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GCN Circulars

GCN Circulars are rapid bulletins submitted by and distributed to the community. 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"

11553 results found.

  1. GRB 260114A: Fermi GBM Final Real-time Localization
  2. Konus-Wind detection of GRB 260101A
  3. GRB 260111A: Swift-XRT observations
  4. GRB 260111A: COLIBRÍ optical afterglow candidate
  5. GRB 260111A: GECAM-B observation of a burst
  6. GRB 260111A: Fermi GBM Observation
  7. GRB 260111A: GOTO optical upper limits
  8. GRB 260112B: Fermi GBM Final Real-time Localization
  9. GRB 260111A: Swift/BAT-GUANO arcminute localization of a burst
  10. GRB 260112A: Fermi GBM Final Real-time Localization
  11. IceCube-260111A - IceCube observation of a high-energy neutrino candidate track-like event
  12. Fermi GRB 260111A: Global MASTER-Net observations report
  13. GRB 260111A: Fermi GBM Final Real-time Localization
  14. EP260105b / GRB 260105C : Fermi-GBM Sub-Threshold Detection
  15. GRB 260109B: Fermi GBM Final Real-time Localization
  16. GRB 260109A: Fermi GBM Final Real-time Localization
  17. Fermi GRB 260107A: Global MASTER-Net observations report
  18. GRB 260107A: Fermi GBM Final Real-time Localization
  19. Fermi GRB 260105A: Global MASTER-Net observations report
  20. GRB 260105B: Fermi GBM Detection
  21. GRB 260105B: BALROG localization (Fermi Trigger 789348101 / GRB 260105973)
  22. GRB 260105A: SVOM/GRM observation
  23. GRB 260105B: SVOM/GRM observation
  24. Fermi GRB 260105B: Global MASTER-Net observations report
  25. GRB 260105B: Fermi GBM Final Real-time Localization
  26. GRB 260105A: Fermi GBM Final Real-time Localization
  27. GRB 260101A: COLIBRÍ optical upper limits
  28. GRB 260104C: Fermi GBM Final Real-time Localization
  29. Fermi GRB 260104B: Global MASTER-Net observations report
  30. GRB 260104B: Fermi GBM Final Localization
  31. Fermi-LAT Gamma-ray Observations of IceCube-251225A
  32. GRB 260101A: COLIBRÍ optical observations
  33. GRB 260102B: Fermi GBM Final Real-time Localization
  34. Fermi GBM Sub-Threshold Detection of GRB 260102A
  35. Fermi Gamma-ray Burst Monitor trigger 789047602/260102495 is not a GRB
  36. GRB 260101A: Fermi GBM Observation
  37. GRB 260101A: GECAM-B detection
  38. GRB 260101A: NOT spectroscopic observations
  39. GRB 260101A: SVOM/GRM observation
  40. GRB 260101A: OSIRIS+ redshift z = 2.623 for the new year burst
  41. GRB 260101A: LCO detection of the optical counterpart
  42. GRB 260101A: Fermi GBM Final Real-time Localization
  43. Fermi Gamma-ray Burst Monitor trigger 788833547/251231018 is not a GRB
  44. GRB 251231A: Fermi GBM Final Real-time Localization
  45. GRB 251222A: Mondy Optical Observations
  46. GRB 251222A/EP251222b: 1.6m Mephisto optical followup
  47. Fermi GRB 251228A: Global MASTER-Net observations report
  48. GRB 251228A: Fermi GBM Final Real-time Localization
  49. GRB 251226A: GECAM-B detection
  50. IceCube-251225A - IceCube observation of a high-energy neutrino candidate track-like event
  51. Fermi Gamma-ray Burst Monitor trigger 788368008/251225630 is not a GRB
  52. GRB 251222A/EP251222b: Optical detection with Kinder observations
  53. GRB 251222A/EP251222b: FTW optical and NIR observations
  54. GRB 251205A: Kilonova-Catcher optical afterglow detection
  55. GRB 251222A: AbAO optical observations
  56. GRB 251222A / EP251222b: Kilonova-Catcher optical afterglow detection
  57. GRB 251222A: ZTSH BVRI optical observations
  58. GRB 251222A: SVOM/COLIBRÍ (FM-GFT) optical observations
  59. GRB 251222A: Continued 1.3m DFOT optical observation
  60. GRB 251222A: Fermi GBM Observation
  61. GRB 251222A / EP251222b: GECAM-B observation
  62. Konus-Wind detection of GRB 251222A / EP251222b
  63. GRB 251222A / EP251222b: LCO detection of the optical counterpart
  64. GRB 251222A / EP251222b: GOTO optical counterpart detection
  65. GRB 251222A / EP251222b: LCO optical observations
  66. GRB 251222A: 1.3m DFOT optical detection
  67. GRB251221A: 7DT optical upper limits
  68. GRB 251222A / EP251222b: VLT/X-shooter spectroscopic redshift z = 3.171
  69. GRB 251222A / EP251222b: SVOM/VT optical rebrightening
  70. EP251222b/GRB 251222A: SVOM/GRM observation
  71. GRB 251222A: PRIME near-infrared detection
  72. GRB 251222A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  73. GRB 251222A: NOT optical observations
  74. IPN triangulation of GRB 251220B (short)
  75. GRB 251222A: BALROG localization (Fermi Trigger / GRB 251222712)
  76. GRB 251222A: SVOM detection of a long burst
  77. GRB 251222A: Fermi GBM Final Real-time Localization
  78. GRB 251221A: PRIME near-infrared observation
  79. GRB 251221A: UAFO and Mondy optical upper limit
  80. Fermi Gamma-ray Burst Monitor trigger 788028118/251221696 is not a GRB
  81. GRB 251221A: Fermi GBM Observation
  82. GRB 251221B: Fermi GBM Final Real-time Localization
  83. GRB 251220B: SVOM/GRM observation of a short burst
  84. GRB 251221A: COLIBRÍ detection of the optical counterpart
  85. GRB 251221A: Fermi GBM Final Real-time Localization
  86. GRB 251220B: Fermi GBM Final Real-time Localization
  87. Fermi-LAT Gamma-ray Observations of IceCube-251218A
  88. IceCube-251218A - IceCube observation of a high-energy neutrino candidate track-like event
  89. GRB 251214B: VIRT Optical Upper Limit
  90. Fermi trigger No 787736968: Global MASTER-Net observations report
  91. Fermi GRB 251217A: Global MASTER-Net observations report
  92. GRB 251217A: Fermi GBM Final Real-time Localization
  93. GRB 251215A: Swift/UVOT Upper LImits
  94. GRB 251215A: Fermi GBM Observation
  95. Fermi GRB 251216A: Global MASTER-Net observations report
  96. GRB 251202A/EP251202a: Koshka optical upper limit
  97. GRB 251214B: Mondy optical upper limit
  98. GRB 251215A: COLIBRÍ optical upper limit
  99. GRB 251216A: Fermi GBM Final Real-time Localization
  100. Fermi GRB 251215A: Global MASTER-Net observations report

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