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) PHY 688 seminar in Spring 2009

2/35 Areas 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

3/35 Brown Dwarfs: Link between Stars and Giant Planets Burrows et al. (2001) stars brown dwarfs “planets” giant planet formation 13 M Jup 10 M Jup 5 M Jup 1 M Jup stars brown dwarfs “planets”  no H fusion  substellar objects  <0.08 M  ~ 80 M Jup  star-like formation  planet-like properties?  no H fusion  substellar objects  <0.08 M  ~ 80 M Jup  star-like formation  planet-like properties? M 73 M Jup 80 M Jup 211 M Jup = 0.2 M 

4/35 The Stellar/Substellar Continuum Sun M dwarfT dwarfL dwarfJupiter brown dwarfsplanetsstars 5700 K~3500 K ~2000 K~1000 K160 K (G dwarf) R. Hurt (Caltech/IPAC) visible light

5/35 Brown 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) WMAP

6/35 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?

7/35 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?

8/35 First L and T Dwarfs Discovered as Companions to Stars GD 165 B: first L dwarf U Hawai’i 2.2 m telescope Gl 229 B: first T dwarf Palomar 1.5 m discovery Palomar 1.5 m discovery Becklin & Zuckerman (1988); Nakajima et al. (1995) Hubble Telescope confirmation Hubble Telescope confirmation JHK

9/35 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) (AO) Gl 229 B 1″1″ HD A/B Palomar AO AO off AO on

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11/35 What Planets May Look Like  K s = 11.3 mag ( ) at 2.6”  K s = 13.6 mag ( ) at 3.3” Palomar 5m telescope + AO K s band (2.16µm); Neptune’s orbit (a = 30 AU)

12/35 Mazeh et al. (2003) planets10–15%browndwarfs<0.5%stars~22% Planet Detection: Precision Radial Velocity Context

13/35 Planet Detection: Direct Imaging Has Lagged planets brown dwarfs stars Chauvin (2007) HST, Gemini, Keck, VLT: now J S M 2 (M Jup ) Physical Separation (AU) conventional AO brown dwarf desert <0.5% companion frequency brown dwarf desert <0.5% companion frequency

14/35 Metchev & Hillenbrand (2008) Companion Imaging Survey Success Rates (r.v.) Survey sensitivity: <13 M Jup 13–30 M Jup >30 M Jup

15/35 Project 1  Search for faint substellar companions to stars  Characterize their atmospheres  Search for faint substellar companions to stars  Characterize their atmospheres Lick 3m California Keck 3m Hawaii Spitzer 0.9m Space Telescope

16/35 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? ???

17/35 Brown Dwarf Properties CIA H 2  L dwarfs (stars+brown dwarfs)  metallic hydrides, H 2, H 2 O  T dwarfs (brown dwarfs)  CH 4, H 2, H 2 O  L dwarfs (stars+brown dwarfs)  metallic hydrides, H 2, H 2 O  T dwarfs (brown dwarfs)  CH 4, H 2, H 2 O IRTF Spectral Library, Cushing et al. (2005) J H K

18/35 The Stellar/Substellar Continuum Sun M dwarfT dwarfL dwarfJupiter brown dwarfsplanetsstars 5700 K~3500 K ~2000 K~1000 K160 K (G dwarf) R. Hurt (Caltech/IPAC) visible light

19/35 The Stellar/Substellar Continuum Sun M dwarfT dwarfL dwarfJupiter brown dwarfsplanetsstars 5700 K~3500 K ~2000 K~1000 K160 K (G dwarf) R. Hurt (Caltech/IPAC) near-infrared light

20/35 Brown Dwarf Properties  L dwarfs (stars+brown dwarfs)  metallic hydrides, H 2, H 2 O  red in visible and in near-IR  T eff < 2300 K  T dwarfs (brown dwarfs)  CH 4, H 2, H 2 O  red in visible, vast color range in near-IR  T eff < 1400 K  L dwarfs (stars+brown dwarfs)  metallic hydrides, H 2, H 2 O  red in visible and in near-IR  T eff < 2300 K  T dwarfs (brown dwarfs)  CH 4, H 2, H 2 O  red in visible, vast color range in near-IR  T eff < 1400 K L T0–T4 T5–T8 visible LT near-IR LT F 2.1µm / F 1.6µm F 1.6µm / F 1.2µm

21/35 Finding Nearby Brown Dwarfs  near-IR 2MASS J MASS J (1.2µm)2MASS H (1.6µm)2MASS K S (2.1µm) POSS–I R (0.6µm)POSS–II R (0.6µm) Kirkpatrick et al. (1997) Strauss et al. (1999) SDSS i (0.8µm) SDSS z (0.9µm)

22/35 Most L’s and T’s Now Found from Large-Area Imaging Surveys >500~100>500~100 DwarfArchives.org

23/35 L T0–T4 T5–T8 10 –5 10 –4 10 –3 10 –2  (SpT) [pc –3 SpT –1 ] L0L5T0T5T8 Cool Brown Dwarfs: Numerous but Difficult to Find Burgasser (2006) ; Cruz et al. (2007) 2MASS

24/35 10 –5 10 –4 10 –3 10 –2  (SpT) [pc –3 SpT –1 ] L0L5T0T5T8 Burgasser (2006) ; Cruz et al. (2007) 2MASS ; Metchev et al. (2008) SDSS i SDSS z 2MASS K S 2MASS J z = 19.1 J = 15.9 Cool Brown Dwarfs: Use Database Cross-Correlation

25/35 Project 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 3m Hawaii Palomar 5m California

26/35 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? ???

27/35 From Stars to Disks to Planets Bok globules in IC 2944 HST/WFPC2 1´ = 0.5 pc Reipurth et al. (1997) Orion protoplanetary disks HST/WFPC2 O’Dell & Wien (1994) 1" = 400 AU  Pictoris debris disk 500 AU 25" (Kalas & Jewitt 1996) Beckwith (1996)

28/35 Disk evolution movie

29/35 Debris Disks: Context for the Solar System  zodiacal light, asteroid belt, Kuiper belt analogs Solar System debris disk (P. Kalas, UC Berkeley)  Pictoris debris disk 500 AU 25" (Kalas & Jewitt 1996) L IR / L star = 10 –3 10 Myr L IR / L star = 10 –7 4.5 Gyr

30/35 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)

31/35 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 model 23 µm grains HD diskHST/ACS (Ardila et al. 2004)

32/35 Evidence for Embedded Planets is Strong: Fomalhaut Kalas et al. (2005) HST/ACS a = 119 AU planet (Quillen 2006) 13" 100 AU

33/35 HD : A Face-on Ring Metchev et al., in preparation Solar System model Liou & Zook (1999) 50–200 AU (HST) HST survey of 40 more debris disks

34/35 Project 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 0.9m Space Telescope Hubble 2.4m Space Telescope

35/35  Imaging of substellar companions  Properties of nearby brown dwarfs  Modeling of debris disks  Imaging of substellar companions  Properties of nearby brown dwarfs  Modeling of debris disks Areas of Interest