منابع مشابه
Planets in 47 Tuc
We consider the survivability of planetary systems in the globular cluster 47 Tucanae. We compute the cross sections for the breakup of planetary systems via encounters with single stars and binaries. We also compute the cross sections to leave planets on eccentric orbits. We find that wider planetary systems (d > ∼ 0.3 AU) are likely to be broken up in the central regions of 47 Tucanae (within...
متن کاملLithium observations in 47 Tuc ⋆
We present high resolution observations (FWHM=15 km s) of the Li region in 5 stars belonging to the old (≈14 Gyrs), metal rich ([Fe/H]≈-0.7) globular cluster 47Tuc. At the ESO NTT telescope we obtained EMMI spectra for three V∼17.4 magnitude stars located at the turnoff with Teff on the Spite plateau. In two of the turnoff stars the lithium line is clearly detected and the mean lithium content ...
متن کاملPhotometry of the Globular Cluster 47 Tuc
We present BV I photometry for about 16000 stars from a 220 arcmin field centered 8 arcmin east of the center of 47 Tuc. We have identified eight likely blue stragglers located in the outer parts of the cluster. Four of these objects are easy targets for spectroscopic studies with ground-based telescopes. Six candidates for blue horizontal branch stars were identified. However, it is possible t...
متن کاملMixed Populations in Globular Clusters : Et Tu , 47 Tuc ? 1
We exploit the large number of archival HST images of 47 Tuc to examine its subgiant branch (SGB) and main sequence (MS) for signs of multiple populations. In the cluster core, we find that the cluster's SGB exhibits a clear spread in luminosity, with at least two distinct components: a brighter one with a spread that is real but not bimodal, and a second one about 0.05 mag fainter, containing ...
متن کاملLack of Planets in 47 Tucanae from an HST Search
We report results from a large Hubble Space Telescope project to observe a significant (∼34,000) ensemble of main sequence stars in the globular cluster 47 Tucanae with a goal of defining the frequency of inner-orbit, gas-giant planets. Simulations based on the characteristics of the 8.3 days of time-series data in the F555W and F814W WFPC2 filters show that ∼17 planets should be detected by ph...
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ژورنال
عنوان ژورنال: Monthly Notices of the Royal Astronomical Society
سال: 2001
ISSN: 0035-8711,1365-2966
DOI: 10.1046/j.1365-8711.2001.04336.x