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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. GRB 180703B: Fermi-LAT detection
  2. GRB 180703A: Fermi-LAT detection
  3. GRB 180703A: Tiled Swift observations
  4. GRB 180630A: Swift/UVOT Detection
  5. GRB 180701A: MAXI/GSC detection
  6. GRB 180626C : GOTO optical observations
  7. GRB 180626B : GOTO optical observations
  8. GRB 180630A: Swift-BAT refined analysis
  9. GRB 180630A: Swift-XRT refined Analysis
  10. GRB 180630A: Fermi GBM detection
  11. GRB 180626C / Fermi trigger 551697835: MASTER inspection
  12. GRB 180630A: Enhanced Swift-XRT position
  13. GRB 180630A: Swift detection of a burst with an optical counterpart
  14. GRB 180626C: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 551697835)
  15. GRB 180626A: TSHAO optical upper limit
  16. Konus-Wind observation of GRB 180626A
  17. Konus-Wind observation of GRB 180626C
  18. GRB 180624A: NOT optical counterpart
  19. Konus-Wind observation of GRB 180626B
  20. GRB 180626A: RATIR Optical Observations
  21. IPN Triangulation of GRB 180626C (short)
  22. IPN Triangulation of GRB 180626B (short)
  23. GRB 180626A: Swift-BAT refined analysis
  24. GRB 180626A: KAIT Optical Upper Limit
  25. GRB 180626A: Swift-XRT refined Analysis
  26. GRB 180626A: COATLI Optical Detection
  27. GRB 180624A: LCO Haleakala observations
  28. GRB 180626A: Swift/UVOT Detection
  29. Konus-Wind observation of GRB 180623A
  30. GRB 180626A: RATIR Optical Detection
  31. GRB 180626A: LCO Haleakala observations
  32. GRB 180626A: ISON-MN optical observations
  33. GRB 180626A: Enhanced Swift-XRT position
  34. GRB 180626A: A long GRB detected by INTEGRAL
  35. GRB 180626A: Swift detection of a burst with an optical counterpart
  36. GRB 180623B: CALET Gamma-Ray Burst Monitor detection
  37. GRB 180624A: Swift-BAT refined analysis
  38. AT2018cow: Swift/BAT data search
  39. GRB 180624A: RATIR Optical Observations
  40. GRB 180624A: LBT/MODS redshift measurement
  41. GRB 180620B: AstroSat CZTI detection
  42. GRB 180620A: AstroSat CZTI detection
  43. GRB 180618A: AstroSat CZTI detection
  44. GRB 180613A: LCO Afterglow detection
  45. GRB 180624A: GROND observations
  46. GRB 180624A: LCO Siding Springs afterglow candidate
  47. GRB 180624A: MITSuME Okayama optical upper limits
  48. GRB 180624A: Swift-XRT refined Analysis
  49. GRB 180624A: Swift/UVOT Upper Limits
  50. GRB 180624A: Enhanced Swift-XRT position
  51. GRB 180623A: retraction of the Swift/UVOT Detection
  52. GRB 180623A: Swift-BAT refined analysis
  53. GRB 180624A: Swift detection of a burst
  54. GRB 180623A: Swift/UVOT Detection
  55. GRB 180623A: Swift-XRT refined Analysis
  56. GRB 180623A: Enhanced Swift-XRT position
  57. GRB 180623A: Swift detection of a burst
  58. GRB 180620B: Swift/UVOT Detection
  59. GRB 180620A iTelescope observation
  60. Konus-Wind observation of GRB 180620B
  61. Konus-Wind observation of GRB 180620A
  62. GRB 180620B: VLT/X-shooter redshift
  63. Konus-Wind observation of GRB 180618A (a short GRB with extended emission)
  64. GRB 180620B: Swift-BAT refined analysis
  65. GRB 180613A: Afterglow confirmation and added photometry
  66. GROND observations of GRB 180620B
  67. GROND observations of GRB 180620A
  68. GRB 180620B: Swift-XRT refined Analysis
  69. GRB 180618B: CALET Gamma-Ray Burst Monitor detection
  70. GRB 180620A: Swift-BAT refined analysis
  71. GRB 180620B: Enhanced Swift-XRT position
  72. GRB 180620B: Fermi GBM detection
  73. GRB 180620A: KAIT Optical Observations
  74. GRB 180620A: Xinglong-2.16m optical observations
  75. GRB 180618A: Swift/UVOT Detection
  76. GRB 180618A: TSHAO optical upper limit
  77. GRB 180620A: Swift-XRT refined Analysis
  78. GRB 180620B: Swift detection of a burst with an optical counterpart
  79. GRB 180620A: COATLI Detection and Light Curve
  80. GRB 180620A: Swift/UVOT Detection
  81. GRB 180618A: Xinglong-2.16m optical upper limit
  82. GRB 180620A: LCO McDonald observations
  83. GRB 180620A: Enhanced Swift-XRT position
  84. GRB 180620A: MASTER OT observation
  85. GRB 180620A: ISON-MN afterglow confirmation
  86. GRB 180620A: RATIR Optical Afterglow Detection
  87. GRB 180620A: Swift detection of a burst with an optical counterpart
  88. GRB 180618A: MASTER OT observation (a short GRB with extended emission)
  89. GRB 180618A: Swift-BAT refined analysis (a short GRB with extended emission)
  90. GRB 180611A: AstroSat CZTI detection
  91. GRB 180618A: Fermi GBM detection
  92. GRB 180618A: Swift-XRT refined Analysis
  93. GRB 180618A: LT prompt observations
  94. GRB 180618A: Enhanced Swift-XRT position
  95. GRB 180618A: Swift detection of a burst with an optical counterpart
  96. GRB 180614A: AbAO optical observations
  97. GRB 180614A: 1.5m OSN I-band observation
  98. GRB 180614A: Swift/UVOT Upper Limits
  99. GRB 180614A: Swift-BAT refined analysis
  100. GRB 180529A: AstroSat CZTI detection

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