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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"

35263 results found.

  1. GRB 090126A: Swift-XRT afterglow confirmation
  2. Fermi Gamma-ray Burst Monitor trigger 255342766 is not a GRB
  3. Konus-Wind observation of GRB 090201
  4. GRB 090202: Fermi GBM detection
  5. GRB 090131: Fermi GBM detection
  6. GRB 090201: Swift-XRT refined analysis
  7. GRB090201: Swift UVOT upper limits
  8. GRB 090201: object inside the enhanced XRT error circle
  9. GRB 090201: Enhanced Swift-XRT position
  10. GRB 090201: VLT NIR observations
  11. GRB 090201: Swift-BAT refined analysis
  12. GRB 090201: VLT afterglow candidate
  13. GRB 090201: Swift-XRT detection of the possible X-ray afterglow
  14. GRB090113: MAGIC telescope GeV observation
  15. GRB 090201: ROTSE-III Optical Limits
  16. GRB 090201: Swift detection of a burst
  17. GRB 090126A: Swift/UVOT Upper Limits
  18. Konus-Wind observation of bright burst from AXP/SGR 1E1547.0-5408 on January 29
  19. GRB 090129: Swift-BAT refined analysis
  20. GRB 090129: Swift detection of a burst
  21. IBAS Alert N. 5442 is not a GRB
  22. GRB 090102: HST observations and host galaxy
  23. GRB 090126C: Fermi GBM detection
  24. GRB 090126A: Swift-XRT Refined Analysis
  25. GRB 090126B: Fermi GBM detection
  26. GRB 090126: SuperAGILE Localization of a Long GRB
  27. GRB 090118: no afterglow candidate
  28. GRB 090123: GROND detection
  29. GRB 090123: Swift XRT refined analysis
  30. GRB 090123: Swift/UVOT Observations
  31. AXP 1E1547.0-5408: Suzaku WAM detections of the current activity
  32. GRB 090123: Swift-BAT refined analysis
  33. GRB 090123: Swift detection of a burst
  34. AXP 1E1547.0-5408: long bursts with INTEGRAL SPI-ACS
  35. GRB 090118: Swift XRT Observations - Confirmation of an Afterglow
  36. Swift-BAT trigger 340734 is not a GRB
  37. AXP 1E1547.0-5408: INTEGRAL SPI-ACS confirms activity increase
  38. GRB 090117C: Suzaku WAM observation of the prompt emission
  39. Trigger 340734: Swift detection of a possible short burst
  40. GRB 090118: Subaru NIR Observation
  41. GRB 090118: KPNO 4m 2nd Epoch Observations
  42. GRB 090118 (BATSS): GRT Optical Observation
  43. GRB 090118: KPNO 4m Detection of Candidate Afterglow
  44. GRB 090118: Swift-XRT observations
  45. GRB090118 Swift/UVOT upper limits
  46. GRB 090118: GROND Upper Limits
  47. GRB 090118: Possible burst detection from Swift-BAT slew data
  48. GRB 090117B : Fermi GBM detection
  49. GRB 090117: confirmation of the X-ray afterglow
  50. GRB 090117C - Fermi GRB Detection
  51. GRB 090117 - Fermi GBM Observations
  52. GRB 090117: GROND Upper Limits
  53. GRB090117 Swift/UVOT upper limits
  54. GRB090117: Swift-XRT detection of a possible candidate afterglow
  55. GRB 090117 - SuperAGILE Localization of a long GRB
  56. GRB 090112B: Suzaku WAM observation of the prompt emission
  57. GRB 090113: LOAO Detection Limits in R, I, z, Y-band
  58. GRB 090113: Swift UVOT upper limits
  59. GRB 090113: GROND Upper Limits
  60. GRB 090113: Swift-XRT refined analysis
  61. GRB 090113: Observations from NOT
  62. GRB 090113: Enhanced Swift-XRT position
  63. GRB 090113: Swift-BAT refined analysis
  64. GRB 090113: ROTSE-III Optical Limits
  65. GRB 090112B: Fermi GBM Detection
  66. GRB 090113: Swift detection of a burst
  67. GRB 090112: Fermi GBM detection
  68. GRB 090109: Fermi GBM detection
  69. GRB 090108B: Fermi GBM detection
  70. GRB 090111, Swift-BAT refined analysis
  71. GRB 090111: Swift UVOT Upper Limits
  72. GRB 090108: Fermi GBM Detection
  73. GRB 090111: Swift-XRT refined analysis
  74. GRB 090111: Enhanced Swift-XRT position
  75. GRB 090111: Swift detection of a burst
  76. GRB 090107B: Suzaku WAM observation of the prompt emission
  77. GRB090107B: Fermi GBM Detection
  78. GRB 090102: WSRT Radio Observations
  79. GRB 090107B: Swift XRT afterglow confirmation
  80. GRB 090107B: Swift/UVOT Observations
  81. GRB 090107B: Swift-XRT detection of possible afterglow
  82. GRB 090107B optical observations
  83. GRB 090107B: ROTSE-III Optical Limits
  84. GRB 090107B: a long GRB localized by INTEGRAL
  85. Fermi/GBM detection of GRB 081226A
  86. Fermi/GBM detection of GRB 081225
  87. GRB 090107: Swift-BAT refined analysis
  88. GRB 090107: Swift detection of a burst
  89. GRB 081231: Fermi GBM Detection
  90. GRB 090102: optical decay
  91. VLA radio upper limit on GRB 090102
  92. GRB 090102: GRT Optical Observation
  93. Konus-Wind observation of GRB 090102
  94. GRB 081229: Fermi GBM detection
  95. GRB 090102: Hobby-Eberly Telescope Spectroscopy
  96. GRB 090102: P60 Imaging and P200 Spectroscopy
  97. GRB 090102 Observations from IAC80
  98. GRB 090102: GROND observations of the optical afterglow
  99. Swift UVOT observations of GRB 090102
  100. GRB 090102: Swift-BAT refined analysis

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