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[en] In the present comprehensive study of the abundance of Li in the moderately old galactic cluster NGC 7789, the value obtained for stars on the main-sequence turnoff is cosmic, or log epsilon (Li) = 3.0, while some evidence exists of Li depletion or dilution in stars just beyond the turnoff. In most of the NGC 7789 giants, Li is more abundant than average for low mass giants; this is probably due to the higher mass. The decline in Li abundance with effective temperature in the cluster giants can probably be attributed to the destruction of Li at the base of the convective envelope. The giant star Kuestner 301 is tentatively identified as a weak G-band star, on the basis of its exceptionally high Li abundance. 47 references

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[en] A revision of the Bubble Nebula Region (NGC 7635) and the Trifid Nebula Region (NGC 6514) whose images were taken by the Hubble Space Telescope HST gives clues of the ubiquitous character of the dark giants, which were found for the first time in the Carina Nebula Region (NGC 3324). The formation of dark giants, due to the extreme ageing of red giant cocoon stars, can explain the enormous quantity of dark giants pointing out their presence of dark matter as a residual material from successive generations of stars. The dark giants might be as many as 98.9% of dark matter needed to represent the gravitational support of the optical stars in the galactic discs

[en] The paper presents the abundances of carbon, nitrogen, and oxygen and the carbon and oxygen isotopic ratios measured in the CN-strong giant star Mu Leo from CO and CN lines derived from a new 2-2.5 spectrum and published equivalent widths of C2 and forbidden O I lines. The relative abundances of C-12, N-14, and O-16 and the C-12/C-13 ratio suggest that Mu Leonis has undergone the first red-giant dredge-up. The CNO abundances suggest that Mu Leo is probably a metal-rich red giant that has experienced the first dredge-up. 34 references

[en] We report novel observational evidence on the evolutionary status of lithium-rich giant stars by combining asteroseismic and lithium abundance data. Comparing observations and models of the asteroseismic gravity-mode period spacing ΔΠ₁, we find that super-Li-rich giants (SLRs, A(Li) > 3.2 dex) are almost exclusively young red-clump (RC) stars. Depending on the exact phase of evolution, which requires more data to refine, SLR stars are either (i) less than ∼2 Myr or (ii) less than ∼40 Myr past the main core helium flash (CHeF). Our observations set a strong upper limit for the time of the inferred Li-enrichment phase of <40 Myr post-CHeF, lending support to the idea that lithium is produced around the time of the CHeF. In contrast, the more evolved RC stars (>40 Myr post-CHeF) generally have low lithium abundances (A(Li) <1.0 dex). Between the young, super-Li-rich phase, and the mostly old, Li-poor RC phase, there is an average reduction of lithium by about 3 orders of magnitude. This Li destruction may occur rapidly. We find the situation to be less clear with stars having Li abundances between the two extremes of super-Li-rich and Li-poor. This group, the “Li-rich” stars (3.2 > A(Li) > 1.0 dex), shows a wide range of evolutionary states.

[en] We measured the angular diameter of the lithium-rich K giant star HD 148293 using Georgia State University's Center for High Angular Resolution Astronomy Array interferometer. We used our measurement to calculate the star's effective temperature, which allowed us to place it on an H-R diagram to compare it with other Li-rich giants. Its placement supports the evidence presented by Charbonnel and Balachandran that it is undergoing a brief stage in its evolution where Li is being created.

[en] We present a catalogue of stellar objects with 1612 MHz maser emission extracted from the literature published between 1963 and 1983. A total of 442 sources were found. Some unpublished data are also included. A nearly full reference list (updated to 1987) is given. We discuss briefly the nature of the sources

No abstract available