normal
star (1995)
But these are large planets (1 Jupiter Mass 318
Earth masses) AND many are very close to their
central stars. The masses listed are lower
limits.
9
Where is the most interesting search volume?
10
Search for Terrestrial Planets

• SIM adds direct information on masses and orbits
  for fuller characterization of planets from
  Earths?Jupiters
• SIM planet search program has a strong
  terrestrial planets component balanced by a
  broad survey of 2000 stars of Uranus mass
  planets The nominal SIM deep planet search
  program occupies 17 of SIM time, and can search
  250 stars _at_ 50 2D visits over 5 years. (or 125
  stars _at_ 100 2D visits or 60 stars _at_ 200 visits)
• 50 2D visits 3 Mearth for 1AU orbit around
  the Sun _at_ 10pc
• The exact observational program will be modified
  according to best available data at the time, e.g
  RV on individual stars and on the value of
  hearth from the Kepler mission. (Just as TPF-Cs
  plan will be modified according to best available
  knowledge from, e.g. SIM)

11
Search for Terrestrial Planets

• Blue, all terrestrial size planets.
• Green/Yellow Habitable zones around 14 Lsun
• Sample size 60250 stars depending on hearth in
  habitable zone (from COROT/Kepler)

(18 pc)
12
Planet Mass I (Planet and Star Orbit)

• The planet and star orbit around their common
  center of mass.
• The orbits are mirror images of each other, the
  planet orbit is 100,000 times larger.
• The mass of the planet is deduced by measuring
  the motion of the star. (the mass of the star is
  measured by watching the planet
• MPlanet MstarRstar/RPlanet
• SIM measures Rplanet by using Keplers 3rd law,
  from the period of the planet and the mass of the
  star.

13
Planet mass sensitivity vs distance
Best 240 targets are all within 30 pc
14
False-alarm probability (FAP)
FAP at a given detection threshold is the
probability that a noise peak could exceed the
threshold
Monte Carlo of peak periodogram power for 100,000
realizations of Gaussian noise
Choose detection threshold for 1 FAP
Gaussian noise has power at all frequencies more
frequencies searched ? more false alarms
15
Finding Planets Indirectly

• Gravitational Effects on Parent Star
• Radial Velocity Changes
• Favors large planets in close to star
• Independent of distance
• Positional Wobble (Astrometry)
• Favors large planets far from star
• Angular displacement decreases with distance
• SIMs technique
• Effect of Planet on Stars Brightness
• Transits of edge-on systems
• Small fraction of a percent for a few hours (10-5
  for an Earth)
• Gravitational Lensing
• Planetary companion of lensing star affects
  magnification of background star by few percent
  for a few hours

16
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17
Planetary Gravitational Lensing
18
An Important Example of Using Astrometry

• Deduce planets orbiting nearby stars
• Motion of our sun (1990-2020) due to all planets
  in our solar system as viewed from 10 parsec (a
  little more than 30 light years) away

Scales are 0.001 arc sec 1 milli arc
second 1000 micro arc sec 5 nano-radian
Motion of stars optical center is a few thousand
micro arc seconds (µas)
SIM could measure this motion with an accuracy of
about 1 µas (5 pico-radian) (quite a bit
thinner than the line plotted here)
19
Exoplanets Found by Doppler Shift of Starlight
One Jupiter mass (1 MJ) corresponds to 318
Earth masses.
SIM will eliminate orbit inclination ambiguity of
radial velocity method and detect smaller planets
in longer period orbits
20
NEWS
Scientists discover first of a new class of
extrasolar planets
21
Principle of Astrometric Planet Detection
1000 µas
How Much Wobble?
1000 µas
22
Astrometric Planet DetectionWhat do we derive
from SIM measurements?
Astrometry can measure all of the orbital
parameters of all planets. Orbit parameter
Planet Property Mass
Atmosphere? Semimajor axis
Temperature Eccentricity Variation
of temp Orbit Inclination Coplanar
planets? Period
1A.U. 150,000,000 km
Suns reflex motion (Jupiter) 500 µas Suns
motion from the Earth 0.3 µas
80 A.U.
23
What are the SIM Planet-Finding Plans?

• The SIM planet science program has 3 components.
• Searching 200 nearby stars for terrestrial
  planets, in its Deep Search at (1 µas).
• Searching 2000 stars in a Broad Survey at lower
  but still extremely high accuracy (4 µas) to
  study planetary systems throughout this part of
  the galaxy.
• Studying the birth of planetary systems around
  Young Stars so we can understand how planetary
  systems evolve.
• Do multiple Jupiters form and only a few or none
  survive during the birth of a star/planetary
  system?
• Is orbital migration caused primarily by
  Planet-Planet interaction or by Disk-planet
  interaction?

24
Masses and Orbits of Planets SIM Can Detect
Planetary systems inducing low radial velocities
(through the astrometric displacement of the
parent star.
25
Deep Search for Terrestrial Planets
Masses of 104 known planets
E
J
S
U
N
V

• Ground-based radial velocity technique detects
  planets above a Saturn mass
• SIM will detect planets down to a few Earth
  masses and measure their masses

26
But What is a Habitable Planet?

• Not too big
• Not too small
• Not too hot or too cold

A good planet is
SIM can find planets similar in mass to Earth, at
the right distance from their parent stars
27
Broad Survey of Planetary Systems

• Out of 100 planetary systems discovered to-date,
  only one resembles our solar system
• So
• Is our solar system normal or unusual?
• Are planets more common around sun-like stars?
• What are the architectures of other planetary
  systems

28
Planets around Young Stars

• How do planetary systems evolve?
• Is the evolution conducive to the formation of
  Earth-like planets in stable orbits?
• Do multiple Jupiters form and only a few (or
  none) survive?
• SIM will
• Search for Jupiter-mass planets around young
  stars
• Pick stars with a range of ages
• Measure the ages and evolutionary state of
  young stars
• Need precise distances and companion orbits

29
The Close Candidates
30
HST Fine Guidance Sensors
31
FGS-TRANS
32
NICMOS Discoveries
33
MLR of VLMs
34
Primary SIM Targets

• 250 A, F, G, K, M dwarfs within 15 pc
• Doppler Recon. _at_ 1 m s-1
• Jupiters Saturns within 5 AU
• SIM 30 obs. during 5 yr (1 mas)
• 3 MEarth _at_ 0.5 - 1.5 AU
• 6 K-giant reference stars _at_ 0.5 - 1 kpc
• Located within 1 deg of each target
• Doppler vetting for binaries _at_ 25 m/s

5 s
35
Radial Velocity Planet Searches

• 15 - 20 Mearth
• Gl 436
• 55 Cnc d
• m Ara
• RV Limitations
• Only a
• M 10 Mearth
• ( Butler et al. McArthur et al., Santos et al. )

Detection Limit 0.2 MJUP _at_ 1 AU
36
Can RV Detect Rocky Planets at 1 AU ?

• Benchmark 1 Earth Mass at 1 AU.
• RV Amplitude K 0.09 m/s
• RV Errors s 1.0 m/s
• S/N K / s 0.1
• RV Cannot Find
• Earths Anywhere Near HZ
• (Even with 1 m/s)

Exception M Dwarfs
37
Nominal SIM Discovery Space
Unique SIM Domain 3 - 30 MEARTH Near
Habitable Zones
3000
300
MASS (MEarth )
30
3
.
.
SIM Domain
.

• Unambiguous Mass
• Co-planarity of orbits in
• multi-planet systems
• Orbital a, P, e

1 Mearth _at_ 1 AU for d 1 pc 3 microarcsec
38
DemocritusPre-Socratic Greek philosopher (460
- 370 BC).

• There are innumerable worlds of different
  sizes. These worlds are at irregular distances,
  more in one direction and less in another, and
  some are flourishing, others declining. Here they
  come into being, there they die, and they are
  destroyed by collision with one another. Some of
  the worlds have no animal or vegetable life nor
  any water.

39
Doppler Survey of 1330 Nearby Sun-like Stars
Extrapolation 6 of stars have giant
planets beyond 3 AU
Poor Detect- ability
Rise?
Model Inward Migration Planets left behind as
disk vanishes
Armitage, Livio, Lubow, Pringle et al.
2002 Trilling, Benz, Lunine 2002
40
Planet Metallicity Correlation
Abundance Analysis of all 1000 stars
Spectral Synthesis
1.6 Pplanet (NFe/ NH)
Fe/H
Fischer Valenti 2005
Valenti Fischer 2005
41
Formation of Planetary Systems

• The Solar System Paradigm

Models of Protoplanetary Disks of Gas Dust

• Observations
• mm-wave dust emission
• IR Excess/Spectra SEDs
• HST Imaging
• ? MDISK 10-100 MJUP
• Disk Lifetime 3 Myr

• Theoretical
• Planet-Formation
• Dust Growth ?
• pebbles/rocks
• Grav. Runaway
• Gas Accretion
• Migration Interactions

42
Multi-Planet Interactions

• 100 Planet Embryos (MEarth)
• Scatter, Collide, Stick,
• Accrete Gas

Levison, Lissauer, Duncan1998
After 21.5 Myr
Chaos
After 30 Myr
Lone Close-in, Jupiter in Eccentric Orbit.
43
Levison, Lissauer, Duncan 1998
Monte Carlo Examples of Planetary Systems

• Size ? Planet mass
• (in M earth ) above each planet.
• Peri - Apo of orbit

-
-
-
Rocky Planets will Outnumber jupiters.
AU
44
Low-Precision Planet Search

• 400 AFGKM stars at 10-30 pc
• SIM precision 4 mas
• Use SIM GRID (not nearby Ref Stars)
• Doppler Recon. at 1 m/s
• Jupiters and Saturns within 5 AU
• 4 mas _at_ 30 pc reveals
• 30 Mearth at 1 AU

45
SIM 3 Earth-Mass Planets
precision 1 microarcsec
d 5pc
Error bars are 1 uas
46
61 Cygni A

• Exp. Error
• Photons
• Angle sep.
• Planet jitter
• Failure Prob.

1o
47
RV Vetting of Reference Stars
Typical M Dwarf Companion
Eliminate Companions 25 m/s RV Precision
Planets around K giants get through
48
Nuisance StarsFringe Contaminationif within
2 arcsec
61 Cygni A Proper Motion
49
SIM Synergy with TPF

• SIM 250 closest stars
• Identify targets for TPF-c
• Definite targets SIM finds rocky planets -
  in the habitable zone
• Potential targets 2-s SIM earths -
• enrich TPF target lists
• Avoid targets SIM finds a giant planet in
  the
  habitable zone

TPF Timing
Catch planets when they are 4 l/d 65 mas from
star.
Inner Working Distance
50
Epicurus (341-270 B.C.)
Greek philosopher in Athens where he opened a
school of philosophy

• There are infinite worlds both like and unlike
  this world of ours ... we must believe that in
  all worlds there are living creatures and plants
  and other things we see in this world

51
Gliese 436 Velocity vs. Phase
M 21 MEarth a 0.03 AU K Mpl / a1/2 3
Mearth at 1 AU K 10 cm/s At 1 AU, RV can
detect 20 MEarth
Msini 21 MEarth
52
How Do Planetary Systems Form and Evolve?

• What fraction of young stars have gas-giant
  planets?
• Only SIM astrometry can find planets around young
  stars since active stellar atmospheres and rapid
  rotation preclude radial velocity or transit
  searches
• Do gas-giant planets form at the
  water-condensation line?
• SIM will survey 200 stars to a level adequate
  to find Jovian or smaller planets on orbits
  to 5 AU around stars from 25-150 pc
• 4 mas precision NAngle (50-150 pc) and 12 mas
  precision WAngle (25-50 pc)
• Does the incidence, distribution, and orbital
  parameters of planets change with age and
  protostellar disk mass?
• Study of clusters with ages spanning 1-100 Myr to
  test orbital migration theories
• Correlate with Spitzer results on disks (4-24 mm)
• Where, when, and how do terrestrial planets form
  ?
• Understand the formation and orbital migration
  mechanisms of the giant planets
• No other technique before and possibly including
  TPF (RV, AO imaging, IR interferometry) can
  credibly claim to find planets down to
  Saturn-Jupiter mass within 1-10 AU of parent
  stars at 25-150 pc

53
JWST and AO Imaging Will Find Young Jupiters in
Large Orbits (30 AU)

• ESO and other telescopes beginning to identify
  possible gas giants at 10s-100s of AU
• At 5 mm NIRCAM on JWST will be powerful tool for
  finding distant planets outside of 50 AU
  (3l/D0.575"30100 AU at 50-150 pc)

54
Possible Detections for 1 M? primary with 500 m/s

• 1 M? companion, 4 AU ?vrad 11 km/s, P
  11 yrs (SB2)
• 50 MJ companion, 1 AU ?vrad 2 km/s, P
  1.5 yrs (few years)
• 50 MJ companion, 0.1 AU ?vrad 6 km/s, P
  15 days (few days)
• 10 MJ companion, 0.3 AU ?vrad 600 m/s, P 50
  days (few months)

55
Adaptive Optics Results

• AO Observations of Northern targets nearly
  complete from Palomar (Tanner, Dumas,
  Hillenbrand, Beichman)
• DK9 mag at 1-2?
• 14 out of 14 Pleiades targets
• 5 targets have 8 visual companions (2.5?)
• 16 out of 19 Tau Aur targets
• 11 have 20 visual companions (2.5?)
• 80 hours scheduled for March 2004 to observe 15
  stars in Sco Cen and Upper Sco with VLT AO (Dumas
  et al.)
• Speckle observations of Northern targets planned
  from Keck (Ghez)
• In 2000, identified 3 potential targets with
  companions
• Keck-Interferometer suggests V830 Tau is multiple

BP Tau
3.1"
Hii1309 (Pleiades)