For a sample of 57 evolved stars (spectral type from F5III to G5III), typically stars located near and along the Hertzsprung gap, we derived lithium abundances from spectral synthesis method compared to new high resolution spectroscopic data. Lithium is detected for about half of this large sample stars and high Li-contents (ALi > 2.8) are reported for 8 stars. We examined the Li abundances along Teff, v sin i, the single/binary status and along the stellar mass and the evolutionary status (inferred from the HIPPARCOS data).

High rotating low-mass K giants can be considered as interesting new “laboratories” for studies of the mixing process and mass loss. By means of high spectral resolution observations of some rapidly rotating K giants we found a series of connections between rotation, stellar activity, high Li abundance and mass loss. These giants show low 14N and high 13C enrichment. Nearly half of them are Li rich. This frequency is much higher than the ~ 2% corresponding to common, low rotating K giants. They are also the most suitable objects to test new models of rotation-induced mixing or planet engulfing scenarios.

We report on preliminary results of new high-resolution spectroscopic observations of the roAp star HD 3980 in the Li I 6708 Å line region. Strong variations of position and intensity of this line with the rotation phase enable us to consider this star as a new member of the intriguing group of “Li-spotted” CP stars.

We present the results of high resolution spectroscopic observations of Li I resonance doublet at λ 6707.8 Å for fast rotating single stars of luminosity class II and Ib. We present a discussion on the link between rotation and Li content in intermediate mass giant stars, with emphasis on their evolutionary status. At least one of the observed stars, HD 232862, a G8II with an unusual vsini of 20 km/s, present a Li-rich behavior.

Brown dwarfs and very low mass (VLM) stars are the last frontier on the map of the angular momentum histories of star-like objects. Until the advent of 8-m class telescopes, it was impossible to obtain spectra with enough resolution to detect their rotation. The very existence of brown dwarfs was only established then. It was immediately apparent that there are differences between VLM objects and their heftier stellar cousins. Field VLM objects were found to be very rapidly rotating, yet they did not display the strong magnetic activity that would be expected of convective objects in that case. We now have a good preliminary understanding of the situation near the substellar boundary. I summarize the rotational data (both spectroscopic and photometric) on VLM objects, and how rotation and temperature fit into the production of magnetic activty. I also report more recent work on VLM objects when they are very young. There is increasing evidence that they form much like stars, beginning (when they become visible) as relatively slow rotators for the most part, followed by spin-up as they contract. Their disk lifetimes may be shorter, and they are more magnetically active when they are young. The subsequent angular momentum history of VLM objects is different from solar-type stars, as the usual magnetic braking mechanisms do not operate as in the stellar case. Much of the new work reported here is from the thesis of Subanjoy Mohanty, and was supported by NSF/AST-0098468.

In this paper, I review most of the current knowledge about the strong correlation observed between the rotation rates and the magnetic fields of cool active stars. I concentrate in particular on the most recent observational results, derived from studies on dynamo field generation in stellar convective envelopes from magnetic imaging of very active rapidly rotating low mass stars. I also mention the latest attempts at investigating the large scale magnetospheric structure of these objects from extrapolations of the measured photospheric field maps, as well its dependence/influence on rotation. I finally discuss the new discovery of the feedback effects that dynamo magnetic fields generate on the global dynamics of stellar convective envelopes.

We present the results of a Chandra observation of the old open cluster M 67; 25 cluster members and 13 suspected members were detected, including 22 binaries. We believe that the X-rays of most systems can be explained by enhanced activity due to rapid rotation in a tidally locked orbit. This cannot be the case for the blue and yellow stragglers with orbital periods between 40 and 5000 d, like the new source S 997. We do not understand the X-rays of these long-period binaries.

Main-sequence chemically peculiar stars of spectral types A and B, which are characterised by photospheric abundance anomalies resulting from element segregation in the stellar outer layers, rotate slower than normal stars of similar temperatures. The mechanisms by which such slow rotation is achieved are not well understood yet; different processes may be involved for different types of chemical peculiarities, including stellar magnetic fields and multiplicity. Relevant existing observational data are reviewed.

Fast spinning Hertzsprung gap giants display super-rotational broadening of UV “hot” lines like Fe XXI λ1354 and C IV λ1548, with FWHM's up to twice that expected from the photospheric v sin i. This possibly is the result of extended fossil magnetospheres enveloping the gap giants, a new type of stellar corona. The magnetospheric phase is short-lived, however, as the rapidly evolving giants develop a competing dynamo-generated surface field in the so-called Rapid Braking Zone.

We studied the activity and evolutionary stage of 14 low and intermediate mass single giants that should meet the conditions for dynamo action and Li–enrichment. Only small part of them exhibit either moderate to fast rotation and evidences for magnetic activity and/or high Li abundance. There are also intermediate–mass giants with fast rotation, but no evidences for magnetic activity was found in them and their Li–content is low one. on the other hand, no fast rotation and activity were observed in some of the Li–rich giants. There is a large difference in the activity properties and Li content in stars with similar masses and evolutionary stage.

Observational evidence, based both on spectroscopic Doppler imaging and long-term photometry, of strongly nonaxisymmetric spot distributions in magnetically very active late-type stars, with a special cyclic behaviour (the “flip-flop” effect), is presented. Theoretical implications of these results are discussed from the point of view of nonlinear mean-field dynamo theory.

We present and discuss statistical relation between rotation and X-ray activity for giant and supergiant stars.”

Zeeman-Doppler Imaging enables one to estimate the short term temporal evolution of surface brightness and magnetic structures, under the effect of differential rotation. We present here spectropolarimetric observations secured between 1998 and 2002 for two evolved active stars: the K1 subgiant of the RS CVn system HR 1099 and the single FK Com giant HD 199178. Differential rotation is detected both from brightness and magnetic images, indicating that the rotational shear, roughly solar in magnitude for the single star, is significantly weaker in the binary system. This result suggests that tidal forces, rather than stellar evolution, could be responsible for the lower rotational shear and thus the longer spot lifetime reported for binary systems.

This general discussion was open on the papers presented in oral session II and related posters.

Helioseismology has provided detailed inferences about the internal rotation of the Sun, and hence stringent constraints on any attempt to understand the properties and evolution of stellar rotation. Here I briefly discuss the techniques used in the analysis and review the results that have been obtained. Strikingly, these results are markedly different from the predictions made before the helioseismic data became available, emphasizing the difficulties in the modelling of phenomena as complex as stellar internal rotation.

Helioseismology has been developed to extract internal sound speed, rotation and magnetic field. Such informations will put strong constraints on the present missing dynamical phenomena. Starting from the present observations on the rotation, I discuss quantitatively two important regions, the transition region between radiation and convection, called tachocline and the radiative region. In the tachocline, lithium indicator shows that a turbulent mixing is certainly present in main sequence solar like stars. on the other end, a detailed study of pre-main sequence stars encourages also the introduction of magnetic effects in addition to such a term below 10 Myr. For the solar radiative zone, the difficulty to determine the rotation profile is first noticed and discussed showing the great advantage of the gravity modes or mixed modes in addition to the acoustic modes. A possible profile, decreasing from 0.4 to 0.2 R⊙ and then increasing in the very central region is suggested by the present observations. The consequences in terms of dynamical processes are discussed.

The Eddington mission was given full approval by the European Space Agency on the 23rd May 2002, as part of the new “Cosmic Vision” Science programme, with launch scheduled for 2007. Its twin science objectives are asteroseismology and planet finding. In its current design it consists of 4 × 60 cm folded Schmidt telescopes, each with 5° × 5° field of view and its own CCD array camera. The current observing plan is to spend 2 years primarily devoted to asteroseismology with 1–3 months on different target fields monitoring up to 50,000 stars per field, and 3 years continuously on a single target field monitoring upwards of 100,000 stars as required for planet searching. The asteroseismic goal is to be able to detect oscillations frequencies with a precision 0.1–0.3 μHz.

The sun is supposedly a very simple star, halfway along its long and possibly boring life on the main sequence. Yet it has some distinguishing features. Since we live close to it, our existence is probably blessed by this star having only modest cycles of magnetic activity and weak winds. By being so close, we can observe many aspects of the diverse range of motions and magnetic fields linked to turbulent convection in its convection zone. And this turns out to be anything but simple as we consider the dynamical coupling of convection, rotation and magnetism within this modest star. The lessons that have emerged from recent helioseismic probing of the solar interior and from 3–D numerical simulations of turbulent convection have bearing on differential rotation and magnetic dynamo action also occurring within more complex stars. We consider recent findings from both helioseismology and theoretical modelling on the operation of the deep shell of vigorous convection within our nearest star.

Due to its own rotation, it is expected that the visual figure of the Sun is a spheroid; this is not truly the case because the solar rotation is not constant both over all heliographic latitudes and in depth. The photospheric shape is thus sensitive to the interior structure: accurate measurements of both limb shape distortions and solar rotation rates determination provide useful constraints on the internal layers (density, shear zones, …). We show why and how the implication of the successive gravitational moments are important to probe the solar interior, and we compare measurements obtained either from space (SOHO/MDI) or from ground-based experiments (scanning heliometer at the Pic du Midi). The found faint departures to the sphericity, not exceeding 22 mas, could explain fluctuations that are not yet taken into account in the classical modelling of the solar irradiance. A crude model could explain the asphericities which is based on a core rotating at a nearly uniform rate combined with a prolate tachocline and an oblate outer convective zone.

We investigate the coronal structure of rapidly-rotating, solar-like stars using Chandra HETGS spectra of the short-period binary ER Vul, and by comparison with X-ray observations of the Sun and other dwarf stars. ER Vul consists of two solar-like (G0 + G5) dwarfs with rotation rates ~ 40 times that of the Sun. This binary is not interacting and these stars are the fastest rotating G dwarfs suitable for high resolution X-ray spectroscopy. X-ray (1.8-40 Å) spectra were obtained on 2001 March 29-30 along with 10.5 hours of simultaneous VLA monitoring at 3.6 and 20 cm. These spectra show hot, multi-temperature coronal emission with emission lines ranging in temperature from O VII (2 MK) to Fe XXIV (30 MK). ER Vul showed only low-level variability during the X-ray observation. Unlike the behaviour of longer period active binaries, no large, long-duration flares were detected, consistent with previous X-ray observations of this binary. No evidence for eclipses is seen in either the X-ray or radio emission. The coronal emission measure distribution and elemental abundances were derived for ER Vul.