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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"

6096 results found.

  1. GRB 220606A: Fermi GBM observation
  2. GRB 220606B: Fermi GBM Observation
  3. GRB 220606B: Swift follow-up observations
  4. GRB 220528A: Fermi GBM Observation
  5. Konus-Wind observation of GRB 220527A
  6. GRB 220527A: MeerLICHT afterglow observations
  7. GRB 220527A: Swift/UVOT detection
  8. GRB 220527A: Swift-XRT afterglow detection
  9. GRB 220527A: Fermi GBM Observation
  10. GRB 220527A: Fermi-LAT detection
  11. Fermi-LAT Gamma-ray Observations of IceCube-220524A
  12. GRB 220521A: Gemini Observations
  13. GRB 220521A: Fermi GBM detection
  14. GRB 220521A: Swift-XRT refined Analysis
  15. GRB 220521A: NOT optical afterglow detection
  16. GRB 220518A: Swift-XRT refined Analysis
  17. Continued Chandra monitoring of GW170817 at ~4.8 yr post-merger
  18. GRB 220514A: GRANDMA Optical Afterglow Observations
  19. GRB 220514A: Fermi GBM observation
  20. GRB 220514B: Swift-XRT observations
  21. GRB 220511A: Swift-XRT afterglow detection
  22. Fermi-LAT Gamma-ray Observations of IceCube-220513A
  23. IceCube-220513A: No significant detection in HAWC
  24. GRB 220514A: MeerLICHT optical afterglow candidate
  25. IceCube-220509A: No significant detection in HAWC
  26. GRB 220511A: Fermi GBM observation
  27. GRB 220511A: Swift-XRT observations
  28. Fermi-LAT Gamma-ray Observations of IceCube-220509A
  29. GRB 220506A: GIT optical upper limit.
  30. GRB 220506A: Swift-XRT afterglow detection
  31. GRB 220430A: GIT optical upper limits
  32. Fermi-LAT Gamma-ray Observations of IceCube-220501A
  33. GRB 220501A: Fermi GBM observation
  34. GRB 220430A: Swift-XRT refined Analysis
  35. GRB 220426A: Swift-XRT and UVOT observations
  36. GRB 220427A: Swift-XRT refined Analysis
  37. GRB 220426A: Fermi GBM detection
  38. Fermi-LAT Gamma-ray Observations of IceCube-220425A
  39. Fermi-LAT Gamma-ray Observations of IceCube-220424A
  40. GRB 220421A: Fermi GBM observation
  41. Fermi-LAT Gamma-ray Observations of IceCube-220421A
  42. GRB 220418B: Swift-XRT observations
  43. GRB 220418B Fermi GBM observation
  44. GRB 220403C: Further Swift-XRT observations
  45. GRB 220417A: Fermi GBM detection
  46. GRB 220412B: Fermi GBM observation
  47. GRB 220408B: Fermi GBM observation
  48. GRB 220412B: Swift-XRT observations
  49. GRB 220408B: Fermi-LAT detection
  50. GRB 220408A: HCT optical upper limit
  51. GRB 220412B: GIT optical upper limit
  52. GRB 220412A: Swift-XRT refined Analysis
  53. GRB 220408A: GRANDMA observations
  54. GRB 220403B: 1.3m DFOT Optical upper limit
  55. GRB 220403C: Swift-XRT observations
  56. GRB 220408A: Swift-XRT refined Analysis
  57. GRB 220408A: GIT optical upper limit
  58. GRB 220408A: Fermi GBM observation
  59. Chandra upper limit at the location of GRB 220408A
  60. Fermi-LAT Gamma-ray Observations of IceCube-220405B
  61. Fermi-LAT Gamma-ray Observations of IceCube-220405A
  62. GRB 220403B: Fermi GBM detection
  63. GRB 220403B: Swift-XRT refined Analysis
  64. GRB 220403B: Nanshan/NEXT optical afterglow power-law decay
  65. GRB 220401A: Fermi GBM observation
  66. GRB 220325A: Swift-XRT refined Analysis
  67. GRB 220325A: 1.3m DFOT Optical upper limit
  68. GRB 220317A: Fermi GBM detection
  69. GRB 220319A: Swift-XRT refined Analysis
  70. Fermi-LAT Gamma-ray Observations of IceCube-220317A
  71. GRB 220311A: Fermi GBM observation
  72. GRB 220310C: Fermi GBM observation
  73. GRB 220310C: Swift-XRT observations
  74. GRB 220310A: GIT confirmation of optical afterglow.
  75. GRB 220308B: Fermi GBM detection
  76. IceCube-220306A: No significant detection in HAWC
  77. IceCube-220303A: No significant detection in HAWC
  78. GRB 220304A Fermi GBM detection
  79. Fermi-LAT Gamma-ray Observations of IceCube-220306A
  80. GRB 220306B: Swift-XRT refined Analysis
  81. GRB 220306B: Fermi GBM observation
  82. Fermi-LAT Gamma-ray Observations of IceCube-220304A
  83. GRB 220305A: Swift-XRT refined Analysis
  84. Correction to GCN 31689: Fermi GBM Report of GRB 220305A should be GRB 220305B
  85. GRB 220305A: Fermi GBM observation
  86. Fermi-LAT Gamma-ray Observations of IceCube-220303A
  87. GRB 220302A: Swift-XRT refined Analysis
  88. GRB 220228A: Fermi GBM observation
  89. GRB 220228A: Fermi-LAT detection
  90. Fermi-LAT Gamma-ray Observations of IceCube-220225A
  91. Konus-Wind observation of GRB 220219B
  92. GRB 220219B: Swift-XRT observations
  93. ZTF22aaajecp/AT2022cmc: Swift Observation and a UV Detection
  94. ZTF22aabjpxh/AT2022cva: NICER X-ray detection is consistent with a GRB afterglow
  95. Fermi-LAT Gamma-ray Observations of IceCube-220221A
  96. ZTF22aaajecp: GIT optical follow-up observations
  97. GRB 220211A: Fermi GBM observation
  98. GRB 220209A: Fermi-LAT detection
  99. GRB 220210A: Fermi-LAT detection
  100. Fermi GRB 220211A: Global MASTER-Net observations report

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