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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"

45714 results found.

  1. IceCube-251218A: Upper limits from a search for additional neutrino events in IceCube
  2. IceCube-251218A: COLIBRÍ optical upper limits
  3. SVOM GRB251219.11: Global MASTER-Net observations report
  4. IceCube-251218A - IceCube observation of a high-energy neutrino candidate track-like event
  5. IceCube Alert 251218.85: Global MASTER-Net observations report
  6. GRB 251214B: VIRT Optical Upper Limit
  7. Fermi trigger No 787736968: Global MASTER-Net observations report
  8. Fermi GRB 251217A: Global MASTER-Net observations report
  9. GRB 251217A: Fermi GBM Final Real-time Localization
  10. GRB 251215A: Swift/UVOT Upper LImits
  11. GRB 251215A: Fermi GBM Observation
  12. Fermi GRB 251216A: Global MASTER-Net observations report
  13. GRB 251202A/EP251202a: Koshka optical upper limit
  14. GRB 251214B: Mondy optical upper limit
  15. GRB 251215A: COLIBRÍ optical upper limit
  16. GRB 251216A: Fermi GBM Final Real-time Localization
  17. EP251214b: KAIT optical upper limit
  18. GRB 251215A: Swift-XRT observations
  19. Fermi GRB 251215A: Global MASTER-Net observations report
  20. EP251214a: Optical upper limit with Kinder observations
  21. GRB 251214B: 1.6m Mephisto observations with newly installed mosaic cameras
  22. GRB 251215A: Glowbug gamma-ray detection
  23. GRB 251214B: UAFO optical upper limit
  24. GRB 251214B: VLT/X-shooter observations
  25. GRB 251213A: GRID-10B observation
  26. GRB 251214B: Swift-BAT refined analysis
  27. GRB 251202A: radio detection with the VLA
  28. EP251214b: Global MASTER-Net observations report
  29. EP251214b : Einstein Probe detection of a fast X-ray transient
  30. EP251214b : Einstein Probe detection of a fast X-ray transient
  31. GRB 251214B: AbAO optical observations
  32. GRB 251214B: LCO detection of the optical counterpart
  33. GRB 251209A: GECAM-B observation of a long burst
  34. GRB 251214D: GECAM-B observation of a long burst
  35. GRB 251214B: Fermi GBM Observation
  36. GRB 251209A: Insight-HXMT/HE detection
  37. GRB 251215A: Swift ToO observations
  38. EP251214b (EP trigger 01709250023): LCO optical limits
  39. GRID detection of GRB 251213A
  40. GRB 251203B: AbAO optical observations
  41. GRB 251215A: Swift/BAT-GUANO arcminute localization of a burst
  42. GRB 251214B: GECAM-B observation of a long burst
  43. GRB 251214B: Swift-XRT refined Analysis
  44. GRB 251213A: SVOM/GRM observation
  45. EP251214a: KAIT optical upper limit
  46. GRB 251214D: AstroSat CZTI detection of a long burst
  47. GRB 251213A: AstroSat CZTI detection
  48. GRB 251214A: AstroSat CZTI detection
  49. GRB 251213A: GECAM-B detection
  50. GRB 251214B: Swift/UVOT Detection
  51. GRB 251215A: Fermi GBM Final Real-time Localization
  52. GRB 251214B: COLIBRÍ observations of the afterglow
  53. EP251214a: EP-FXT non-detection and upper limit
  54. GRB 251214A: GECAM-B observation of a likely long burst
  55. GRB 251214B: 1.3m DFOT optical detection
  56. EP251214a: Global MASTER-Net observations report
  57. GRB 251214B: Enhanced Swift-XRT position
  58. GRB 251214B: Xinglong-2.16m optical observation
  59. GRB 251214C: Fermi GBM Final Localization
  60. GRB 251214B : MASTER optical afterglow detection
  61. Fermi trigger No 787396657: Global MASTER-Net observations report
  62. GRB 251214B: SVOM/C-GFT optical observations
  63. EP251214a: COLIBRÍ optical upper limit
  64. Swift GRB 251214B: Global MASTER-Net observations report
  65. EP251214.305: COLIBRÍ optical upper limit
  66. GRB 251214B: Swift detection of a burst with an optical counterpart
  67. GRB 251214B: Fermi GBM Final Real-time Localization
  68. EP251214a: EP-WXT detection of an X-ray transient possibly associated with GRB 251214A
  69. Fermi GRB 251214A: Global MASTER-Net observations report
  70. GRB 251214A: Fermi GBM Final Real-time Localization
  71. EP251212a: Global MASTER-Net observations report
  72. EP251212a: KAIT optical upper limit
  73. EP251212a / GRB 251212A: AstroSat CZTI detection
  74. EP251212a: EP-FXT follow-up observation
  75. GRB 251211B: AstroSat CZTI detection
  76. IceCube-251210A: No Candidate Transients from the Zwicky Transient Facility
  77. GRB 251209A: NuSTAR detection of prompt emission
  78. EP251212a : COLIBRÍ optical upper limit
  79. EP251212a: Einstein Probe detection of an X-ray transient
  80. Fermi-LAT Gamma-ray Observations of IceCube-251210A
  81. IceCube-251210A: Upper limits from a search for additional neutrino events in IceCube
  82. Fermi GRB 251211B: Global MASTER-Net observations report
  83. GRB 251211B: Fermi GBM Final Real-time Localization
  84. IceCube-251210A: DDOTI Optical Upper Limit
  85. SVOM GRB251211.12: Global MASTER-Net observations report
  86. GRB 251211A: Fermi GBM Final Real-time Localization
  87. GRB 251209A: Fermi GBM observation
  88. GRB 251205A: 1.3m DFOT optical upper limit
  89. GRB 251209A: AstroSat CZTI detection
  90. IceCube Alert 251210.46: Global MASTER-Net observations report
  91. IceCube-251210A - IceCube observation of a high-energy neutrino candidate track-like event
  92. EP251124a: Mondy optical upper limit
  93. GRB 251129A/EP251129a: AbAO and Mondy optical observations
  94. EP251130a: Mondy and AbAO optical observations
  95. GRB 251208A: AstroSat CZTI detection
  96. Fermi GBM Sub-Threshold Detection of GRB 251205A
  97. GRB 251208A: Glowbug gamma-ray detection
  98. GRB 251208B: COLIBRÍ optical upper limits
  99. EP251118a / GRB 251118C: VLT/MUSE redshift confirmation
  100. GRB 251208C: GECAM-B observation of a short burst

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