منابع مشابه
Multisite campaign on the open cluster M 67 . II . Evidence for solar - like oscillations in red giant stars
Measuring solar-like oscillations in an ensemble of stars in a cluster, holds promise for testing stellar structure and evolution more stringently than just fitting parameters to single field stars. The most ambitious attempt to pursue these prospects was by Gilliland et al. (1993) who targeted 11 turn-off stars in the open cluster M67 (NGC 2682), but the oscillation amplitudes were too small (...
متن کاملShallow extra mixing in solar twins inferred from Be abundances ⋆
Context. Lithium and beryllium are destroyed at different temperatures in stellar interiors. As such, their relative abundances offer excellent probes of the nature and extent of mixing processes within and below the convection zone. Aims. We determine Be abundances for a sample of eight solar twins for which Li abundances have previously been determined. The analyzed solar twins span a very wi...
متن کامل1.8-m solar telescope in China: Chinese Large Solar Telescope
For better understanding and forecasting of solar activity, high resolution observations for the Sun are needed. Therefore, the Chinese Large Solar Telescope (CLST) with a 1.8-m aperture is being built. The CLST is a classic Gregorian configuration telescope with an open structure, alt-azimuth mount, retractable dome, and a large mechanical de-rotator. The optical system with an all reflective ...
متن کاملPhotometric variability in the old open cluster M 67 ⋆ II .
We use differential CCD photometry to search for variability in BV I among 990 stars projected in and around the old open cluster M67. In a previous paper we reported results for 22 cluster members that are optical counterparts to X-ray sources; this study focuses on the other stars in our observations. A variety of sampling rates were employed, allowing variability on time scales ranging from ...
متن کاملThe birth of massive twins in M 17
We have imaged the ultra-compact H ii region M 17-UC1 at J, K, N, Q and 1.3 cm. A comparison with results from earlier epochs reveals an increase of the emitted flux both in the mid-infrared and radio continuum. Our N and Q images exhibit a second source of comparable strength 5′′ southwest of M 17-UC1. While M 17-UC1 is not visible at J, faint at K but very bright at 1.3 cm, the second souther...
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ژورنال
عنوان ژورنال: Astronomy & Astrophysics
سال: 2008
ISSN: 0004-6361,1432-0746
DOI: 10.1051/0004-6361:200809714