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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"
  1. Trigger 317393: Swift detection of a possible GRB
  2. Trigger 317205: Swift detection of an outburst from XTE J1701-407
  3. GRB 080714: GROND confirmation of the optical/NIR afterglow
  4. Konus-Wind observation of GRB 080714
  5. GRB 080714: Swift/UVOT Detection of an Optical Afterglow
  6. GRB 080714: Swift-XRT refined analysis
  7. GRB 080714: Enhanced Swift-XRT position
  8. GRB 080714: Swift-BAT refined analysis
  9. GRB 080714: Swift detection of a burst
  10. GRB 080702A: optical upper limit
  11. GRB 080603A: CrAO optical observations
  12. GRB 080603B: optical observations in MAO
  13. GRB 080603B: optical observations in CrAO
  14. GRB 080710: Optical observation with MITSuME Okayama
  15. GRB 080710: TLS observations, steepening afterglow decay
  16. GRB 080702B: Swift XRT confirmation of the afterglow
  17. GRB 080710: Lick IR detection
  18. GRB 080710, Swift-BAT refined analysis
  19. GRB 0800707: optical observations
  20. GRB 080710: Rapid PROMPT Observations
  21. GRB 080710: Swift-XRT refined analysis
  22. GRB080710: Swift/UVOT observations
  23. GRB 080710: Enhanced Swift-XRT position
  24. GRB 080710: Faulkes Telescope North observations
  25. GRB 080710: Gemini spectroscopy and probable redshift
  26. UVOT white band observations of GRB080710
  27. GRB 080710: REM afterglow confirmation & brightening
  28. GRB 080710: KAIT OA candidate
  29. GRB 080710: Swift XRT position
  30. GRB 080710: Swift detection of a burst
  31. GRB 080707: possible break in the X-rays
  32. New Swift-XRT GRB products available online.
  33. GRB 080707: GROND Confirmation of the Optical Afterglow
  34. UVOT observations of GRB080707
  35. GRB 080707, Swift-BAT refined analysis
  36. GRB 080707: Swift XRT refined analysis
  37. GRB 080707: Enhanced Swift-XRT position
  38. GRB 080707: VLT redshift
  39. GRB 080707: GROND Detection of the Optical Afterglow Candidate
  40. GRB 080707: Swift detection of a burst
  41. Refined analysis of Swift Trigger 316063, is IGR J08408-4503
  42. Trigger 316063: Swift detection of a transient
  43. GRB 080703: GROND Upper Limits
  44. GRB 080702B: GROND Upper Limits
  45. GRB 080703: Swift-XRT refined analysis
  46. GRB 080703: UVOT Follow-Up Observation
  47. GRB 080703: VLT observations of the afterglow
  48. GRB 080703: Enhanced Swift-XRT position
  49. GRB 080703, Swift-BAT refined analysis
  50. GRB 080702B Swift-BAT refined analysis
  51. GRB 080703: Swift detection of a burst with optical afterglow
  52. GRB 080703A: ROTSE-III Detection of Optical Counterpart
  53. No radio detection from the short GRB 080702A
  54. GRB 080702b: LCO optical observations
  55. Swift/UVOT observation of GRB080702A
  56. GRB 080702B: Swift XRT and UVOT observations
  57. GRB 080625: Suzaku WAM observation of the prompt emission
  58. GRB 080702A: MITSuME Akeno optical upper limits
  59. GRB 080701A: Early RAPTOR optical limits
  60. Swift Trigger 315630: Swift/UVOT Upper Limits
  61. GRB 080702A, Swift-BAT refined analysis
  62. GRB 080702A: Swift-XRT Team refined analysis
  63. GRB 080702B : Burst detected in BAT during Swift slew
  64. GRB 080702A: Enhanced Swift-XRT position
  65. Swift Trigger 315630: TLS R-band observation
  66. Swift Trigger 315630: Probably not a GRB
  67. GRB 080702: Swift detection of a short burst
  68. GRB 080701: Swift-XRT refined analysis
  69. GRB 080701A, VATT optical upper limit
  70. TLS I-Band Observation of GRB 080701A
  71. GRB 080701A: Swift/UVOT Upper Limits
  72. GRB 080701A: Early Super-LOTIS Observations
  73. GRB 080701: Enhanced Swift-XRT position
  74. GRB 080701A, Swift-BAT refined analysis
  75. Trigger 315630: Swift detection of a possible burst
  76. GRB 080701: Swift-XRT Prompt Analysis
  77. GRB 080701: Swift detection of a burst
  78. GRB 080623: Suzaku WAM observation of the prompt emission
  79. GRB 080625: Swift/UVOT Follow-Up Observations
  80. GRB 080625: Further observations from OSN
  81. GRB 080625:Swift-XRT detection of the afterglow
  82. GRB 080625: Swift/UVOT Detection of an Optical Afterglow
  83. GRB 080625: Observations at OSN
  84. GRB 080625: Gamma Ray Burst Localization by SuperAGILE
  85. GRB 080623: GROND upper limits
  86. GRB080623: Swift UVOT followup observations
  87. GRB 080623: Swift-XRT refined analysis
  88. GRB 080623, Swift-BAT refined analysis
  89. GRB 080623: Enhanced Swift-XRT position
  90. GRB 080623: TAROT La Silla observatory optical observations
  91. GRB 080623: Swift/UVOT Non-Detection of an Optical Afterglow
  92. GRB 080623: Swift XRT prompt analysis
  93. GRB 080623: Swift detection of a burst
  94. Swift trigger 314975 is not a GRB
  95. Swift-BAT trigger 314975 possible burst
  96. GRB080607: optical observation
  97. GRB 080603b: optical observation
  98. GRB 070809: Putative host galaxy and redshift
  99. VLA upper limit on INTEGRAL burst GRB 080613A
  100. GRB 0800603A: optical observation

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