Related papers: Chemically peculiar stars as seen with 2MASS
Massive star formation exhibits an extremely rich chemistry. However, not much evolutionary details are known yet, especially at high spatial resolution. Therefore, we synthesize previously published Submillimeter Array…
The study of planetary nebulae provides important constraints for many aspects of stellar and Galactic evolution. Hen 2-108 is a poorly known planetary nebula with a slight elliptical morphology and a peculiar central star (CS), which has…
Magnetic chemically peculiar stars of the main sequence can present rotational periods as long as many decades. Here we report the results of an observational campaign started in 2001 aimed at establishing these very long periods from the…
Aims. In order to better model massive B-type stars, we need to understand the physical processes taking place in slowly pulsating B (SPB) stars, chemically peculiar Bp stars, and non-pulsating normal B stars co-existing in the same part of…
The aim of this study is to investigate systematic chemical differentiation of molecules in regions of high mass star formation. We observed five prominent sites of high mass star formation in HCN, HNC, HCO+, their isotopes, C18O, C34S and…
We analysed Washington $CMT_1$ photometry of star clusters located along the minor axis of the LMC, from the LMC optical centre up to $\sim$ 39 degrees outwards to the North-West. The data base was exploited in order to search for new star…
The application of the Stromgren photometric luminosity calibrations to different types of CP stars is reexamined in the light of the new Hipparcos data. A first attempt is made to use the LM statistical parallax method (Luri et al., 1996)…
The aim of this work is to shed some light on the problem of the formation of carbon stars of R-type from a detailed study of their chemical composition. We use high-resolution and high signal-to-noise optical spectra of 23 R-type stars…
The conventional picture of coeval, chemically homogeneous, populous star clusters -- known as `simple stellar populations' (SSPs) -- is a view of the past. Photometric and spectroscopic studies reveal that almost all ancient globular…
The J-type carbon (J)-stars constitute 10-15% of the observed carbon stars in both our Galaxy and the Large Magellanic Cloud (LMC). They are characterized by strong 13C absorption bands with low 12C/13C ratios along with other chemical…
Stars with unusual properties can provide a wealth of information about rare stages of stellar evolution and exotic physics. However, determining the true nature of peculiar stars is often difficult. In this work, we conduct a systematic…
The possible existence of strange stars in the universe will help in the understanding of various properties of quantum chromodynamics, like asymptotic freedom and chiral symmetry restoration, which is otherwise very difficult to prove in…
Multiple populations (MPs) in globular clusters (GCs) are stars distinct by their abundances of light elements. The MPs can be directly separated by measuring abundances of C, N, O, Na, Al, Mg with spectroscopy or indirectly from…
The fundamentals of estimating essential stellar parameters of an open cluster-NGC 2360 and globular clusters-NGC 5272 are presented extensively in this work. Here, the evaluation of stellar parameters, by manually fitting the appropriate…
We report results on star clusters located in the South-Eastern half of the Large Magellanic (LMC) bar from Washington $CT_1$ photometry. Using appropriate kernel density estimators we detected 73 star cluster candidates, three of which do…
In the second part of the OGLE-III Catalog of Variable Stars (OIII-CVS) we present 197 type II Cepheids and 83 anomalous Cepheids in the Large Magellanic Cloud (LMC). The sample of type II Cepheids consists of 64 BL Her stars, 96 W Vir…
We matched spectroscopically identified C stars (from low resolution objective prism surveys) in the Magellanic Clouds with 2MASS sources. We confirm that C stars show a large spread in absolute magnitudes, even in the Ks band. We show that…
We present the results of an extensive search for periodic and irregular variable pre-main sequence (PMS) stars in the young (2-4 Myr) open cluster NGC 2664, based on photometric monitoring using the Wide Field Imager (WFI) on the 2.2m…
Recently discovered massive $\alpha$-enriched (MAE) stars have surface chemistry consistent with members of the older thick disk Milky Way population but high masses ($\sim$ 1.5 - 3 M$_{\odot}$) that suggest these stars are young. The…
Before 1985, attempts to detect radio or X-ray emission from Magnetic CP (MCP) stars were either fruitless or ambiguous. However, more successful results have been obtained in the last dozen years: (i) Radio emission has now been detected…