Una%20b

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Una búsqueda de compañeros de estrellas Luyten
con el Observatorio VirtualA search for
companions to Luyten stars with the Virtual
Observatory
José A. Caballero1 F. Xavier Miret2 Joan
Genebriera3 Tòfol Tobal2 Jordi Cairol2 David
Montes1 1 Dpto. de Astrofísica, Universidad
Complutense de Madrd 2 Observatori Astronòmic
del Garraf, Barcelona 3 Observatorio de Tacande,
La Palma
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Albus 1 (Caballero Solano 2007, ApJ, 665,
L151) Serendipitous discovery of a very bright
white dwarf candidate...
...that is actually one of the brightest He-B
subdwarfs (Vennes, Kawka Smith 2007, ApJ, 668,
L59 A. Ulla et al. in prep.)
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Koenigstuhl 1 AB (Caballero 2007a, AA, 462,
L61) The (second) widest ultracool binary a
challenge for very low-mass formation ejection
scenarios!

• Seven astrometric epochs since 1977.6 until
  2004.0
• r 77.76(7) arcsec
• d 23(2) pc
• r 1800(170) AU
• MA 0.103(6) Msol
• MB 0.079(4) Msol

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Koenigstuhl 2 AB (Caballero 2007d, ApJ, 667,
520) A new very low-mass star in a wide binary
the third widest system with MA MB lt 0.4 Msol
(in a draw)
Primary LP 655-23 (Luyten 1979) Secondary
2M0430-08 (M8.0V Cruz et al. 2003) r 450(40)
AU MA 0.26(4) Msol MB 0.086(4) Msol
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Koenigstuhl 3 ABC (Caballero 2007d, ApJ, 667,
520) The widest system containing an L dwarf
component
Frequency of wide multiples with late-type (gtM5)
components 5.0 1.8

• Primary HD 221356
• (F8.0V Hipparcos)
• Secondary 2M2331-04AB (M8.0VL3.0V Gizis et al.
  2000, 2003)
• r 7.530(7) arcmin !
• r 11900(300) AU
• MA 1.02(7) Msol
• MBC 0.0880.072 Msol

And Koenigstuhl 4 AB is coming! (Caballero, in
prep.)
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• The Garraf survey
• an Aladin-based search for common-, high-proper
  motion pairs
• The New Luyten Two Tenths (NLTT) catalogue
  (Luyten 1979), m gt 0.2 arcsec a-1
• Improved astrometry in Salim Gould (2003) 36
  000 stars
• Selection proper motions between 0.5 and 1.0
  arcsec a-1
• Still 1947 stars!
• Using Aladin instead of SuperCOSMOS Science
  Archive

Still a lot of work one person...
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The Garraf survey X.Miret, T.Tobal and
J.Cairol at the Observatori Astrònomic del
Garraf OAG (1976) a non-proffesional centre
dedicated to the study of visual double stars
OAG revised the Comellas 1973.0 and 1980.0
catalogues and coordinated most of
non-proffesional observations of doubles in Spain
from 1990 to 2003 OAG is one the main measurement
providers of the USNO Washington Double Stars
catalogue (104)
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• The Garraf survey
• Methodology
• Data loading and cross-matching USNO-B12MASS
• Proper-motion diagram and candidate selection
• Recovery of known pairs with incorrect USNO-B1
  proper motions with the proper motion filter
• One-by-one inspection of all selected binary
  candidates (SIMBAD, CCDM, Tycho-2...)

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• The Garraf Survey
• Current status
• 160 common-m candidate companions studied to
  date
• 86 rejected systems with bad USNO-B1 astrometry
• 8 pairs with different USNO-B1 proper motions
• 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
• 6 new serendipitously-discovered physical
  systems...

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• Joan Genebriera
• The Tacande astro-photometric follow-up
• A battery of small telescopes in La Palma 40,
  20, 15, 12, 9 cm
• 40 cm Cassegrain Relay, F6/5, with a CCD ST8XE

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Garraf 1AB An example of serendipitous
discovery... A G 125-15, M4.5e, X-ray,
variable, age 300 Ma (Daemgen et al. 2007) B G
125-14, M5.5? Known binary in Giclas et al.
(1971)
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Garraf 1AB A bright, young, very wide, low-mass
binary in the solar neighbourhood Multi-epoch
relative astrometry 1952 Jul 17 POSSI Red 1988
Jun 13 POSSII Blue 1992 Aug 31 POSSII Red 1993
Jun 13 POSSII Infrared 1998 Jun 01 2MASS 2001 Aug
26 CMC14 2008 Mar 07 Tacande
Age? r 46.0 0.3 arcsec ? 347.34 0.16
deg d 176-5 pc r 800300-200 AU MA
0.210.08-0.05 Msol MB 0. 120.04-0.03 Msol
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Garraf 1 AB Optical imaging and low-resolution
spectroscopy of Garraf 1AB with CAFOS / 2.2 m by
David Montes M4.5e M5.0e. Accurate BVRI
magnitudes. New astrometric epoch (2008 Apr 30)
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ConclusionsA search for companions to Luyten
stars with the Virtual ObservatoryWhat
will be a trained investigator be able do with
SDSS UKIDSS LSST GAIA...?
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