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WAVELENGTH SHIFTS IN WAVELENGTH SHIFTS IN SOLAR-TYPE SPECTRASOLAR-TYPE SPECTRA
WAVELENGTH SHIFTS IN WAVELENGTH SHIFTS IN SOLAR-TYPE SPECTRASOLAR-TYPE SPECTRA
!Dainis Dravins, Lennart Lindegren, Hans-Günter Ludwig, Søren Madsen
Lund Observatory, Sweden
Cool Stars 13, Hamburg, July 2004
WAVELENGTH SHIFTS !WAVELENGTH SHIFTS !WAVELENGTH SHIFTS !WAVELENGTH SHIFTS !
Usually interpreted as “Radial
velocity”
"Definition" of radial velocity"Definition" of radial velocity"Definition" of radial velocity"Definition" of radial velocity
"The radial component is stellar movementtoward or away from us. This motion
mustbe measured from a star's spectrum."
C.De Pree & A.Axelrod: The Complete Idiot's
Guide to Astronomy, p.258 (1999)
Astrometric radial velocities IAstrometric radial velocities I
Dravins, Lindegren & Madsen, A&A 348, 1040
Astrometric radial velocities IIAstrometric radial velocities II
Dravins, Lindegren & Madsen, A&A 348, 1040
Astrometric radial velocities IIIAstrometric radial velocities III
Dravins, Lindegren & Madsen, A&A 348, 1040
Pleiades from Hipparcos Proper motions over 120,000 years
STARPATHS (200,000 y)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 GRANULATIONSTELLAR GRANULATION
Hans-Günter Ludwig (Lund)
“Beta Hydri” [G2 IV] Synthetic Fe I line & mirror
profileDravins, 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 SCIENCEPROGRESS IN SCIENCEPROGRESS IN SCIENCEPROGRESS IN SCIENCE
is driven by ...
Confrontation between theory and observation
Falsification of theoretical hypotheses
New observational measures requiring explanation
PROGRESS IN SCIENCEPROGRESS IN SCIENCEPROGRESS IN SCIENCEPROGRESS IN SCIENCE
is not driven by ...
Agreement between theory and observation
(when they agree, not much new can be learned)
PROGRESSPROGRESS ININ STELLARSTELLAR PHYSICSPHYSICSPROGRESSPROGRESS ININ STELLARSTELLAR PHYSICSPHYSICS
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
2-D models by Aleksey Aleksey
GadunGadun, 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 SURFACESIMAGING STELLAR SURFACESIMAGING STELLAR SURFACESIMAGING 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 SURFACESIMAGING STELLAR SURFACESIMAGING STELLAR SURFACESIMAGING STELLAR SURFACES
IMAGING STELLAR SURFACESIMAGING STELLAR SURFACESIMAGING STELLAR SURFACESIMAGING STELLAR SURFACES
Optical VLA
Antoine Labeyrie (Laboratoire d'Interférométrie Stellaire et Exo-planétaire)
WAVELENGTH SHIFTS !WAVELENGTH SHIFTS !WAVELENGTH SHIFTS !WAVELENGTH SHIFTS !
A new diagnostic tool for stellar physicsenabled 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
...
Astrometric radial
velocities from
perspective
acceleration
Dravins, Lindegren & Madsen, A&A
348, 1040
UNDERSTANDINGUNDERSTANDING STELLARSTELLAR
SURFACESSURFACESUNDERSTANDINGUNDERSTANDING STELLARSTELLAR
SURFACESSURFACES
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
