Binary systems:from 0.2 arcsec to 2 deg

Double stars

observers 2010

José Antonio CaballeroCentro de Astrobiología (CSIC-INTA), Madrid

Caballero 2006, PhD

Formation, evolution and multiplicity of brown dwarfs and giant exoplanets

Planets in close orbits: search for transits ( photometric variability)

Planets in wide orbits: deep wide imaging

No planets with CAIN-II/1.5m TCS… An example, a stable, “single” brown dwarf: Kelu 1

Caballero 2006, PhD

Substellar objectsDe fuscis pusillis astris et giganteis exoplanetis

Object2H

burning

1H burning

Mass(Msol

[MJup])

(Zsol)

star yes yes>0.075 [> 72]

Sub-stella

r objec

t

Brown

dwarf

yes no0.075-0.013 [72-14]

Planet no no

<0.013 [< 14]

Caballero 2006, PhD

Search for very low-mass objects surrounding nearby young stars

Direct imaging with near-infrared adaptive optics systems at 4 m-class telescopes:

• Naomi+Ingrid / 4.2 m WHT

• Alfa+Omega-Cass / 3.5 m Calar Alto

• AdOpt-at-TNG / 3.6 m Telescopio Nazionale Galileo

And coronography with:

• NICMOS / Hubble Space Telescope

Caballero 2006, PhD

Search for very low-mass objects surrounding nearby young stars

Complement: wide-field search with CAIN-II / TCS and other instruments

Able to detect all brown dwarfs at s > 50 AU and all planets with M > 0.008 Msol at s > 100 AU...

Example: G 196-3A and B, a young star in the Local Association with an L-type companion of… 0.020-0.030 Msol

Caballero 2006, PhD

HD 189087 AB: from 7 x 7 arcmin2 to 3 x 3 arcsec2

Caballero 2006, PhD

Search for very low-mass objects surrounding nearby young stars

51 systems with features of youth (lithium, chromospheric activity, X-ray emission, membership in moving groups):- 44 with ages 600 Ma- 32 with ages 100 Ma

* 3-4 new stellar companions * Upper limits on the frequency of companions* BUT...

AB Dor CHD 160934 ACHN Peg B

Caballero 2006, PhD

Search for very low-mass objects surrounding nearby young stars

51 systems with features of youth (lithium, chromospheric activity, X-ray emission, membership in moving groups):- 44 with ages 600 Ma- 32 with ages 100 Ma

* 3-4 new stellar companions * Upper limits on the frequency of companions* BUT...

AB Dor CHD 160934 ACHN Peg B

Caballero+

“De Mayrit al cielo”: Orionis cluster ( ~ 3 Ma, d ~ 385 pc)

The most complete initial mass function (from 18 to 0.003 Msol)

Brown dwarfs (with discs, X-ray emission, H emission…) and “isolated” planetary-mass objects

Caballero 2009,

CoolStars15

“De Mayrit al cielo”: Orionis cluster ( ~ 3 Ma, d ~ 385 pc)

Very wide binaries + Statistical approach

• 3 resolved systems with probabilities of alignement by chance of 1% (2 are triple)

• Separations: 7.6-14.1 arcsec (2700-5100 AU)

• And…

Caballero et al.

2006, A&A

“De Mayrit al cielo”: Orionis cluster ( ~ 3 Ma, d ~ 385 pc)

“B”: S Ori 68: L5.0, ~5 MJup, H

“A”: [SE2004] 70: M6.0, ~45 MJup, low-gravity, X-ray flare, H, radial velocity, Li I

= 4.6 arcsec s =1700 AU

The widest “planetary” system?

Caballero+

“De Mayrit al cielo”: Orionis cluster ( ~ 3 Ma, d ~ 385 pc)

Important because:• it illuminates the Horsehead Nebula• X-ray emitter population• discs at 3 Ma• a helium-rich, magnetically-active B2Vp star• Herbig-Haro objects• accretion rates and frequency…

Caballero 2006, PhD

Ori (Uranometria: Bayer 1603)

48 Ori (Flamsteed’s catalogue: Flamsteed 1712)

BD-02 1326 (Bonner Durchmusterung des sudlichen Himmels: Schonfeld 1886)

HD 37468 (Henry Draper catalogue: Cannon & Pickering 1925)

Caballero 2007, AN

Ori E (Tabula Nova Stellarum Duplicium: Mayer 1779)

Ori C, D (Struve et al. 1876)

Ori B (Burnham 1892)

Caballero 2005, AN

10 000 AU

A near-IR counterpart of a mid-IR source: Ori IRS1, an evaporating proplyd?

Also detected in X-rays (Caballero et al. 2010, A&A)

Caballero in prep.

Ori B

Ori IRS1

Ori A

On-going high-resolution (lucky) imaging (with FastCam/1.5 m TCS)

A*: O9.5V, 18 Msol

B: B0.5V, 12 Msol

C: A2.0V, 2.7 Msol

D: B2.0V, 6.8 Msol

E: B2.0Vp, 7.4 Msol

Caballero in prep.

Angular separation of ~ 0.26 arcsec (with FastCam/2.5 m NOT)

Un-published

Angular separation of ~ 0.26 arcsec (with FastCam/2.5 m NOT)

And NaCo/8.4 m VLT resolves Ori IRS1!

Caballero in prep.

Orionis: The most massive “binary” with an astrometric orbit (Mason et al.)

Caballero in prep.

Orionis: The most massive “binary” with an astrometric orbit (Mason et al.)

New fit:a = 0.264 0.006 arcsece = 0.0528 0.013i = 154.9 1.0 degP = 155.4 0.5 a

Simón-Díaz &

Caballero in prep.

On-going high-resolution spectroscopy

(P’~143 d; Aa: O9.5V, 18 Msol, Ab: B0V, 15 Msol)

TAa = 34 kK, vsini = 110km/sTAb = 32 kK, vsini = 30km/sTB = 31 kK, vsini = 60km/s

Up to 18+15+12 = 45 Msol!

Caballero 2008, A&A

Caballero et al.

2007, A&A

The mass function down to the planetary domain in the Orionis cluster

Derivation of the mass function from 0.11 to 0.006 Msol, with index = 0.4-0.6 (N/M M-; Salpeter: = 2.35).

Frequency of Orionis brown dwarfs with discs is 47 ± 9 %

Caballero et al.

2007, A&A

The mass function down to the planetary domain in the Orionis cluster

Derivation of the mass function from 0.11 to 0.006 Msol, with index = 0.4-0.6 (N/M M-; Salpeter: = 2.35).

Frequency of Orionis brown dwarfs with discs is 47 ± 9 %

Caballero 2007a,

A&A

Caballero 2007a,

A&A

Koenigstuhl 1AB: a serendipitous discovery…

A: LEHPM 494 [?]B: DENIS J0021.0-4244 [M9.5V] ~ 1.3 arcmin

B UK Schmidt 1977.6R ESO 1984.9IJK DENIS 1996.5R UK Schmidt 1996.6I UK Schmidt 1999.6JHKs 2MASS 1999.6[3.8:8.0] Spitzer 2004.0

Caballero 2007a,

A&A

Koenigstuhl 1AB: the (second) widest ultracool binary: a challenge for very low-mass formation ejection scenarios!

• = 77.76 ± 0.07 arcsec• d = 23 ± 2 pc• s = 1800 ± 170 AU• MA = 0.103 ± 0.006 Msol

• MB = 0.079 ± 0.004 Msol

Highlight of the week in A&A. Almost cover page!

Caballero 2007b,

ApJ

Koenigstuhl 2 AB: A new very low-mass star in a wide binary (the third widest system with MA + MB < 0.4 Msol)

Primary: LP 655-23(Luyten 1979)

Secondary: 2M0430-08 (M8.0V; Cruz et al. 2003)

• s = 450 ± 40 AU• MA = 0.26 ± 0.04 Msol

• MB = 0.086 ± 0.004 Msol

Caballero 2007b,

ApJ

Koenigstuhl 3 ABC: the widest system containing an L dwarf component

Primary: HD 221356(F8.0V; Hipparcos)

Secondary: 2M2331-04AB (M8.0V+L3.0V; Gizis et al. 2000, 2003)

= 7.530 ± 0.007 arcmin s = 11900 ± 300 AUMA = 1.02 ± 0.07 Msol

MBC = 0.088+0.072 Msol

Caballero, Miret et

al. in prep

A Virtual Observatory search for companions to Luyten stars

•20 physical systems with both star components in Hipparcos

• 29 physical systems with only one star component in Hipparcos

• 19 physical systems with no components in Hipparcos

• Half a dozen new serendipitously-discovered physical systems

Caballero et al.

2010, A&A

G 125-15 AB + G 125-14 = WDS 19312+3607(see paper in folder)

Caballero et al.

2010, A&A

Caballero 2009, A&A

Reaching the boundary between stellar kinematic groups and very wide binaries. I

• WDS stars with the widest angular separations ( > 999 arcsec): N=30

• Visual or unidentified doubles: N=23

• Physical double candidates: N=7 (including Centauri A, B and C)

Caballero 2009, A&A

Reaching the boundary between stellar kinematic groups and very wide binaries. I

• Six stars with s > 0.1 pc (previously assumedupper limit to the distribution of wide binary semimajor axes)

• Four stars with s > 0.2 pc

• Comparison of gravitational binding energies (U=-GMAMB/r)

Caballero 2009, A&A

Caballero 2010, A&A

Reaching the boundary between stellar kinematic groups and very wide binaries. II

The widest binary!

Caballero 2007a,

A&A

Caballero & ???

Future:

• Luyten stars (& Miret et al.)

• nearby young stars (& Alonso-Floriano, Montes)

• ultracool dwarfs (& Montes)

• and much, much more…

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