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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"

3113 results found.

  1. Fermi GRB 230308A: Global MASTER-Net observations report
  2. GRB 230304A: Fermi GBM Final Real-time Localization
  3. Fermi trigger No 699294715: Global MASTER-Net observations report
  4. IceCube-230220A: Upper limits from a search for additional neutrino events in IceCube
  5. Fermi GRB 230220B: Global MASTER-Net observations report
  6. GRB 230217A: Gemini-South Optical Observation
  7. IceCube Alert 230217.87: Global MASTER-Net observations report
  8. Fermi trigger No 697678542: Global MASTER-Net observations report
  9. Fermi GRB 230209B: Global MASTER-Net observations report
  10. Fermi GRB 230207A: Global MASTER-Net observations report
  11. GRB 230205A: BOOTES-5/JGT early optical upper limit
  12. GRB 230204B: Detection by GRBAlpha
  13. GRB 230204B: MAXI/GSC detection
  14. Fermi trigger No 697098930: Global MASTER-Net observations report
  15. GRB 230201A: Fermi GBM Final Real-time Localization
  16. GRB 230130A: Fermi GBM Final Real-time Localization
  17. GRB 230128A: Fermi GBM Final Real-time Localization
  18. GRB 230116D: KGO RC-25 optical observations
  19. GRB 230116D: Sintez-Newton/CrAO optical observations
  20. GRB 230116D: Swift-XRT refined Analysis
  21. IceCube-230112A: No Candidate Counterparts from the Zwicky Transient Facility
  22. Fermi GRB 230112A: Global MASTER-Net observations report
  23. Fermi trigger No 695057654: Global MASTER-Net observations report
  24. IceCube-221223A: No Candidate Counterparts from the Zwicky Transient Facility
  25. Swift GRB221226.95: Global MASTER-Net observations report
  26. Fermi GRB 221226A: Global MASTER-Net observations report
  27. GRB 221226A: Fermi GBM Final Real-time Localization
  28. IceCube-221216A: No Candidate Counterparts from the Zwicky Transient Facility
  29. Integral GRB221218.34: Global MASTER-Net observations report
  30. GRB 221216A: AKO Upper Limit
  31. Fermi trigger No 692713692: Global MASTER-Net observations report
  32. Fermi GRB 221211A: Global MASTER-Net observations report
  33. IceCube Alert 221210.36: Global MASTER-Net observations report
  34. GRB 221206B: Swift/BAT-GUANO candidate arcminute localization
  35. GRB 221206C: Fermi GBM Final Real-time Localization
  36. GRB 221206B: Fermi GBM Final Real-time Localization
  37. Swift GRB221204.45: Global MASTER-Net observations report
  38. Konus-Wind detection of GRB 221124A
  39. Fermi Gamma-ray Burst Monitor trigger 691534074/221130867 is not a GRB
  40. IceCube Alert 221124.66: Global MASTER-Net observations report
  41. GRB 221120A: TURBO Optical Upper Limit
  42. Swift GRB221110.10: Global MASTER-Net observations report
  43. GRB 221107A: Fermi GBM Observation
  44. GRB 221028A: GRANDMA observations
  45. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  46. GRB 221028A: NUTTelA-TAO / BSTI Early Optical Limits
  47. GRB 221027B: COATLI Upper Limits
  48. IPN triangulation of GRB 221022C (short)
  49. Konus-Wind detection of GRB 221023A
  50. GRB 221017A: Swift-XRT observations
  51. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  52. MAXI GRB221017.24: Global MASTER-Net observations report
  53. GRB 221017A: MAXI/GSC detection
  54. GRB 221009A: ATCA radio spectrum
  55. Fermi trigger No 687345829: Global MASTER-Net observations report
  56. Fermi trigger No 687340841: Global MASTER-Net observations report
  57. Fermi trigger No 687337536: Global MASTER-Net observations report
  58. Fermi trigger No 687281393: Global MASTER-Net observations report
  59. Fermi-GBM Observations of High Bursting Activity from SGR J1935+2154
  60. INTEGRAL shows increasing activity in SGR J1935+2154
  61. Fermi GRB 220925A: Global MASTER-Net observations report
  62. GRB 220924A: Fermi GBM Final Real-time Localization
  63. IceCube-220907A: No significant detection in HAWC
  64. Fermi trigger No 684716840: Global MASTER-Net observations report
  65. Fermi GRB 220912A: Global MASTER-Net observations report
  66. IceCube-220907A: One Candidate Counterpart from the Zwicky Transient Facility
  67. Fermi GRB 220902A: Global MASTER-Net observations report
  68. Fermi trigger No 683202084: Global MASTER-Net observations report
  69. Fermi trigger No 683183601: Global MASTER-Net observations report
  70. IceCube-220822A: One Candidate Counterpart from the Zwicky Transient Facility
  71. GRB 220813A: Swift/UVOT Detection
  72. Fermi trigger No 681890304: Global MASTER-Net observations report
  73. Fermi trigger No 681633544: Global MASTER-Net observations report
  74. Swift GRB220806.76: Global MASTER-Net observations report
  75. Fermi trigger No 680782656: Global MASTER-Net observations report
  76. Fermi GRB 220728A: Global MASTER-Net observations report
  77. GRB 220726A: Fermi GBM Final Real-time Localization
  78. Fermi trigger No 679248723: Global MASTER-Net observations report
  79. Fermi GRB 220711B: Global MASTER-Net observations report
  80. GRB 220702B: AstroSat CZTI detection
  81. GRB 220627A: Fermi GBM Detection of a possible Lensed or Ultra-long GRB
  82. Fermi trigger No 678058621: Global MASTER-Net observations report
  83. IceCube Alert 220627.74: Global MASTER-Net observations report
  84. IceCube-220624A: No Candidate Counterparts from the Zwicky Transient Facility
  85. Fermi GRB 220624A: Global MASTER-Net observations report
  86. IceCube Alert 220624.68: Global MASTER-Net observations report
  87. IPN triangulation of GRB 220624A
  88. GRB 220623A: BOOTES-5/JGT optical afterglow detection
  89. Fermi trigger No 677377371: Global MASTER-Net observations report
  90. Fermi GRB 220620A: Global MASTER-Net observations report
  91. GRB 220619A: AstroSat CZTI detection
  92. Fermi GRB 220617A: Global MASTER-Net observations report
  93. Fermi trigger No 676909037: Global MASTER-Net observations report
  94. MAXI GRB220607.31: Global MASTER-Net observations report
  95. MAXI GRB220607.41: Global MASTER-Net observations report
  96. Fermi trigger No 675992935: Global MASTER-Net observations report
  97. IPN triangulation of GRB 220528A (short)
  98. Fermi GRB 220530A: Global MASTER-Net observations report
  99. GRB 220528B: Swift/BAT-GUANO detection outside the coded FOV
  100. Fermi trigger No 675411172: Global MASTER-Net observations report

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