Possible discovery of Calvera's supernova remnant

M. Arias, A. Botteon, C. G. Bassa, S. van der Jagt, R. J. van Weeren, S. P. O'Sullivan, Q. Bosschaart, R. S. Dullaart, M. J. Hardcastle, J. W. T. Hessels, T. Shimwell, M. M. Slob, J. A. Sturm, C. Tasse, N. C. M. A. Theijssen, J. Vink

Research output: Contribution to journalArticlepeer-review

13 Downloads (Pure)


We report the discovery of a ring of low surface brightness radio emission around the Calvera pulsar, a high Galactic latitude, isolated neutron star, in the LOFAR Two-metre Sky Survey (LoTSS). It is centered at α = 14h11m12s.6, δ = +79°23′15″, has inner and outer radii of 14′.2 and 28′.4, and has an integrated flux density at 144 MHz of 1.08 ± 0.15 Jy. The ring center is offset by 4′.9 from the location of the Calvera pulsar. Observations with the Isaac Newton Telescope in the Hα band show no coincident optical emission, but they do show a small (~20″) optical structure internal to the ring. We consider three possible interpretations for the ring: that it is an H II region, a supernova remnant (SNR), or an odd radio circle (ORC). The positional coincidence of the ring, the pulsar, and an X-ray-emitting non-equilibrium ionization plasma previously detected lead us to prefer the SNR interpretation. If the source is indeed a SNR and if its association with the Calvera pulsar is confirmed, then Calvera’s SNR, or G118.4+37.0, will be one of few SNRs in the Galactic halo.
Original languageEnglish
Article numberA71
Pages (from-to)1-8
Number of pages8
JournalAstronomy & Astrophysics
Publication statusPublished - 1 Nov 2022


  • astro-ph.HE
  • astro-ph.GA
  • Surveys
  • Pulsars: individual: 1RXS J141256.0+792204
  • ISM: supernova remnants
  • H II regions
  • ISM: general


Dive into the research topics of 'Possible discovery of Calvera's supernova remnant'. Together they form a unique fingerprint.

Cite this