New intrinsic-colour calibration for uvby-beta photometry


Karatas Y. , Schuster W. J.

NEW ASTRONOMY, cilt.15, ss.444-449, 2010 (SCI İndekslerine Giren Dergi) identifier identifier

  • Cilt numarası: 15 Konu: 5
  • Basım Tarihi: 2010
  • Doi Numarası: 10.1016/j.newast.2009.12.003
  • Dergi Adı: NEW ASTRONOMY
  • Sayfa Sayıları: ss.444-449

Özet

A new intrinsic-colour calibration ((b - y)(o) - beta) is presented for the uvby-beta photometric system, making use of re-calibrated Hipparcos parallaxes and published reddening maps. This new calibration for (b - y)(o) - beta, our Eq. (1), has been based upon stars with d(Hip) < 70 pc in the photometric catalogues of Schuster and Nissen (1988), Schuster et al. (1993, 2006), provides a small dispersion, +/-0.009, and has a positive "standard" +2.239A beta coefficient, which is not too different from the coefficients of Crawford (1975a, +1.11) and of Olsen (1988, +1.34). For 61 stars with spectra from CASPEC, UVES/VLT, and FIES/NOT databases, without detectable Na I lines, the average reddening value < E(b - y)> = -0.001 +/- 0.002 shows that any zero-point correction to our intrinsic-colour equation must be minuscule. (C) 2009 Elsevier B.V. All rights reserved.