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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"

22915 results found.

  1. GRB 090305: Swift/UVOT Upper Limits
  2. GRB 090305: Swift-XRT refined analysis
  3. GRB090305: GMOS-S Candidate Optical Afterglow
  4. GRB 090305: Swift detection of a short burst
  5. GRB 090303: Fermi GBM detection
  6. GRB 090304: Fermi GBM detection
  7. Konus-RF catches first GRB and SGR bursts
  8. GRB 090228B: Fermi GBM detection
  9. IPN localization of short bright GRB 090227B
  10. GRB 090301B: Fermi GBM detection
  11. GRB 090227B: Fermi GBM detection
  12. GRB 090301: Swift detection of a burst
  13. GRB 090228: Fermi GBM detection
  14. GRB 090227: Fermi GBM detection
  15. GRB 090206: Fermi GBM detection
  16. GRB 081211B: Nearby cluster
  17. GRB 090222: Fermi GBM detection
  18. GRB 090219: Fermi GBM detection
  19. GRB090217: XRT analysis
  20. IPN localization of GRB 090217
  21. GRB 090213: Fermi GBM detection
  22. GRB 090217: Fermi GBM detection
  23. SGR activity seen by BAT during ICSP Ionospheric Events
  24. GRB 090207 - Fermi GBM Observations
  25. VLA radio upper limit on GRB 090205
  26. GRB 090205: VLT optical decay
  27. GRB 090205: Swift/UVOT Upper Limits
  28. GRB 090205: Swift-XRT refined analysis
  29. GRB 090205: GROND observations and photometric redshift estimate
  30. GRB 090205: VLT candidate afterglow
  31. GRB 090205: Swift-BAT refined analysis
  32. GRB 090205: Enhanced Swift-XRT position
  33. GRB 090205: Swift detection of a burst
  34. GRB 080319B: IceCube upper limit on high-energy neutrino flux
  35. GRB 090202: Fermi GBM detection
  36. GRB 090131: Fermi GBM detection
  37. GRB090201: Swift UVOT upper limits
  38. GRB 090201: object inside the enhanced XRT error circle
  39. GRB 090201: Enhanced Swift-XRT position
  40. GRB 090201: VLT NIR observations
  41. GRB 090201: VLT afterglow candidate
  42. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  43. GRB 090201: ROTSE-III Optical Limits
  44. GRB 090201: Swift detection of a burst
  45. GRB 090126A: Swift/UVOT Upper Limits
  46. GRB 090129: Swift detection of a burst
  47. Suzaku ToO Observation of AXP 1E 1547.0-5408
  48. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  49. GRB 090102: HST observations and host galaxy
  50. GRB 090126C: Fermi GBM detection
  51. GRB 090126A: Swift-XRT Refined Analysis
  52. GRB 090126B: Fermi GBM detection
  53. GRB 090126: SuperAGILE Localization of a Long GRB
  54. GRB 090118: no afterglow candidate
  55. GRB 090123: GROND detection
  56. GRB 090123: Swift/UVOT Observations
  57. GRB 090123: Swift-BAT refined analysis
  58. GRB090123: Enhanced Swift-XRT position
  59. GRB 090123: Swift detection of a burst
  60. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  61. Trigger 340734: Swift detection of a possible short burst
  62. AXP 1E1547.0-5408 activity with SGR bursts
  63. GRB 090118: Subaru NIR Observation
  64. GRB 090118: KPNO 4m 2nd Epoch Observations
  65. GRB 090118 (BATSS): GRT Optical Observation
  66. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  67. GRB 090118: Swift-XRT observations
  68. GRB090118 Swift/UVOT upper limits
  69. GRB 090118: GROND Upper Limits
  70. GRB 090118: Possible burst detection from Swift-BAT slew data
  71. GRB 090117B : Fermi GBM detection
  72. GRB 090117C - Fermi GRB Detection
  73. GRB 090117: GROND Upper Limits
  74. GRB090117 Swift/UVOT upper limits
  75. GRB090117: Swift-XRT detection of a possible candidate afterglow
  76. GRB 090117 - SuperAGILE Localization of a long GRB
  77. GRB 090112B: Suzaku WAM observation of the prompt emission
  78. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  79. GRB 090113: Swift UVOT upper limits
  80. GRB 090113: GROND Upper Limits
  81. GRB 090113: Observations from NOT
  82. GRB 090113: Enhanced Swift-XRT position
  83. GRB 090113: ROTSE-III Optical Limits
  84. GRB 090112B: Fermi GBM Detection
  85. GRB 090113: Swift detection of a burst
  86. GRB 090112: Fermi GBM detection
  87. GRB 090109: Fermi GBM detection
  88. GRB 090108B: Fermi GBM detection
  89. GRB 090111, Swift-BAT refined analysis
  90. GRB 090111: Swift UVOT Upper Limits
  91. GRB 090108: Fermi GBM Detection
  92. GRB 090111: Enhanced Swift-XRT position
  93. GRB 090111: Swift detection of a burst
  94. GRB 090107B: Swift XRT afterglow confirmation
  95. GRB 090107B: Swift/UVOT Observations
  96. GRB 090107B: Swift-XRT detection of possible afterglow
  97. GRB 090107B: ROTSE-III Optical Limits
  98. Fermi/GBM detection of GRB 081226A
  99. Fermi/GBM detection of GRB 081225
  100. GRB 090107: Swift detection of a burst

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