Skip to main content

Detecting weak beryllium lines with CUBES


Beryllium is a light element with one single stable isotope, \(^9\)Be, which is a pure product of cosmic-ray spallation in the interstellar medium. Beryllium abundances in late-type stars can be used in studies about evolutionary mixing, Galactic chemical evolution, planet engulfment, and the formation of globular clusters. Some of these uses of Be abundances figure among the science cases of the Cassegrain U-Band Efficient Spectrograph (CUBES), a new near-UV low- and medium-resolution spectrograph under development for the Very Large Telescope. Here, we report on a study about beryllium abundances in extremely metal-poor stars in the context of the phase A of CUBES. Our motivation is to understand the limits for the detection of weak lines in extremely metal-poor stars of low Be abundances. We analyze simulated CUBES observations, performed in medium-resolution mode, based on synthetic spectra for four mock stars with [Fe/H] \(\le\) −3.0. We find that detecting the Be lines is possible in certain cases, but is very challenging and requires high signal-to-noise ratio. Depending on the atmospheric parameters of the target stars, and if signal-to-noise per pixel of about 400 can be achieved, it should be possible to detect Be abundances between \(\log\)(Be/H) −13.1 and −13.6, with a typical uncertainty of ± 0.15 dex. Using CUBES, the required data for such studies can be obtained for stars that are fainter by two magnitudes with respect to what is possible with current instrumentation.

This is a preview of subscription content, access via your institution.

Fig. 1
Fig. 2
Fig. 3
Fig. 4
Fig. 5
Fig. 6
Fig. 7
Fig. 8

Data availability

The line list used to compute our synthetic spectra is available in Github, The other datasets generated during and/or analysed during the current study are available from the corresponding author on reasonable request.


  1. When referring to metallicity we mean the iron abundance, [Fe/H], which is the usual rough indicator of the total metal content of a star. Abundances in the bracket notation for two elements A and B, i.e. [A/B], mean the difference between the logarithm of the ratio of the abundances by number in a star and the logarithm of the same ratio in the Sun: [A/B] = \(\log\)[N(A)/N(B)]\(_{\star }\) - \(\log\)[N(A)/N(B)]\(_{\odot }\). The abundances by number are given in a scale where the number of hydrogen atoms is N(H) = 10\(^{12}\).

  2. Used within AstroConda, which is maintained by the Space Telescope Science Institute (STScI). See


  1. Anstee, S.D., O’Mara, B.J.: An investigation of Brueckner’s theory of line broadening with application to the sodium D lines. MNRAS 253, 549–560 (1991).

    ADS  Article  Google Scholar 

  2. Barbuy, B., Bawden Macanhan, V., Bristow, P., Castilho, B., Dekker, H., Delabre, B., Diaz, M., Gneiding, C., Kerber, F., Kuntschner, H., La Mura, G., Maciel, W., Meléndez, J., Pasquini, L., Pereira, C.B., Petitjean, P., Reiss, R., Siqueira-Mello, C., Smiljanic, R., Vernet, J.: CUBES: cassegrain U-band Brazil-ESO spectrograph. Ap&SS 354(1), 191–204 (2014).

    ADS  Article  Google Scholar 

  3. Barklem, P.S., O’Mara, B.J.: The broadening of strong lines of Ca\(^{+}\), Mg\(^{+}\) and Ba\(^{+}\) by collisions with neutral hydrogen atoms. MNRAS 300(3), 863–871 (1998).

  4. Barklem, P.S., O’Mara, B.J.: Broadening of lines of Beii, Srii and Baii by collisions with hydrogen atoms and the solar abundance of strontium. MNRAS 311(3), 535–540 (2000).

    ADS  Article  Google Scholar 

  5. Beers, T.C., Suzuki, T.K., Yoshii, Y.: The Light Elements Be and B as Stellar Chronometers in the Early Galaxy. In: da Silva, L., de Medeiros, R., Spite, M. (eds.) The Light Elements and their Evolution, vol. 198, p. 425. (2000) arXiv:astro-ph/0002056

  6. Belokurov, V., Erkal, D., Evans, N.W., Koposov, S.E., Deason, A.J.: Co-formation of the disc and the stellar halo. MNRAS 478(1), 611–619 (2018). arXiv:1802.03414

    ADS  Article  Google Scholar 

  7. Boesgaard, A.M., Novicki, M.C.: Beryllium in disk and halo stars: Evidence for a beryllium dispersion in old stars. ApJ 641(2), 1122–1130 (2006). arXiv:astro-ph/0512317

    ADS  Article  Google Scholar 

  8. Boesgaard, A.M., Rich, J.A., Levesque, E.M., Bowler, B.P.: Beryllium and alpha-element abundances in a large sample of metal-poor stars. ApJ 743(2), 140 (2011). arXiv:1110.2823

    ADS  Article  Google Scholar 

  9. Bollinger, J.J., Wells, J.S., Wineland, D.J., Itano, W.M.: Hyperfine structure of the 2p sup2Psub1/2 state in sup9Besup+. Physical Review A 31(4), 2711–2714 (1985).

    ADS  Article  Google Scholar 

  10. Boyd, R.N., Kajino, T.: Can 9Be Provide a test of cosmological theories? ApJ 336, L55 (1989).

    ADS  Article  Google Scholar 

  11. Bristow, P., Barbuy, B., Macanhan, V.B., Castilho, B., Dekker, H., Delabre, B., Diaz, M., Gneiding, C., Kerber, F., Kuntschner, H., La Mura, G., Reiss, R., Vernet, J.: Introducing CUBES: the Cassegrain U-band Brazil-ESO spectrograph. In: Ramsay, S.K., McLean, I.S., Takami, H. (eds.) Ground-based and Airborne Instrumentation for Astronomy V, Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, vol. 9147, p. 914709, (2014)

  12. Chiba, M., Beers, T.C.: Kinematics of metal-poor stars in the galaxy. III. Formation of the stellar halo and thick disk as revealed from a large sample of nonkinematically selected stars. AJ 119(6), 2843–2865 (2000). arXiv:astro-ph/0003087

    ADS  Article  Google Scholar 

  13. Coc, A., Uzan, J.P., Vangioni, E.: Standard big bang nucleosynthesis and primordial CNO abundances after Planck. J. Cosmol. Astropart. Phys. 2014(10), 050 (2014). arXiv:1403.6694

    Article  Google Scholar 

  14. Dekker, H., D’Odorico, S., Kaufer, A., Delabre, B., Kotzlowski, H.: Design, construction, and performance of UVES, the echelle spectrograph for the UT2 Kueyen Telescope at the ESO Paranal Observatory. In: Iye, M., Moorwood, A.F. (eds.) Optical and IR Telescope Instrumentation and Detectors, Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, vol. 4008, pp. 534–545. (2000)

  15. Duncan, D.K., Lambert, D.L., Lemke, M.: The abundance of boron in three halo stars. ApJ 401, 584 (1992).

    ADS  Article  Google Scholar 

  16. Duncan, D.K., Primas, F., Rebull, L.M., Boesgaard, A.M., Deliyannis, C.P., Hobbs, L.M., King, J.R., Ryan, S.G.: The evolution of galactic boron and the production site of the light elements. ApJ 488(1), 338–349 (1997).

    ADS  Article  Google Scholar 

  17. Emery, G.: Hyperfine Structure in Springer handbook of atomic, molecular, and optical physics, Springer Science+Business Media, Inc., p 253. (2006)

  18. Ernandes, H., Evans, C.J., Barbuy, B., Castilho, B., Cescutti, G., Christlieb, N., Cristiani, S., Di Marcantonio, P., Hansen, C., Quirrenbach, A., Smiljanic, R.: Stellar astrophysics in the near-UV with VLT-CUBES. In: Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, vol. 11447, p. 1144760. (2020), arXiv:2102.02205

  19. Ernandes, H., Barbuy, B., Friaça, A., Hill, V., Spite, M., Spite, F., Castilho, B.V., Evans, C.J.: Be, V, and Cu in the halo star CS 31082–001 from near-UV spectroscopy. MNRAS 510(4), 5362–5375 (2022). arXiv:2202.04450

    ADS  Article  Google Scholar 

  20. Evans, C.J., Puech, M., Rodrigues, M., Barbuy, B., Cuby, J.G., Dalton, G., Fitzsimons, E., Hammer, F., Jagourel, P., Kaper, L., Morris, S.L., Morris, T.J.: Science requirements and trade-offs for the MOSAIC instrument for the European ELT. In: Evans, C.J., Simard, L., Takami, H. (eds.) Ground-based and Airborne Instrumentation for Astronomy VI, Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, vol. 9908, p. 99089J. (2016), arXiv:1608.06542

  21. Evans, C.J., Barbuy, B., Castilho, B., Smiljanic, R., Melendez, J., Japelj, J., Cristiani, S., Snodgrass, C., Bonifacio, P., Puech, M., Quirrenbach, A. Revisiting the science case for near-UV spectroscopy with the VLT. In: Society of Photo-Optical Instrumentation Engineers (SPIE) Conference Series, vol. 10702, p. 107022E (2018), arXiv:1806.11173

  22. Fuhr, J.R., Wiese, W.L.: Tables of atomic transition probabilities for beryllium and boron. Journal of Physical and Chemical Reference Data 39(1), 013101–013101 (2010).

    ADS  Article  Google Scholar 

  23. Collaboration, Gaia, Prusti, T., de Bruijne, J.H.J., Brown, A.G.A., Vallenari, A., et al.: The Gaia mission. A&A 595, A1 (2016). arXiv:1609.04153

    ADS  Article  Google Scholar 

  24. Collaboration, Gaia, Babusiaux, C., van Leeuwen, F., Barstow, M.A., Jordi, C., Vallenari, A., et al.: Gaia Data Release 2. Observational Hertzsprung-Russell diagrams. A&A 616, A10 (2018). arXiv:1804.09378

    ADS  Article  Google Scholar 

  25. Gilmore, G., Edvardsson, B., Nissen, P.E.: First detection of beryllium in a very metal poor star: A test of the standard big bang model. ApJ 378, 17 (1991).

    ADS  Article  Google Scholar 

  26. Gilmore, G., Gustafsson, B., Edvardsson, B., Nissen, P.E.: Is beryllium in metal-poor stars of galactic or cosmological origin? Nature 357(6377), 379–384 (1992).

    ADS  Article  Google Scholar 

  27. Gustafsson, B., Edvardsson, B., Eriksson, K., Jørgensen, U.G., Nordlund, Å., Plez, B.: A grid of MARCS model atmospheres for late-type stars. I. Methods and general properties. A&A 486(3), 951–970 (2008). arXiv:0805.0554

    ADS  Article  Google Scholar 

  28. Haywood, M., Di Matteo, P., Lehnert, M.D., Snaith, O., Khoperskov, S., Gómez, A.: In disguise or out of reach: first clues about in situ and accreted stars in the stellar halo of the milky way from gaia DR2. ApJ 863(2), 113 (2018). arXiv:1805.02617

    ADS  Article  Google Scholar 

  29. Helmi, A., Babusiaux, C., Koppelman, H.H., Massari, D., Veljanoski, J., Brown, A.G.A.: The merger that led to the formation of the Milky Way’s inner stellar halo and thick disk. Nature 563(7729), 85–88 (2018). arXiv:1806.06038

    ADS  Article  Google Scholar 

  30. Ito, H., Aoki, W., Beers, T.C., Tominaga, N., Honda, S., Carollo, D.: Chemical analysis of the ninth magnitude carbon-enhanced metal-poor star BD+44\(^{\circ }\)493. ApJ 773(1), 33 (2013). arXiv:1306.3614

  31. Korotin, S., Kučinskas, A.: Abundance of beryllium in the Sun and stars: The role of non-local thermodynamic equilibrium effects. A&A 657, L11 (2022). arXiv:2201.00532

    ADS  Article  Google Scholar 

  32. Kramida, A.E.: Critical compilation of wavelengths and energy levels of singly ionized beryllium (Be II). Physica Scripta 72(4), 309–319 (2005).

    ADS  Article  Google Scholar 

  33. Krieger, A., Nörtershäuser, W., Geppert, C., Blaum, K., Bissell, M.L., Frömmgen, N., Hammen, M., Kreim, K., Kowalska, M., Krämer, J., Neugart, R., Neyens, G., Sánchez, R., Tiedemann, D., Yordanov, D.T., Zakova, M.: Frequency-comb referenced collinear laser spectroscopy of Be\(^{+}\) for nuclear structure investigations and many-body QED tests. Applied Physics B: Lasers and Optics 123(1), 15 (2017). arXiv:1609.07655

  34. Kusakabe, M., Kim, K.S., Cheoun, M.K., Kajino, T., Kino, Y., Mathews, G.J.: Revised big bang nucleosynthesis with long-lived, negatively charged massive particles: updated recombination rates, primordial \(^{9}\)Be nucleosynthesis, and impact of new \(^{6}\)Li limits. ApJS 214(1), 5 (2014). arXiv:1403.4156

  35. Kusakabe, M., Mathews, G.J., Kajino, T., Cheoun, M.K.: Review on effects of long-lived negatively charged massive particles on big bang nucleosynthesis. International Journal of Modern Physics E 26(8), 1741004–64 (2017). arXiv:1706.03143

    ADS  Article  Google Scholar 

  36. Lingenfelter, R.E.: The origin of cosmic rays: how their composition defines their sources and sites and the processes of their mixing, injection, and acceleration. ApJS 245(2), 30 (2019). arXiv:1903.06330

    ADS  Article  Google Scholar 

  37. Mathar, R.J.: Corrigendum to “Universal factorization of 3n-j (j\(>\)2) symbols...” [J. Phys. A: Math. Gen. 37 (2004) 3259] (2011) arXiv:1102.5125

  38. Molaro, P., Beckman, J.: An upper limit to the abundance of 9Be in the population II star HD 76932 from a high resolution spectrum with the IUE. A&A 139, 394–400 (1984)

    ADS  Google Scholar 

  39. Molaro, P., Beckman, J.E., Castelli, F.: An upper limit to the beryllium abundance in the population II star HD 140283 from a high resolution IUE spectrum. In: Rolfe, E. (ed.) Fourth European IUE Conference, ESA Special Publication, vol. 218, pp. 197–201 (1984)

  40. Molaro, P., Cescutti, G., Fu, X.: Lithium and beryllium in the Gaia-Enceladus galaxy. MNRAS 496(3), 2902–2909 (2020). arXiv:2006.00787

    ADS  Article  Google Scholar 

  41. Nörtershäuser, W., Geppert, C., Krieger, A., Pachucki, K., Puchalski, M., Blaum, K., Bissell, M.L., Frömmgen, N., Hammen, M., Kowalska, M., Krämer, J., Kreim, K., Neugart, R., Neyens, G., Sánchez, R., Yordanov, D.T.: Precision test of many-body QED in the Be\(^{+}\) 2 p fine structure doublet using short-lived isotopes. Phys. Rev. Lett. 115(3), 033002 (2015). arXiv:1507.03830

  42. Orito, M., Kajino, T., Boyd, R.N., Mathews, G.J.: Geometrical effects of baryon density inhomogeneities on primordial nucleosynthesis. ApJ 488(2), 515–523 (1997). arXiv:astro-ph/9609130

  43. Pasquini, L.: UV opportunities at ESO. Ap&SS 354(1), 121–124 (2014).

  44. Pasquini, L., Bonifacio, P., Randich, S., Galli, D., Gratton, R.G.: Beryllium in turnoff stars of NGC 6397: Early Galaxy spallation, cosmochronology and cluster formation. A&A 426, 651–657 (2004). arXiv:astro-ph/0407524

  45. Pasquini, L., Galli, D., Gratton, R.G., Bonifacio, P., Randich, S., Valle, G.: Early star formation in the Galaxy from beryllium and oxygen abundances. A&A 436(3), L57–L60 (2005). arXiv:astro-ph/0505396

  46. Pasquini, L., Bonifacio, P., Randich, S., Galli, D., Gratton, R.G., Wolff, B.: Beryllium abundance in turn-off stars of NGC 6752. A&A 464(2), 601–607 (2007). arXiv:astro-ph/0612710

  47. Placco, V.M., Beers, T.C., Roederer, I.U., Cowan, J.J., Frebel, A., Filler, D., Ivans, I.I., Lawler, J.E., Schatz, H., Sneden, C., Sobeck, J.S., Aoki, W., Smith, V.V.: Hubble space telescope near-ultraviolet spectroscopy of the bright CEMP-no Star BD+44\(^{\circ }\)493. ApJ 790(1), 34 (2014). arXiv:1406.0538

  48. Plez, B.: Turbospectrum: Code for spectral synthesis. (2012) arXiv:1205004

  49. Pospelov, M., Pradler, J. Steffen, F.D.: Constraints on supersymmetric models from catalytic primordial nucleosynthesis of beryllium. J. Cosmol. Astropart. Phys. 2008(11), 020 (2008). arXiv:0807.4287

  50. Prantzos, N.: Production and evolution of Li, Be, and B isotopes in the Galaxy. A&A 542, A67 (2012). arXiv:1203.5662

  51. Primas, F., Asplund, M., Nissen, P.E., Hill, V.: The beryllium abundance in the very metal-poor halo star G 64–12 from VLT/UVES observations. A&A 364, L42–L46 (2000). arXiv:astro-ph/0009482

  52. Primas, F., Molaro, P., Bonifacio, P., Hill, V.: First UVES observations of beryllium in very metal-poor stars. A&A 362, 666–672 (2000). arXiv:astro-ph/0008402

  53. Puchalski, M., Pachucki, K.: Fine and hyperfine splitting of the 2P state in Li and Be\(^{+}\). Physical Review A 79(3), 32510 (2009). arXiv:0901.2633

  54. Puchalski, M., Pachucki, K.: Ground-state hyperfine splitting in the Be\(^{+}\) ion. Physical Review A 89(3), 032510 (2014). arXiv:1402.4573

  55. Puchalski, M., Pachucki, K.: Quantum electrodynamics m \({\alpha }^{6}\) and m \({\alpha }^{7}\)ln \({\alpha }\) corrections to the fine splitting in Li and Be\(^{+}\). Phys. Rev. A 92(1), 012513 (2015), arXiv:1506.02462

  56. Rebolo, R., Molaro, P., Abia, C., Beckman, J.E.: Abundances of 9Be in a sample of highly metal-deficient dwarfs: implications for early galactic nucleosynthesis and primordial lithium. A&A 193, 193–201 (1988)

  57. Rich, J.A., Boesgaard, A.M.: Beryllium, Oxygen, and Iron abundances in extremely metal-deficient stars. ApJ 701(2), 1519–1533 (2009). arXiv:0906.3296

  58. Ryan, S.G., Norris, J.E., Bessell, M.S., Deliyannis, C.: Evolution of beryllium abundances in the galactic halo. ApJ 388, 184 (1992).

  59. Safronova, U.I., Safronova, M.S.: Relativistic many-body calculation of energies, lifetimes, polarizabilities, and hyperpolarizabilities in Li-like Be\(^{+}\). Phys. Rev. A 87(3), 032502 (2013).

  60. Shukla, N., Arora, B., Sharma, L., Srivastava, R.: Two-dipole and three-dipole dispersion coefficients for interaction of alkaline-earth-metal atoms with alkaline-earth-metal atoms and alkaline-earth-metal ions. Phys. Rev. A 102(2), 022817 (2020). arXiv:2008.04341

  61. Smiljanic, R.: Stellar abundances of beryllium and CUBES. Ap&SS 354(1), 55–64 (2014). arXiv:1403.6276

  62. Smiljanic, R., Pasquini, L., Bonifacio, P., Galli, D., Gratton, R.G., Randich, S., Wolff, B.: Beryllium abundances and star formation in the halo and in the thick disk. A&A 499(1), 103–119 (2009). arXiv:0902.0483

  63. Smiljanic, R., Zych, M.G., Pasquini, L.: Inhomogeneity in the early Galactic chemical enrichment exposed by beryllium abundances in extremely metal-poor stars. A&A 646, A70 (2021). arXiv:2012.07438

  64. Soubiran, C., Le Campion, J.F., Brouillet, N., Chemin, L.: The PASTEL catalogue: 2016 version. A&A 591, A118 (2016). arXiv:1605.07384

  65. Spite, M., Bonifacio, P., Spite, F., Caffau, E., Sbordone, L., Gallagher, A.J.: Be and O in the ultra metal-poor dwarf 2MASS J18082002–5104378: the Be-O correlation. A&A 624, A44 (2019). arXiv:1902.11048

  66. Suda, T., Katsuta, Y., Yamada, S., Suwa, T., Ishizuka, C., Komiya, Y., Sorai, K., Aikawa, M., Fujimoto, M.Y.: Stellar abundances for the galactic archeology (SAGA) database – compilation of the characteristics of known extremely metal-poor stars. PASJ 60, 1159 (2008). arXiv:0806.3697

  67. Suzuki, T.K., Yoshii, Y.: A new model for the evolution of light elements in an inhomogeneous galactic halo. ApJ, 549(1):303–319 (2001) arXiv:astro-ph/0010108

  68. Suzuki, T.K., Yoshii, Y., Kajino, T.: Evolution of beryllium and boron in the inhomogeneous early galaxy. ApJ 522(2), L125–L128 (1999). arXiv:astro-ph/9907182

  69. Tan, K., Zhao, G.: A possible signature of non-uniform Be-\({\alpha }\) relationships for the galaxy. ApJ 738(2), L33 (2011). arXiv:1108.2074

  70. Tan, K.F., Shi, J.R., Zhao, G.: Beryllium abundances in metal-poor stars. MNRAS 392(1), 205–215 (2009). arXiv:0810.2600

  71. Tang, L.Y., Zhang, J.Y., Yan, Z.C., Shi, T.Y., Babb, J.F., Mitroy, J.: Calculations of polarizabilities and hyperpolarizabilities for the Be\(^{+}\) ion. Phys. Rev. A 80(4), 042511 (2009). arXiv:0908.4060

  72. Tatischeff, V., Gabici, S.: Particle acceleration by supernova shocks and spallogenic nucleosynthesis of light elements. Ann. Rev. Nuclear Particle Sci. 68(1), 377–404 (2018). arXiv:1803.01794

  73. Valle, G., Ferrini, F., Galli, D., Shore, S.N.: Evolution of Li, Be, and B in the Galaxy. ApJ 566(1), 252–260 (2002). arXiv:astro-ph/0110327

  74. Woodgate, G.K.: Elementary Atomic Structure. Oxford University Press, Oxford (1970)

  75. Yan, Z.C., Tambasco, M., Drake, G.W.F.: Energies and oscillator strengths for lithiumlike ions. Phys. Rev. A 57(3), 1652–1661 (1998).

  76. Yerokhin, V.A.: Hyperfine structure of Li and Be\(^{+}\). Physi. Rev. A 78(1), 012513 (2008). arXiv:0805.0677

Download references

Author information

Authors and Affiliations


Corresponding author

Correspondence to Rodolfo Smiljanic.

Ethics declarations

Conflicts of interest

The authors declare that they have no conflict of interest.

Additional information

Publisher’s note

Springer Nature remains neutralwithregard to jurisdictional claims in published mapsand institutional affiliations.

The authors acknowledge support by the National Science Centre, Poland, project 2018/31/B/ST9/01469.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Smiljanic, R., da Silva, A.R. & Giribaldi, R.E. Detecting weak beryllium lines with CUBES. Exp Astron (2022).

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI:


  • Low-mass stars
  • Population II stars
  • Stellar abundances
  • Stellar spectral lines