IAU Colloquium 187 Exotic Stars as Challenges to Evolution Conference Evaluation

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IAU Colloquium 187Exotic Stars as Challenges to
EvolutionConference Evaluation

• Simon JefferyArmagh Observatory, Northern Ireland

I am grateful to the IAU and the Royal Society
for travel funds
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Disclaimer

• Objectives
• to summarize the proceedings - and remember to
  mention all the contributions.
• to evaluate, in some sense, what we have learnt.
• to congratulate and encourage the contributors.
• to be brief.
• Projected score
• 0/4
• Apologies to everyone who feels they have been
  misrepresented, undervalued or ignored

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IAU Colloquium 187Exotic Stars as Challenges to
Evolution

• So, was it worth it?

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what is an exotic star?

• The A1A bar - where the stars hang out all
  night - The Ramada Marco Polo Beach Resort
  Hotel - CLOSED
• not whether a star is exotic or not, but
  whether it is perceived to be exotic Milone
  
• objects (or people) are only normal when you
  dont know them very well Trimble
  cited by Knapp
• the more we know about this star, the more
  normal it gets Tout

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courtesy of SOHO/ESA/NASA
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familiar faces

• ? Lyr, ? Cas, ? Aur, ? Car, Sirius,
  Vega,...
• can we avoid more data less understanding ?
  Zwitter?
• people tend to argue a lot about ? Car, makes
  it fun Smith
• too many things are known about this star ?
  Cas Harmanec
• I can hardly believe that thirty years later I
  am still talking about HR2142
  Peters
• little did I think that 32 years later I would
  be talking about this object V471 Tau
  Bond ... Howard Bond
• ? Aur I shall use 2150 years of observations,
  to no avail Guinan

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double trouble

• binary frequency 50-150 Ivanova
• V379 Cep, OW Gem, V643 OriIll refer to the
  components as star 1 and star 2 - if I can
  remember to do so I dont really know which is
  star 1 here. Eggleton
• RT Lac not an exotic star, but a member of an
  exclusive club Milone
• TU Mus exotic because it is so remarkably well
  behaved Terrell
• ? Aur probing circumstellar gas Griffin
• Invisible companions
• V505 Mon et al. Chochol
• ? Car? You ascend into free parameter
  heaven Smith
• sdB stars Han
• GR Tau, AH Cnc, and the rest Yamasaki, Branly

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threes a crowd

• if you cant understand a binary, its probably
  a triple no prizes
• SuWt2 triple scenario 2a is least
  objectionable Bond
• AS Cam 3rd body to explain discrepant U
  Van Hamme
• ? Ori A Harvin
• V471 Tau lots of people !

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mores a factory

• Star clusters LMXBs, msPs, BSs, sdBs
  Hurley

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stars that go bump in the night

• Massive mergers Ivanova
• Producing sdB stars Han
• V652 Her and the extreme helium stars Jeffery

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About the movie...
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disks, spots, shells, streams, jets, ...

• ? Car kinda like a volcano or geyser
  Smith
• ? Aur the mother of all accretion disks
  Guinan
• ? Lyr where does the UV Fe emission forest come
  from? Linnell
• Nova Sco, SS433 Tout, Chakrabarti
• ? Pic theres one gorgeous picture of ? Car,
  there are lots of lovely pictures of ?
  Pic Lissauer
• Icy planets ? and masers in YSO disks
  Slysh, Valtts
• AG Dra this is as symbiotic as it gets
  Wilson
• ? Cas over 900 papers since 1930, but few
  systematic or penetrative analyses
  Harmanec
• High L Be stars Miroschnichenko

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geometry

• it depends which end of the star youre talking
  about, whether you mean the front end or the back
  end
• Im just trying to imagine a star living through
  this experience
• rotational distortion
• Roche geometry, criteria for RLOF Han
• radiative distortion Beer
• spots
• ? Car Smith, Langer, Scholler
• RY Sct Smith
• V471 Tau Vaccaro, Guinan, Bond
• HST planetaries Bond
• Next time you discover some peculiar
  variability, you might want to keep in mind that
  it could be one of these magnetically driven
  torques Lai

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is the chemistry working?

• Przybylskis star dont claim to believe the
  observations unless you understand them
  Kurtz
• HD965, HD217522 Hubrig
• ? Leo Griffin
• HD331319 He/Fe1.63 what was
  Fe/H? Miroshnichenko
• WeBo1 PNN is Ba star! Bond
• BI Lyn answers on a postcard, please
  Jeffery

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the extremethe bizarrethe surprisingthe
deviant the wrecks

• SS433 the most spectacular image in the X-ray
  sky Katani, Chakrabarti
• CW Leo not a particularly weird or unusual star
  - but it does cover the largest extent on the
  sky Knapp
• FG Sge one of Herbigs fruit stars
  Kraft?
• not H-deficient, not s-process rich
  Schönberner
• V605 Aql, V4334 Sgr, V838 Mon
  Hinkle, Rauch
• the born-again-again stars? Lawlor
• H150465 an O-Ne-Mg white dwarf ? Werner

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absent friends

• All PPEs incomprehensible binaries except the
  three that were finally selected.
• RCrB, V348 Sgr and friends
• ? Ori E, HD144941
• HD185510, HD128220
• AA Dor, FF Aqr, GP Com, PG1336-018
• ? Sgr extraordinary star - got a mention, but
  deserves better
• loads of pulsars, LMXBs, CVs, .

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PG1336-018 pulsations and eclipses
Secondary too faint to detect either
photometrically or spectroscopically. We tried!
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solutions?

• data
• to understand stars better, need less data, not
  more Eggleton
• GAIA the grand armada of astrometric
  missions Munari/Zwitter
• reclaiming the archives Griffin
• INTEGRAL Gimenez
• WSO/UV ?
• models
• choose a simpler star

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the truth is out there

• things in the heavens might not be quite as
  complex as things here on earth Eggleton
• automating the identification of what is
  peculiar Kotani
• thats another can of worms I dont want to get
  into Knapp
• A star is exotic because it, in some way, extends
  our knowledge of how stars behave. As we make new
  observations we discover new phenomena that we do
  not understand. As we approach an understanding,
  those phenomena seem less exotic. That is
  nature. Our task is to keep the cycle of
  exploration, discovery and interpretation
  turning.

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impressions

• a family gathering renewing old acquaintances,
  making new ones
• a landscape snapshots of stellar evolution at
  all sorts of stages
• a health check great progress in some areas,
  comparatively little in others
• a network there are ties between different types
  of stars that may have been overlooked
• a technology shortfall translate the cartoons
  into 1-2-3d models with hydrodynamics, radiative
  transfer, etc... as required. We need to
  understand the geometry, then we can look at
  evolution.
• a wake-up call stars are really really
  interesting. We have just demonstrated this.
  Its a good story. We have a duty to tell it to
  our public.

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please will you thank...

• The SOC
• Andreas Burkert
• Peter Eggleton
• Zhanwen Han
• Pavel Kroupa
• Norbert Langer
• Chris Tout
• Walter Van Hamme
• Patricia Whitelock
• Bob Wilson

• The LOC
• (the real stars)
• Rolando Branly
• Caroline Simpson
• Walter Van Hamme
• James Webb