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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"
  1. GRB 090309: Swift/UVOT Upper Limits
  2. GRB090305B: Fermi GBM detection
  3. GRB 090309B: Fermi GBM detection
  4. GRB 090309: Swift-XRT refined analysis
  5. GRB 090309: Enhanced Swift-XRT position
  6. GRB 090306B: INTEGRAL SPI-ACS light curve
  7. GRB 090309, Swift-BAT refined analysis
  8. GRB 090308: GROND observations
  9. GRB 090308: Gemini GMOS Observations
  10. GRB 090309: Swift detection of a burst
  11. GRB 090308B: Fermi GBM detection
  12. GRB 090308: Swift/UVOT Upper Limits
  13. GRB 090307B: Fermi GBM detection
  14. GRB 090306C: Fermi GBM detection
  15. GRB 090307: GROND Upper Limits
  16. GRB 090306B: GROND Upper Limits
  17. GRB 090305C: Suzaku WAM observation of the prompt emission
  18. GRB 090308: Swift-XRT refined analysis
  19. Radio observation of GRB 090201 with ATCA
  20. Radio observation of GRB 090117 with ATCA
  21. Radio observation of GRB 081226b with ATCA
  22. Radio observation of GRB 081226a with ATCA
  23. Radio observation of GRB 081007 with ATCA
  24. ATCA observation of SGR J1550-5418
  25. GRB 090308: Swift-BAT refined analysis
  26. GRB 090308: Swift detection of a burst
  27. GRB 090306B: Possible XRT afterglow
  28. GRB 090307: Swift-XRT afterglow confirmation and analysis
  29. GRB 090307: Swift-BAT refined analysis of trigger 345551
  30. GRB 090306B: Burst detection from Swift-BAT slew data
  31. Swift Trigger 345551 is probably not a GRB
  32. Swift-BAT trigger 345396 is not a GRB
  33. IPN localization of short GRB 090305C
  34. Fermi GBM trigger 090305784 is not a GRB
  35. GRB 090306: Swift detection of a possible burst
  36. GRB 090305: Swift/UVOT Upper Limits
  37. GRB 090305: Swift-XRT refined analysis
  38. GRB 090305, Swift-BAT refined analysis
  39. GRB 090227A: Suzaku WAM observation of the prompt emission
  40. GRB 090305: Magellan confirmation of the optical afterglow
  41. GRB090305: GMOS-S Candidate Optical Afterglow
  42. GRB 090305: Swift detection of a short burst
  43. GRB 090303: Fermi GBM detection
  44. GRB 090304: Fermi GBM detection
  45. GRB 090301A: Suzaku WAM observation of the prompt emission
  46. Konus-RF catches first GRB and SGR bursts
  47. GRB 090228B: Fermi GBM detection
  48. Konus-Wind observation of bright short GRB 090227B
  49. IPN localization of short bright GRB 090227B
  50. Konus-Wind observation of GRB 090301A
  51. GRB 090301A: Swift-BAT refined analysis
  52. GRB 090301B: Fermi GBM detection
  53. GRB 090227B: Fermi GBM detection
  54. GRB 090301: Swift detection of a burst
  55. Swift_BAT_Lightcurve Notice for Trigger Number 344565 is not valid
  56. GRB 090228: Fermi GBM detection
  57. GRB 090227: Fermi GBM detection
  58. GRB 090206: Fermi GBM detection
  59. SGR J1550-5418
  60. GRB 081211B: Nearby cluster
  61. Ongoing activity of AXP/SGR 1E1547.0-5408
  62. GRB 090222: Fermi GBM detection
  63. GRB 090219: Fermi GBM detection
  64. Swift Restored
  65. Swift Trigger 343319 is not a GRB
  66. GRB 090217: Suzaku WAM observation of the prompt emission
  67. GRB090217: XRT analysis
  68. Konus-Wind observation of GRB 090217
  69. IPN localization of GRB 090217
  70. GRB 090213: Fermi GBM detection
  71. GRB090217: Fermi-LAT Detection
  72. GRB 090217: Fermi GBM detection
  73. SGR activity seen by BAT during ICSP Ionospheric Events
  74. Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
  75. GRB 090207 - Fermi GBM Observations
  76. Fermi Gamma-ray Burst Monitor trigger 255729682 is not a GRB
  77. GRB 090129: Fermi GBM detection
  78. VLA radio upper limit on GRB 090205
  79. GRB 090205: VLT optical decay
  80. Fermi Gamma-ray Burst Monitor trigger 255541748 cannot be classified
  81. GRB 090205: Swift/UVOT Upper Limits
  82. GRB 090205: VLT refined redshift
  83. GRB 090205: Swift-XRT refined analysis
  84. GRB 090205: Swift burst of interest
  85. GRB 090205: VLT spectroscopic redshift
  86. GRB 090205: GROND observations and photometric redshift estimate
  87. GRB 090205: VLT candidate afterglow
  88. GRB 090205: Swift-BAT refined analysis
  89. GRB 090205: Enhanced Swift-XRT position
  90. GRB 090205: Swift detection of a burst
  91. GRB 080319B: IceCube upper limit on high-energy neutrino flux
  92. GRB 090131: Suzaku WAM observation of the prompt emission
  93. ICSP VLF observation of the signatures of SGR/AXP 1E1547.0-5408 bursts
  94. GRB 090126A: Swift-XRT afterglow confirmation
  95. Fermi Gamma-ray Burst Monitor trigger 255342766 is not a GRB
  96. Konus-Wind observation of GRB 090201
  97. GRB 090202: Fermi GBM detection
  98. GRB 090131: Fermi GBM detection
  99. GRB 090201: Swift-XRT refined analysis
  100. GRB090201: Swift UVOT upper limits

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Download all Circulars as a .tar.gz archive (updated once a day):
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