{
  "abstract": "We present the first multi-object spectroscopy of Boötes V, Leo Minor I, and DELVE 2 -- three small (20 pc $\\le r_{1/2}\\le$ 26 pc), ultra-faint ($-3.2\\le M_V\\le-2.1$) stellar systems in the outer Galactic halo (71 kpc $\\le D_\\odot\\le$ 102 kpc) with heretofore ambiguous classifications. Leveraging at least two epochs of Keck/DEIMOS or Magellan/IMACS observations targeting each satellite, we identify 13, 7, and 7 spectroscopic members in the three systems, respectively. We tentatively resolve a $σ_v=2.1^{+1.5}_{-0.9}$ km s$^{-1}$ velocity dispersion for DELVE 2 but place upper limits of $σ_v<2.7$ km s$^{-1}$ and $σ_v<7.8$ km s$^{-1}$ for Boötes V and Leo Minor I. We find that all three systems are very metal-poor, with mean iron abundances $-2.85\\le\\overline{\\rm [Fe/H]}\\le-2.15$. Both Boötes V and Leo Minor I display unambiguous metallicity spreads ($σ_{\\rm [Fe/H]}=0.46^{+0.18}_{-0.12}$ dex and $σ_{\\rm [Fe/H]}=0.57^{+0.23}_{-0.18}$ dex), while DELVE 2 displays a modestly significant spread ($σ_{\\rm [Fe/H]}=0.52^{+0.29}_{-0.25}$ dex) across three stars. Based primarily on these metallicity measurements, we confidently classify Boötes V and Leo Minor I as dwarf galaxies and determine that DELVE 2 is most likely a dwarf galaxy as well. We explore the orbit of each satellite in a joint Milky Way + LMC potential, confirming for the first time that DELVE 2 is a long-term bound satellite of the LMC. Finally, we review the empirical Milky Way satellite classification landscape and find that nearly every spectroscopically characterized satellite with azimuthally averaged half-light radius $r_{1/2}>15$ pc and surface brightness $μ_{V,1/2}>26.5$ mag arcsec$^{-2}$ is likely a dwarf galaxy. This result can guide initial probabilistic classifications for satellites discovered by $\\textit{Rubin}$, $\\textit{Roman}$, and $\\textit{Euclid}$.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.07182",
  "author_total": 25,
  "authors": [
    {
      "name": "W. Cerny"
    },
    {
      "name": "M. Geha"
    },
    {
      "name": "J. D. Simon"
    },
    {
      "name": "T. S. Li"
    },
    {
      "name": "A. B. Pace"
    },
    {
      "name": "R. P. van der Marel"
    },
    {
      "name": "N. Kallivayalil"
    },
    {
      "name": "A. P. Ji"
    },
    {
      "name": "A. Drlica-Wagner"
    },
    {
      "name": "D. Crnojević"
    },
    {
      "name": "G. Limberg"
    },
    {
      "name": "N. E. D. Noël"
    },
    {
      "name": "A. H. Riley"
    },
    {
      "name": "D. J. Sand"
    },
    {
      "name": "G. S. Stringfellow"
    },
    {
      "name": "Y. Choi"
    },
    {
      "name": "P. S. Ferguson"
    },
    {
      "name": "C. E. Martínez-Vázquez"
    },
    {
      "name": "P. Massana"
    },
    {
      "name": "G. E. Medina"
    },
    {
      "name": "B. Mutlu-Pakdil"
    },
    {
      "name": "J. D. Sakowska"
    },
    {
      "name": "C. Y. Tan"
    },
    {
      "name": "A. K. Vivas"
    },
    {
      "name": "J. Bruce"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/0hmxmq7ewsvef.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.07182",
  "fulltext_url": null,
  "id": "0hmxmq7ewsvef",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.07182",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7220933043",
  "pdf_url": "https://arxiv.org/pdf/2610.07182",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-05",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/0hmxmq7ewsvef.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:22Z",
      "native_id": "2610.07182",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.07182"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "Spectroscopic Confirmation of the Milky Way Satellites Boötes V and Leo Minor I and the LMC Satellite DELVE 2: Three Small Ultra-Faint Dwarf Galaxies",
  "title_text": "Spectroscopic Confirmation of the Milky Way Satellites Boötes V and Leo Minor I and the LMC Satellite DELVE 2: Three Small Ultra-Faint Dwarf Galaxies",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:22Z",
  "url": "https://research.draconitic.com/paper/0hmxmq7ewsvef",
  "venue": "arXiv",
  "versions": []
}