Diagnostics of Inhomogeneity in the Outer Atmospheres/Winds of M Supergiants
The Physical Properties of Red Supergiants Emily Levesque IfA, University of Hawaii/SAO, Harvard Hot...
-
Upload
georgina-mcgee -
Category
Documents
-
view
214 -
download
0
Transcript of The Physical Properties of Red Supergiants Emily Levesque IfA, University of Hawaii/SAO, Harvard Hot...
The Physical The Physical Properties of Red Properties of Red
SupergiantsSupergiants
Emily Levesque Emily Levesque
IfA, University of Hawaii/SAO, HarvardIfA, University of Hawaii/SAO, Harvard
Hot Massive Stars: A Lifetime of InfluenceHot Massive Stars: A Lifetime of InfluenceLowell Observatory Lowell Observatory
10.13.0810.13.08
Collaborators:Collaborators:Philip Massey (Lowell Observatory)Philip Massey (Lowell Observatory)
Knut Olsen (NOAO) Knut Olsen (NOAO)
Bertrand Plez (Université de Bertrand Plez (Université de Montpellier)Montpellier)
Eric Josselin (Université de Eric Josselin (Université de Montpellier)Montpellier)
Andre Maeder (Geneva Observatory)Andre Maeder (Geneva Observatory)
Georges Meynet (Geneva Observatory)Georges Meynet (Geneva Observatory)
Geoff Clayton (Louisiana State Geoff Clayton (Louisiana State University)University)
Dave Silva (NOAO/TMT)Dave Silva (NOAO/TMT)
Brian Skiff (Lowell Observatory)Brian Skiff (Lowell Observatory)
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
What What isis a red a red supergiant?supergiant?
Red supergiants are a Red supergiants are a He-He-burningburning evolutionary stage evolutionary stage of of moderately high-mass moderately high-mass (10 - 40 M(10 - 40 M)) stars. stars.
• physically largest stars in the physically largest stars in the universeuniverse
• high visual luminosities (Mhigh visual luminosities (MVV = -6 = -6 to -9) allow study beyond our to -9) allow study beyond our galaxygalaxy
• populate upper right region of populate upper right region of HRD HRD
Red Supergiants and the H-R Red Supergiants and the H-R DiagramDiagram
Why are we interested in Why are we interested in them?them?
Massive star evolutionary tracks didn’t agree with the position of red supergiants on the H-R diagram.
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2005
Hayashi Hayashi limit limit
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2005
forbiddenforbidden region region
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
Red Supergiants and the H-R Red Supergiants and the H-R DiagramDiagram
Why are we interested in them?Why are we interested in them?
Massive star evolutionary tracks don’t agree with the position of red supergiants on the H-R diagram.
Why?- Difficulties with the evolutionary tracks:
uncertain opacities highly extended atmosphere high-velocity convective layers
- …or problems with the observationally-determined location of these stars
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2005
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
Fitting Red Supergiant SpectraFitting Red Supergiant Spectra
How do I get the parameters from How do I get the parameters from spectral fitting?spectral fitting?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
Fitting Red Supergiant SpectraFitting Red Supergiant Spectra
How do I get the parameters from How do I get the parameters from spectral fitting?spectral fitting?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
TiO band strengthsTiO band strengths
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
Fitting Red Supergiant SpectraFitting Red Supergiant Spectra
How do I get the parameters from How do I get the parameters from spectral fitting?spectral fitting?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2005
We can fit spectrophotometry of RSGswith the MARCS stellar atmosphere models:
K2 I 4000 K K5 I 3750 K
M3 I 3500 KM1 I 3625 K
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2005
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
Determining Physical Determining Physical PropertiesProperties What we observe: , ,
What we want:
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.QuickTime™ and a
TIFF (LZW) decompressorare needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
MW
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2005
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
Levesque et al. 2005
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
Excess NUV flux, correlated with high “excess”
reddening excess circumstellar dust
adapted from Levesque et al. 2005
Dust and Red SupergiantsDust and Red Supergiants• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
For Milky Way RSGs, dust production rate is about8.5 x 10-9 M yr-1 kpc2
In starburst galaxies at large lookback times, we would expect RSGs to be major contributors to the ISM
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
• What are the mechanisms that drive this dust production?
• How does this mass-loss relation change with metallicity?
• What reddening law does the dust follow? How does this affect our determinations of RSG luminosities?
Dust and Red SupergiantsDust and Red Supergiants• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
VY Canis MajorisVY Canis Majoris: a particularly unusual RSG -extraordinarily luminous -large dust reflection nebula, high mass loss rate -previous work assigned a very cold temperature (2800 K)
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
adapted from Massey et al. 2006
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
!
VY CMa
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
VY Canis MajorisVY Canis Majoris: a particularly unusual RSG -extraordinarily luminous -large dust reflection nebula, high mass loss rate -previous work assigned a very cold temperature (2800 K)
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
3650 K
3450 K
Massey et al. 2006
VY CMa
We measured a much warmer temperature of ~3650 K, which in turn suggests a much smaller radius and a lower luminosity.
(note additional fit in the blue, showing a disparity between red and blue lines)
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
adapted from Massey et al. 2006
but…but…
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
- luminosity of dust emission is ~5 times higher than our reported VY CMa luminosity!
- suggests our measure of the luminosity is too low
Smith et al. 2001
…our luminosity estimate is contradicted by VY CMa’s measured thermal dust emission
One explanation: If the circumstellar dust envelope is large-grain and “grey”, this would lead to our underestimate of VY CMa’s luminosity.
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
Red Supergiants in the Magellanic Red Supergiants in the Magellanic CloudsClouds
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
Levesque et al. 2006
0.47Z
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
Red Supergiants in the Magellanic Red Supergiants in the Magellanic CloudsClouds
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
Levesque et al. 2006
0.47Z
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
Levesque et al. 2006
0.47Z
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
SMCSMC
0.27Z
Levesque et al. 2006
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
LMC SMC
Milky Way
Levesque et al. 2006
Red Supergiants in the Magellanic Red Supergiants in the Magellanic CloudsClouds
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
0.47Z
New effective temperature scales give much better agreement with the LMC:
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
Levesque et al. 2006
0.47Z
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
Levesque et al. 2006
0.47Z
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
0.47Z
New effective temperature scales give much better agreement with the LMC:
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
Levesque et al. 2006
0.47Z
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
Levesque et al. 2006
0.47Z
But when it comes to the SMC…
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
SMCSMC
0.27Z
Levesque et al. 2006
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
There’s still a few problems…
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
SMCSMC
0.27Z
Levesque et al. 2006
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
There’s still a few problems…
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
SMCSMC
0.27Z
Levesque et al. 2006
weaker MS stellar winds at low metallicityincreased rotational mixing as a resultenhanced He abundance from mixing
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
0.47Z
The cool new LMC RSG: WOH The cool new LMC RSG: WOH G64G64
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
Levesque et al. 2006
0.47Z
van Loon et al. (2005) placed it similarly to VY CMa…
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
0.47Z
The cool new LMC RSG: WOH The cool new LMC RSG: WOH G64G64
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
Levesque et al. 2006
0.47Z
Ohnaka et al. (2008) recently updated its luminosity…
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
0.47Z
The cool new LMC RSG: WOH The cool new LMC RSG: WOH G64G64
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
LMCLMC
Levesque et al. 2006
0.47Z
We suspect that Teff still needs to be re-examined…
?
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
The average RSG subtype in the Clouds shifts to earlier types with decreasing metallicity:
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
adapted from Massey & Olsen 2003
K0-1 K2-5 K5-7 M0 M1 M2 M3 M4 M5
Milky Way Z
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
The average RSG subtype in the Clouds shifts to earlier types with decreasing metallicity:
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
adapted from Massey & Olsen 2003
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
LMC 0.47Z
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
K0-1 K2-5 K5-7 M0 M1 M2 M3 M4 M5
The average RSG subtype in the Clouds shifts to earlier types with decreasing metallicity:
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
adapted from Massey & Olsen 2003
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
SMC 0.27Z
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
K0-1 K2-5 K5-7 M0 M1 M2 M3 M4 M5
Shift in Spectral SubtypeShift in Spectral Subtype
1) Line depth effects from changing metallicity
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2005
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2005
K2 I K5 I
M1 I M3 I
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
3650 K M2 I (MW), M1-1.5 I (LMC), K5-M0 I (SMC)
LMC SMC
Milky Way
Shift in Spectral SubtypeShift in Spectral Subtype
1) Line depth effects from changing metallicity
Levesque et al. 2006
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
Shift in Spectral SubtypeShift in Spectral Subtype
2) Metallicity-dependent shift of Hayashi limit
Limits of hydrostatic equilibrium get warmer at lower metallicities, imposing limits on how cool (and hence, how late-type), massive stars can get…
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2006
Milky Way
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
Shift in Spectral SubtypeShift in Spectral Subtype
2) Metallicity-dependent shift of Hayashi limit
Limits of hydrostatic equilibrium get warmer at lower metallicities, imposing limits on how cool (and hence, how late-type), massive stars can get…
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2006
LMC
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
Shift in Spectral SubtypeShift in Spectral Subtype
2) Metallicity-dependent shift of Hayashi limit
Limits of hydrostatic equilibrium get warmer at lower metallicities, imposing limits on how cool (and hence, how late-type), massive stars can get…
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2006
SMC
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
The Late-Type Red Supergiant The Late-Type Red Supergiant SampleSampleDespite evolutionary limitations, some Cloud RSGs are later than would be expected
Investigated the properties of 7 late-type LMC stars and 5 late-type SMC stars, reobserved in 2005
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
M 4.5
M 3-4
SMC 055188
LMC 143035
Levesque et al. 2007
SMC average is K5-M0
LMC average is M 1
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
HV 11423HV 11423 - an unusual find in the SMC
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
Date of Observation2004
Spectral Type:K0 I
Temperature:4300
Reddening (AV):
1.35
V magnitude:11.84
Bolometric magnitude:-9.1
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
HV 11423HV 11423 - an unusual find in the SMC
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
Date of Observation2004 2005
Spectral Type:K0 I M4 I
Temperature:4300 3500
Reddening (AV):
1.35 0.10
V magnitude:11.84 12.46
Bolometric magnitude:-9.1 -8.5
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
HV 11423HV 11423 - an unusual find in the SMC
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
Date of Observation2004 2005
Spectral Type:K0 I M4 I
Temperature:4300 3500
Reddening (AV):
1.35 0.10
V magnitude:11.84 12.46
Bolometric magnitude:-9.1 -8.5
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
HV 11423HV 11423 - an unusual find in the SMC
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Date of Observation2004 2005
Spectral Type:K0 I M4 I
Temperature:4300 3500
Reddening (AV):
1.35 0.10
V magnitude:11.84 12.46
Bolometric magnitude:-9.1 -8.5
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
HV 11423HV 11423 - an unusual find in the SMC
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
Date of Observation2004 2005
Spectral Type:K0 I M4 I
Temperature:4300 3500
Reddening (AV):
1.35 0.10
V magnitude:11.84 12.46
Bolometric magnitude:-9.1 -8.5
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
20042004
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
HV 11423HV 11423 - an unusual find in the SMC
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
Date of Observation2004 2005
Spectral Type:K0 I M4 I
Temperature:4300 3500
Reddening (AV):
1.35 0.10
V magnitude:11.84 12.46
Bolometric magnitude:-9.1 -8.5
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
20052005
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
HV 11423HV 11423 - an unusual find in the SMC
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
Date of Observation2004 2005
Spectral Type:K0 I M4 I
Temperature:4300 3500
Reddening (AV):
1.35 0.10
V magnitude:11.84 12.46
Bolometric magnitude:-9.1 -8.5
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Massey et al. 2007
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423• Where to next?
When HV 11423 gets warmer it is also brighter, dustier, and more luminous.
Three more Three more “unusual “unusual finds”…finds”…
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
M4.5 I
M1.5 I
M4.5 I
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
M2 I
M4.5 I
M3-4 I
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Mo I
M2 I
K2-3 I
Levesque et al. 2007
Two more SMC stars and one LMC star exhibit the same unusual behaviors: when these stars are warmer they are also brighter, dustier, and more luminous.
While V variability in RSGs is common, such spectral variability is unheard of!
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423 & Co.!• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2007
20042004
Two more SMC stars and one LMC star exhibit the same unusual behaviors: when these stars are warmer they are also brighter, dustier, and more luminous.
Three more Three more “unusual “unusual finds”…finds”…
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423 & Co.!• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2007
20052005
Two more SMC stars and one LMC star exhibit the same unusual behaviors: when these stars are warmer they are also brighter, dustier, and more luminous.
Three more Three more “unusual “unusual finds”…finds”…
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423 & Co.!• Where to next?
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Levesque et al. 2007
We suspect that these stars are in a unique unstable We suspect that these stars are in a unique unstable evolutionary state not previously observed in red supergiants.evolutionary state not previously observed in red supergiants.
Two more SMC stars and one LMC star exhibit the same unusual behaviors: when these stars are warmer they are also brighter, dustier, and more luminous.
Three more Three more “unusual “unusual finds”…finds”…
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423 & Co.!• Where to next?
Where To Next?Where To Next? Continuing to expand our
metallicity rangeIn published work: factor of 4In Local Group: factor of 15!
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423 & Co.!• Where to next?
Where To Next?Where To Next? Continuing to expand our
metallicity rangeIn published work: factor of 4In Local Group: factor of 15!
M31: 2Z 2Z
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423 & Co.!• Where to next?
Where To Next?Where To Next? Continuing to expand our
metallicity rangeIn published work: factor of 4In Local Group: factor of 15!
M31: 2Z…Z? Z
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423 & Co.!• Where to next?
Where To Next?Where To Next? Continuing to expand our
metallicity rangeIn published work: factor of 4In Local Group: factor of 15!
M31: 2Z…Z?
WLM: 0.12Z
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Local Group Galaxy Local Group Galaxy SurveySurvey
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423 & Co.!• Where to next?
Where To Next?Where To Next? Continuing to expand our
metallicity rangeIn published work: factor of 4In Local Group: factor of 15!
M31: 2Z…Z?
WLM: 0.12Z
Improved studies of RSGs and dust
Study these variables in more detail!
- What effect does this behavior have on stellar yields and mass-loss-dependent properties?- What new properties and environmental effects should evolutionary models strive to accommodate?- What will these variable stars evolve into?
• Galactic RSGs - Teff scale - H-R Diagram - Dust & VY CMa• Cloud RSGs - H-R Diagram - WOH-G64 - Spectral types• HV 11423 & Co.!• Where to next?