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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"

33621 results found.

  1. Fermi GRB 220617A: Global MASTER-Net observations report
  2. GRB 220617A: Fermi GBM Final Real-time Localization
  3. GRB 220611A: Gemini Ks counterpart detection
  4. Konus-Wind detection of GRB 220613A
  5. IPN triangulation of GRB 220613A
  6. GRB 220611A: Gemini South Infrared Detection
  7. IPN triangulation of GRB 220606C
  8. GRB 220611A: Swift/UVOT Upper Limits
  9. GRB 220612A: CALET Gamma-Ray Burst Monitor detection
  10. GRB 220612A: Swift/BAT-GUANO detection
  11. GRB 220611A: Swift-BAT refined analysis
  12. GRB 220608B: Detection by VZLUSAT-2
  13. Swift GRB 220611A: Global MASTER-Net observations report
  14. GRB 220611A: Swift-XRT refined Analysis
  15. GRB 220610B: AstroSat CZTI detection
  16. GRB 220611A: Enhanced Swift-XRT position
  17. GRB 220611A: Swift detection of a burst
  18. IPN triangulation of GRB 220609B
  19. Fermi GRB 220610A: Global MASTER-Net observations report
  20. GRB 220610A: Fermi GBM Final Real-time Localization
  21. GRB 220609B: AstroSat CZTI detection
  22. GRB 220609B: CALET Gamma-Ray Burst Monitor detection
  23. GRB 220608A: AstroSat CZTI detection
  24. GRB 220609A: Fermi GBM Final Real-time Localization
  25. GRB 220606A: Fermi GBM observation
  26. GRB 220606C: CALET Gamma-Ray Burst Monitor detection
  27. Fermi GRB 220608A: Global MASTER-Net observations report
  28. GRB 220608A: Fermi GBM Final Real-time Localization
  29. GRB 220606B: Gemini South Optical Observations
  30. GRB 220606B: Fermi GBM Observation
  31. GRB 220606B: Swift follow-up observations
  32. Konus-Wind detection of GRB 220601A
  33. GRB 220606A: Swift/BAT-GUANO detection
  34. GRB 220606B: GUANO coordinate correction to GCN 32167
  35. GRB 220527A: A BdHN I with a clear UPE phase
  36. GRB 220606B: Swift ToO observations
  37. GRB 220606B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  38. Fermi GRB 220606B: Global MASTER-Net observations report
  39. GRB 220606B: Fermi GBM Final Real-time Localization
  40. GRB 220606A: Fermi GBM Final Real-time Localization
  41. IPN triangulation of GRB 220601A (long)
  42. GRB 220603A: Swift/BAT-GUANO detection outside the coded FOV
  43. GRB 220527A: MITSuME Akeno continued optical observation
  44. GRB 220527A: Lick 3m Optical Observations
  45. Konus-Wind detection of GRB 220528A
  46. IPN triangulation of GRB 220528A (short)
  47. GRB 220528A: Fermi GBM Observation
  48. Fermi GRB 220530A: Global MASTER-Net observations report
  49. Konus-Wind observation of GRB 220527A
  50. GRB 220530A: Fermi GBM Final Real-time Localization
  51. Correction to GCN 32148: Should be GRB 220528A
  52. GRB 220528B: Swift/BAT-GUANO detection outside the coded FOV
  53. GRB 220528A: Fermi GBM Final Localization
  54. GRB 220527A: AST3-3 Yaoan Optical Observation
  55. GRB 220527A: REM optical/NIR observations
  56. GRB 220527A: VLT/X-shooter spectroscopic redshift
  57. GRB 220527A: MeerLICHT afterglow observations
  58. GRB 220527A: NOT optical photometry and spectroscopic redshift
  59. GRB 220527A: AstroSat CZTI detection
  60. GRB 220527A: CALET Gamma-Ray Burst Monitor detection
  61. GRB 220527A: MITSuME Akeno optical observation
  62. GRB 220527A: Swift/UVOT detection
  63. GRB 220527A: Swift-XRT afterglow detection
  64. GRB 220527A: Fermi GBM Observation
  65. GRB 220527A: Swift ToO observations
  66. GRB 220527A: Fermi-LAT detection
  67. GRB 220527A: Fermi GBM Final Localization
  68. GRB 220527A: AGILE detection
  69. GRB 220521B: CALET Gamma-Ray Burst Monitor detection
  70. GRB 220525A: Fermi GBM Detection
  71. GRB 220525A: CALET Gamma-Ray Burst Monitor detection
  72. GRB 220523B: CALET Gamma-Ray Burst Monitor detection
  73. Konus-Wind detection of GRB 220524B
  74. Konus-Wind detection of GRB 220525A
  75. Konus-Wind detection of GRB 220524A
  76. Fermi GRB 220525A: Global MASTER-Net observations report
  77. IPN triangulation of GRB 220525A
  78. IPN triangulation of GRB 220524B
  79. IPN triangulation of GRB 220524A
  80. GRB 220525A: BALROG localization (Fermi Trigger 675130259 / GRB 220525008)
  81. GRB 220525A: Fermi GBM Final Real-time Localization
  82. GRB 220521A: ATCA detection
  83. GRB 220521A: ALMA detection
  84. Konus-Wind detection of GRB 220522B
  85. IPN triangulation of GRB 220522B
  86. GRB 220521A: BOOTES-2/TELMA and CAHA 2.2m telescope optical upper limit
  87. Konus-Wind detection of GRB 220521B
  88. GRB 220521A: classification and detection by SPI-ACS/INTEGRAL
  89. IPN triangulation of GRB 220521B
  90. GRB 220521A: ISON-Castelgrande observatory optical observations
  91. GRB 220521A: MITSuME Akeno optical upper limits
  92. Fermi GRB 220523B: Global MASTER-Net observations report
  93. GRB 220521A: Gemini Observations
  94. GRB 220523B: Fermi GBM detection
  95. GRB 220521A: MMT Afterglow Imaging
  96. GRB 220521A: REM optical/NIR upper limits
  97. GRB 220514A: Swift/BAT-GUANO detection outside the coded FOV
  98. Fermi GRB 220523A: Global MASTER-Net observations report
  99. GRB 220523A: Fermi GBM Final Real-time Localization
  100. GRB 220521A: LCO Optical Detection

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