About

Katia Cunha is an Associate Research Professor at Steward Observatory within the Department of Astronomy. Her areas of interest include high-resolution spectroscopy, the characterization of exoplanet host stars, stellar abundances, and galactic archaeology. She is involved in research that focuses on understanding stellar compositions and the broader structure and evolution of our galaxy through detailed spectroscopic analysis. Her work contributes to the field of astrophysics by providing insights into stellar properties and the chemical evolution of the galaxy, supporting the scientific community's efforts to explore planetary systems and galactic history.

Research topics

• Astronomy
• Computer Science
• Astrophysics
• Physics
• Geography
• Database
• Meteorology
• Geology
• Chemistry
• Operating system
• Remote sensing

Selected publications

• Chemical tagging with APOGEE, <i>Gaia</i> , MUSE, and <i>HST</i> : constraints on the formation of ω Centauri

  Monthly Notices of the Royal Astronomical Society · 2026-03-04

  articleOpen access

  ABSTRACT Current evidence suggests that $\omega$ Cen is the nuclear star cluster of a galaxy that merged with the Milky Way at early times. We use Apache Point Observatory Galactic Evolution Experiment (APOGEE), Gaia, Multi Unit Spectroscopic Explorer, and Hubble Space Telescope data supplemented by galaxy chemical evolution models to place constraints on the assembly and chemical enrichment history of $\omega$ Cen. The APOGEE data reveal three stellar populations occupying separate loci on canonical chemical planes. One population resembles metal-poor halo field stars (P1), a second shows light-element abundance anticorrelations typical of metal-poor globular clusters (IM), and a third population (P2) is characterized by an extreme ‘second-generation’ abundance pattern. Both P1 and P2 populations cover a broad range of metallicity, consistent with extended histories of bursty star formation (SF), which is also evident from their light and $\alpha$-element abundance patterns. Conversely, the IM stars exhibit a narrow metallicity spread, combined with Al–Mg, Na–O, and C–N anticorrelations resembling metal-poor Galactic globular clusters. Moreover, these three populations alone seem to account for the distribution of $\omega$ Cen stars in the chromosome map. We discuss these findings in the context of a scenario according to which $\omega$ Cen formed by a combination of in situ SF within the host galaxy (P1), followed by the spiralling in of gas-rich globular clusters (IM), leading to another burst of SF (P2). We perform a robust comparison of the chemical composition of $\omega$ Cen with those of halo substructures well represented in APOGEE DR17, finding no chemical associations to a high confidence level.

  PublisherDOI

• OS EFEITOS DA PROPOSTA DE EXCLUSÃO DO CÔNJUGE DO DIREITO À HERANÇA: UMA ANÁLISE CONTEMPORANEA DA LEGITIMIDADE DOS CÔNJUGES COMO HERDEIROS

  Revista Ibero-Americana de Humanidades, Ciências e Educação · 2025-05-15

  articleOpen accessSenior author

  Esse artigo apresenta o seguinte questionamento: quais os efeitos da exclusão dos cônjuges do direito a herança na contemporaneidade? O objetivo geral da pesquisa busca identificar as vantagens e desvantagens da eventual reforma no Código Civil, descrevendo a implementação de reforma no direito de família e sucessões, visando refletir sobre a exclusão do cônjuge na herança, bem como a forma em que a população participa das decisões e mudanças na sociedade. A natureza da pesquisa é qualitativa, finalidade descritiva, seus meios são bibliográficos e documentais, e o instrumento de coleta de dados é a análise de documentos. Os resultados apontam que tal reforma possibilita um planejamento sucessório eficiente, entretanto, a maioria da população ainda não tem o entendimento e o incentivo para essa organização post mortem das renovações trazidas pelo Projeto de Lei 4/2025 que trata da reforma do Código Civil.

  PublisherOA PDFDOI

• Chemical Abundances of M and G Dwarfs in the Hyades and Coma Berenices Open Clusters from APOGEE Spectra

  The Astrophysical Journal · 2025-11-07

  articleOpen accessCorresponding

  Abstract Open clusters are one of the best astrophysical laboratories we have available for stellar astrophysics studies. This work presents metallicities and individual abundances for 14 M dwarfs and six G dwarfs from two well-known open clusters: Hyades and Coma Berenices. Our analysis is based on near-infrared (1.51–1.69 μ m), high-resolution ( R ∼ 22,500) spectra obtained from the Sloan Digital Sky Survey (SDSS) IV/APOGEE Survey. Using one-dimensional, plane-parallel MARCS model atmospheres, the APOGEE line list, and the Turbospectrum radiative transfer code in local thermodynamic equilibrium, we derived spectroscopic stellar parameters for the M dwarfs, along with abundances of 13 elements (C, O, Na, Mg, Al, Si, K, Ca, Ti, V, Cr, Mn, and Fe) for both M and G dwarfs. We find a high degree of chemical homogeneity within each cluster when comparing abundances derived from M and G dwarfs: δ [M/H] (M dwarfs–G dwarfs) of 0.01 ± 0.04, and 0.02 ± 0.03 for the Hyades and Coma Berenices, respectively. The overall cluster metallicities derived from M dwarfs (Hyades: 0.16 ± 0.03 and Coma Berenices: 0.02 ± 0.06) are consistent with previous literature determinations. Finally, we demonstrate the value of M dwarfs as key tracers in Galactic archeology, emphasizing their potential for studying Galactic metallicity gradients and chemical evolution.

  PublisherDOI

• The Apache Point Observatory extra-Galactic Evolution Experiment (APOeGEE): Chemical Abundance Trends for Seven Dwarf Spheroidal Galaxies in the APOGEE Survey

  ArXiv.org · 2025-11-06

  preprintOpen access

  In addition to comprehensive surveys of the Milky Way bulge, disk, and halo, the Apache Point Galactic Evolution Experiment (APOGEE) project observed seven dwarf spheroidal satellites (dSphs) of the Milky Way: Carina, Sextans, Sculptor, Draco, Ursa Minor, Bootes 1, and Fornax. APOGEE radial velocities, stellar parameters, and Gaia EDR3 proper motions are used to identify member stars in the vicinity of each dwarf. To properly analyze the abundance patterns of these galaxies, a novel procedure was developed to determine the measurable upper limits of the APOGEE chemical abundances as a function of the effective temperature and the spectral signal-to-noise ratio. In general, the APOGEE abundance patterns of these galaxies (limited to [Fe/H] $&gt;$ -2.5) agree with those found in high-resolution optical studies after abundance offsets are applied. Most of the galaxies studied have abundance patterns that are distinctly different from the majority of stars found in the MW halo, suggesting that these galaxies contributed little to the MW halo above [Fe/H] $&gt;$ -2.0. From these abundance patterns, we find that these dSphs tend to follow two types of chemical evolution paths: episodic and continuous star formation, a result that is consistent with previous photometric studies of their star formation histories. We explore whether mass and/or environment have an impact on whether a galaxy has an episodic or continuous star formation history, finding evidence that, in addition to the galaxy's mass, proximity to a larger galaxy and the cessation of star formation may drive the overall shape of the chemical evolution.

  PublisherOA PDFDOI

• Stellar Characterization, Magnesium Abundances, and Chromospheric Activity Analysis of Stars with Confirmed Exoplanets from the K2 Mission

  The Astrophysical Journal Supplement Series · 2025-12-01 · 2 citations

  preprintOpen accessCorresponding

  Abstract We present a homogeneous spectroscopic analysis of confirmed Kepler's extended mission (K2) exoplanet-hosting stars, comprising 301 targets with high-resolution optical spectra from HIRES and TRES taken from ExoFOP. We derived effective temperatures, surface gravities, and iron and magnesium abundances in local thermodynamic equilibrium by measuring the equivalent widths of Fe I , Fe II , and Mg I lines. Three estimates of stellar masses and radii were obtained via the Stefan–Boltzmann and isochrone methods using the codes PARAM and isochrones . These were used to derive exoplanetary radii reaching internal precisions of 2.5%, 2.6%, and 6.6%, respectively, and the radius gap was consistently detected near 1.9 R ⊕ . We measured chromospheric activity from the Ca II H and K and H α lines. Within the low-activity range ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi>log</mml:mi> <mml:mi>R</mml:mi> <mml:msub> <mml:mo accent="true">′</mml:mo> <mml:mi>HK</mml:mi> </mml:msub> <mml:mo>&lt;</mml:mo> <mml:mo>−</mml:mo> <mml:mn>4.75</mml:mn> </mml:math> ), stellar activity appears to decrease with increasing planetary radius from super-Earths, sub-Neptunes, sub-Saturns, into the Jupiter regime. According to the [Mg/Fe] measurements, most of our K2 planet hosts belong to the Galactic thin disk, but our sample has a population from the thick disk (high-alpha sequence). Most stars show consistent chemodynamical behavior. We find that the [Mg/Fe] ratios are indistinguishable between systems containing large or small exoplanets, as well as single- or multi-exoplanetary systems. Both the [Fe/H] and [Mg/H] distributions reveal that stars hosting large planets are more iron and magnesium enhanced than those having only small planets, further confirming the link between stellar abundances and exoplanetary size, but no significant differences are found between the single- versus multi-exoplanetary systems.

  PublisherDOI

• FERRAMENTA PARA CELERIDADE NAS PUBLICAÇÕES DE SENTENÇAS NOS JUIZADOS ESPECIAIS CÍVEIS

  Revista Ibero-Americana de Humanidades, Ciências e Educação · 2025-04-23

  articleOpen accessSenior author

  Esse artigo buscou analisar a prestação jurisdicional que ocorre quando o Judiciário entrega ao demandante uma resposta ao seu direito procurado em um tempo razoável. Para isso ocorrer, é preciso uma aceleração no processo na Justiça do Juizado Especial. Diante disto, os objetivos deste estudo são de apresentar a problemática envolvendo a grande demanda do Poder Judiciário nos Juizados Especiais Cíveis, verificar o tempo médio de tramitação dos processos judiciais, demonstrando que as implicações encontradas podem ser resolvidas sem maiores gastos, especificamente até a publicação das sentenças proferidas nos autos, apresentando ferramenta para a diminuição da morosidade.

  PublisherOA PDFDOI

• The Gaia-ESO Survey: Projected Rotational Velocities of B stars in the Carina Nebula

  ArXiv.org · 2025-07-01

  preprintOpen access

  The Carina Nebula is an active star-forming region with several open clusters rich in massive OB stars, thus making it an optimal target for studying stellar properties such as rotation for large samples of these early-type stars. We studied a sample of early-type stars probable members of the 8 open clusters in the Carina Complex. The observational data consist of high-resolution spectra from the Gaia-ESO public Spectroscopic Survey. Astrometric and photometric data from Gaia EDR3 and radial velocities measured from the observed spectra are used to confirm the cluster members. The projected rotational velocities of 330 early-type stars of Carina are derived from the widths of \ion{He}{i} lines at 4388 and 4471 Å. The reported \Vsini\ values are the first estimates for 222 early-type stars. The \Vsini\ distribution for the Carina clusters peaks at $\sim$100-150 \kms, consistent with the distributions for B stars in Galactic clusters. \Vsini\ estimates for stars members of the clusters Trumpler 15, Collinder 228, Collinder 232, and Bochum 11 are presented for the first time in the literature. For a subsample of stars with earlier spectral types from B0 to B3, we find a bimodal distribution, with a third, small peak towards the upper values of \Vsini. When the full sample is split according to the parent cluster, we find that the oldest cluster in our sample, NGC 3293, presents a higher concentration of rapidly rotating stars. In contrast, Collinder 228 presents a larger number of stars with lower \Vsini.

  PublisherOA PDFDOI

• Tracing Red Giant Members of the Globular Cluster Palomar 5 with APOGEE and Gaia

  The Astrophysical Journal · 2025-09-12

  articleOpen access

  Abstract The globular cluster Palomar 5 (Pal 5) is in the process of being tidally shredded as it orbits the Milky Way. Its core is currently at a heliocentric distance of ∼21 kpc, near apogalacticon (∼18 kpc), and it reaches ∼5–7 kpc at perigalacticon. Pal 5’s leading and trailing arms stretch over 20° on the sky, making them sensitive probes of the Milky Way’s mass distribution. In this work, we search for red giant members of Pal 5 using spectroscopic data from APOGEE DR17 and photometric and astrometric data from Gaia data release 3. Based on position and proper motion, we identify eight members of Pal 5: six in the core and two in the stream. The clustering algorithm HDBSCAN finds these same eight. We then use chemical tagging with APOGEE abundances to search for additional members across five APOGEE fields overlapping Pal 5. While several dozen candidates are identified, most deviate (some significantly) from known kinematic and color–magnitude trends, suggesting that they are less likely to be true members. We estimate the expected number of giants in the APOGEE pointings based on the area and stellar mass of the streams. Given APOGEE’s limiting magnitude, we find that few, if any, new giants are expected, especially if the stream is more diffuse at these locations. Our results support the presence of density variations in Pal 5’s tidal streams, consistent with earlier studies attributing such features to baryonic perturbers in the Milky Way, dark matter subhalos, or interactions with passing globular clusters.

  PublisherOA PDFDOI

• A Galactic Self-portrait: Density Structure and Integrated Properties of the Milky Way Disk

  The Astrophysical Journal · 2025-09-10 · 5 citations

  articleOpen accessCorresponding

  Abstract The evolutionary history of the Milky Way disk is imprinted in the ages, positions, and chemical compositions of individual stars. In this study, we derive the intrinsic density distribution of different stellar populations using the final data release of the Apache Point Observatory Galactic Evolution Experiment (APOGEE) survey. A total of 203,197 red giant branch stars are used to sort the stellar disk ( R ≤ 20 kpc) into subpopulations of metallicity (Δ[M/H] = 0.1 dex), age ( <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mi mathvariant="normal">Δ</mml:mi> <mml:mi>log</mml:mi> <mml:mo stretchy="false">(</mml:mo> <mml:mfrac> <mml:mrow> <mml:mi mathvariant="normal">age</mml:mi> </mml:mrow> <mml:mrow> <mml:mi mathvariant="normal">yr</mml:mi> </mml:mrow> </mml:mfrac> <mml:mo stretchy="false">)</mml:mo> <mml:mspace width="0.25em"/> <mml:mo>=</mml:mo> <mml:mspace width="0.25em"/> <mml:mn>0.1</mml:mn> </mml:math> ), and α -element abundances ([ α /M]). We fit the present-day structural parameters and density distribution of each stellar subpopulation after correcting for the survey selection function. The low- α disk is characterized by longer scale lengths and shorter scale heights, and is best fit by a broken exponential radial profile for each population. The high- α disk is characterized by shorter scale lengths and larger scale heights, and is generally well-approximated by a single exponential radial profile. These results are applied to produce new estimates of the integrated properties of the Milky Way from early times to the present day. We measure the total stellar mass of the disk to be <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mn>5.2</mml:mn> <mml:msubsup> <mml:mrow> <mml:mn>7</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1.5</mml:mn> </mml:mrow> <mml:mrow> <mml:mo>+</mml:mo> <mml:mn>0.2</mml:mn> </mml:mrow> </mml:msubsup> <mml:mo>×</mml:mo> <mml:mn>1</mml:mn> <mml:msup> <mml:mrow> <mml:mn>0</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> </mml:msup> </mml:math> M ⊙ , and the average mass-weighted scale length is R d = 2.37 ± 0.2 kpc. The Milky Way’s present-day color of ( g − r ) = 0.72 ± 0.02 is consistent with the classification of a red spiral galaxy, although it has only been in the “green valley” region of the galaxy color–mass diagram for the last ∼3 Gyr.

  PublisherDOI

• ABANDONO AFETIVO NA MODALIDADE DE GUARDA COMPARTILHADA E O SEU IMPACTO NO DESENVOLVIMENTO DA SAÚDE MENTAL DO MENOR: UMA ANÁLISE COMPARATIVA NO ANO DE 2021/2022 EM MANAUS-AM

  Revista Políticas Públicas & Cidades · 2025-03-26 · 1 citations

  articleOpen access

  A pesquisa explorou a percepção dos pais e a vivência dos adolescentes, com foco na ausência paterna e seus impactos. A maioria dos adolescentes entrevistados, com idades entre 15 e 17 anos, reside com as mães, e muitos não têm contato com os pais, o que está associado a sentimentos de tristeza, ansiedade, baixa autoestima e solidão. A falta de apoio psicológico foi mencionada por 85% dos adolescentes, destacando a sobrecarga materna, que precisa assumir ambos os papéis parentais. Estudos indicam que a ausência paterna compromete o desenvolvimento emocional e social dos jovens, podendo causar insegurança e dificuldades de relacionamento. A guarda compartilhada, embora prevista legalmente, não é efetivamente aplicada na prática, com muitos adolescentes vivendo principalmente com as mães. Essa dinâmica pode gerar desequilíbrio financeiro e emocional, aumentando a sobrecarga da mãe. Além disso, a falta de participação ativa do pai no desenvolvimento dos filhos prejudica sua autoestima e estabilidade emocional. A pesquisa reforça a necessidade de políticas públicas que promovam a corresponsabilidade parental e apoio psicológico para os adolescentes, visando garantir um ambiente mais equilibrado e saudável para o desenvolvimento emocional e social dos jovens.

  PublisherOA PDFDOI

Recent grants

• Collaborative Research: Chemical History of the Milky Way as Seen Through Open Clusters using SDSS and Gaia

  NSF · $55k · 2022–2025

• Collaborative Research: Adding a Magnetic Dimension to M-dwarf Stars Observed by APOGEE

  NSF · $277k · 2020–2024

• Metallicity Gradients in the Milky Way Disk

  NSF · $431k · 2009–2013

Frequent coauthors

• Verne V. Smith

  Community Science and Data Center

  1010 shared

• D. A. García–Hernández

  Instituto de Astrofísica de Canarias

  474 shared

• Carlos Allende Prieto

  440 shared

• Steven R. Majewski

  University of Virginia

  420 shared

• Dmitry Bizyaev

  New Mexico State University

  335 shared

• José G. Fernández-Trincado

  Universidad Católica del Norte

  332 shared

• O. Zamora

  299 shared

• Gail Zasowski

  290 shared

Labs

• Research Infrastructure Support GroupPI

Awards & honors

• Kenneth G. Gibbs Doctoral Fellowship in Astronomy and Astrop…