Study of the properties and spectral energy distributions of the Herbig AeBe stars HD 34282 and HD 141569
| Jazyk: | angličtina |
|---|---|
| Rok vydání: | 2004 |
| Předmět: |
stars : pre-main sequence
T-TAURI STARS INFRARED-EMISSION Astrophysics::Cosmology and Extragalactic Astrophysics VEGA-LIKE STARS YOUNG OBJECTS stars : planetary systems : protoplanetary disks stars : fundamental parameters AE/BE STARS CIRCUMSTELLAR DISKS ACCRETION DISKS Astrophysics::Solar and Stellar Astrophysics Astrophysics::Earth and Planetary Astrophysics INTERMEDIATE-MASS STARS MAIN-SEQUENCE STARS Astrophysics::Galaxy Astrophysics PARTICLE-SIZE DISTRIBUTION |
| Zdroj: | Astronomy & astrophysics. 419(1):301-318 |
| ISSN: | 0004-6361 |
| Popis: | 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 arc 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. |
| Databáze: | OpenAIRE |
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