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

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