Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5487748 | New Astronomy | 2018 | 9 Pages |
Abstract
The study of chemically peculiar (CP) stars in open clusters provides valuable information about their evolutionary status. Their detection can be performed using the Îa photometric system, which maps a characteristic flux depression at λâ¯â¼â¯5200â¯Ã
. This paper aims at studying the occurrence of CP stars in the earliest stages of evolution of a stellar population by applying this technique to Hoggâ¯16, a very young Galactic open cluster (â¯â¼â¯25â¯Myr). We identified several peculiar candidates: two B-type stars with a negative Îa index (CD - 60â¯4701, CPD - 60â¯4706) are likely emission-line (Be) stars, even though spectral measurements are necessary for a proper classification of the second one; a third object (CD - 60â¯4703), identified as a Be candidate in literature, appears to be a background B-type supergiant with no significant Îa index, which does not rule out the possibility that it is indeed peculiar as the normality line of Îa for supergiants has not been studied in detail yet. A fourth object (CD - 60â¯4699) appears to be a magnetic CP star of 8⯠Mâ, but obtained spectral data seem to rule out this hypothesis. Three more magnetic CP star candidates are found in the domain of early F-type stars. One is a probable nonmember and close to the border of significance, but the other two are probably pre-main sequence cluster objects. This is very promising, as it can lead to very strong constraints to the diffusion theory. Finally, we derived the fundamental parameters of Hoggâ¯16 and provide for the first time an estimate of its metal content.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Astronomy and Astrophysics
Authors
Stefano Cariddi, Naira M. Azatyan, Petr Kurfürst, Lýdia Å tofanová, Martin Netopil, Ernst Paunzen, Olga I. Pintado, Yael J. Aidelman,