E. Solano¹, N. Lodieu², M. Aberasturi¹, M.R. Zapatero-Osorio¹, E. Martín¹ 1.- Centro de Astrobiología (INTA-CSIC), Madrid, Spain 2.- Instituto de Astrofísica de Canarias, Tenerife, Spain Discovery of ultracool subdwarfs using Virtual Observatory tools
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E. Solano¹, N. Lodieu², M. Aberasturi¹, M.R. Zapatero-Osorio¹, E. Martín¹ 1.- Centro de Astrobiología (INTA-CSIC), Madrid, Spain 2.- Instituto de Astrofísica.
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E. Solano¹, N. Lodieu², M. Aberasturi¹,
M.R. Zapatero-Osorio¹, E. Martín¹
1.- Centro de Astrobiología (INTA-CSIC), Madrid, Spain
2.- Instituto de Astrofísica de Canarias, Tenerife, Spain
Discovery of ultracool subdwarfs
using Virtual Observatory tools
Ultracool subdwarfs: properties
• Metal-poor dwarfs with spectral type later than M7.Metal-poor dwarfs with spectral type later than M7.
• Less luminous (actually hotter) than their solar-metallicity Less luminous (actually hotter) than their solar-metallicity
counterparts due to the dearth of metals in their atmospheres.counterparts due to the dearth of metals in their atmospheres.
• Metal-poor dwarfs with spectral type later than M7.Metal-poor dwarfs with spectral type later than M7.
• Less luminous (actually hotter) than their solar-metallicity Less luminous (actually hotter) than their solar-metallicity
counterparts due to the dearth of metals in their atmospheres.counterparts due to the dearth of metals in their atmospheres.
Ultracool subdwarfs: Identification
• Halo regionsHalo regions
• No contamination by disk stars.No contamination by disk stars.
• Low luminosity.Low luminosity.
• Trigonometrical parallaxes and spectra unobtainable.Trigonometrical parallaxes and spectra unobtainable.
• Solar neighbourhoodSolar neighbourhood
• Low luminosity.Low luminosity.
• Hard to find because of their local scarcity (4 out of 348 at d<10 pc, Henry Hard to find because of their local scarcity (4 out of 348 at d<10 pc, Henry
et al. 2006, AJ, 132, 2360). et al. 2006, AJ, 132, 2360).
• Halo regionsHalo regions
• No contamination by disk stars.No contamination by disk stars.
• Low luminosity.Low luminosity.
• Trigonometrical parallaxes and spectra unobtainable.Trigonometrical parallaxes and spectra unobtainable.
• Solar neighbourhoodSolar neighbourhood
• Low luminosity.Low luminosity.
• Hard to find because of their local scarcity (4 out of 348 at d<10 pc, Henry Hard to find because of their local scarcity (4 out of 348 at d<10 pc, Henry
et al. 2006, AJ, 132, 2360). et al. 2006, AJ, 132, 2360).