A Newly Discovered VVVX Star Cluster Surfing the Galactic Disk

@misc{garro2026newly,
  title = {{A Newly Discovered VVVX Star Cluster Surfing the Galactic Disk}},
  author = {Elisa R. Garro and José G. Fernández-Trincado and Casmir O. Obasi and Dante Minniti and Matías Gómez and Roberto K. Saito and Javier Alonso-García and Alonso Luna and Valentin D. Ivanov and Maria Gabriela Navarro and Sara Federle and Bernardo P. L. Pereira and Beatriz Barbuy and Devika Bhadrakumar Sindhu and Bruno Dias and Tali Palma and Ilaria Petralia and Sasi Saroon},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.24811},
  eprint = {2609.24811},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.24811},
  note = {CC BY 4.0},
}

TY  - UNPB
TI  - A Newly Discovered VVVX Star Cluster Surfing the Galactic Disk
AU  - Elisa R. Garro
AU  - José G. Fernández-Trincado
AU  - Casmir O. Obasi
AU  - Dante Minniti
AU  - Matías Gómez
AU  - Roberto K. Saito
AU  - Javier Alonso-García
AU  - Alonso Luna
AU  - Valentin D. Ivanov
AU  - Maria Gabriela Navarro
AU  - Sara Federle
AU  - Bernardo P. L. Pereira
AU  - Beatriz Barbuy
AU  - Devika Bhadrakumar Sindhu
AU  - Bruno Dias
AU  - Tali Palma
AU  - Ilaria Petralia
AU  - Sasi Saroon
PY  - 2026
DA  - 2026/09/21
PB  - arXiv
DO  - 10.48550/arxiv.2609.24811
UR  - https://arxiv.org/abs/2609.24811
AB  - We report the discovery of Garro 04, a previously unidentified stellar cluster toward the Galactic disc, uncovered as part of the ESO/KMOS VVVX-GalCen Spectroscopic Survey. This object was serendipitously confirmed as a stellar overdensity in the VISTA Variables in the Vía Láctea eXtended (VVVX) survey footprint and subsequently confirmed through medium-resolution K-band spectroscopy obtained with the K-band Multi Object Spectrograph (KMOS) at the ESO Very Large Telescope. The combined photometric and spectroscopic analysis reveals a coherent stellar population with common radial velocities and chemical properties, supporting its classification as a genuine star cluster rather than a statistical fluctuation of the disk field. We derive the fundamental properties of Garro 04, including its structural parameters, distance, kinematics, and compute its orbital properties, finding that its motion remains confined to the Galactic disk region. Finally, our analysis suggests that Garro~04 is likely an old open cluster, or an object straddling the boundary between the canonical globular and open cluster classifications, with an estimated Age $ = 5 \pm 2$ Gyr and a metallicity of [Fe/H] = −0.5 ± 0.2, finding an excellent agreement between the photometric and spectroscopic determinations.
ER  -