Planets to Stars in the ELT era

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Planets to Stars in the ELT era

• S. R. Kulkarni
• California Institute of Technology
• Pasadena

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Outline

• Next Generation Telescope
• Disclaimer
• Size is not everything
• Natural Food Chain
• Why ELT?

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Next Generation Teacup/Telescope
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In honor of Johannes Brahms
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I. Discover vs Uncover

• Discovery The first object is blindingly bright.
  
• In retrospect any fool could have done it
• Need to cover large phase space
• Thus not suited for a singular instrument
• Uncover Well suited for specialized approaches
• eg. Cosmometry with SN Ia

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II. Size is not everything

• Arecibo 305-m telescope
• VLA WSRT 100-m (effectively) telescope
• Parkes 64-m telescope
• Parkes multibeam survey discovered more pulsars
  than the rest of the world.
• However, discoveries were made with raw power
  Crab pulsar, binary pulsar and millisecond pulsar

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III. Telescopes versus Backends

• Telescopes have always been expensive
• Ratio of backends/telescopes has changed
  dramatically
• Mt. Wilson 60-inch, (photographic plate)
• Mt. Wilson 100-inch (spectrograph)
• Palomar 200-inch (plates -gt CCDs)
• Keck (10m/instrument10 100m)

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IV. High Throughput Instruments are expensive

• Scuba .. (JCMT)
• SDSS .. (detectors, software)
• Parkes Multibeam
• Atacama 30-m telescope entirely based around
  detector innovations (KIDS)

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V. Natural Food Chain

• Large telescopes are best served by the natural
  food chain model
• Small telescopes for discoveries
• Experiments (focussed efforts) for systematic
  exploration
• Detailed studies of specific objects by the large
  telescopes

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Why ELT?

• Previous growth was driven by collecting area
  (60-inch -gt 400-inch)
• Angular resolution appears to be a big part of
  ELT design.
• However, all ELT designs have considered circular
  pupils!
• Nancay, WSRT, VLA, VLBA (counter-examples)

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ELT Main Drivers

• Cosmology
• Faint objects
• Near IR
• Extra-solar planet research
• High contrast imaging/spectroscopy
• Spectroscopy of eclipsing systems
• Companions to low mass/brown dwarfs
• Disks around stars

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ELT Galactic Context

• Other areas of Galactic research are more or less
  incidental
• Star clusters (globular/young)
• Nearby galaxies as natural stellar laboratories
• Stellar evolution, chronometry
• Compact objects

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Galactic Astronomy over the next decade

• Best served by dedicated projects
• Large sky surveys
• High throughput machines (e.g. RV)
• COROT, Kepler, Gaia, SIM

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Neglected areas for ELTs

• Astrometry over large field of view, especially
  IR
• eg. Galactic center
• Transient object astronomy
• This is a virtually open topic!

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Planet in a triple star system
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Shao Colavita
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Very Narrow Angle Astrometry
Shao Colavita
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Scanning the Fringe
Lane Mutterspaugh
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Phases Survey
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Cameron
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(No Transcript)
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del Equulei
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Stellar Astronomy
Astrometric orbits determined with the Palomar
Testbed Inteferometer when combined with our
precision velocities routinely deliver stellar
parameters (masses, distances) of stunning
accuracy
64 Psc (HD4676) MA 1.210 0.015 MSun
MB 1.169 0.014 MSun
iota Peg (HD210027) MA 1.345 0.0023 MSun
MB 0.837
0.0016 MSun
Precision of 0.2 -- a new bar for stellar
theorists. SIM era is upon us!
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Questions

• Should angular resolution be prime driver for ELT
  (e.g. non-circular pupils)?
• Should there be a linkage between interferometry
  and ELT?
• How should ELT be coupled to other developments?
  (important for Galactic science)
• eg. Transient Object Astronomy (LSST/Panstarrs)
• eg. RAVE, Gaia, SIM
• Should ELT also focus on large field of view
  astrometry?