| 1. |
- Kochukhov, Oleg
(författare)
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Magnetic fields in A stars besides Ap stars
- 2014
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Ingår i: PUTTING A STARS INTO CONTEXT. - 9785000862735 ; , s. 389-397
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Konferensbidrag (refereegranskat)abstract
- I review ongoing efforts to understand the incidence of magnetism in intermediate-mass stars that are different from the magnetic Ap stars. This includes the search for magnetic fields in chemically peculiar stars of the Am and HgMn types as well as in normal A and late-B stars. I discuss different techniques for detecting weak stellar magnetic fields, and present a critical evaluation of recent magnetic detections in non-Ap stars. Special attention is given to the magnetic status of HgMn stars and to the discovery of weak polarization signatures in Sirius and Vega.
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| 2. |
- Piskunov, Nikolai, et al.
(författare)
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Methodology for measuring fundamental parameters and associated uncertainties for middle and cool main-sequence stars
- 2014
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Ingår i: PUTTING A STARS INTO CONTEXT. - 9785000862735 ; , s. 130-135
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Konferensbidrag (refereegranskat)abstract
- We have performed a study of a representative group of main-sequence stars in the temperature range 5000-10000 K in order to test our methodology for determining fundamental parameters and for the assesment of associated uncertainties. The stars selected have reasonably well-established parameters. This paper presents all the steps of our method, from the selection of spectral intervals and atomic/molecular data, to the determination of effective temperatures, surface gravities and metallicities.
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| 3. |
- Rusomarov, Naum, et al.
(författare)
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Magnetic fields of Ap stars from full Stokes spectropolarimetric observations
- 2014
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Ingår i: PUTTING A STARS INTO CONTEXT. - 9785000862735 ; , s. 380-385
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Konferensbidrag (refereegranskat)abstract
- Current knowledge about stellar magnetic fields relies almost entirely on observations of circular polarization. Few objects have been observed in all four Stokes parameters. The magnetic Ap star HD24712 (DO Eri, HR 1217) was recently observed in the Stokes IQUV parameters with the HARPSpol instrument at the 3.6-m ESO telescope as part of our project at investigating Ap stars in all four Stokes parameters. The resulting spectra have dense phase coverage, resolving power >10(5), and S/N ratio of 300-600. These are the highest quality full Stokes observations obtained for any star other than the Sun. We present preliminary results from magnetic Doppler imaging of HD24712. This analysis is the first step towards obtaining detailed 3-D maps of magnetic fields and abundance structures for HD24712 and for other Ap stars that we are currently observing with HARPSpol.
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| 4. |
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