intro misc concl
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The slides in this collection are all related andshould be useful in preparing a presentation on SIMPlanetQuest. Note, however, that there is someredundancy in the collection to allow users tochoose slides best suited to their needs.
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Presented by
Presenter
Using materials shamelessly stolen fromthe SIM PlanetQuest Science Team,
the Internet, and some familiar motion pictures
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SIM PlanetQuest is part of NASAsOrigins Program
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Focus on manned mission toMoon and Mars, roboticexploration of solar system, andsearch for life around other stars
Among 20 goals the Presidentset for NASA is the following: Conduct advanced
telescope searches for Earth-like planets and habitableenvironments around other
stars
International participation --- This is not a race
The Presidential Vision
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National Academy of Sciences
SIM was prioritized in the 1991 AASC report asthe fourth-ranked space program of moderate classScience goals as specified in the 1991 report:
definitive searches for planets around stars asfar 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, V=20
(italics added)
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National Academy of Sciences (2)
The scientific capabilities explicitly called for by the 2001AASC 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 Galaxy1,000 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 explicitstatements about SIM and its scientific goals than thoseincluded in the main AASC report, stressed that"the primary scientific objective of the SIM mission isultrahigh accuracy astrometry .
(italics added)
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What is NASAs Astronomical Search for Origins?
To understand how stars and planetarysystems form and to determine whether life-sustaining planets exist around other stars.
To understand how life originated onEarth and to determine if it began andmay still exist elsewhere as well.
To understand how galaxies formed in the
early universe and to determine the role ofgalaxies in the appearance of stars,planetary systems and life.
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How to do that?
With SIM!
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Hipparcos
PositionalError Circle(0.64 mas)
How Precise is SIM?
HST Positional Error Circle (~1.5 mas)
Microarcsecond precision opens a new window to a multitudeof phenomena observable with SIM.
Reflex Motion of Sunfrom 100pc (axes 100as)
ParallacticDisplacementof GalacticCenter
Apparent GravitationalDisplacement of aDistant Star due to
Jupiter 1 degree away
SIM PositionalError Circle
(4 as)
.
Jupiter
Galilean Satellites
Dia. = 1000-2000 mas
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HipparcosPositionalError Circle(0.64 mas)
How Precise is SIM?
HST Positional Error Circle (~1.5 mas)
Microarcsecond precision opens a new window to a multitudeof phenomena observable with SIM.
Reflex Motion of Sunfrom 100pc (axes 100as)
ParallacticDisplacementof GalacticCenter
Apparent GravitationalDisplacement of aDistant Star due toJupiter 1 degree away
SIM PositionalError Circle
(4as)
.
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Why go to space ?
Space has no air
Ground interferometers limited byatmosphere 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
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Parallax is a small effect:James Bradley searched for it in 1725 - but discovered Stellar Aberration instead ( 20 arcsec).
Friedrich Wilhelm Bessel detected it in1838 (< 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 (AndromedaGalaxy) 1.3 mas
Measuring Distances
using parallax
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SIM Covers the Entire Galaxy
Hipparcos100 pc
SIM25 kpc(10%)
SIM2.5 kpc(1%)
You are here
What is a parsec ? Parallax of one arcsecond At 1 pc Earth-Sun distancesubtends 1 arcsec
1 parsec = 3.26 light-years~ distance to closest stars
What is a microarcsecond (as)?1 as = 4.8 x 10 -12 radians
= thickness of a nickelat the distance of the Moon!
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Stellar Evolution and the Distance Scale Distances in the Universe are
uncertain because we dontknow the distances to standardcandle stars SIM will measure accurate
distances Masses of most stars are very
poorly known SIM will measure accuratemasses (to 1%) by using
binary orbits Stellar evolution models cant
be further tested withoutaccurate masses for exoticobjects SIM will measure the
masses of OB (massive)
stars, supergiants, browndwarfs
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Galaxies and Beyond
Study the classical problems of size, mass distribution, androtational dynamics of the MilkyWay galaxy.
Dynamics of Galaxy Groupswithin 5 Mpc.
Quasar Astrophysics
SIM can determine if thevisible light from quasarsoriginates in hot gas aroundan accretion disk or from arelativistic plasma jet..
SIM can detect the orbitalmotions of two merging blackholes in the centers of massive galaxies.
Replace the current InternationalCelestial Reference Frame.
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SIM PlanetQuest Science Summary Planet searching:
Search for astrometric signature of terrestrial planets around nearbystars
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 galacticnuclei
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
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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 P=days 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= 84 and 82 , 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 evenout to the Magellanic Clouds SIM is a technical marvel:
SIM engineers have scheduled new inventions for
precise measurement of spacecraft mechanicalcomponents 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, especiallyat the fainter end of its sensitivity range
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Attractive Features of SIM
Galactic reach: 10 as is 20% luminosityerror 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-gradeoutput
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Comparison of SIM with GAIA
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0 5 10 15 20 25
M i s s i o n
A c c u r a c y
( P a r a
l l a x , m
a s
)
SIM
Each point represents a targetrequested by a SIM Key Project PI
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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 as (position, ~4.6 as parallax, ~2 as/yr prop motion) Mag limit to 20mag (18 mag ~2hr/target)
Grid (set of stars ~5 Deg spacing over 4 pi) ~1300 stars and 25~50 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 as over 1 deg. (900 sec obs, 10 mag) Mission accuracy for 30 obs/5yrs ~0.2 as.
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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 as
Without baseline rotation (multi-color fringe synthesis) ~ 25as Photometry (in 80 spectral channels from 0.45 to 1.0 m) < 1% Fringe visibility accuracy < 1% in each of 80 spectral channels.
(dia of star ~ 6 as could be measured to ~1%) Wavelength calibration (of 80 spectral channels) < 0.1 nm
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Searching for Planets with SIM A Deep Search for Earths
Focus on 60~250 stars like theSun (F, G, K) within 20 pc
Detection limit of ~3 M e at 10 pc Sensitivity limit of ~1.0 M e at 6
pc (if limited to 60 stars) Perhaps 7~8 times as many
terrestrial planet as terrestrial planets in the HZ
A Broad Survey for Planets Is our solar system unusual?Survey ~2,000 stars within ~50 pc withsensitivity to Neptune massExpect to find ~400 planets (fromcurrent RV statistics)Planets around wide variety of stellar typesMultiple planet systems
Coplanarity
Mass distributionEccentricity and Orbit radius
Evolution of Planets Survey ~200 1~50Myr stars How do systems evolve?
Is the evolution conducive tothe formation of Earth-like planets in stable orbits?
Do multiple Jupiters formand only a few (or none)survive?
What We Dont Know Are planetary systems like our own common? What is the distribution of
planetary masses? Only astrometry measures planet massesunambiguously
Are there low-mass planets inhabitable zone ?
I i Wi h I f
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Imaging With Interferometers
SIM HST/ACS I i Q li
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SIM vs. HST/ACS Imaging Quality
If 1 (1.4 nm @ 500 nm), thenSIM 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 SIMsaperture.
SIM observations simulated: 10 m & 8.5 m baselines
2 orientation angle intervals Bright star V = 10 30/3000 min. on-target time
HST/ACS d i li i
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HST/ACS detection limits
J. Krist (2004)
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SIM Science TeamTeam Member Institution Area of Interest/Discipline
Key Science ProjectsDr. Geoffrey Marcy University of California, Berkeley Planetary SystemsDr. Michael Shao NASA/JPL Extrasolar PlanetsDr. Charles Beichman NASA/JPL Young Planetary Systems and Stars
Dr. Andrew Gould Ohio State University Astrometric Micro-LensingDr. Edward Shaya University of Maryland Dynamic Observations of GalaxiesDr. Kenneth Johnston U.S. Naval Observatory Reference Frame-Tie Objects
Dr. Brian Chaboyer Dartmouth College Population II Distances & Globular
Clusters AgesDr. Todd Henry Georgia State University Stellar Mass-Luminosity Relation
Dr. Steven Majewski University of Virginia Measuring the Milky WayDr. Ann Wehrle NASA/JPL Active Galactic Nuclei
Mission ScientistsDr. Guy Worthey Washington State University Education & Public Outreach ScientistDr. Andreas Quirrenbach Leiden University Data ScientistDr. Stuart Shaklan JPL Instrument ScientistDr. Shrinivas Kulkarni California Institute of Technology Interdisciplinary ScientistDr. Ronald Allen Space Telescope Science Institute Synthesis Imaging Scientist
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A universe to study.
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