| Issue |
A&A
Volume 710, June 2026
|
|
|---|---|---|
| Article Number | A48 | |
| Number of page(s) | 9 | |
| Section | Galactic structure, stellar clusters and populations | |
| DOI | https://doi.org/10.1051/0004-6361/202659508 | |
| Published online | 28 May 2026 | |
The Bulge Cluster Origin (BulCO) survey with CRIRES at the ESO-VLT: A chemical screening of the globular cluster NGC 6553★
1
Dipartimento di Fisica e Astronomia, Università degli Studi di Bologna,
Via Gobetti 93/2,
40129
Bologna,
Italy
2
INAF, Osservatorio di Astrofisica e Scienza dello Spazio di Bologna,
Via Gobetti 93/3,
40129
Bologna,
Italy
3
European Southern Observatory,
Karl-Schwarzschild-Strasse 2,
85748
Garching bei München,
Germany
4
Excellence Cluster ORIGINS,
Boltzmann-Strasse 2,
85748
Garching Bei München,
Germany
★★ Corresponding author: This email address is being protected from spambots. You need JavaScript enabled to view it.
Received:
19
February
2026
Accepted:
20
April
2026
Abstract
In this paper, we present the chemical screening of the stellar population belonging to the globular cluster NGC 6553 in the Galactic bulge. This study has been conducted in the contest of the Bulge Cluster Origin (BulCO) survey, an ESO-VLT Large Program that is currently ongoing with CRIRES in the near-infrared (NIR) domain. This survey is performing an unprecedented chemical screening of 17 stellar systems orbiting the Milky Way bulge, with the aim of unveiling their origin and true nature. Here we present and discuss the abundances of 18 elements produced via distinct nucleosynthetic channels for 14 red giant branch stars belonging to NGC 6553. We found a mean [Fe/H] = −0.20 ± 0.01 deX, and about solar-scaled iron-peak elements, confirming that this is one of the most metal-rich globular clusters in the Milky Way. We also found [X/Fe] enhancement of α and several other light elements. Furthermore, we assessed the presence of multiple populations typical of genuine globular clusters from the significant spreads in Na, N, and C, along with an almost vertical Na-O anticorrelation. Finally, by using classical ([α/Fe] versus [Fe/H]) and newly-defined ([V/Fe] and [Zn/Fe] versus [Fe/H]) “chemical DNA tests”, we have proven its in situ formation within the Galactic bulge.
Key words: techniques: spectroscopic / stars: abundances / stars: late-type / Galaxy: bulge / infrared: stars / globular clusters: individual: NGC 6553
Based on observations collected at the Very Large Telescope of the European Southern Observatory at Cerro Paranal (Chile) under Large Program 110.24A4 (PI: Ferraro).
© The Authors 2026
Open Access article, published by EDP Sciences, under the terms of the Creative Commons Attribution License (https://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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