Chemically peculiar stars in the field of NGC 2244 ?
نویسنده
چکیده
Low-resolution long-slit spectra of reference stars, including MKK standard stars and well-known chemically peculiar stars, are used to develop a spectroscopic method for the detection of the 5200 Å flux depression in CP stars. This new method is shown to be as sensitive a detection tool as the photometrical techniques, and provides a higher resolution view of the excess blocking. Application to stars in the field of NGC 2244 allows us to estimate and eliminate reddening effects. CP stars detected in this field include two members (# 334 and # 276) of the very young stellar group NGC 2244 (age ≈ 3× 106 yr) and two or three foreground stars (# 381, # 625 and maybe # 629). # 334 and # 625 are strongly peculiar.
منابع مشابه
2 00 5 Is the emerging massive cluster NGC 2244 a twin cluster ?
We present in this paper the first near infrared study of the young open cluster NGC 2244, which is well known for its partially embedded nature in the Rosette Nebula. Based on the spatially complete 2 Micron All Sky Survey, the young OB cluster indicates apparent substructures. It is surprisingly resolved into a compact core that matches well the congregation of massive OB stars in the optical...
متن کاملThe Chemical Evolution of Globular Clusters - I. Reactive Elements and Non-Metals
We propose a new chemical evolution model aimed at explaining the chemical properties of globular clusters (GC) stars. Our model depends upon the existence of (i) a peculiar pre-enrichment phase in the GC’s parent galaxy associated with very lowmetallicity Type II supernovae (SNe II), and (ii) localized inhomogeneous enrichment from a single Type Ia supernova (SNe Ia) and intermediate-mass (4-7...
متن کاملOn the highly reddened members in 6 young galactic star clusters - a multiwavelength study ⋆
The spectral and reddening properties of 211 highly reddened proper motion members with V < 15 mag in 6 young galactic star clusters are investigated using low resolution spectroscopic, broad-band UBV RIJHK and mid-IR data. We report emission features in CaII HK and HI lines for a sample of 29 stars including 11 stars reported for the first time and also provide either a new or more reliable sp...
متن کاملRotation and chemical abundances of Ap / Bp stars in the open cluster NGC 6475
The connection between age, rotation and chemical abundance of magnetic Ap stars is poorly understood. Using open clusters, we are able to study samples of stars that are both co-eval and co-environmental. By determining rotation and chemical abundance for Ap star members of clusters with various ages, the variations of these properties as a function of age and environment can be derived. All f...
متن کاملphotometric search for peculiar stars in open clusters . VIII . King 21 , NGC 3293 , NGC 5999 , NGC 6802 , NGC 6830 , Ruprecht 44 , Ruprecht 115 , and Ruprecht 120 ⋆
Context. We continue our survey for magnetic chemically peculiar (CP2) stars in galactic open clusters to shed more light on their origin and evolution. Aims. To study the group of CP2 stars, it is essential to find these objects in different galactic environments and at a wide range of evolutionary stages. The knowledge of open clusters ages and metallicities can help to find a correlation of ...
متن کامل