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WAVELENGTH SHIFTS IN SOLAR-TYPE SPECTRA  ! Dainis Dravins, Lennart Lindegren, Hans-Günter Ludwig, Søren Madsen Lund Observatory, Sweden Cool Stars 13, Hamburg, July 2004

WAVELENGTH SHIFTS !  Usually interpreted as “Radial velocity”

"Definition" of radial velocity "The radial component is stellar movement toward or away from us. This motion must be measured from a star's spectrum." C.De Pree & A.Axelrod: The Complete Idiot's Guide to Astronomy, p.258 (1999)

Astrometric radial velocities I Dravins, Lindegren & Madsen, A&A 348, 1040

Astrometric radial velocities II Dravins, Lindegren & Madsen, A&A 348, 1040

Astrometric radial velocities III Dravins, Lindegren & Madsen, A&A 348, 1040

Pleiades from Hipparcos Proper motions over 120,000 years

STARPATHS (200,000 y) Madsen, Dravins & Lindegren, A&A 381, 446

Hyades from Hipparcos D. Dravins, IAU Symp. 215 (2004)

Hyades lineshifts Madsen, Dravins & Lindegren, A&A 381, 446

Gravitational redshifts D. Dravins IAU Symp. 210

STELLAR GRANULATION Hans-Günter Ludwig (Lund)

“Beta Hydri” [G2 IV] Synthetic Fe I line & mirror profile Dravins, Lindegren, Nordlund & VandenBerg, ApJ 403, 385

Lineshift & stellar rotation Madsen, Dravins & Lindegren, A&A 381, 446 & Dravins, IAU Symp. 215

Atmospheric shockwaves (Hartmut Holweger, Kiel)

PROGRESS IN SCIENCE is driven by...  Confrontation between theory and observation  Falsification of theoretical hypotheses  New observational measures requiring explanation

PROGRESS IN SCIENCE is not driven by...  Agreement between theory and observation (when they agree, not much new can be learned)

PROGRESS IN STELLAR PHYSICS Requires disagreement between theory and observation !

Non-LTE in convective lineshifts Dravins & Nordlund, A&A 228, 184 Dravins, IAU Symp. 210

Fe II lineshifts at solar disk center Dravins, IAU Symp. 210 Solar data: Allende Prieto & García López, A&AS 131, 341 Laboratory wavelengths: S. Johansson (Lund)

Fe II lineshifts at solar disk center Aleksey Gadun 2-D models by Aleksey Gadun, Kyiv, Ukraine Dravins, IAU Symp. 210

Ni I lineshifts at solar disk center Dravins, IAU Symp. 210 Solar data: Allende Prieto & García López, A&AS 131, 341 Laboratory wavelengths: U. Litzén, J.W.Brault, A.P.Thorne, Phys.Scr. 47, 628

429 Ti I bisectors at solar disk center Solar data: “Hamburg photosphere” H. Neckel, Solar Phys. 184, 421 Kurucz et al.: Solar Flux Atlas from 296 to 1300 nm Laboratory wavelengths: P. Forsberg, Phys.Scr. 44, 446 U. Litzén (Lund)

Same spectral line in different stars Dravins, IAU Symp. 210 Adapted from Dravins & Nordlund, A&A 228, 203

IMAGING STELLAR SURFACES ESO VLTI : AT1 and domes of the 8.2 m unit telescopes

Same spectral line in different stars Adapted from Dravins & Nordlund, A&A 228, 203

IMAGING STELLAR SURFACES

Optical VLA Antoine Labeyrie (Laboratoire d'Interférométrie Stellaire et Exo-planétaire)

WAVELENGTH SHIFTS ! A new diagnostic tool for stellar physics enabled by...  Astrometric radial velocities throughout the Hertzsprung-Russell diagram  High-resolution spectrometers with accurate wavelength calibration  Accurate laboratory wavelengths for several atomic species

The End

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Astrometric radial velocities from perspective acceleration Dravins, Lindegren & Madsen, A&A 348, 1040

UNDERSTANDING STELLAR SURFACES theory and observations interact about...  Spectral-line strengths  Spectral-line widths  Line-profile shapes  Line asymmetries and bisector patterns  Time variability in irradiance and spectrum  Stellar surface imaging  Relative & absolute wavelength shifts