Skip to content
DraconiticResearch
Search Sources API
182,549 studies31 sourcesUpdated 54 min ago
PreprintCC BY-NC-ND 4.0arXiv

Massive stars in the SDSS-V survey: New O2 stars in the Large Magellanic Cloud

  • A. Roman-Lopes
  • J. G. Fernández-Trincado
  • Marina Kounkel
  • A. A. C. Sander
  • Carlos G. Román-Zúñiga
  • A. Z. Lugo-Aranda
  • Sergio Sánchez-Sanjuán
  • Abhinna Sundar Samantaray
  • José Eduardo Méndez Delgado
  • Christian Moni Bidin
Open at sourcePDFDOICite

Abstract

{O2 stars define the hottest end of the normal O-star sequence, but their identification requires blue-optical nitrogen diagnostics absent from many surveys.} {We reassess three luminous Large Magellanic Cloud (LMC) sources with multi-epoch Sloan Digital Sky Survey V (SDSS-V) spectroscopy obtained with the Baryon Oscillation Spectroscopic Survey (BOSS) spectrographs: \wsi, \lh, and \sk.} {We measure visit-resolved radial velocities and H, He, and N equivalent widths (EWs), compare robust combinations with LMC O2 templates at a common effective resolution, and use OSTAR2002 spectral energy distribution (SED) fits and a Gaia colour--magnitude diagram (CMD) as broad-band checks.} {The weighted log|EW(niv λ4058)/EW(niii λ4640)| values are 0.64±0.29, 0.48±0.23, and 0.34±0.44 for \wsi, \lh, and \sk. The detection of \nv~λλ4604,4620 supports the O2~If∗ and O2~V--III classifications adopted for \wsi\ and \lh, respectively. For \sk, the uncertain \niv/\niii\ ratio and non-detection of \nv\ motivate O2--3~V--III. Weak \hei~λ4471 may indicate unresolved later-type contamination in \wsi\ and \sk. The radial velocities of \sk\ show suggestive but non-significant variability. OSTAR2002 fits over 45--55~kK and the Gaia CMD place all three sources in the luminous very-early-O regime; \wsi\ shows a strong mid-infrared (MIR) excess, \lh\ is nearly photospheric, and \sk\ shows only a modest $3−−8\,μ$m excess.} {The BOSS spectra add \wsi\ and \lh\ to the LMC very-early-O population and identify \sk\ as an additional O2--3 source. These cases show how incomplete blue coverage and ambiguous catalogue associations can conceal the hottest massive stars.}

Related

  1. The MeerKAT 1.3 GHz survey of the Large Magellanic Cloud: Point Source Catalogue
    N Rajabpour, M D Filipović, W D Cotton +6
    Monthly Notices of the Royal Astronomical SocietyPeer-reviewedCC BY 4.0Full textSolar & stellar physicsCrossref
  2. Revisiting candidates for non-pulsating stars located in the Cepheid instability strip in the Large Magellanic Cloud
    W. Narloch, C. Galan, G. Pietrzynski +5
    arXivPreprintarXiv licenceFull textSolar & stellar physicsarXiv
  3. Light curve spectral energy distribution fitting of 13 carbon-rich Mira variable stars in the Small Magellanic Cloud
    A. Liberatori, M. Trabucchi, D. Hatzidimitriou +8
    Astronomy & AstrophysicsPeer-reviewedPublisher termsSolar & stellar physicsCrossref
  4. Precise Physical and Kinematical Parameters of Massive Eclipsing Binaries in the Small Magellanic Cloud
    M. Kaya, Ö. Çakirli, B. Hoyman +3
    The Astronomical JournalPeer-reviewedCC BY 4.0Full textSolar & stellar physicsCrossref
  5. Precise physical and kinematical parameters of massive eclipsing binaries in the Small Magellanic Cloud
    M. Kaya, Ö. Çakırlı, B. Hoyman +3
    arXivPreprintCC BY 4.0Full textGalaxiesSolar & stellar physicsarXiv

Cite

BibTeXRIS
BibTeX
@misc{romanlopes2026massive,
  title = {{Massive stars in the SDSS-V survey: New O2 stars in the Large Magellanic Cloud}},
  author = {A. Roman-Lopes and J. G. Fernández-Trincado and Marina Kounkel and A. A. C. Sander and Carlos G. Román-Zúñiga and A. Z. Lugo-Aranda and Sergio Sánchez-Sanjuán and Abhinna Sundar Samantaray and José Eduardo Méndez Delgado and Christian Moni Bidin},
  howpublished = {arXiv},
  year = {2026},
  month = sep,
  doi = {10.48550/arxiv.2609.25464},
  eprint = {2609.25464},
  archivePrefix = {arXiv},
  url = {https://arxiv.org/abs/2609.25464},
  note = {CC BY-NC-ND 4.0},
}
RIS
TY  - UNPB
TI  - Massive stars in the SDSS-V survey: New O2 stars in the Large Magellanic Cloud
AU  - A. Roman-Lopes
AU  - J. G. Fernández-Trincado
AU  - Marina Kounkel
AU  - A. A. C. Sander
AU  - Carlos G. Román-Zúñiga
AU  - A. Z. Lugo-Aranda
AU  - Sergio Sánchez-Sanjuán
AU  - Abhinna Sundar Samantaray
AU  - José Eduardo Méndez Delgado
AU  - Christian Moni Bidin
PY  - 2026
DA  - 2026/09/21
PB  - arXiv
DO  - 10.48550/arxiv.2609.25464
UR  - https://arxiv.org/abs/2609.25464
AB  - {O2 stars define the hottest end of the normal O-star sequence, but their identification requires blue-optical nitrogen diagnostics absent from many surveys.} {We reassess three luminous Large Magellanic Cloud (LMC) sources with multi-epoch Sloan Digital Sky Survey V (SDSS-V) spectroscopy obtained with the Baryon Oscillation Spectroscopic Survey (BOSS) spectrographs: \wsi, \lh, and \sk.} {We measure visit-resolved radial velocities and H, He, and N equivalent widths (EWs), compare robust combinations with LMC O2 templates at a common effective resolution, and use OSTAR2002 spectral energy distribution (SED) fits and a Gaia colour--magnitude diagram (CMD) as broad-band checks.} {The weighted log|EW(niv λ4058)/EW(niii λ4640)| values are 0.64±0.29, 0.48±0.23, and 0.34±0.44 for \wsi, \lh, and \sk. The detection of \nv~λλ4604,4620 supports the O2~If^∗ and O2~V--III classifications adopted for \wsi\ and \lh, respectively. For \sk, the uncertain \niv/\niii\ ratio and non-detection of \nv\ motivate O2--3~V--III. Weak \hei~λ4471 may indicate unresolved later-type contamination in \wsi\ and \sk. The radial velocities of \sk\ show suggestive but non-significant variability. OSTAR2002 fits over 45--55~kK and the Gaia CMD place all three sources in the luminous very-early-O regime; \wsi\ shows a strong mid-infrared (MIR) excess, \lh\ is nearly photospheric, and \sk\ shows only a modest $3−−8\,μ$m excess.} {The BOSS spectra add \wsi\ and \lh\ to the LMC very-early-O population and identify \sk\ as an additional O2--3 source. These cases show how incomplete blue coverage and ambiguous catalogue associations can conceal the hottest massive stars.}
ER  -