From Brown Dwarfs to Giant Planets
From Brown Dwarfs to Giant Planets
Stan Metchev(Stony Brook Astronomy Group)
Stan Metchev(Stony Brook Astronomy Group)
Artist’s rendition of a brown dwarf: R. Hurt (NASA)Artist’s rendition of a brown dwarf: R. Hurt (NASA)PHY 688 seminar in Spring 2009PHY 688 seminar in Spring 2009
2/352/35
Areas of InterestAreas of Interest
Imaging of brown dwarf companions to stars
Properties of nearby brown dwarfs
Modeling of circumstellar disks
Imaging of brown dwarf companions to stars
Properties of nearby brown dwarfs
Modeling of circumstellar disks
3/353/35
Brown Dwarfs: Link between Stars and Giant Planets
Brown Dwarfs: Link between Stars and Giant Planets
Burrows et al. (2001)Burrows et al. (2001)
starsbrown dwarfs“planets”
giant planet formationgiant planet formation
13 MJup10 M
Jup
5 MJup
1 MJupstars
brown dwarfs“planets”
no H fusion substellar objects
<0.08 M ~ 80 MJup
star-like formation planet-like
properties?
no H fusion substellar objects
<0.08 M ~ 80 MJup
star-like formation planet-like
properties?
M
73 MJup
80 MJup
211 MJup = 0.2 M
4/354/35
The Stellar/Substellar ContinuumThe Stellar/Substellar Continuum
Sun
M dwarf T dwarfL dwarf Jupiter
brown dwarfs planetsstars
5700 K ~3500 K ~2000 K ~1000 K 160 K
(G dwarf)
R. Hurt (Caltech/IPAC)R. Hurt (Caltech/IPAC)visible light
5/355/35
Brown Dwarfs: Population is UncertainBrown Dwarfs: Population is Uncertain detection is challenging more numerous than stars? relevance:
bottom of star-like formation galaxy mass-to-light ratios dark matter
detection is challenging more numerous than stars? relevance:
bottom of star-like formation galaxy mass-to-light ratios dark matter
Reid et al. (1999); Allen et al. (2005)Reid et al. (1999); Allen et al. (2005)WMAP€
N(M)∝M−α
6/356/35
Some Outstanding Questions
Some Outstanding Questions
????????????
What are the properties of substellar companions? can we image extrasolar planets?
What are the properties of isolated brown dwarfs? do cooler, planetary-mass objects exist in isolation?
How do planetary systems evolve? is the Solar System typical?
What are the properties of substellar companions? can we image extrasolar planets?
What are the properties of isolated brown dwarfs? do cooler, planetary-mass objects exist in isolation?
How do planetary systems evolve? is the Solar System typical?
7/357/35
Some Outstanding Questions
Some Outstanding Questions
????????????
What are the properties of substellar companions? can we image extrasolar planets?
What are the properties of isolated brown dwarfs? do cooler, planetary-mass objects exist in isolation?
How do planetary systems evolve? is the Solar System typical?
What are the properties of substellar companions? can we image extrasolar planets?
What are the properties of isolated brown dwarfs? do cooler, planetary-mass objects exist in isolation?
How do planetary systems evolve? is the Solar System typical?
8/358/35
First L and T Dwarfs Discovered as Companions to Stars
First L and T Dwarfs Discovered as Companions to Stars
GD 165 B: first L dwarfGD 165 B: first L dwarf
U Hawai’i 2.2 m telescopeU Hawai’i 2.2 m telescope
Gl 229 B: first T dwarfGl 229 B: first T dwarf
Palomar 1.5 m
discovery
Palomar 1.5 m
discovery
Becklin & Zuckerman (1988); Nakajima et al. (1995)Becklin & Zuckerman (1988); Nakajima et al. (1995)
Hubble Telescope
confirmation
Hubble Telescope
confirmation
J H K
9/359/35
Brown Dwarfs Companions to Stars
Brown Dwarfs Companions to Stars
independent constraints on substellar properties: age distance (luminosity) internal chemistry
lowest mass substellar companions: planets
young stars are optimal targets
independent constraints on substellar properties: age distance (luminosity) internal chemistry
lowest mass substellar companions: planets
young stars are optimal targets
Nakajima et al. (1995)Nakajima et al. (1995)
(AO)
Gl 229 B
1″
HD 18940 A/B
Palomar AO
AO off
AO on
11/3511/35
What Planets May Look LikeWhat Planets May Look Like
Ks = 11.3 mag (104.5) at 2.6”
Ks = 13.6 mag (105.4) at 3.3”
Palomar 5m telescope + AO
Ks band (2.16µm);
Neptune’s orbit(a = 30 AU)
12/3512/35Mazeh et al. (2003)Mazeh et al. (2003)
planetsplanets
10–15%10–15%
brownbrowndwarfsdwarfs<0.5%<0.5%
starsstars
~22%~22%
Planet Detection:Precision Radial Velocity Context
Planet Detection:Precision Radial Velocity Context
13/3513/35
Planet Detection:Direct Imaging Has Lagged
Planet Detection:Direct Imaging Has Lagged
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture.
plan
ets
brow
ndw
arfs
star
s
Chauvin (2007)
HST, Gemini, Keck, VLT: now
J
S
M2
(MJu
p)
Physical Separation (AU)
1
10
100
conventional AO
brown dwarf desert
<0.5% companion frequency
brown dwarf desert
<0.5% companion frequency
14/3514/35
Metchev & Metchev & Hillenbrand (2008)Hillenbrand (2008)
Companion Imaging Survey Success Rates
(r.v.)
Survey sensitivity:
<13 MJup
13–30 MJup
>30 MJup
15/3515/35
Project 1Project 1
Search for faint substellar companions to stars
Characterize their atmospheres
Search for faint substellar companions to stars
Characterize their atmospheres
Lick 3mCalifornia
Keck 3mHawaii
Spitzer 0.9mSpace Telescope
16/3516/35
Some Outstanding Questions
Some Outstanding Questions
What are the properties of substellar companions? can we image extrasolar planets?
What are the properties of isolated brown dwarfs? do cooler, planetary-mass objects exist in isolation?
How do planetary systems evolve? is the Solar System typical?
What are the properties of substellar companions? can we image extrasolar planets?
What are the properties of isolated brown dwarfs? do cooler, planetary-mass objects exist in isolation?
How do planetary systems evolve? is the Solar System typical?
????????????
17/3517/35
Brown Dwarf PropertiesBrown Dwarf Properties
CIA H2
L dwarfs (stars+brown dwarfs) metallic hydrides, H2, H2O
T dwarfs (brown dwarfs) CH4, H2, H2O
L dwarfs (stars+brown dwarfs) metallic hydrides, H2, H2O
T dwarfs (brown dwarfs) CH4, H2, H2O
IRTF Spectral Library, Cushing et al. (2005)IRTF Spectral Library, Cushing et al. (2005)
J H K
18/3518/35
The Stellar/Substellar ContinuumThe Stellar/Substellar Continuum
Sun
M dwarf T dwarfL dwarf Jupiter
brown dwarfs planetsstars
5700 K ~3500 K ~2000 K ~1000 K 160 K
(G dwarf)
R. Hurt (Caltech/IPAC)R. Hurt (Caltech/IPAC)visible light
19/3519/35
The Stellar/Substellar ContinuumThe Stellar/Substellar Continuum
Sun
M dwarf T dwarfL dwarf Jupiter
brown dwarfs planetsstars
5700 K ~3500 K ~2000 K ~1000 K 160 K
(G dwarf)
R. Hurt (Caltech/IPAC)R. Hurt (Caltech/IPAC)near-infrared light
20/3520/35
Brown Dwarf PropertiesBrown Dwarf Properties
L dwarfs (stars+brown dwarfs) metallic hydrides, H2, H2O red in visible and in near-IR Teff < 2300 K
T dwarfs (brown dwarfs) CH4, H2, H2O red in visible, vast color
range in near-IR Teff < 1400 K
L dwarfs (stars+brown dwarfs) metallic hydrides, H2, H2O red in visible and in near-IR Teff < 2300 K
T dwarfs (brown dwarfs) CH4, H2, H2O red in visible, vast color
range in near-IR Teff < 1400 K
L
T0–T4
T5–T8
visible
L T
near-IR
L TF2.1µm / F1.6µm
F1.
6µm /
F1.
2µm
21/3521/35
Finding Nearby Brown DwarfsFinding Nearby Brown Dwarfs
near-IRnear-IR2MASS J04454316+2540233
2MASS J (1.2µm) 2MASS H (1.6µm) 2MASS KS (2.1µm)
POSS–I R (0.6µm) POSS–II R (0.6µm)Kirkpatrick et al. (1997)Kirkpatrick et al. (1997) Strauss et al. (1999)Strauss et al. (1999)
SDSS i (0.8µm)
SDSS z (0.9µm)
22/3522/35
Most L’s and T’s Now Found from Large-Area Imaging Surveys
Most L’s and T’s Now Found from Large-Area Imaging Surveys
0
50
100
150
200
250
300
2MASS SDSS DENIS Companions Others
L
T
>500>500
~100~100
>500>500
~100~100
DwarfArchives.orgDwarfArchives.org
23/3523/35
L
T0–T4
T5–T810–5
10–4
10–3
10–2
(S
pT)
[pc
–3 S
pT–1
]
L0 L5 T0 T5 T8
Cool Brown Dwarfs: Numerous but Difficult to Find
Cool Brown Dwarfs: Numerous but Difficult to Find
Burgasser (2006)Burgasser (2006) ; Cruz et al. (2007); Cruz et al. (2007)
2MASS
24/3524/35
10–5
10–4
10–3
10–2
(S
pT)
[pc
–3 S
pT–1
]
L0 L5 T0 T5 T8
Burgasser (2006)Burgasser (2006) ; Cruz et al. (2007); Cruz et al. (2007)
2MASS
; Metchev et al. (2008); Metchev et al. (2008)
SDSS i SDSS z
2MASS KS2MASS J
z = 19.1
J = 15.9
Cool Brown Dwarfs: Use Database Cross-Correlation
Cool Brown Dwarfs: Use Database Cross-Correlation
25/3525/35
Project 2Project 2
complete nearby T dwarf census in SDSS + 2MASS
search for the coolest brown dwarfs
complete nearby T dwarf census in SDSS + 2MASS
search for the coolest brown dwarfs
NASA IRTF 3mHawaii
Palomar 5mCalifornia
26/3526/35
Some Outstanding Questions
Some Outstanding Questions
What are the properties of substellar companions? can we image extrasolar planets?
What are the properties of isolated brown dwarfs? do cooler, planetary-mass objects exist in isolation?
How do planetary systems evolve? is the Solar System typical?
What are the properties of substellar companions? can we image extrasolar planets?
What are the properties of isolated brown dwarfs? do cooler, planetary-mass objects exist in isolation?
How do planetary systems evolve? is the Solar System typical?
????????????
27/3527/35
From Stars to Disks to PlanetsFrom Stars to Disks to Planets
QuickTime™ and aTIFF (Uncompressed) decompressor
are needed to see this picture. Bok globules in IC 2944HST/WFPC2
1´ = 0.5 pc
Reipurth et al. (1997)
Orion protoplanetary disksHST/WFPC2
O’Dell & Wien (1994)
1" = 400 AU
Pictoris debris disk
500 AU
25"
(Kalas & Jewitt 1996)
Beckwith (1996)
29/3529/35
Debris Disks:Context for the Solar System
Debris Disks:Context for the Solar System
zodiacal light, asteroid belt, Kuiper belt analogs
zodiacal light, asteroid belt, Kuiper belt analogs
Solar System debris disk
(P. Kalas, UC Berkeley)
Pictoris debris disk
500 AU
25"
(Kalas & Jewitt 1996)
LIR / Lstar = 10–3
10 Myr
LIR / Lstar = 10–7
4.5 Gyr
30/3530/35
Debris Disks:Context for the Solar System
Debris Disks:Context for the Solar System
zodiacal light, asteroid belt, Kuiper belt analogs
comets
zodiacal light, asteroid belt, Kuiper belt analogs
comets
Beichman et al. (2005)
31/3531/35
Debris Disks:Context for the Solar System
Debris Disks:Context for the Solar System
zodiacal light, asteroid belt, Kuiper belt analogs
comets
embedded planets
zodiacal light, asteroid belt, Kuiper belt analogs
comets
embedded planets
(Liou & Zook 1999)60 AU
Solar System model23 µm grains
HD 107146 disk HST/ACS
(Ardila et al. 2004)
32/3532/35
Evidence for Embedded Planets is Strong: Fomalhaut
Evidence for Embedded Planets is Strong: Fomalhaut
Kalas et al. (2005)HST/ACS
a = 119 AU planet (Quillen 2006)
13"100 AU
33/3533/35
HD 107146: A Face-on RingHD 107146: A Face-on Ring
Metchev et al., in preparation
Solar System modelLiou & Zook (1999)
50–200 AU
(HST)
HST survey of 40 more debris disks
34/3534/35
Project 3Project 3
Analyze the properties of circumstellar debris disks
Search for dynamical evidence of embedded planets
Analyze the properties of circumstellar debris disks
Search for dynamical evidence of embedded planets
Spitzer 0.9mSpace Telescope
Hubble 2.4mSpace Telescope