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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"

12385 results found.

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

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