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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"

19549 results found.

  1. GRB 090306C: Fermi GBM detection
  2. GRB 090307: GROND Upper Limits
  3. GRB 090306B: GROND Upper Limits
  4. GRB 090308: Swift-XRT refined analysis
  5. GRB 090308: Swift detection of a burst
  6. GRB 090306B: Possible XRT afterglow
  7. GRB 090307: Swift-XRT afterglow confirmation and analysis
  8. GRB 090307: Swift-BAT refined analysis of trigger 345551
  9. Swift Trigger 345551 is probably not a GRB
  10. IPN localization of short GRB 090305C
  11. GRB 090306: Swift detection of a possible burst
  12. GRB 090305: Swift/UVOT Upper Limits
  13. GRB 090305: Swift-XRT refined analysis
  14. GRB090305: GMOS-S Candidate Optical Afterglow
  15. GRB 090305: Swift detection of a short burst
  16. GRB 090228B: Fermi GBM detection
  17. GRB 090301B: Fermi GBM detection
  18. GRB 090228: Fermi GBM detection
  19. GRB 090227: Fermi GBM detection
  20. GRB 090206: Fermi GBM detection
  21. GRB 081211B: Nearby cluster
  22. GRB 090222: Fermi GBM detection
  23. GRB 090219: Fermi GBM detection
  24. GRB090217: XRT analysis
  25. GRB 090217: Fermi GBM detection
  26. SGR activity seen by BAT during ICSP Ionospheric Events
  27. GRB 090207 - Fermi GBM Observations
  28. GRB 090129: Fermi GBM detection
  29. VLA radio upper limit on GRB 090205
  30. GRB 090205: Swift/UVOT Upper Limits
  31. GRB 090205: GROND observations and photometric redshift estimate
  32. GRB 090205: VLT candidate afterglow
  33. GRB 090205: Enhanced Swift-XRT position
  34. GRB 090205: Swift detection of a burst
  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: Swift-BAT refined analysis
  42. GRB 090201: VLT afterglow candidate
  43. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  44. GRB 090201: ROTSE-III Optical Limits
  45. GRB 090126A: Swift/UVOT Upper Limits
  46. Suzaku ToO Observation of AXP 1E 1547.0-5408
  47. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  48. GRB 090102: HST observations and host galaxy
  49. GRB 090126B: Fermi GBM detection
  50. GRB 090118: no afterglow candidate
  51. GRB 090123: GROND detection
  52. GRB 090123: Swift/UVOT Observations
  53. GRB090123: Enhanced Swift-XRT position
  54. GRB 090123: Swift detection of a burst
  55. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  56. Trigger 340734: Swift detection of a possible short burst
  57. GRB 090118: Subaru NIR Observation
  58. GRB 090118: KPNO 4m 2nd Epoch Observations
  59. GRB 090118 (BATSS): GRT Optical Observation
  60. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  61. GRB090118 Swift/UVOT upper limits
  62. GRB 090118: GROND Upper Limits
  63. GRB 090118: Possible burst detection from Swift-BAT slew data
  64. GRB 090117B : Fermi GBM detection
  65. GRB 090117C - Fermi GRB Detection
  66. GRB 090117 - Fermi GBM Observations
  67. GRB 090117: GROND Upper Limits
  68. GRB090117 Swift/UVOT upper limits
  69. GRB090117: Swift-XRT detection of a possible candidate afterglow
  70. GRB 090112B: Suzaku WAM observation of the prompt emission
  71. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  72. GRB 090113: Swift UVOT upper limits
  73. GRB 090113: GROND Upper Limits
  74. GRB 090113: Observations from NOT
  75. GRB 090113: Enhanced Swift-XRT position
  76. GRB 090113: ROTSE-III Optical Limits
  77. GRB090113: XRT position
  78. GRB 090112B: Fermi GBM Detection
  79. GRB 090113: Swift detection of a burst
  80. GRB 090112: Fermi GBM detection
  81. GRB 090109: Fermi GBM detection
  82. GRB 090108B: Fermi GBM detection
  83. GRB 090111: Swift UVOT Upper Limits
  84. GRB 090108: Fermi GBM Detection
  85. GRB 090111: Swift-XRT refined analysis
  86. GRB 090111: Enhanced Swift-XRT position
  87. GRB 090111: Swift detection of a burst
  88. GRB090107B: Fermi GBM Detection
  89. GRB 090102: WSRT Radio Observations
  90. GRB 090107B: Swift XRT afterglow confirmation
  91. GRB 090107B: Swift/UVOT Observations
  92. GRB 090107B: Swift-XRT detection of possible afterglow
  93. GRB 081231: Fermi GBM Detection
  94. VLA radio upper limit on GRB 090102
  95. GRB 090102: GRT Optical Observation
  96. Swift triggered on the HMXB 1A 1118-61
  97. GRB 081229: Fermi GBM detection
  98. GRB 090102: P60 Imaging and P200 Spectroscopy
  99. GRB 090102 Observations from IAC80
  100. GRB 090102: GROND observations of the optical afterglow

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