Bibcode
Merín, B.; Montesinos, B.; Eiroa, C.; Solano, E.; Mora, A.; D'Alessio, P.; Calvet, N.; Oudmaijer, R. D.; de Winter, D.; Davies, J. K.; Harris, A. W.; Collier Cameron, A.; Deeg, H. J.; Ferlet, R.; Garzón, F.; Grady, C. A.; Horne, K.; Miranda, L. F.; Palacios, J.; Penny, A.; Quirrenbach, A.; Rauer, H.; Schneider, J.; Wesselius, P. R.
Referencia bibliográfica
Astronomy and Astrophysics, v.419, p.301-318 (2004)
Fecha de publicación:
5
2004
Revista
Número de citas
109
Número de citas referidas
100
Descripción
We present a study of the stellar parameters, distances and spectral
energy distributions (SEDs) of HD 34282 and
HD 141569, two pre-main sequence Herbig AeBe stars.
Both objects have been reported to show ``anomalous positions'' in the
HR diagram in the sense that they appear below the main sequence. A
significant result of this work is that both stars are metal-deficient.
The Hipparcos distance of HD 34282 is very uncertain and the current
study places the star at the expected evolutionary position in the HR
diagram, i.e. as a PMS star. The distance for HD 141569 found in this
work matches the Hipparcos distance, and the problem of its anomalous
position is solved as a result of the low metallicity of the object:
using the right metallicity tracks, the star is in the PMS region. The
SEDs are constructed using data covering ultraviolet to millimetre
wavelengths. Physical, non-parametric models, have been applied in order
to extract some properties of the disks surrounding the stars. The disk
around HD 34282 is accreting actively, it is massive and presents large
grains in the mid-plane and small grains in the surface. HD 141569 has a
very low mass disk, which is in an intermediate stage towards a
debris-type disk.
Based on observations made with the CST, NOT, INT and WHT telescopes of
the Canary Islands observatories under the auspices of its International
Time Programme. Also based on observations made with the 2.2 m telescope
at Calar Alto Observatory (Almería).