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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"

35962 results found.

  1. GRB 220527A: CALET Gamma-Ray Burst Monitor detection
  2. GRB 220527A: MITSuME Akeno optical observation
  3. GRB 220527A: Swift/UVOT detection
  4. GRB 220527A: Swift-XRT afterglow detection
  5. GRB 220527A: Fermi GBM Observation
  6. GRB 220527A: Swift ToO observations
  7. GRB 220527A: Fermi-LAT detection
  8. GRB 220527A: Fermi GBM Final Localization
  9. GRB 220527A: AGILE detection
  10. GRB 220521B: CALET Gamma-Ray Burst Monitor detection
  11. GRB 220525A: Fermi GBM Detection
  12. GRB 220525A: CALET Gamma-Ray Burst Monitor detection
  13. GRB 220523B: CALET Gamma-Ray Burst Monitor detection
  14. Konus-Wind detection of GRB 220524B
  15. Konus-Wind detection of GRB 220525A
  16. Konus-Wind detection of GRB 220524A
  17. Fermi GRB 220525A: Global MASTER-Net observations report
  18. IPN triangulation of GRB 220525A
  19. IPN triangulation of GRB 220524B
  20. IPN triangulation of GRB 220524A
  21. GRB 220525A: BALROG localization (Fermi Trigger 675130259 / GRB 220525008)
  22. GRB 220525A: Fermi GBM Final Real-time Localization
  23. GRB 220521A: ATCA detection
  24. GRB 220521A: ALMA detection
  25. Konus-Wind detection of GRB 220522B
  26. IPN triangulation of GRB 220522B
  27. GRB 220521A: BOOTES-2/TELMA and CAHA 2.2m telescope optical upper limit
  28. Konus-Wind detection of GRB 220521B
  29. GRB 220521A: classification and detection by SPI-ACS/INTEGRAL
  30. IPN triangulation of GRB 220521B
  31. GRB 220521A: ISON-Castelgrande observatory optical observations
  32. GRB 220521A: MITSuME Akeno optical upper limits
  33. Fermi GRB 220523B: Global MASTER-Net observations report
  34. GRB 220521A: Gemini Observations
  35. GRB 220523B: Fermi GBM detection
  36. GRB 220521A: MMT Afterglow Imaging
  37. GRB 220521A: REM optical/NIR upper limits
  38. GRB 220514A: Swift/BAT-GUANO detection outside the coded FOV
  39. Fermi GRB 220523A: Global MASTER-Net observations report
  40. GRB 220523A: Fermi GBM Final Real-time Localization
  41. GRB 220521A: LCO Optical Detection
  42. GRB 220521A: Swift-BAT refined analysis
  43. GRB 220521A: Fermi GBM detection
  44. GRB 220521A: Sintesz-Newton/CrAO optical upper limit
  45. GRB 220521A: RATIR Optical and NIR Observations
  46. GRB 220521A: Swift-XRT refined Analysis
  47. GRB 220521A: Swift/UVOT Upper Limits
  48. Fermi GRB 220522A: Global MASTER-Net observations report
  49. GRB 220521A: SAO RAS optical observations
  50. GRB 220521A: Enhanced Swift-XRT position
  51. GRB 220522A: Fermi GBM Final Real-time Localization
  52. GRB 220521A: NOT spectroscopic redshift
  53. GRB 220521A: NOT optical afterglow detection
  54. GRB 220521A: Prompt enhanced Swift-XRT position
  55. GRB 220521A: Swift detection of a burst
  56. GRB 220521A: Fermi GBM Final Real-time Localization
  57. Konus-Wind detection of GRB 220519A
  58. IPN triangulation of GRB 220519A
  59. GRB 220514A: AstroSat CZTI detection
  60. GRB 220518A: Swift-BAT refined analysis
  61. GRB 220518A: Swift-XRT refined Analysis
  62. Fermi GRB 220518B: Global MASTER-Net observations report
  63. GRB 220518B: Fermi GBM Final Real-time Localization
  64. GRB 220518A: Swift/UVOT Detection
  65. GRB 220518A: Enhanced Swift-XRT position
  66. Swift GRB 220518A: Global MASTER-Net observations report
  67. GRB 220518A: Swift detection of a burst
  68. GRB 220514A: MITSuME Akeno optical observation
  69. GRB 220514A: GRANDMA Optical Afterglow Observations
  70. Konus-Wind detection of GRB 220506A
  71. Konus-Wind detection of GRB 220514B
  72. GRB 220514A: Fermi GBM observation
  73. GRB 220514B: Swift-XRT observations
  74. GRB 220511A: Swift-XRT afterglow detection
  75. GRB 220514A: KAIT Optical Afterglow Confirmation
  76. GRB 220514B: Tiled Swift observations
  77. GRB 220514B: MAXI/GSC detection
  78. GRB 220514A: MeerLICHT optical afterglow candidate
  79. Fermi GRB 220514A: Global MASTER-Net observations report
  80. GRB 220514A: a long GRB detected by INTEGRAL
  81. GRB 220514A: BALROG localization (Fermi Trigger 674223877 / GRB 220514517)
  82. GRB 220514A: Fermi GBM Final Real-time Localization
  83. Fermi GRB 220513A: Global MASTER-Net observations report
  84. GRB 220513A: Fermi GBM Final Real-time Localization
  85. Konus-Wind detection of GRB 220511A
  86. GRB 220427A: MeerLICHT afterglow observations
  87. GRB 220511A: Fermi GBM observation
  88. GRB 220511A: Swift-XRT observations
  89. GRB 220511A: AstroSat CZTI detection
  90. GRB 220511A: BOOTES-2/TELMA optical upper limit
  91. Fermi GRB 220512A: Global MASTER-Net observations report
  92. GRB 220512A: Fermi GBM Final Real-time Localization
  93. GRB 220511A: Swift ToO observations
  94. GRB 220511A: Swift/BAT-GUANO arcminute localization
  95. Fermi GRB 220511A: Global MASTER-Net observations report
  96. GRB 220511A: AGILE detection
  97. GRB 220511A: BALROG localization (Fermi Trigger 673969321/ GRB 220511571)
  98. GRB 220511A: Fermi GBM Final Real-time Localization
  99. GRB 220507A: AstroSat CZTI detection
  100. GRB 220506A: MITSuME Akeno optical upper limits

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