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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').
Advanced Search

To narrow the search results, use advanced search syntax. This allows for specifying which circular field to search (submitter, subject, and/or body). For additional information, refer to the advanced search documentation.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

865 results found.

  1. GRB030329 observed as a sudden ionospheric disturbance (SID)
  2. IPN triangulation of GRB030131 - CORRECTION
  3. IPN triangulation of GRB021219
  4. IPN detection of continued activity from SGR1806-20
  5. IPN detection of renewed activity from SGR1806-20
  6. IPN detection of continued SGR1900+14 activity
  7. IPN confirmation of the reactivation of SGR1900+14
  8. IPN detection of possible reactivation of SGR1900+14
  9. IPN triangulation of GRB021119 (annulus)
  10. IPN triangulation of bursts from SGR1900+14, November 1-2, 2002
  11. SGR1900+14 activity, November 2-4, 2002
  12. Detection of activity from SGR 1900+14 with the RXTE/PCA
  13. IPN triangulation of GRB021025 (annulus)
  14. IPN detection of a burst from SGR1900+14
  15. Gemini IR Detection of AXP 1E 2259+586 Post-Burst
  16. SGR-like X-ray Bursts from AXP 1E 2259+586: follow-up
  17. AXP 1E2259+586: quasi-simultaneous optical observation
  18. AXP 1E2259+586 optical observations
  19. SGR-like Bursts from the AXP 1E 2259+586
  20. IPN detection of possible bursts from SGR1806-20
  21. IPN triangulation of GRB020525
  22. XRF 020427: Sudden Ionospheric Disturbance (SID)
  23. Mars Odyssey joins the IPN
  24. IPN detection and localization of Cygnus X-1 flares
  25. RXTE Observations of SGR 1900+14
  26. SGR1900+14 activity
  27. IPN/HETE Detection of Bursts from SGR1900+14
  28. IPN detection of further activity from SGR1806-20
  29. Optical observation of SGR 1806-20 at the 6-m SAO telescope
  30. Probable SGR or Short Duration GRB Detected by HETE
  31. Dramatic Increase in the Rate of X-ray Bursts Reported by HETE
  32. Possible burst from SGR1806-20
  33. IPN detection of SGR1900+14
  34. X-ray precursors to the large flare from SGR 1900+14
  35. SGR 1900+14: No evidence of extended X-ray emission
  36. SGR 1900+14 : RXTE observations
  37. BeppoSAX/NFI Follow-up Observation of SGR 1900+14
  38. SGR1900+14
  39. SGR 1900+14: Correction to GCN 1049
  40. Millimeter observation of SGR 1900+14
  41. SGR 1900+14: Detection of extended X-ray emission
  42. Chandra Observations of SGR 1900+14
  43. SGR 1900+14, Chandra observations
  44. Chandra Observations of SGR 1900+14
  45. SGR1900+14, I-band observations
  46. IPN triangulation of GRB 001004
  47. SGR 1806-20 burst activity
  48. GRB 991216--Summary of RXTE Observations
  49. BATSE GRB trigger criteria
  50. X-ray/GRB 1SAX J0835.9+5118, BATSE Observation
  51. GRB990308 not a new SGR
  52. GRB990308, Possible new SGR~0209+70
  53. SGR1900+14, BeppoSAX-GRBM observations
  54. SGR1627-41
  55. SGR1627-41, RXTE/ASM observations
  56. Reduced error box of SGR 1627-41
  57. SGR 1627-41
  58. Discovery of a new SGR source, SGR1627-41
  59. SGR 1900+14
  60. SGR1900+14
  61. SGR1900+14
  62. BATSE on-board GRB trigger change
  63. IRAS 18119-1342 and the possible new SGR
  64. Possible new SGR from US Naval Observatory
  65. RXTE Observations of SGR 1814-13

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