Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

GN-z11-flash from a man-made satellite not a gamma-ray burst at redshift 11

The Original Article was published on 14 December 2020

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

Access options

Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.

Fig. 1: Brightness of Breeze-M debris as a function of distance from the observer.
Fig. 2: Trajectory of Breeze-M debris in the field of view of MOSFIRE/Keck during the GN-z11-flash detection.

Data availability

The sources of all data used in this work are detailed in the Methods.

Code availability

The details of all code used in this work are provided in the Methods.


  1. Salvaterra, R. et al. GRB 090423 at a redshift of z ≈ 8.1. Nature 461, 1258–1260 (2009).

    ADS  Article  Google Scholar 

  2. Tanvir, N. R. et al. A γ-ray burst at a redshift of z ≈ 8.2. Nature 461, 1254–1257 (2009).

    ADS  Article  Google Scholar 

  3. Cucchiara, A. et al. A photometric redshift of z~9.4 for GRB 090429B. Astrophys. J. 736, 7 (2011).

    ADS  Article  Google Scholar 

  4. Jiang, L. et al. Evidence for GN-z11 as a luminous galaxy at redshift 10.957. Nat. Astron. 5, 256–261 (2021).

    ADS  Article  Google Scholar 

  5. Oesch, P. A. et al. The most luminous z~9-10 galaxy candidates yet found: the luminosity function, cosmic star-formation rate, and the first mass density estimate at 500 Myr. Astrophys. J. 786, 108–126 (2014).

    ADS  Article  Google Scholar 

  6. Oesch, P. A. et al. A remarkably luminous galaxy at z = 11.1 measured with Hubble Space Telescope grism spectroscopy. Astrophys. J. 819, 129–139 (2016).

    ADS  Article  Google Scholar 

  7. Jiang, L. et al. A possible bright ultraviolet flash from a galaxy at redshift z ≈ 11. Nat. Astron. 5, 262–267 (2021).

    ADS  Article  Google Scholar 

  8. Padmanabhan, H. & Loeb, A. GN-z11-flash: a shock-breakout in a Population III supernova at Cosmic Dawn? Preprint at (2021).

  9. Kann, D. A., Blazek, M., de Ugarte Postigo, A. & Thöne, C. C. GN-z11-flash in the context of gamma-ray burst afterglows. Res. Not. Am. Astron. Soc. 4, 247 (2020).

    ADS  Google Scholar 

  10. Steinhardt, C. L. et al. A more probable explanation for a continuum flash towards a redshift ≈ 11 galaxy. Nat. Astron. (2021).

  11. Jiang, L. et al. L. Jiang et al. reply. Nat. Astron. (2021).

  12. Nir, G., Ofek, E. O. & Gal-Yam, A. The GN-z11-flash event can be a satellite glint. Res. Not. Am. Astron. Soc. 5, 27 (2021).

    ADS  Google Scholar 

  13. Nir, G. et al. A high-rate foreground of sub-second flares from geosynchronous satellites. Mon. Not. R. Astron. Soc. 505, 2477–2484 (2021).

    ADS  Article  Google Scholar 

  14. McLean, I. S., Steidel, C. C., Matthews, K., Epps, H. & Adkins, S. M. MOSFIRE: a multiobject near-infrared spectrograph and imager for the Keck Observatory. SPIE Conf. Ser. 7014, 2–13 (2008).

    ADS  Google Scholar 

  15. Vallado, D., Crawford, P., Hujsak, R. & Kelso, T. Revisiting spacetrack report #3. In AIAA/AAS Astrodynamics Specialist Conference and Exhibit (AIAA, 2006).

  16. Giorgini, J. D. et al. JPL’s on-line solar system data service. Bull. Am Astron. Soc. 28, 25.04 (1996).

    Google Scholar 

  17. Giorgini, J. D., Chodas, P. W. & Yeomans, D. K. Orbit uncertainty and close-approach analysis capabilities of the Horizons on-line Ephemeris System. Bull. Am. Astron. Soc. 33, 58.13 (2001).

    Google Scholar 

  18. Maisonobe, L., Pommier, V. & Parraud, P. Orekit: an open-source library for operational flight dynamics applications. In Proc. 4th Int. Conf. of Astrodynamics Tools and Techniques (ESA, 2010).

  19. Rhodes, B. Skyfield: high precision research-grade positions for planets and Earth satellites generator. Astrophysics Source Code Library ascl:1907.024 (2019)..

  20. Flohrer, T., Krag, H., Klinkrad, H., Bastida Virgili, B. & Fruh, C. Improving ESA’s collision risk estimates by an assessment of the TLE orbit errors of the US SSN catalouge. Proc. Fifth European Conference on Space Debris (Ed. Lacoste, H.) Vol. 672, 27 (ESA, 2009).

Download references


We thank J. Baradziej, L. Jiang and C. Steinhardt for useful discussions. M.J.M. acknowledges support from the National Science Centre, Poland, through the SONATA BIS grant number 2018/30/E/ST9/00208. We acknowledge the use of the Space-Track database, JPL Horizons, OREKIT and SkyField packages. This research has made use of the Keck Observatory Archive (KOA), which is operated by the W. M. Keck Observatory and the NASA Exoplanet Science Institute (NExScI), under contract with the National Aeronautics and Space Administration.

Author information

Authors and Affiliations



M.J.M. designed this project and led the writing of the manuscript. K.K. and M.K.K. searched for the satellite, calculated its properties, planned and analysed the RBT observations, made the figures and contributed to the manuscript writing. E.W. also calculated the trajectory of the satellite.

Corresponding authors

Correspondence to Michał Jerzy Michałowski or Krzysztof Kamiński.

Ethics declarations

Competing interests

The authors declare no competing interests.

Additional information

Peer review information Nature Astronomy thanks Bahram Mobasher and the other, anonymous, reviewer(s) for their contribution to the peer review of this work.

Publisher’s note Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Michałowski, M.J., Kamiński, K., Kamińska, M.K. et al. GN-z11-flash from a man-made satellite not a gamma-ray burst at redshift 11. Nat Astron 5, 995–997 (2021).

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI:

Further reading


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing