509 citations · 4.3k across the 61 of their papers we have counts for
20 papers · 1 filter
Multi-Conjugate Adaptive Optics VLT imaging of the distant old open cluster FSR1415
Y. Momany, S. Ortolani, C. Bonatto +2
We employ the recently installed near infrared Multi-Conjugate Adaptive optics demonstrator (MAD) to determine basic properties of a newly identified, old and distant, Galactic ope…
The old metal-poor open cluster ESO 92-SC05: accreted from a dwarf galaxy?
S. ortolani, E. Bica, B. Barbuy
The study of old open clusters outside the solar circle can bring constraints on formation scenarios of the outer disk. In particular, accretion of dwarf galaxies has been proposed…
El Roque de Los Muchachos Site Characteristics. III. Analysis of Atmospheric Dust and Aerosol Extinction
G. Lombardi, V. Zitelli, S. Ortolani +2
Canary Islands are normally interested by dominant North-East winds that, in some meteorological conditions, can transport sand at high altitude from the Sahara desert. The dust ma…
FSR1767 - a new globular cluster in the Galaxy
Charles Bonatto, Eduardo Bica, Sergio Ortolani +1
The globular cluster (GC) nature of the recently catalogued candidate FSR 1767 is established in the present work. It results as the closest GC so far detected in the Galaxy. The n…
Distances of the bulge globular clusters Terzan 5, Liller 1, UKS 1 and Terzan 4 based on HST NICMOS photometry
S. Ortolani, B. Barbuy, E. Bica +2
A large number of pulsars and X-rays sources are detected in globular clusters. To understand the structure and content of these clusters, accurate distances are required. We deriv…
El Roque de Los Muchachos Site Characteristics. II. Analysis of Wind, Relative Humidity and Air Pressure
G. Lombardi, V. Zitelli, S. Ortolani +1
In this paper we present an analysis of wind speed, wind direction, relative humidity and air pressure taken at TNG, CAMC and NOT at Observatorio del Roque de Los Muchachos, in the…
Oxygen, Sodium, Magnesium and Aluminium as tracers of the Galactic Bulge Formation
A. Lecureur, V. Hill, M. Zoccali +5
This paper investigates the peculiar behaviour of the light even (alpha-elements) and odd atomic number elements in red giants in the galactic bulge, both in terms of the chemical…
VLT-UVES abundance analysis of four giants in NGC 6553
A. Alves-Brito, B. Barbuy, M. Zoccali +9
Metal-rich globular clusters trace the formation of bulges. Abundance ratios in the metal-rich globular clusters such as NGC 6553 can constrain the formation timescale of the Galac…
El Roque de Los Muchachos site characteristics, I.Temperature analysis
G. Lombardi, V. Zitelli, S. Ortolani +1
In this paper we present an analysis of temperature taken at two telescopes located at the Observatorio del Roque de Los Muchachos in the Canary Islands. More than 20 years of meas…
Detection of Ks-excess stars in the 14Myr open cluster NGC4755
C. Bonatto, E. Bica, S. Ortolani +1
We derive the structure, distribution of MS and PMS stars and dynamical state of the young open cluster NGC 4755. We explore the possibility that, at the cluster age, some MS and P…
Globular cluster system and Milky Way properties revisited
Eduardo Bica, Charles Bonatto, Beatriz Barbuy +1
Updated data of the 153 Galactic globular clusters are used to readdress fundamental parameters of the Milky Way. We build a reduced sample, decontaminated of the clusters younger…
On the jet structure and magnetic field configuration of GRB 020813
D. Lazzati, S. Covino, J. Gorosabel +32
The polarization curve of GRB 020813 is discussed and compared to different models for the structure, evolution and magnetisation properties of the jet and the interstellar medium…
Gemini-Phoenix infrared high-resolution abundance analysis of five giants in the bulge globular cluster NGC 6553
J. Melendez, B. Barbuy, E. Bica +4
A detailed abundance analysis of 5 giants of the metal-rich bulge globular cluster NGC 6553 was carried out using high resolution infrared spectra in the H band, obtained at the Ge…
NTT infrared imaging of star cluster candidates towards the central parts of the Galaxy
C. M. Dutra, S. Ortolani, E. Bica +3
We address the issue whether the central parts of the Galaxy harbour young clusters other than Arches, Quintuplet and the Nuclear Young Cluster. A large sample of centrally project…
The Wilson--Bappu Effect: a tool to determine stellar distances
Giancarlo Pace, Luca Pasquini, Sergio Ortolani
Wilson and Bappu (1957) have shown the existence of a remarkable correlation between the width of the emission in the core of the K line of Ca II and the absolute visual magnitude…
Age and Metallicity Distribution of the Galactic Bulge from Extensive Optical and Near-IR Stellar Photometry
M. Zoccali, A. Renzini, S. Ortolani +7
We present a new determination of the metallicity distribution, age, and luminosity function of the Galactic bulge stellar population. By combining near-IR data from the 2MASS surv…
The Field population towards NGC 6553
A. Vallenari, S. Ortolani
We analyze the colour magnitude diagram of the field population in the direction of the bulge cluster NGC 6553 to discuss the stellar field component projected towards the cluster.…
Bright Stars and Metallicity Spread in the Globular Cluster Omega Centauri
Sergio Ortolani, Stefano Covino, Giovanni Carraro
The globular cluster Omega Centauri (NGC 5139) is the most massive and brightest cluster in our Galaxy. It has also a moderately high mass to light ratio (3.6) and an anomalous fla…
Capture of field stars by globular clusters in dense bulge regions
Eduardo Bica, Horacio Dottori, Irapuan Rodrigues de Oliveira F. +2
The recent detection of a double Red Giant Branch in the optical color-magnitude diagram (CMD) of the bulge globular cluster HP1 (Ortolani et al. 1997), a more populated metal-poor…
The White Dwarf Distance to the Globular Cluster NGC 6752 (and its Age) with the Hubble Space Telescope (Based on observations made with the NASA/ESA Hubble Space Telescope (HST))
Alvio Renzini, Angela Bragaglia, Francesco R. Ferraro +6
Deep Hubble Space Telescope (HST) observations with WFPC2 of the nearby globular cluster NGC 6752 have allowed us to obtain accurate photometry for the cluster white dwarfs (WD). A…