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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"

20496 results found.

  1. GRB 090309: Swift/UVOT Upper Limits
  2. GRB 090309: Enhanced Swift-XRT position
  3. GRB 090308: GROND observations
  4. GRB 090308: Gemini GMOS Observations
  5. GRB 090309: Swift detection of a burst
  6. GRB 090308: Swift/UVOT Upper Limits
  7. GRB 090307B: Fermi GBM detection
  8. GRB 090307: GROND Upper Limits
  9. GRB 090306B: GROND Upper Limits
  10. GRB 090305C: Suzaku WAM observation of the prompt emission
  11. GRB 090308: Swift-XRT refined analysis
  12. GRB 090308: Swift detection of a burst
  13. GRB 090306B: Possible XRT afterglow
  14. GRB 090307: Swift-XRT afterglow confirmation and analysis
  15. Swift Trigger 345551 is probably not a GRB
  16. IPN localization of short GRB 090305C
  17. GRB 090306: Swift detection of a possible burst
  18. GRB 090305: Swift/UVOT Upper Limits
  19. GRB 090305: Swift-XRT refined analysis
  20. GRB 090227A: Suzaku WAM observation of the prompt emission
  21. GRB 090305: Magellan confirmation of the optical afterglow
  22. GRB090305: GMOS-S Candidate Optical Afterglow
  23. GRB 090305: Swift detection of a short burst
  24. GRB 090301A: Suzaku WAM observation of the prompt emission
  25. Konus-Wind observation of bright short GRB 090227B
  26. Konus-Wind observation of GRB 090301A
  27. GRB 090301A: Swift-BAT refined analysis
  28. GRB 090301B: Fermi GBM detection
  29. GRB 081211B: Nearby cluster
  30. Ongoing activity of AXP/SGR 1E1547.0-5408
  31. GRB 090217: Suzaku WAM observation of the prompt emission
  32. GRB090217: XRT analysis
  33. Konus-Wind observation of GRB 090217
  34. GRB090217: Fermi-LAT Detection
  35. SGR activity seen by BAT during ICSP Ionospheric Events
  36. Detailed lightcurves of ICSP VLF Observation of SGR/AXP 1E1547.0-5408
  37. VLA radio upper limit on GRB 090205
  38. GRB 090205: Swift/UVOT Upper Limits
  39. GRB 090205: Swift-XRT refined analysis
  40. GRB 090205: GROND observations and photometric redshift estimate
  41. GRB 090205: VLT candidate afterglow
  42. GRB 090205: Swift-BAT refined analysis
  43. GRB 090205: Enhanced Swift-XRT position
  44. GRB 090205: Swift detection of a burst
  45. GRB 080319B: IceCube upper limit on high-energy neutrino flux
  46. GRB 090131: Suzaku WAM observation of the prompt emission
  47. Konus-Wind observation of GRB 090201
  48. GRB090201: Swift UVOT upper limits
  49. GRB 090201: object inside the enhanced XRT error circle
  50. GRB 090201: Enhanced Swift-XRT position
  51. GRB 090201: VLT NIR observations
  52. GRB 090201: Swift-BAT refined analysis
  53. GRB 090201: VLT afterglow candidate
  54. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  55. GRB090113: MAGIC telescope GeV observation
  56. GRB 090201: ROTSE-III Optical Limits
  57. GRB 090126A: Swift/UVOT Upper Limits
  58. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  59. Suzaku ToO Observation of AXP 1E 1547.0-5408
  60. Konus-Wind observation of AXP/SGR 1E1547.0-5408 bursting activity
  61. GRB 090102: HST observations and host galaxy
  62. GRB 090118: no afterglow candidate
  63. GRB 090123: GROND detection
  64. GRB 090123: Swift/UVOT Observations
  65. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  66. GRB090123: Enhanced Swift-XRT position
  67. GRB 090123: Swift detection of a burst
  68. AXP 1E1547.0-5408: long bursts with INTEGRAL SPI-ACS
  69. AXP 1E1547.0-5408: Fermi GBM detection of additional bursts
  70. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  71. GRB 090117C: Suzaku WAM observation of the prompt emission
  72. Trigger 340734: Swift detection of a possible short burst
  73. GRB 090118: Subaru NIR Observation
  74. GRB 090118: KPNO 4m 2nd Epoch Observations
  75. GRB 090118 (BATSS): GRT Optical Observation
  76. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  77. GRB090118 Swift/UVOT upper limits
  78. GRB 090118: GROND Upper Limits
  79. GRB 090118: Possible burst detection from Swift-BAT slew data
  80. GRB 090117C - Fermi GRB Detection
  81. GRB 090117 - Fermi GBM Observations
  82. GRB 090117: GROND Upper Limits
  83. GRB090117 Swift/UVOT upper limits
  84. GRB090117: Swift-XRT detection of a possible candidate afterglow
  85. GRB090102: MAGIC telescope GeV observation
  86. GRB 090112B: Suzaku WAM observation of the prompt emission
  87. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  88. GRB 090113: Swift UVOT upper limits
  89. GRB 090113: GROND Upper Limits
  90. GRB 090113: Observations from NOT
  91. GRB 090113: Enhanced Swift-XRT position
  92. GRB 090113: ROTSE-III Optical Limits
  93. GRB 090113: Swift detection of a burst
  94. GRB 090109: Fermi GBM detection
  95. GRB 090111: Swift UVOT Upper Limits
  96. GRB 090111: Enhanced Swift-XRT position
  97. GRB 090111: Swift detection of a burst
  98. GRB 090107B: Suzaku WAM observation of the prompt emission
  99. GRB 090107B: Swift XRT afterglow confirmation
  100. GRB 090107B: Swift/UVOT Observations

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