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

• Presented by
• Presenter
• Using materials shamelessly stolen from
• the SIM PlanetQuest Science Team,
• the Internet, and some familiar motion pictures

3
SIM PlanetQuest is part of NASAs Origins Program
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The Presidential Vision

• Focus on manned mission to Moon and Mars, robotic
  exploration of solar system, and search for life
  around other stars
• Among 20 goals the President set for NASA is the
  following
• Conduct advanced telescope searches for
  Earth-like planets and habitable environments
  around other stars
• International participation --- This is not a
  race

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National Academy of Sciences

• SIM was prioritized in the 1991 AASC report as
  the fourth-ranked space program of moderate
  classScience goals as specified in the 1991
  report
• definitive searches for planets around stars
  as far away as 500 light-years through the
  wobbles of the parent star, trigonometric
  determination of distances throughout the galaxy,
  and the study of the mass distributions of nearby
  galaxies from stellar orbits."
• 30 mas, V20
• (italics added)

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National Academy of Sciences (2)

• The scientific capabilities explicitly called
  for by the 2001 AASC were". . . enabling the
  discovery of planets much more similar to Earth
  in mass and orbit than those detectable now, and
  . . . permitting astronomers to survey the
  Milky Way Galaxy 1,000 times more accurately than
  is possible now."The report emphasized the
  "particular attraction" of the dual capability of
  the new SIM.
• The report of the 2001 AASC's Panel on
  Ultraviolet, Optical, and Infrared Astronomy from
  Space (UVOIR Panel), which contains more detailed
  and explicit statements about SIM and its
  scientific goals than those included in the main
  AASC report, stressed that
• "the primary scientific objective of the SIM
  mission is ultrahigh accuracy astrometry.
• (italics added)

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What is NASAs Astronomical Search for Origins?
To understand how galaxies formed in the early
universe and to determine the role of galaxies in
the appearance of stars, planetary systems and
life.
To understand how stars and planetary systems
form and to determine whether life-sustaining
planets exist around other stars.
To understand how life originated on Earth and to
determine if it began and may still exist
elsewhere as well.
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How to do that?
With SIM!
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How Precise is SIM?
Microarcsecond precision opens a new window to a
multitude of phenomena observable with SIM.
Reflex Motion of Sun from 100pc (axes 100 µas)
Jupiter
Parallactic Displacement of Galactic Center
Galilean Satellites Dia. 1000-2000 mas
Apparent Gravitational Displacement of a Distant
Star due to Jupiter 1 degree away
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How Precise is SIM?
Microarcsecond precision opens a new window to a
multitude of phenomena observable with SIM.
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Why go to space ?

• Space has no air
• Ground interferometers limited by atmosphere to
  1 mas over wide angles
• High precision metrology measurements can be made
• Space is quiet
• Optical Path Difference (OPD) and pointing jitter
  are easier to control
• Space can be made thermally benign
• stable thermal environment ? stability of optical
  system

12
Measuring Distances using parallax

• Parallax is a small effect
• James Bradley searched for it in 1725 - but
  discovered Stellar Aberration instead ( 20
  arcsec).
• Friedrich Wilhelm Bessel detected it in 1838 (lt
  0.5 arcsec).
• Nearest star (Proxima Cen)
• 0.77 arcsec
• Brightest Star (Sirius) 0.38 arcsec
• Galactic Center (8.5 kpc) 0.00012 arcsec
• 118 mas
• Far edge of Galactic disk (20 kpc)
• 50 mas
• Nearest spiral galaxy (Andromeda
  Galaxy) 1.3 mas

13
SIM Covers the Entire Galaxy
What is a parsec? Parallax of one arcsecond At
1 pc Earth-Sun distance subtends 1 arcsec 1
parsec 3.26 light-years distance to closest
stars What is a microarcsecond (µas)? 1 µas
4.8 x 10-12 radians thickness of a
nickel at the distance of the Moon!
Hipparcos 100 pc
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Stellar Evolution and the Distance Scale

• Distances in the Universe are uncertain because
  we dont know the distances to standard candle
  stars
• SIM will measure accurate distances
• Masses of most stars are very poorly known
• SIM will measure accurate masses (to 1) by using
  binary orbits
• Stellar evolution models cant be further tested
  without accurate masses for exotic objects
• SIM will measure the masses of OB (massive)
  stars, supergiants, brown dwarfs

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Galaxies and Beyond

• Study the classical problems of size, mass
  distribution, and rotational dynamics of the
  Milky Way galaxy.
• Dynamics of Galaxy Groups within 5 Mpc.
• Quasar Astrophysics
• SIM can determine if the visible light from
  quasars originates in hot gas around an accretion
  disk or from a relativistic plasma jet..
• SIM can detect the orbital motions of two merging
  black holes in the centers of massive galaxies.
• Replace the current International Celestial
  Reference Frame.

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SIM PlanetQuest Science Summary

• Planet searching
• Search for astrometric signature of terrestrial
  planets around nearby stars
• Statistics and properties of planetary systems
• Distances and Luminosities
• Calibration of the cosmic distance ladder
• Ages of globular clusters
• Galaxy and star cluster dynamics and structure
• Mass distribution in the halo of our Galaxy
• Spiral structure of our Galaxy
• Internal dynamics of globular clusters
• Masses and distances to gravitational lenses
• Dynamics of our Local Group of galaxies
• Quasars
• Origin of light
• Binary black holes
• Imaging demonstration
• Simple systems within 2 arcsec field of view

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SIM Science Summary (in descending order of
size scale)

• Proper motions of nearby active galactic nuclei
• Dynamics of our Local Group of galaxies
• Dwarf spheroidal galaxies - tidal tails
• Mass distribution in the halo of our Galaxy
• Spiral structure of our Galaxy
• Astrometric signatures of MACHO microlensing
  events

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SIM Science Summary (cont.)

• Internal dynamics of globular clusters
• Ages of globular clusters
• Accurate masses for low-mass binary stars
• Masses and evolution of stars in close binary
  systems
• Astrometric search for brown dwarfs and massive
  planets
• Astrometric search for planets around nearby
  stars
• Test General Relativistic effects in the Solar
  System
• Astrometry of minor bodies in the Solar System

19
Searching for Other Earths
http//planetquest.jpl.nasa.gov/SIM/sim_index.html
and http//planetquest.jpl.nasa.gov/Navigator/sim
_nav.html
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Unique SIM PlanetQuest Science

• Obviously, high-precision orbits
• Many planets and astrophysical phenomena
• Link optical to radio reference frame (ICRF)
• Origin of radio emissions
• Stellar evolution theory
• Controversial issues in astronomy and
  astrophysics
• Star spots
• Mass of Galactic black holes, clustered around 7
  M_solar?
• Short period signal measurement
• Signals with Pdays are hard for non-pointed
  mission to study.
• esp. when multiple frequencies are present.

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Controversial Issues in Astronomy

• Is it possible to have two perpendicular orbits ?
  (i 84º and 82º, separately)
• Are Galactic black holes clustered at masses
  around 7M??
• Is it possible to have a black-hole X-ray binary
  with distance of 190 pc (Hipparcos)?
• What is the upper mass limit of neutron stars?

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What is SIM PlanetQuest?

• SIM is the planet scout
• SIM will help to identify planetary systems of
  interest to future missions
• SIM is a yardstick to the stars
• SIM will measure precise distances by simple
  triangulation to stars all over the Galaxy, and
  even out to the Magellanic Clouds
• SIM is a technical marvel
• SIM engineers have scheduled new inventions for
  precise measurement of spacecraft mechanical
  components
• SIM is an odyssey
• SIM scientists and engineers have been dedicated
  to this mission for more than 15 years

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Proto-type for SIM for the Masses

• Many open problems in stellar astrophysics are
  due to lack of knowledge about distances
• Our example X-ray binaries
• AGB and post-AGB stars
• Extremely luminous stars
• Chemically peculiar stars
• SIM accuracy outperforms GAIA, especially at the
  fainter end of its sensitivity range

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Attractive Features of SIM

• Galactic reach 10µas is 20 luminosity error
  at 10 kpc
• Very precise for nearby stars (1 at 500pc)
• Modest projects (of order 10 stars) can be
  executed with a few hours of mission time
• Using SIM wide-angle data is easy
• Standard pipeline produces science-grade output

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Comparison of SIM with GAIA
Each point represents a target requested by a SIM
Key Project PI
Mission Accuracy (Parallax, ?as)
GAIA
SIM
Target Magnitude (V)
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SIM Measurement Capabilities

• SIM has two primary astrometric observational
  modes
• Wide angle (global) astrometry
• Narrow angle (relative) astrometry
• Global Astrometry (inertial ref frame tied to
  Quasars)
• 4 µas (position, 4.6 µas parallax, 2 µas/yr
  prop motion)
• Mag limit to 20mag (18 mag 2hr/target)
• Grid (set of stars 5 Deg spacing over 4 pi)
• 1300 stars and 2550 QSOs
• On average 10.5 mag K giants, down to 12 mag
• Narrow angle astrometry (relative astrometry)
• Absolution positions and proper motion,
  parallaxes only as good as global astrometry. But
  relative positions, parallaxes, much better
• Single measurement accuracy 1 µas over 1 deg.
  (900 sec obs, 10 mag)
• Mission accuracy for 30 obs/5yrs 0.2 µas.

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Miscellaneous Properties

• Crowded field astrometry
• This is an active area of study, preliminary
  results presented
• Identify two objects as two objects.
• With baseline rotation (synthesis imaging)
  resolution l/B 12 µas
• Without baseline rotation (multi-color fringe
  synthesis) 25 µas
• Photometry (in 80 spectral channels from 0.45 to
  1.0 µm) lt 1
• Fringe visibility accuracy lt 1 in each of 80
  spectral channels. (dia of star 6 µas could be
  measured to 1)
• Wavelength calibration (of 80 spectral channels)
  lt 0.1 nm

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Searching for Planets with SIM

• A Deep Search for Earths
• Focus on 60250 stars like the Sun (F, G, K)
  within 20 pc
• Detection limit of 3 Me at 10 pc
• Sensitivity limit of 1.0 Me at 6 pc (if limited
  to 60 stars)
• Perhaps 78 times as many terrestrial planet as
  terrestrial planets in the HZ

• What We Dont Know
• Are planetary systems like our own common?
• What is the distribution of planetary masses?
• Only astrometry measures planet masses
  unambiguously
• Are there low-mass planets in habitable zone ?

• A Broad Survey for Planets
• Is our solar system unusual?
• Survey 2,000 stars within 50 pc with
  sensitivity to Neptune mass
• Expect to find 400 planets (from current RV
  statistics)
• Planets around wide variety of stellar types
• Multiple planet systems
• Coplanarity
• Mass distribution
• Eccentricity and Orbit radius

• Evolution of Planets
• Survey 200 150Myr stars
• How do 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?

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Imaging With Interferometers
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SIM vs. HST/ACS Imaging Quality

• If ?? ? 1?(1.4 nm _at_ 500 nm), then SIM appears to
  surpass HST/ACS
• For r 0.5? on direct image
• For r 0.25? on the direct subtracted image
• Everywhere inside the 0. 9? stop on coronagraphic
  images
• Reason for this is the lack of correlation of
  zonal errors on SIMs aperture.
• SIM observations simulated
• 10 m 8.5 m baselines
• 2? orientation angle intervals
• Bright star V 10
• 30/3000 min. on-target time

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HST/ACS detection limits
J. Krist (2004)
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SIM Science Team
Team Member Institution Area of
Interest/Discipline Key Science Projects Dr.
Geoffrey Marcy University of California,
Berkeley Planetary Systems Dr. Michael
Shao NASA/JPL Extrasolar Planets Dr. Charles
Beichman NASA/JPL Young Planetary Systems and
Stars Dr. Andrew Gould Ohio State
University Astrometric Micro-Lensing Dr. Edward
Shaya University of Maryland Dynamic Observations
of Galaxies Dr. Kenneth Johnston U.S. Naval
Observatory Reference Frame-Tie Objects Dr. Brian
Chaboyer Dartmouth College Population II
Distances Globular Clusters Ages Dr.
Todd Henry Georgia State University Stellar
Mass-Luminosity Relation Dr. Steven
Majewski University of Virginia Measuring the
Milky Way Dr. Ann Wehrle NASA/JPL Active Galactic
Nuclei Mission Scientists Dr. Guy
Worthey Washington State University Education
Public Outreach Scientist Dr. Andreas
Quirrenbach Leiden University Data Scientist Dr.
Stuart Shaklan JPL Instrument Scientist Dr.
Shrinivas Kulkarni California Institute of
Technology Interdisciplinary Scientist Dr. Ronald
Allen Space Telescope Science Institute Synthesis
Imaging Scientist
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A universe to study.