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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"

5059 results found.

  1. Ultra-long GRB 220525B: Konus-Wind and Fermi-GBM detection
  2. Fermi GRB 220925A: Global MASTER-Net observations report
  3. Fermi trigger No 685748699: Global MASTER-Net observations report
  4. Fermi trigger No 684894705: Global MASTER-Net observations report
  5. IceCube-220907A: No significant detection in HAWC
  6. Fermi GRB 220912A: Global MASTER-Net observations report
  7. GRB 220831A: Gemini-South Infrared Observations
  8. IceCube-220907A: One Candidate Counterpart from the Zwicky Transient Facility
  9. IceCube Alert 220907.28: Global MASTER-Net observations report
  10. Fermi GRB 220902A: Global MASTER-Net observations report
  11. Fermi trigger No 683654200: Global MASTER-Net observations report
  12. GRB 220827A: Fermi GBM Final Real-time Localization
  13. Fermi trigger No 683202084: Global MASTER-Net observations report
  14. Fermi trigger No 683183601: Global MASTER-Net observations report
  15. IceCube-220822A: One Candidate Counterpart from the Zwicky Transient Facility
  16. GRB 220823A: Fermi GBM detection
  17. Fermi trigger No 682918137: Global MASTER-Net observations report
  18. GRB 220813A: Swift detection of a burst with an optical counterpart
  19. Fermi trigger No 681890304: Global MASTER-Net observations report
  20. Fermi trigger No 681719116: Global MASTER-Net observations report
  21. Fermi trigger No 681633544: Global MASTER-Net observations report
  22. Fermi trigger No 681271717: Global MASTER-Net observations report
  23. GRB 220803A: AstroSat CZTI detection
  24. Fermi trigger No 681212354: Global MASTER-Net observations report
  25. Fermi trigger No 680782656: Global MASTER-Net observations report
  26. Fermi GRB 220728A: Global MASTER-Net observations report
  27. Fermi trigger No 680421061: Global MASTER-Net observations report
  28. GRB 220724A: Fermi GBM Final Real-time Localization
  29. GRB 220714B: UVOT afterglow discovery
  30. Fermi GRB 220711B: Global MASTER-Net observations report
  31. GRB 220706A : NICER detection of re-brightening 1 day after the Swift trigger
  32. GRB 220701A: COATLI Optical Upper Limit
  33. IceCube-220629A: No significant detection in HAWC
  34. IceCube-220627A: No significant detection in HAWC
  35. IceCube Alert 220627.74: Global MASTER-Net observations report
  36. GRB 220623A: BOOTES-5/JGT optical afterglow detection
  37. Swift GRB220620.02: Global MASTER-Net observations report
  38. Fermi trigger No 677307509: Global MASTER-Net observations report
  39. IPN triangulation of GRB 220606C
  40. Fermi trigger No 676909037: Global MASTER-Net observations report
  41. GRB 220608A: AstroSat CZTI detection
  42. Fermi GRB 220608A: Global MASTER-Net observations report
  43. GRB 220608A: Fermi GBM Final Real-time Localization
  44. GRB 220606B: Fermi GBM Observation
  45. GRB 220606B: Swift/BAT-GUANO candidate arcminute localization of a short burst
  46. Fermi GRB 220606B: Global MASTER-Net observations report
  47. GRB 220606B: Fermi GBM Final Real-time Localization
  48. Fermi trigger No 675992935: Global MASTER-Net observations report
  49. Fermi trigger No 675411172: Global MASTER-Net observations report
  50. GRB 220527A: NOT optical photometry and spectroscopic redshift
  51. GRB 220521B: CALET Gamma-Ray Burst Monitor detection
  52. IPN triangulation of GRB 220524A
  53. IPN triangulation of GRB 220522B
  54. Konus-Wind detection of GRB 220521B
  55. IPN triangulation of GRB 220521B
  56. Fermi GRB 220523B: Global MASTER-Net observations report
  57. GRB 220521A: Swift detection of a burst
  58. GRB 220518A: Swift/UVOT Detection
  59. GRB 220514A: KAIT Optical Afterglow Confirmation
  60. GRB 220514B: MAXI/GSC detection
  61. MAXI GRB220514.98: Global MASTER-Net observations report
  62. Fermi GRB 220513A: Global MASTER-Net observations report
  63. GRB 220512A: Fermi GBM Final Real-time Localization
  64. GRB 220427A: Swift detection of a burst with an optical counterpart
  65. Fermi trigger No 672492774: Global MASTER-Net observations report
  66. GRB 220421B: Detection by VZLUSAT-2
  67. IPN triangulation of GRB 220411A
  68. Fermi GRB 220417A: Global MASTER-Net observations report
  69. Fermi trigger No 671729344: Global MASTER-Net observations report
  70. GRB 220412A: Continued RATIR Observations and Steepening of the Light Curve
  71. GRB 220412A: BOOTES-network optical upper limits
  72. GRB 220412B: BOOTES-1 optical upper limit
  73. GRB 220412A: RATIR Observations of the Fading Afterglow
  74. Correction to GCN 31888: GRB 220412A: Swift-XRT refined Analysis
  75. GRB 220408A: Swift-BAT refined analysis
  76. Fermi GRB 220411A: Global MASTER-Net observations report
  77. GRB 220408A: NOT optical observations and archival detection
  78. Fermi GRB 220408B: Global MASTER-Net observations report
  79. GRB 220408A: Swift detection of a burst with an optical counterpart, possibly associated with M51
  80. ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, SAO RAS, CrAO)
  81. GRB 220403B: 1.5m OSN optical observation
  82. GRB 220403B: Kitab optical observations
  83. GRB 220403B: NUTTelA-TAO / BSTI Early Optical Limits (Preliminary)
  84. GRB 220403B: Fermi GBM detection
  85. GRB 220403B: Nanshan/NEXT optical afterglow power-law decay
  86. GRB 220403A: Tautenburg observations
  87. Fermi GRB 220403A: Global MASTER-Net observations report
  88. Swift Trigger 1100848 is likely not a GRB
  89. Swift GRB220402.16: Global MASTER-Net observations report
  90. Fermi GRB 220401B: Global MASTER-Net observations report
  91. Fermi GRB 220330A: Global MASTER-Net observations report
  92. ZTF22aaajecp/AT2022cmc: 1.3m DFOT Optical observations
  93. GRB 220325A: Swift-BAT refined analysis
  94. ZTF22aaajecp/AT2022cmc: continued optical observations (Mondy, TSHAO, AbAO)
  95. GRB 220325A: Tautenburg observations
  96. GRB 220325A: 1.3m DFOT Optical upper limit
  97. GRB 220325A: MASTER Global Robotic Net optical observations
  98. GRB 220324A: AstroSat CZTI detection
  99. GRB 220323A: AstroSat CZTI detection
  100. GRB 220323A: AGILE/MCAL detection

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