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South America has several types of activities that could be relevant within the context of Laboratory astrophysics. The presentation will provide information about the different activities, groups and initiatives from South American colleagues. The presentation will be illustrative, but not exhaustive with respect to the topics and/or number of groups.

The presence of nitrogen-enriched stars in globular clusters provides key evidence for multiple stellar populations (MPs), as has been demonstrated with globular cluster spectroscopic data towards the bulge, disk, and halo. In this work, we employ the VVV Infrared Astrometric Catalogue (VIRAC) and the DR16 SDSS-IV release of the APOGEE survey to provide the first detailed spectroscopic study of the bulge globular cluster UKS 1. Based on these data, a sample of six selected cluster members was studied. We find the mean metallicity of UKS 1 to be [Fe/H] = −0.98 ± 0.11, considerably more metal-poor than previously reported, and a negligible metallicity scatter, typical of that observed by APOGEE in other Galactic globular clusters. In addition, we find a mean radial velocity of 66.1 ± 12.9 km s−1 , which is in good agreement with literature values, within 1σ. By selecting stars in the VIRAC catalogue towards UKS 1, we also measure a mean proper motion of (µα cos(δ), µδ) = (−2.77 ± 0.23, −2.43 ± 0.16) mas yr−1 . We find strong evidence for the presence of MPs in UKS 1, since four out of the six giants analysed in this work have strong enrichment in nitrogen ([N/Fe] & +0.95) accompanied by lower carbon abundances ([C/Fe] . −0.2). Overall, the light- (C, N), α- (O, Mg, Si, Ca, Ti), Fe-peak (Fe, Ni), Odd-Z (Al, K), and the s-process (Ce, Nd, Yb) elemental abundances of our member candidates are consistent with those observed in globular clusters at similar metallicity. Furthermore, the overall star-to-star abundance scatter of elements exhibiting the multiple-population phenomenon in UKS 1 is typical of that found in other global clusters (GCs), and larger than the typical errors of some [X/Fe] abundances. Results from statistical isochrone fits in the VVV colour-magnitude diagrams indicate an age of 13.10+0.93 −1.29 Gyr, suggesting that UKS 1 is a fossil relic in the Galactic bulge.

We present a catalog of star clusters, associations and related extended objects in the Small Magellanic Cloud and the Magellanic Bridge with 2741 entries, a factor 2 more than a previous version from a decade ago. Literature data till December 2018 are included. The identification of star clusters was carried out with digital atlases in various bands currently available in DSS and MAMA imaging surveys. In particular, we cross-identified recent cluster samples from the VMC, OGLE-IV and SMASH surveys, confirming new clusters and pointing out equivalencies. A major contribution of the present catalog consists in the accurate central positions for clusters and small associations, including a new sample of 45 clusters or candidates in the SMC and 19 in the Bridge, as well as a compilation of the most reliable age and metallicity values from the literature. A general catalog must also deal with the recent discoveries of 27 faint and ultra-faint star clusters and galaxies projected on the far surroundings of the Clouds, most of them from the DES survey. The information on these objects has been complemented with photometric, spectroscopic and kinematical follow-up data from the literature. The underluminous galaxies around the Magellanic System, still very few as compared to the predictions from $\Lambda$ Cold Dark Matter simulations, can bring constraints to galaxy formation and hierarchical evolution. Furthermore, we provide diagnostics, when possible, of the nature of the ultra-faint clusters, searching for borders of the Magellanic System extensions into the Milky Way gravitational potential., Comment: 21 pages, 13 figures and 4 tables. Updated to match accepted version in AJ. The updated catalog is provided in full as ancillary file

The VISCACHA(VIsible Soar photometry of star Clusters in tApii and Coxi HuguA) Survey is an ongoing project based on deep photometric observations of Magellanic Cloud star clusters, collected using the SOuthern Astrophysical Research (SOAR) telescope together with the SOAR Adaptive Module Imager. Since 2015 more than 200 h of telescope time were used to observe about 130 stellar clusters, most of them with low mass (M < 104M ) and/or located in the outermost regions of the Large Magellanic Cloud and the Small Magellanic Cloud.With this high-quality data set, we homogeneously determine physical properties from statistical analysis of colour–magnitude diagrams, radial density profiles, luminosity functions, and mass functions. Ages, metallicities, reddening, distances, present-day masses, mass function slopes, and structural parameters for these clusters are derived and used as a proxy to investigate the interplay between the environment in theMagellanic Clouds and the evolution of such systems. In this first paper we present the VISCACHA Survey and its initial results, concerning the SMC clusters AM3, K37, HW20, and NGC 796 and the LMC ones KMHK228, OHSC3, SL576, SL61, and SL897, chosen to compose a representative subset of our cluster sample. The project’s long-term goals and legacy to the community are also addressed.

Aims. Globular clusters are tracers of the history of star formation and chemical enrichment in the early Galaxy. Their abundance pattern can help understanding their chemical enrichment processes. In particular, the iron-peak elements have been relatively little studied so far in the Galactic bulge. Methods. The main aim of this work is to verify the strength of abundances of iron-peak elements for chemical tagging in view of identifying different stellar populations. Besides, the nucleosynthesis processes that build these elements are complex, therefore observational data can help constraining theoretical models, as well as give suggestions as to the kinds of supernovae that enriched the gas before these stars formed. Results. The abundances of iron-peak elements are derived for the sample clusters, and compared with bulge field, and thick disk stars. We derived abundances of the iron-peak elements Sc, V, Mn, Cu, and Zn in individual stars of five bulge globular clusters (NGC 6528, NGC 6553, NGC 6522, NGC 6558, HP 1), and of the reference thick disk/or inner halo cluster 47 Tucanae (NGC 104). High resolution spectra were obtained with the UVES spectrograph at the Very Large Telescope over the years. Conclusions. The sample globular clusters studied span metallicities in the range –1.2≤Fe/H]≤ 0.0. V and Sc appear to vary in lockstep with Fe, indicating that they are produced in the same supernovae as Fe. We find that Mn is deficient in metal-poor stars, confirming that it is underproduced in massive stars; Mn-over-Fe steadily increases at the higher metallicities due to a metallicity-dependent enrichment by supernovae of type Ia. Cu behaves as a secondary element, indicating its production in a weak-s process in massive stars. Zn has an alpha-like behaviour at low metallicities, which can be explained in terms of nucleosynthesis in hypernovae. At the metal-rich end, Zn decreases with increasing metallicity, similarly to the alpha-elements.

The fourth generation of the Sloan Digital Sky Survey (SDSS-IV) began observations in July 2014. It pursues three core programs: APOGEE-2, MaNGA, and eBOSS. In addition, eBOSS contains two major subprograms: TDSS and SPIDERS. This paper describes the first data release from SDSS-IV, Data Release 13 (DR13), which contains new data, reanalysis of existing data sets and, like all SDSS data releases, is inclusive of previously released data. DR13 makes publicly available 1390 spatially resolved integral field unit observations of nearby galaxies from MaNGA, the first data released from this survey. It includes new observations from eBOSS, completing SEQUELS. In addition to targeting galaxies and quasars, SEQUELS also targeted variability-selected objects from TDSS and X-ray selected objects from SPIDERS. DR13 includes new reductions of the SDSS-III BOSS data, improving the spectrophotometric calibration and redshift classification. DR13 releases new reductions of the APOGEE-1 data from SDSS-III, with abundances of elements not previously included and improved stellar parameters for dwarf stars and cooler stars. For the SDSS imaging data, DR13 provides new, more robust and precise photometric calibrations. Several value-added catalogs are being released in tandem with DR13, in particular target catalogs relevant for eBOSS, TDSS, and SPIDERS, and an updated red-clump catalog for APOGEE. This paper describes the location and format of the data now publicly available, as well as providing references to the important technical papers that describe the targeting, observing, and data reduction. The SDSS website, http://www.sdss.org, provides links to the data, tutorials and examples of data access, and extensive documentation of the reduction and analysis procedures. DR13 is the first of a scheduled set that will contain new data and analyses from the planned ~6-year operations of SDSS-IV.

We use deep multi-epoch near-IR images of the VISTA Variables in the Vía Láctea (VVV) Survey to search for RR Lyrae stars toward the Southern Galactic plane. Here, we report the discovery of a group of RR Lyrae stars close together in VVV tile d025. Inspection of the VVV images and PSF photometry reveals that most of these stars are likely to belong to a globular cluster that matches the position of the previously known star cluster FSR 1716. The stellar density map of the field yields a >100σ detection for this candidate globular cluster that is centered at equatorial coordinates R.A.J2000 = 16:10:30.0, decl.J2000 = −53:44:56 and galactic coordinates l = 329.77812, b = −1.59227. The color–magnitude diagram of this object reveals a well-populated red giant branch, with a prominent red clump at Ks = 13.35±0.05, and J−Ks = 1.30±0.05. We present the cluster RR Lyrae positions, magnitudes, colors, periods, and amplitudes. The presence of RR Lyrae indicates an old globular cluster, with an age >10 Gyr. We classify this object as an Oosterhoff type I globular cluster, based on the mean period of its RR Lyrae type ab, áPñ = 0.540 days, and argue that this is a relatively metal-poor cluster with [Fe/H] = −1.5±0.4 dex. The mean extinction and reddening for this cluster are AKs = 0.38 0.02 and E( J−Ks) = 0.72±0.02 mag, respectively, as measured from the RR Lyrae colors and the near-IR color– magnitude diagram. We also measure the cluster distance using the RR Lyrae type ab stars. The cluster mean distance modulus is (m−M)0 = 14.38±0.03 mag, implying a distance D = 7.5±0.2 kpc and a Galactocentric distance RG = 4.3 kpc.

The VISTA Variables in the V\'ia L\'actea (VVV) survey is one of six public ESO surveys, and is now in its 4th year of observing. Although far from being complete, the VVV survey has already delivered many results, some directly connected to the intended science goals (detection of variables stars, microlensing events, new star clusters), others concerning more exotic objects, e.g. novae. Now, at the end of the fourth observing period, and comprising roughly 50% of the proposed observations, the actual status of the survey, as well some of the results based on the VVV data, are presented., Comment: 5 pages, 7 figures

Deep Galileo (Telescopio Nazionale Galileo) B, V and I images of Segue 3, reaching V ∼ 25, reveal that it is the youngest globular cluster known so far in the Galaxy.Ayoung age of 3.2 Gyr is found, differently from a previous estimate of 12Gyr. It also appears to be moderately metal rich with [Fe/H]∼−0.8, rather than [Fe/H]∼−1.7, as previously suggested by Fadely et al. A main difference in the age derivation relative to Fadely et al. comes from the consideration of subgiant branch stars in the isochrone fitting. A deduced distance of d = 29.1 kpc is compatible with the outer halo location of other low luminosity globular clusters.

Well determined radial velocities and abundances are essential for analyzing the properties of the Globular Cluster system of the Milky Way. However more than 50% of these clusters have no spectroscopic measure of their metallicity. In this context, this work provides new radial velocities and abundances for twenty Milky Way globular clusters which lack or have poorly known values for these quantities. The radial velocities and abundances are derived from spectra obtained at the Ca II triplet using the FORS2 imager and spectrograph at the VLT, calibrated with spectra of red giants in a number of clusters with well determined abundances. For about half of the clusters in our sample we present significant revisions of the existing velocities or abundances, or both. We also confirm the existence of a sizable abundance spread in the globular cluster M54, which lies at the center of the Sagittarius dwarf galaxy. In addition evidence is provided for the existence of a small intrinsic internal abundance spread (sigma [Fe/H](int) ~ 0.11-0.14 dex, similar to that of M54) in the luminous distant globular cluster NGC 5824. This cluster thus joins the small number of Galactic globular clusters known to possess internal metallicity ([Fe/H]) spreads., 15 figures, 22 pages, accepted for publication in A&A

We employ optical and near-infrared photometry to study the stars in the direction of the star cluster candidate Kronberger 49. The optical color–magnitude diagrams (V, I, and Gunn z photometry obtained with the Galileo Telescope) are tight and present evidence of a main-sequence turnoff. We may be dealing with a low-mass, metalrich globular cluster located in the bulge at a distance from the Sun of d = 8 ± 1 kpc. Alternatively, it may be a dust hole through which we are sampling the bulge stellar population affected by a very low amount of differential reddening.

The globular cluster HP1 is projected on the bulge, very close to the Galactic center. The Multi-Conjugate Adaptive Optics (MCAO) Demonstrator (MAD) at the Very Large Telescope (VLT) allowed to acquire high resolution deep images that, combined with first epoch New Technology Telescope (NTT) data, enabled to derive accurate proper motions. The cluster and bulge field stellar contents were disentangled by means of this process, and produced unprecedented definition in the color-magnitude diagrams for this cluster. The metallicity of [Fe/H] ~ -1.0 from previous spectroscopic analysis is confirmed, which together with an extended blue horizontal branch, imply an age older than the halo average. Orbit reconstruction results suggest that HP1 is spatially confined within the bulge.

Teutsch 145 and Teutsch 146 are shown to be open clusters (OCs) orbiting well inside the solar circle, a region where several dynamical processes combine to disrupt most OCs on a timescale of a few 10 8 yr. BVI photometry from the GALILEO telescope is used to investigate the nature and derive the fundamental and structural parameters of the optically faint and poorly known OCs Teutsch 145 and 146. These parameters are computed by means of fieldstar- decontaminated colour–magnitude diagrams and stellar radial density profiles (RDPs). Cluster mass estimates are made based on the intrinsic mass functions (MFs). We derive the ages 200+100 −50 and 400 ± 100 Myr, and the distances from the Sun dʘ = 2.7 ± 0.3 and 3.8 ± 0.2 kpc, respectively, for Teutsch 145 and 146. Their integrated apparent and absolute magnitudes are mV ≈ 12.4 and 13.3 and MV ≈ −5.6 and −5.3. The MFs (detected for stars with m > ~1Mʘ) have slopes similar to Salpeter’s initial mass function. Extrapolated to the Hburning limit, the MFs would produce total stellar masses of ~1400Mʘ , typical of relatively massive OCs. Both OCs are located deep into the inner Galaxy and close to the Crux–Scutum arm. Since cluster-disruption processes are important, their primordial masses must have been higher than the present-day values. The conspicuous stellar density excess observed in the innermost bin of both RDPs might reflect the dynamical effects induced by a few 10 8 yr of external tidal stress.

The Large Magellanic Cloud (LMC) has a rich star cluster system spanning a wide range of ages and masses. One striking feature of the LMC cluster system is the existence of an age gap between 3 and 10 Gyr. But this feature is not clearly seen among field stars. Three LMC fields containing relatively poor and sparse clusters whose integrated colours are consistent with those of intermediate-age simple stellar populations have been imaged in BVI with the Optical Imager (SOI) at the Southern Telescope for Astrophysical Research (SOAR). A total of six clusters, five of them with estimated initial massesM

We provide evidence that indicates the star cluster Pfleiderer 2, which is projected in a rich field, as a newly identified Galactic globular cluster. Since it is located in a crowded field, core extraction and decontamination tools were applied to reveal the cluster sequences in B, V, and I color–magnitude diagrams (CMDs). The main CMD features of Pfleiderer 2 are a tilted red giant branch and a red horizontal branch, indicating a high metallicity around solar. The reddening is E(B − V ) = 1.01. The globular cluster is located at a distance of d = 16 ± 2 kpc from the Sun. The cluster is located 2.7 kpc above the Galactic plane and at a distance of RGC = 9.7 kpc from the Galactic center, which is unusual for a metal-rich globular cluster.

Context. NGC 6522 has been the first metal-poor globular cluster identified in the bulge by Baade. Despite its importance, very few high-resolution abundance analyses of stars in this cluster are available. The bulge metal-poor clusters may be important tracers of the early chemical enrichment of the Galaxy. Aims. The main purpose of this study is to determine metallicity and elemental ratios in individual stars of NGC 6522. Methods. High-resolution spectra of 8 giants of the bulge’s globular cluster NGC 6522 were obtained at the 8m VLT UT2-Kueyen telescope with the FLAMES+GIRAFFE spectrograph. Multiband V, I, J, Ks photometry was used to derive effective temperatures as reference values. Spectroscopic parameters were derived from Fe i and Fe ii lines, and adopted for the derivation of abundance ratios. Results. The present analysis provides a metallicity [Fe/H] = −1.0 ± 0.2. The α-elements oxygen, magnesium and silicon show [O/Fe] = +0.4 ± 0.3, [Mg/Fe] = [Si/Fe]=+0.25 ± 0.15, whereas calcium and titanium show shallower ratios of [Ca/Fe] = [Ti/Fe]=+0.15± 0.15. The neutron-capture r-process element europium appears to be overabundant by [Eu/Fe]=+0.4± 0.4. The neutron-capture s-elements lanthanum and barium are enhanced by [La/Fe]=+0.35 ± 0.2 and [Ba/Fe]=+0.5± 0.5. The large internal errors, indicating the large star-to-star variation in the barium and europium abundances, are also discussed. Conclusions. The moderate metallicity combined to a blue horizontal branch (BHB), are characteristics similar to those of HP 1 and NGC 6558, pointing to a population of very old globular clusters in the Galactic bulge. Also, the abundance ratios in NGC 6522 resemble those in HP 1 and NGC 6558. The ultimate conclusion is that the bulge is old, and went through an early prompt chemical enrichment.

Aims. We investigate the nature of the recently catalogued star cluster candidate FSR 584, which is projected in the direction of the molecular cloud W 3 and may be the nearest globular cluster to the Sun. Methods. 2MASS colour-magnitude diagrams, the stellar radial density profile, and proper motions are employed to derive fundamental and structural parameters. Results. The colour-magnitude diagram morphology and the radial density profile show that FSR 584 is an old star cluster. With proper motions, the properties of FSR 584 are consistent with a metal-poor ([Fe/H] ≈ −2) globular cluster with a well-defined turnoff and evidence of a blue horizontal-branch. FSR 584 might be a Palomar-like halo globular cluster that is moving towards the Galactic plane, currently at ≈20 pc above it. The distance from the Sun is dʘ ≈ 1.4 kpc, and it is located at ≈1 kpc outside the Solar circle. The radial density profile is characterized by a core radius of Rcore = 0.3 ± 0.1 pc. However, we cannot exclude the possibility of an old open cluster. Conclusions. Near-infrared photometry coupled to proper motions support the scenario where FSR 584 is a new globular cluster in the Galaxy. The absorption is AV = 9.2 ± 0.6, which makes it a limiting object in the optical and explains why it has so far been overlooked.

We present, for the first time, a detailed abundance analysis of five giant stars in the moderately metal-poor bulge globular cluster NGC 6558. Spectra have been obtained at the VLT with the multifiber spectrograph FLAMES in GIRAFFE mode (R~22,000). The resulting iron abundance is [Fe/H]= −0.97±0.15, in good agreement with the metallicity inferred from the slope of the red giant branch, but unusually high for a cluster with such a blue horizontal branch, possibly indicating an old age. A color-magnitude diagram in Vand I, based on photometry obtained with the Wide-Field Imager at ESO, is also presented. An isochrone of 14 Gyr fits the evolutionary sequences, confirming an old age. NGC 6558 is another ‘‘second-parameter’’ bulge cluster. The metallicity derived is near the end of the low-metallicity tail of the bulge field-star distribution; hence, it presumably formed at the very early stages of the bulge formation. Abundance ratios showenhancements of the -elements oxygen, magnesium, and silicon,with [O/Fe] = +0.38, [Mg/Fe] = +0.24, [Si/Fe] = +0.23, and solar calcium and titanium. The r-element europium is also enhanced by [Eu/Fe] = +0.36. The odd-Z elements sodium and aluminum, as well as the s-elements barium and lanthanum, show solar ratios. A heliocentric radial velocity of vr hel = −197.3 ±4 km s-ˡ is found for NGC 6558.

Aims. We derive the structure, distribution of MS and PMS stars and dynamical state of the young open cluster NGC4755. We explore the possibility that, at the cluster age, some MS and PMS stars still present infrared excesses related to dust envelopes and proto-planetary discs. Methods. J, H and Ks 2MASS photometry is used to build CMD and colour–colour diagrams, radial density profiles, luminosity and mass functions. Field-star decontamination is applied to uncover the cluster’s intrinsic CMD morphology and detect candidate PMS stars. Proper motions from UCAC2 are used to determine cluster membership. Results. The radial density profile follows King’s law with a core radius Rcore = 0.7 ± 0.1 pc and a limiting radius Rlim = 6.9 ± 0.1 pc. The cluster age derived from Padova isochrones is 14 ± 2 Myr. Field-star decontamination reveals a low-MS limit at ≈1.4 Mʘ. The core MF (χ = 0.94 ± 0.16) is flatter than the halo’s (χ = 1.58 ± 0.11). NGC 4755 contains ∼285 candidate PMS stars of age ∼1−15 Myr, and a few evolved stars. The mass locked up in PMS,MS and evolved stars amounts to ∼1150 M . Proper motions show that Ks-excess MS and PMS stars are cluster members. Ks-excess fractions in PMS and MS stars are 5.4 ± 2.1% and 3.9 ± 1.5% respectively, consistent with the cluster age. The core is deficient in PMS stars, as compared with MS ones. NGC4755 hosts binaries in the halo but they are scarce in the core. Conclusions. Compared to open clusters in different dynamical states studied with similar methods, NGC4755 fits relations involving structural and dynamical parameters in the expected locus for its age and mass. On the other hand, the flatter core MF probably originates from primordial processes related to parent molecular cloud fragmentation and mass segregation over ∼14 Myr. Star formation in NGC4755 began ≈14 Myr ago and proceeded for about the same length of time. Detection of Ks-excess emission in member MS stars suggests that some circumstellar dust discs survived for ∼107 yr, occurring both in some MS and PMS stars for the age and spread observed in NGC4755.

Context. Metal-poor globular clusters in the bulge are important tracers of early chemical evolution. HP-1 is among the six metal-poor clusters within 5. of the Galactic center, and could be the one closest to the center Aims. The main purpose of this study is the determination of metallicity and elemental ratios. Methods. High resolution spectra of two giants of the bulge globular cluster HP-1 were obtained at the 8m VLT UT2-Kueyen telescope with the UVES spectrograph. This is the second metal-poor globular cluster in the bulge for which a detailed abundance analysis is presented. Multiband V, I, J, H, Ks photometry was used to derive effective temperatures. Results. The present analysis provides a metallicity [Fe/H] = -1.00 ± 0.2. The α-elements oxygen and silicon show [α/Fe] ≈ +0.3, whereas magnesium, calcium and titanium show solar ratios. A proper motion analysis indicates that the two stars are cluster members. Conclusions. The metallicity is unexpected for a blue Horizontal Branch (BHB) cluster. HP-1 is the first known cluster with such a high metallicity combined with a BHB and a steep Red Giant Branch (RGB). Together with NGC 6388 and NGC 6441 of [Fe/H] ∼ −0.6 it would be third with such characteristics, but it differs from them, since these two other clusters have also a populous Red HB, and a normal slope of the RGB for their metallicity, which is not the case of HP-1.

High resolution spectra of 5 giants, including a horizontal branch star, of the metal-rich globular cluster 47 Tucanae were obtained with the UVES spectrograph at the 8m VLT UT2-Kueyen telescope. The atmospheric parameters (Teff, log g, [Fe/H], vt) were derived from VIJK photometry and spectroscopic data based on Fe I and Fe II lines. Fe I and Fe II iron abundances and respective total errors [Fe I/H] = –0.66 ± 0.12 and [Fe II/H] = –0.69 ± 0.24 are found. Abundances of α (O, Mg, Ca, Si, Ti), odd-Z (Na, Al), s- (Ba, La, Zr), and r-process (Eu) elements were determined by means of spectrum synthesis. The main results are [O/Fe] = +0.35 ± 0.11, [Mg/Fe] ≈ [Si/Fe] ≈ [Ti/Fe]=+0.23 ± 0.17, [Ca/Fe] = 0.0 ± 0.15, [Ba/Fe] = +0.31 ± 0.22 and [Eu/Fe] = +0.33 ± 0.10. Overabundances of the α-elements O, Mg, Si and Ti, and of Eu are similar to those seen in halo metal-poor stars, whereas a solar Ca-to-Fe ratio resembles the values found in bulge stars. An overall metallicity Z = 0.006 or [M/H] = –0.45 is thus obtained, as is a mean heliocentric radial velocity vhel r = −22.43 ± 1.99 km sˉ¹.

The Galileo Telescope was used to carry out BV photometry of five faint open clusters, for which no Colour Magnitude Diagrams were available in the literature. The clusters Berkeley 24, Berkeley 35, Berkeley 78, PWM 1, and PWM 4 are found to be old open clusters. Berkeley 24, Berkeley 35, and PWM 4 show a red clump. We fitted Padova isochrones to derive reddening and distance. The clusters Berkeley 35 and Berkeley 78 show low E(B − V) = 0.0 and 0.01 compatible with their relatively high Galactic latitudes, whereas higher values of E(B − V) = 0.4, 0.94 and 0.62 are found for Berkeley 24, PMW1, PMW4. Their distances to the Sun are in the range 4.4 < dʘ < 7.9 kpc implying that they are at distances of 11.5 to 13.5 kpc from the Galactic center. The isochrone fitting show ages in the range 1.0 < Age (Gyr) < 6.3. Further discussion of the different methods used to derive age is given, in particular using the difference in magnitude between turn-off and giant clump, which gives lower ages. The contribution of the five old open clusters studied here, with basic parameters known, increases the overall sample to 108 objects. An important addition is the very old (6.3 Gyr) open cluster PWM 4.

Photometry in the BVI and JHK bands is presented for the first time for the southern open clusters Danks 1 and 2, located in the Centaurus region. They are relatively rich and compact, and projected at approximately 4 arcmin from each other. The clusters are very reddened, with AV = 8.1 ± 0.45 and 9.3 ± 0.6, respectively. They are young clusters, with ages of approximately 10 Myr, and may be related to the 305◦ HII region complex in the area. Distances from the Sun of d̛ ≈ 3.6 ± 0.5 and 3.4 ± 0.2 kpc are derived for Danks 1 and 2. They might form a physical cluster pair.

We extract J and Ks magnitudes from the 2MASS Point Source Catalog for approximately 6×106 stars with 8 < - Ks < - 13 in order to build an AK extinction map within 10◦ of the Galactic centre. The extinction was determined by fitting the upper giant branch of (Ks , J − Ks ) colour–magnitude diagrams to a dereddened upper giant branch mean locus built from previously studied bulge fields. The extinction values vary from AK =0.05 in the edges of the map up to AK =3.2 close to the Galactic centre. The 2MASS extinction map was compared to that recently derived from DENIS data. Both maps agree very well up to AK = 1.0. Above this limit, the comparison is affected by increased internal errors in both extinction determination methods. The 2MASS extinction values were also compared to those obtained from dust emission in the far-infrared using DIRBE/IRAS. Several systematic effects likely to bias this comparison were addressed, including the presence of dust on the background of the bulk of 2MASS stars used in the extinction determination. For the region with 3◦

New near-infrared observations of NGC6528 are presented. The JHKs observations complement a previous HST/NICMOS data set by Ortolani et al. (2001), in that they sample a larger area, contain a more numerous sample of red giant stars, and include the K band. Also, archival HST data sets (separated by 6.093 years) were used to proper-motion decontaminate the near-infrared sample and extract a clean VJHK catalogue. Using the present wide colour baseline, we compared the cleaned colour-magnitude diagrams of NGC6528 with those of NGC6553 and NGC104 and derived new estimates of reddening and distance, EB−V = 0:55 and (m − M)0 = 14:44 (7.7 kpc). Moreover, the morphology and location of the cleaned red giant branch were used to derive a photometric estimate of the cluster metallicity. The average of 10 metallicity indicators yields a mean value of [M/H] ≈ 0.0, and [Fe/H] − ~−0.20 and +0.08 on the Zinn & West (1984) and Carretta & Gratton (1997) revised metallicity scale, respectively. The best isochrone fit to the cleaned K; V − K diagram is obtained for a 12:6 Gyr and Z = 0.02 isochrone, i.e. the derived metallicity of NGC6528 turns out to be very close to the mean of stars in the Baade’s Window. Five AGB variable star candidates, whose membership has to be confirmed spectroscopically, are bolometrically as bright as the known long period variable stars in NGC6553. As discussed in Guarnieri et al. (1997) for NGC 6553, this may indicate that an “intermediate age” population is not needed to account for the brightest stars in external galaxies such as M32.

WFPC2 images obtained with the Hubble Space Telescope (HST ) 4.16 years apart have allowed us to measure the proper motion of the metal-rich globular cluster NGC 6553 with respect to the background bulge stars. With a space velocity of (II, ,W)=(−3.5, 230, −3) km s-ˡ, NGC 6553 follows the mean rotation of both disk and bulge stars at a galactocentric distance of 2.7 kpc. While the kinematics of the cluster is consistent with either a bulge or a disk membership, the virtual identity of its stellar population with that of the bulge cluster NGC 6528 makes its bulge membership more likely. The astrometric accuracy is high enough for providing a measure of the bulge proper motion dispersion and conÐrming its rotation. A selection of stars based on the proper motions produced an extremely well-deÐned cluster color-magnitude diagram (CMD), essentially free of bulge stars. The improved turno† deÐnition in the decontaminated CMD conÐrms an old age for the cluster (~13 Gyr), indicating that the bulge underwent a rapid chemical enrichment while being built up at in the early universe. An additional interesting feature of the cluster color-magnitude diagram is a signiÐcant number of blue stragglers stars, whose membership in the cluster is Ðrmly established from their proper motions.

Hubble Space Telescope observations in the F555W and F814W bands are presented of the bulge globular cluster Terzan 1. This highly obscured cluster has the smallest projected distance to the Galactic center among all known globulars. Its colour-magnitude diagram shows a red horizontal branch, which is typical of metal-rich clusters, combined to a very steep red giant branch, which instead is typical of metal-poor clusters. These features make it similar to the second parameter halo cluster NGC 362. Terzan 1 is therefore another second parameter cluster in the Galactic bulge, and the first one in the bulge combining a steep red giant branch with a red horizontal branch. As in the case of NGC 362, these features of the colour-magnitude diagram can be accounted for by the cluster being 2 Gyr younger than other clusters with the same metallicity but showing a blue horizontal branch. These findings demonstrate that second parameter effects are not confined to the Galactic halo, but are actually encountered at all galactocentric distances. Despite the unusual sequences in the colour-magnitude diagram, the derivation of reddening and distance is straightforward, and we obtained E(B − V ) = 2:48 0.1, d = 5:2 0.5 kpc, thus placing Terzan 1 within the bulge.

A detailed abundance analysis of 2 giants of the metal-rich bulge globular cluster NGC6553 was carried out using high resolution échelle spectra obtained at the ESO 3.6m telescope. The temperature calibration of metal-rich cool giants needs high quality photometric data.We have obtained JK photometry at ESO and VI photometry with the Hubble Space Telescope for NGC6553. The main purpose of this analysis consists in the determination of elemental abundance ratios for this key bulge cluster, as a basis for the fundamental calibration of metal-rich populations. The present analysis provides a metallicity [Fe/H] = −0.55±0.2 which, combined to overabundances relative to Fe of several elements, results in an overall metallicity Z≈Zʘ.

In the recent years we have concentrated efforts to collect Colour-Magnitude Diagrams of the globular clusters projected in the central parts of the Galaxy. So far we were able to gather photometric data in the V, I and Gunn z bandpasses, for 16 out of the 17 known clusters in the central 5º radius, most of them severely reddened. Reddening, distance and metallicity are estimated from the horizontal and red giant branches. We study the resulting cluster spatial distribution and conclude that essentially no cluster is detected beyond the Galactic Center distance. The results favour a flattened bulge extending from the Galactic Center to 4.5 kpc from the Sun. The density distribution of the clusters follows the current models for bulge field stars.We estimate that missing clusters on the opposite side of the Galaxy bulge may amount ~15 clusters similar to those detected on our side. The projected distribution of clusters is asymmetrical, with higher absorption in the southern Galactic hemisphere. The metallicity distribution of our sample clusters results similar to that of bulge field stars. The present ground-based results coupled to main sequence data of two genuine bulge clusters using the Hubble Space Telescope, point to a scenario of an old flat bulge withcommonorigin for the stellar populations in both globular clusters and field.

We present V, I colour-magnitude diagrams of the globular cluster HP 1 obtained at the European Southern Observatory New Technology Telescope under exceptional seeing conditions. The cluster shows blue horizontal branch (HB) and red giant branch morphologies very similar to clusters of intermediate metallicity such as NGC 6752; we therefore estimate [Fe/H] ~~ - 1.5 for HP 1. The blue HB morphology is extended, which is not unusual for a post-core-collapse cluster. We derive a reddening of E (B - V) = 1.19 and a distance d̛ =6.85 kpc. HP 1 might be a halo cluster crossing the bulge or belong to the low-metallicity tail of the bulge.

We study the globular cluster Terzan 4 projected close to the Galactic center, by means of V, I and Gunn z Colour-Magnitude Diagrams. The images were obtained under exceptional seeing conditions (0.35" - 0.55") at the ESO New Technology Telescope equipped with SUSI. We derive a reddening of E(B-V) = 2.35 amd a distance from the Sun dΘ = 8.3 kpc for Terzan 4. From the similarity of the VI Colour-Magnitude Diagrams of Terzan 4 and M30, in particular the presence of a blue horizontal branch, it could be as metal-poor as [Fe/H] ≈ -2.0. It is therefore another blue horizontal branch globular cluster located close to the Galactic center.

We present V, I photometry of the loose star cluster NGC 6749, and for the first time colour-magnitude diagrams are provided. We confirm that it is a globular cluster and its blue horizontal branch indicates that it is metal-poor. We derive a reddening of E(B - V) = 1.39 ± 0.04 and a distance from the Sun d̛ = 7.3 ± 0.9 kpc (assuming a total-to-selective absorption R = 3.4). The cluster is projected very close to the Galactic plane, and the derived distance implies a Galactic coordinate Z ~~ - 300 pc. lt is thus a halo globular cluster located close to the disc plane. We also discuss the properties of 78 newly discovered long-period variable stars, of which 75 are Miras, projected within 1º of the cluster centre. The variables do not appear to be associated with the globular cluster. From their periods, most of them belong to the metal-rich disc or bulge stellar populations.