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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"

11525 results found.

  1. GRB 220617A: Swift-XRT observations
  2. GRB 220617A: Fermi-LAT detection
  3. GRB 220617B: Swift ToO observations
  4. Fermi GRB 220617A: Global MASTER-Net observations report
  5. GRB 220617A: Fermi GBM Final Real-time Localization
  6. Fermi trigger No 677174940: Global MASTER-Net observations report
  7. Fermi trigger No 676909037: Global MASTER-Net observations report
  8. GRB 220608B: Detection by VZLUSAT-2
  9. GRB 220610B: AstroSat CZTI detection
  10. Fermi GRB 220610A: Global MASTER-Net observations report
  11. GRB 220610A: Fermi GBM Final Real-time Localization
  12. Fermi trigger No 676537486: Global MASTER-Net observations report
  13. GRB 220609B: AstroSat CZTI detection
  14. Fermi trigger No 676366592: Global MASTER-Net observations report
  15. GRB 220608A: AstroSat CZTI detection
  16. GRB 220609A: Fermi GBM Final Real-time Localization
  17. GRB 220606A: Fermi GBM observation
  18. Fermi GRB 220608A: Global MASTER-Net observations report
  19. GRB 220608A: Fermi GBM Final Real-time Localization
  20. GRB 220606B: Gemini South Optical Observations
  21. GRB 220606B: Fermi GBM Observation
  22. GRB 220606A: Swift/BAT-GUANO detection
  23. GRB 220527A: A BdHN I with a clear UPE phase
  24. GRB 220606B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  25. Fermi GRB 220606B: Global MASTER-Net observations report
  26. GRB 220606B: Fermi GBM Final Real-time Localization
  27. GRB 220606A: Fermi GBM Final Real-time Localization
  28. Fermi trigger No 675992935: Global MASTER-Net observations report
  29. Fermi-GBM will trial new SAA regions from Tuesday June 7th
  30. GRB 220527A: MITSuME Akeno continued optical observation
  31. GRB 220527A: Lick 3m Optical Observations
  32. Konus-Wind detection of GRB 220528A
  33. IPN triangulation of GRB 220528A (short)
  34. GRB 220528A: Fermi GBM Observation
  35. Fermi GRB 220530A: Global MASTER-Net observations report
  36. Konus-Wind observation of GRB 220527A
  37. GRB 220530A: Fermi GBM Final Real-time Localization
  38. Correction to GCN 32148: Should be GRB 220528A
  39. GRB 220528B: Swift/BAT-GUANO detection outside the coded FOV
  40. GRB 220528A: Fermi GBM Final Localization
  41. GRB 220527A: AST3-3 Yaoan Optical Observation
  42. GRB 220527A: REM optical/NIR observations
  43. GRB 220527A: VLT/X-shooter spectroscopic redshift
  44. GRB 220527A: MeerLICHT afterglow observations
  45. Fermi trigger No 675411172: Global MASTER-Net observations report
  46. GRB 220527A: NOT optical photometry and spectroscopic redshift
  47. GRB 220527A: AstroSat CZTI detection
  48. GRB 220527A: CALET Gamma-Ray Burst Monitor detection
  49. GRB 220527A: MITSuME Akeno optical observation
  50. GRB 220527A: Swift/UVOT detection
  51. GRB 220527A: Swift-XRT afterglow detection
  52. GRB 220527A: Fermi GBM Observation
  53. GRB 220527A: Swift ToO observations
  54. GRB 220527A: Fermi-LAT detection
  55. GRB 220527A: Fermi GBM Final Localization
  56. GRB 220525A: Fermi GBM Detection
  57. GRB 220525A: CALET Gamma-Ray Burst Monitor detection
  58. GRB 220523B: CALET Gamma-Ray Burst Monitor detection
  59. Konus-Wind detection of GRB 220525A
  60. Fermi GRB 220525A: Global MASTER-Net observations report
  61. IPN triangulation of GRB 220525A
  62. Fermi-LAT Gamma-ray Observations of IceCube-220524A
  63. GRB 220525A: BALROG localization (Fermi Trigger 675130259 / GRB 220525008)
  64. GRB 220525A: Fermi GBM Final Real-time Localization
  65. GRB 220521A: BOOTES-2/TELMA and CAHA 2.2m telescope optical upper limit
  66. GRB 220521A: classification and detection by SPI-ACS/INTEGRAL
  67. GRB 220521A: ISON-Castelgrande observatory optical observations
  68. IceCube-220524A - IceCube observation of a high-energy neutrino candidate track-like event
  69. GRB 220521A: MITSuME Akeno optical upper limits
  70. Fermi GRB 220523B: Global MASTER-Net observations report
  71. GRB 220521A: Gemini Observations
  72. GRB 220523B: Fermi GBM detection
  73. GRB 220521A: MMT Afterglow Imaging
  74. GRB 220521A: REM optical/NIR upper limits
  75. GRB 220514A: Swift/BAT-GUANO detection outside the coded FOV
  76. Fermi GRB 220523A: Global MASTER-Net observations report
  77. GRB 220523A: Fermi GBM Final Real-time Localization
  78. GRB 220521A: LCO Optical Detection
  79. GRB 220521A: Fermi GBM detection
  80. GRB 220521A: Sintesz-Newton/CrAO optical upper limit
  81. Fermi GRB 220522A: Global MASTER-Net observations report
  82. Fermi trigger No 674868783: Global MASTER-Net observations report
  83. GRB 220522A: Fermi GBM Final Real-time Localization
  84. GRB 220521A: Fermi GBM Final Real-time Localization
  85. GRB 220514A: AstroSat CZTI detection
  86. Fermi GRB 220518B: Global MASTER-Net observations report
  87. GRB 220518B: Fermi GBM Final Real-time Localization
  88. GRB 220514A: MITSuME Akeno optical observation
  89. GRB 220514A: GRANDMA Optical Afterglow Observations
  90. Fermi trigger No 674397342: Global MASTER-Net observations report
  91. GRB 220514A: Fermi GBM observation
  92. GRB 220514A: KAIT Optical Afterglow Confirmation
  93. Fermi-LAT Gamma-ray Observations of IceCube-220513A
  94. GRB 220514A: MeerLICHT optical afterglow candidate
  95. Fermi GRB 220514A: Global MASTER-Net observations report
  96. GRB 220514A: a long GRB detected by INTEGRAL
  97. GRB 220514A: BALROG localization (Fermi Trigger 674223877 / GRB 220514517)
  98. GRB 220514A: Fermi GBM Final Real-time Localization
  99. IceCube-220513A - IceCube observation of a high-energy neutrino candidate track-like event
  100. Fermi GRB 220513A: Global MASTER-Net observations report

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