Hot And Cool:
Bridging Gaps in Massive Star Evolution
NASA Herschel Science Center

10 Nov 2008
Registration closed
06 Nov 2008
Proceedings instructions, including LeTeX and Word templates, posted
05 Nov 2008
Final announcement posted
03 Nov 2008
Workshop schedule updated
20 Oct 2008
Workshop schedule posted
13 Oct 2008
Talk and poster abstracts posted
10 Oct 2008
Detailed instructions for presenters posted
03 Oct 2008
Early registration and abstract submission closed
02 Oct 2008
Third announcement posted
25 Sept 2008
Late registration added
12 Sept 2008
Second announcement posted
02 Sept 2008
Venue maps posted
02 July 2008
Mt. Wilson excursion information posted
09 June 2008
First announcement posted
06 June 2008
Registration open
27 May 2008
Workshop website open

Submit Proceedings Manuscript


Research communities addressing the hot and cool parts of the uppermost Hertzsprung-Russell diagram (HRD) have been stubbornly disjoint. This workshop aims to bridge the gap between researchers studying these different sides ofthe HRD. While morphologically separated, stars occupying these extremes of the HRD are intimately related via evolution, as well as both having atmospheric properties affected by extension and stellar wind outflow. At cosmological scales, like in distant starburst galaxies, the historical distinction between blue and red stellar populations becomes obsolete, and understanding the complex relation between the red and blue parts of the HRD is mandatory.

This meeting will allow us to investigate similarities and differences between hot and cool stars, identify the most challenging questions in evolutionary connections, and discuss latest theoretical and observational progress and prospects in certain evolutionary or mass/temperature regimes which will provide a more unified understanding of massive stars and luminous extragalactic stellar populations.

Session Topics:

1.  Evolutionary Connections
  • Evolution across the HRD at different metalicities
  • Evolution of angular momentum across the HRD
  • Role of magnetic fields
  • Binary vs. single-star evolution
2.  Late and End Phases
  • Post-RSG and blue-loop stars
  • Supernovae from red vs. blue progenitors
  • Gamma-ray bursts and their relation to W-R stars
  • Gamma-ray burst hosts as star-forming galaxies
3.  Atmospheres
  • Uncertainties of basic stellar parameters
  • State of the art models
  • Role of convection
  • Abundance determinations in hot and cool supergiants
4.  Mass Loss
  • Mass-loss rates across the upper HRD
  • Mass-loss mechanisms for hot and cool stars
  • Non-standard mechanisms - convection, magnetic fields
  • Episodic mass loss and pulsations in hot and cool stars
5.  Interacting Winds and Circumstellar Environments
  • Interaction between winds from different evolutionary phases
  • Role of shocks
  • Role of binaries, and relation to morphology
  • Resolved circumstellar material
  • Dust formation in RSGs, LBVs, OH-IR stars, W-R stars
See below for a list of invited speakers.

Proceedings of the meeting will be published in the Astronomical Society of the Pacific Conference Series, eds. C. Leitherer, P. Bennett, P. Morris, J. van Loon


The meeting will take place from Mon-Wed., the 10-12th of November 2008, on the Caltech campus.  Attendance must be limited to 80 participants.

For more information on the venue and transportation (including maps) please see Venue and Transportation.

Mt. Wilson Observatory Excursion:

Mt. Wilson
Image courtesy of
Workshop participants are invited to join a guided excursion to the historic Mt. Wilson Observatory on Thursday 13 November. The Observatory is located in the nearby scenic San Gabriel mountains overlooking the LA basin. It hosts the famous 60 - inch and 100-inch optical telescopes, the Snow and 60- and 150-foot solar towers, the innovative optical/IR CHARA and mid-infrared ISI interferometers.

Please indicate your interest in the excursion at the workshop registration page. Costs are expected to be around ~$25/person, payable at registration time. Transportation and lunch arrangements will be provided. We will leave from the Caltech campus around noon and are expected to return 5-6 PM.

Invited Speakers (confirmed):
  • P. Bennett (St. Mary's Univ)
  • C. Crowley (Trinity College)
  • B. Davies (Rochester Inst. Tech.)
  • A. Gal-Yam (Caltech)
  • G. Harper (Univ Colorado)
  • A. Heger (Univ Minnesota)
  • J. Hillier (Univ Pittsburgh)
  • R. Hirschi (Keele Univ)
  • R. Humphreys (Univ Minnesota)
  • C. Kemper (Univ Manchester)
  • G. Koenigsberger (UNAM)
  • C. Leitherer (STScI)
  • E. Levesque (Univ Hawaii)
  • J. van Loon (Keele Univ)
  • P. Massey (Lowell Obs)
  • J. Monnier (Univ Michigan)
  • P. Morris (Caltech)
  • S. Owocki (Univ Deleware)
  • B. Plez (Univ Montpellier)
  • N. Smith (Univ Cal/Berkeley)

  • Scientific Organizing Committee: Local Organizing Comittee:
  • P. Bennett (St. Mary's Univ)
  • G. Koenigsberger (UNAM)
  • C. Leitherer (STScI) - chair
  • J. van Loon (Keele Univ)
  • P. Massey (Lowell Obs)
  • J. Monnier (Univ Michigan)
  • P. Morris (Caltech/NHSC)
  • S. Owocki (Univ Delaware)
  • N. Smith (Univ Cal/Berkeley)
  • A. Boogert (Caltech/NHSC)
  • S. van Dyk (Caltech/SSC)
  • W. Latter (Caltech/NHSC)
  • A. McCrary (Caltech/NHSC)
  • M.E. McElveney (Caltech/NHSC)
  • P. Morris (Caltech/NHSC) - chair
  • H. Mycroft (Caltech/JPL)
  • R. Scholey (Caltech/IPAC)
  • E. Scire (Caltech/SSC)
  • S. Stolovy (Caltech/SSC)
  • Contact:

    If you have any questions or concerns, please email

    Infrared Processing and Analysis CenterJet Propulsion LaboratoryNASA