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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"

19551 results found.

  1. GRB 090308: Swift/UVOT Upper Limits
  2. GRB 090307B: Fermi GBM detection
  3. GRB 090306C: Fermi GBM detection
  4. GRB 090307: GROND Upper Limits
  5. GRB 090306B: GROND Upper Limits
  6. GRB 090308: Swift-XRT refined analysis
  7. GRB 090308: Swift detection of a burst
  8. GRB 090306B: Possible XRT afterglow
  9. GRB 090307: Swift-XRT afterglow confirmation and analysis
  10. GRB 090307: Swift-BAT refined analysis of trigger 345551
  11. Swift Trigger 345551 is probably not a GRB
  12. IPN localization of short GRB 090305C
  13. GRB 090306: Swift detection of a possible burst
  14. GRB 090305: Swift/UVOT Upper Limits
  15. GRB 090305: Swift-XRT refined analysis
  16. GRB090305: GMOS-S Candidate Optical Afterglow
  17. GRB 090305: Swift detection of a short burst
  18. GRB 090228B: Fermi GBM detection
  19. GRB 090301B: Fermi GBM detection
  20. GRB 090228: Fermi GBM detection
  21. GRB 090227: Fermi GBM detection
  22. GRB 090206: Fermi GBM detection
  23. GRB 081211B: Nearby cluster
  24. GRB 090222: Fermi GBM detection
  25. GRB 090219: Fermi GBM detection
  26. GRB090217: XRT analysis
  27. GRB 090217: Fermi GBM detection
  28. SGR activity seen by BAT during ICSP Ionospheric Events
  29. GRB 090207 - Fermi GBM Observations
  30. GRB 090129: Fermi GBM detection
  31. VLA radio upper limit on GRB 090205
  32. GRB 090205: Swift/UVOT Upper Limits
  33. GRB 090205: GROND observations and photometric redshift estimate
  34. GRB 090205: VLT candidate afterglow
  35. GRB 090205: Enhanced Swift-XRT position
  36. GRB 090205: Swift detection of a burst
  37. GRB 090202: Fermi GBM detection
  38. GRB 090131: Fermi GBM detection
  39. GRB090201: Swift UVOT upper limits
  40. GRB 090201: object inside the enhanced XRT error circle
  41. GRB 090201: Enhanced Swift-XRT position
  42. GRB 090201: VLT NIR observations
  43. GRB 090201: Swift-BAT refined analysis
  44. GRB 090201: VLT afterglow candidate
  45. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  46. GRB 090201: ROTSE-III Optical Limits
  47. GRB 090126A: Swift/UVOT Upper Limits
  48. Suzaku ToO Observation of AXP 1E 1547.0-5408
  49. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  50. GRB 090102: HST observations and host galaxy
  51. GRB 090126B: Fermi GBM detection
  52. GRB 090118: no afterglow candidate
  53. GRB 090123: GROND detection
  54. GRB 090123: Swift/UVOT Observations
  55. GRB090123: Enhanced Swift-XRT position
  56. GRB 090123: Swift detection of a burst
  57. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  58. Trigger 340734: Swift detection of a possible short burst
  59. GRB 090118: Subaru NIR Observation
  60. GRB 090118: KPNO 4m 2nd Epoch Observations
  61. GRB 090118 (BATSS): GRT Optical Observation
  62. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  63. GRB090118 Swift/UVOT upper limits
  64. GRB 090118: GROND Upper Limits
  65. GRB 090118: Possible burst detection from Swift-BAT slew data
  66. GRB 090117B : Fermi GBM detection
  67. GRB 090117C - Fermi GRB Detection
  68. GRB 090117 - Fermi GBM Observations
  69. GRB 090117: GROND Upper Limits
  70. GRB090117 Swift/UVOT upper limits
  71. GRB090117: Swift-XRT detection of a possible candidate afterglow
  72. GRB 090112B: Suzaku WAM observation of the prompt emission
  73. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  74. GRB 090113: Swift UVOT upper limits
  75. GRB 090113: GROND Upper Limits
  76. GRB 090113: Observations from NOT
  77. GRB 090113: Enhanced Swift-XRT position
  78. GRB 090113: ROTSE-III Optical Limits
  79. GRB090113: XRT position
  80. GRB 090112B: Fermi GBM Detection
  81. GRB 090113: Swift detection of a burst
  82. GRB 090112: Fermi GBM detection
  83. GRB 090109: Fermi GBM detection
  84. GRB 090108B: Fermi GBM detection
  85. GRB 090111: Swift UVOT Upper Limits
  86. GRB 090108: Fermi GBM Detection
  87. GRB 090111: Swift-XRT refined analysis
  88. GRB 090111: Enhanced Swift-XRT position
  89. GRB 090111: Swift detection of a burst
  90. GRB090107B: Fermi GBM Detection
  91. GRB 090102: WSRT Radio Observations
  92. GRB 090107B: Swift XRT afterglow confirmation
  93. GRB 090107B: Swift/UVOT Observations
  94. GRB 090107B: Swift-XRT detection of possible afterglow
  95. GRB 081231: Fermi GBM Detection
  96. VLA radio upper limit on GRB 090102
  97. GRB 090102: GRT Optical Observation
  98. Swift triggered on the HMXB 1A 1118-61
  99. GRB 081229: Fermi GBM detection
  100. GRB 090102: P60 Imaging and P200 Spectroscopy

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