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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. See the documentation for help with subscribing to or submitting Circulars.

Search for Circulars by submitter, subject, or body text (e.g. 'Fermi GRB').
To navigate to a specific circular, enter the associated Circular ID (e.g. 'gcn123', 'Circular 123', or '123').

42 results found.

  1. GRB 250215A / EP250215A: Encouraging Follow-up Observations of a BdHN I with a Rest-Frame Duration 2.3 s at z=4.61
  2. GRB 241025A: The discovery of a BdHN I from data of Swift, Fermi, SVOM and Einstein Probe telescopes
  3. GRB 240825A: INTEGRAL SPI ACS LIGHT CURVE
  4. GRB 240825A: The nature of the afterglow motivates the search of the associated supernova
  5. AT2023sva / GRB230916B: GIT observations of the afterglow
  6. transient AT2023sva: A Binary Driven Hypernova with a possible associated supernova
  7. GRB 230430A: A short GRB from a neutron star merger
  8. GRB 221009A: Determination of the black holes mass and spin
  9. GRB 221009A: Peak luminosity of the supernova vs. synchrotron afterglow
  10. GRB 221009A X-ray light-curve and the indication of TeV light-curve
  11. GRB 221009A: A type I BdHN of exceptional energetics
  12. GRB 220527A: A BdHN I with a clear UPE phase
  13. GRB 220101A: The first example of a Petanova
  14. GRB 220101A: The most powerful GRB and BDHN I in 26 years
  15. GRB 211023A: A BdHN of type I
  16. GRB 210411C: A very significant early X-ray afterglow
  17. GRB 210410A: A twin of short GRB 090510 with complementary observations
  18. GRB 210210A as a BdHN II
  19. GRB 190114C: A type 1 BdHN with TeV emission
  20. GRB 180728A: A long GRB of the X-ray flash (XRF) subclass, expecting supernova appearance
  21. GRB 180720B: Testing the universality of the newly born neutron star in BdHNe
  22. GRB 160521B: Theoretical estimate of the redshift and urgent need for further x-ray observations
  23. GRB 151027A: the missing GeV component
  24. GRB 150906B: Further analysis of the Konus-Wind data
  25. GRB 150906B - NGC 3313 association: Constraints from Ep-Eiso and Ep-Liso Relations
  26. GRB 150906B: theoretical estimation of redshift and isotropic energy
  27. GRB 150513A: request for X-ray follow up
  28. GRB 140206A: NOT redshift
  29. GRB 140206A: theoretical prediction of redshift and of supernova occurrence
  30. GRB 140108A: theoretical prediction of redshift and of supernova occurrence
  31. GRB131202A : GROND observations
  32. GRB 131202A: theoretical estimation of the redshift
  33. GRB 060614: theoretical derivation of the redshift and need for deeper search of the host galaxy
  34. GRB 130925A: Possible signatures of binary nature in the afterglow - Request for observations
  35. GRB 130603B: Analogy with GRB 090510A and possible connection with a supernova
  36. GRB 130609B: Theoretical redshift estimation
  37. GRB 130427A: Tautenburg 2nd epoch: No break, no clear SN
  38. GRB 130427A: Predictions about the occurrence of a supernova
  39. GRB 121217A theoretical estimate of redshift and of supernova occurrence
  40. Redshift of GRB 110402A theoretically estimated (revised)
  41. Redshift of GRB 110402A theoretically estimated
  42. Request for Supernova related data for GRB 101023A

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