相关论文: Spectroscopy of LMC Cluster Stars
High-resolution spectroscopic observations were taken of 29 extended main sequence turn-off (eMSTO) stars in the young ($\sim$200 Myr) LMC cluster, NGC 1866 using the Michigan/Magellan Fiber System and MSpec spectrograph on the…
Rapidly rotating stars have been recently recognized as having a major role in the interpretation of colour-magnitude diagrams of young and intermediate-age star clusters in the Magellanic Clouds and in the Milky Way. In this work, we…
We present an analysis of high-resolution optical spectra recorded for 30 stars of the split extended main-sequence turnoff (eMSTO) of the young ($\sim$ 40 Myr) Small Magellanic Cloud (SMC) globular cluster NGC 330. Spectra were obtained…
The cluster NGC 3603 hosts some of the most massive stars in the Galaxy. With a modest 50 ks exposure with the Chandra High Energy Grating Spectrometer, we have resolved emission lines in spectra of several of the brightest cluster members…
We present the results of a spectroscopic investigation of two Large Magellanic Cloud globular clusters, NGC 1953 and NGC 1856. Both clusters have similar ages (250 and 300 Myr, respectively). Spectra were recorded with the…
We present new FLAMES@VLT spectroscopic observations of 30 stars in the field of the LMC stellar cluster NGC 1866. NGC 1866 is one of the few young and massive globular cluster that is close enough so that its stars can be individually…
High-resolution spectroscopic measurements of blue horizontal-branch stars in six metal-poor globular clusters -- M3, M13, M15, M68, M92, and NGC 288 -- reveal remarkable variations in photospheric composition and rotation velocity as a…
We have conducted a photometric survey of the globular cluster NGC 6397 in a search for variable stars. We obtained ~11h of time-resolved photometric images with one ne European Southern Observatory-Very Large Telescope using the FOcal…
We present the first results of our variability survey for the globular cluster NGC 362. We found numerous variable stars in the field including 23 RR Lyr stars, 4 eclipsing binaries and 5 other pulsating stars. Four of the RR Lyr ae stars…
The $13.6\times 13.6$ arcmin$^{2}$ field covering the central part of the globular cluster NGC~6397 was surveyed in a search for short-period variable stars. We obtained light curves for 6 close binaries, 2 SX~Phe stars and 1 RR~Lyrae…
We have used DOLORES at the TNG to obtain B,V time series photometry of NGC 2419, one of the most distant and bright clusters in the Galactic halo. These data will be used to study its variable star population in order to check whether the…
The young populous cluster NGC 1866 in the Large Magellanic Cloud LMC), which is probably one of the most massive object formed in the LMC during the last ~ 3 Gyr, appears to have an unexpectedly high mass-to-light ratio. From its velocity…
We present the results of a high spectral resolution study of a few spectroscopic binaries with HgMn primary stars. We detect for the first time in the spectra of HgMn stars that for many elements the line profiles are variable over the…
We present results of a variability search in the intermediate-age open cluster NGC 6866 from 29 nights over two observing seasons. We find 28 periodic variables, of which 19 are newly identified. The periods of these variables, which have…
We report on new WFPC2 observations of the globular cluster NGC 288, focusing our attention on peculiar stars. A very pronounced binary sequence, paralleling the ordinary Main Sequence (MS) is clearly observed in the Color Magnitude Diagram…
We obtained a series of more than two hundred R-band CCD images for the crowded central (115"x77") region of the metal-poor globular cluster M15 with an angular resolution of 0.5"-0.9" in most images. Optimal image subtraction was used to…
The young open cluster NGC 6611 includes among its candidate members a class of peculiar objects with interesting properties: blue stars with infrared IR excesses. These stars show excesses in IR bands, signature of the presence of a…
Luminous elliptical galaxies generally display a rich star cluster system, whose properties provide strong constraints on the physics of galaxy formation and evolution. Star cluster system studies, however, concentrate on galaxies located…
We present a detailed analysis of stellar rotation along the main sequences of NGC 1866 and NGC 1856, two young (~200-300 Myr) massive clusters in the Large Magellanic Cloud, using MUSE integral field spectroscopy. Differences in stellar…
We have observed a sample of 35 long-period variables and four Cepheid variables in the vicinity of 23 Galactic globular clusters using the Infrared Spectrograph on the Spitzer Space Telescope. The long-period variables in the sample cover…