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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"

28221 results found.

  1. EP251222b/GRB 251222A: Einstein Probe detection of an X-ray transient
  2. EP251222a: Einstein Probe detection of an X-ray transient
  3. GRB 251222A: PRIME near-infrared detection
  4. GRB 251222A: NOT optical observations
  5. IPN triangulation of GRB 251220B (short)
  6. GRB 251222A: Swift ToO observations
  7. GRB 251222A: SVOM detection of a long burst
  8. GRB 251222A: Fermi GBM Final Real-time Localization
  9. GRB 251221A: PRIME near-infrared observation
  10. GRB 251221A: UAFO and Mondy optical upper limit
  11. GRB 251221A: Swift-XRT refined Analysis
  12. EP251221a: Einstein Probe detection of a fast X-ray transient
  13. GRB 251221A: Swift/UVOT Upper Limits
  14. GRB 251221A: Enhanced Swift-XRT position
  15. GRB 251221B: Fermi GBM Final Real-time Localization
  16. EP251220a: EP-FXT follow-up observation
  17. EP251220a: COLIBRÍ confirmation of fading and photometric redshift upper limit of z < 3.4
  18. EP 251220a: GOTO optical counterpart detection
  19. GRB 251221A: COLIBRÍ detection of the optical counterpart
  20. EP 251220a: COLIBRÍ detection of the optical counterpart
  21. GRB 251221A: Swift detection of a burst
  22. GRB 251221A: Fermi GBM Final Real-time Localization
  23. EP251220a: EP detection of a fast X-ray transient
  24. GRB 251220B: Fermi GBM Final Real-time Localization
  25. GRB 251219A: GECAM-B detection of a possible magnetar X-ray burst from SGR 1830-0645
  26. GRB 251220A: MAXI/GSC detection
  27. GRB 251215A: Swift-XRT afterglow detection
  28. IceCube-251218A - IceCube observation of a high-energy neutrino candidate track-like event
  29. GRB 251214B: VIRT Optical Upper Limit
  30. GRB 251217A: Fermi GBM Final Real-time Localization
  31. GRB 251215A: Swift/UVOT Upper LImits
  32. GRB 251215A: Fermi GBM Observation
  33. GRB 251215A: COLIBRÍ optical upper limit
  34. GRB 251216A: Fermi GBM Final Real-time Localization
  35. GRB 251215A: Swift-XRT observations
  36. EP251214a: Optical upper limit with Kinder observations
  37. GRB 251214B: 1.6m Mephisto observations with newly installed mosaic cameras
  38. GRB 251215A: Glowbug gamma-ray detection
  39. GRB 251214B: VLT/X-shooter observations
  40. GRB 251213A: GRID-10B observation
  41. GRB 251202A: radio detection with the VLA
  42. EP251214b : Einstein Probe detection of a fast X-ray transient
  43. EP251214b : Einstein Probe detection of a fast X-ray transient
  44. GRB 251214B: AbAO optical observations
  45. GRB 251214B: LCO detection of the optical counterpart
  46. GRB 251209A: Insight-HXMT/HE detection
  47. GRB 251215A: Swift ToO observations
  48. EP251214b (EP trigger 01709250023): LCO optical limits
  49. GRID detection of GRB 251213A
  50. GRB 251215A: Swift/BAT-GUANO arcminute localization of a burst
  51. GRB 251214B: Swift-XRT refined Analysis
  52. GRB 251214D: AstroSat CZTI detection of a long burst
  53. GRB 251213A: AstroSat CZTI detection
  54. GRB 251214A: AstroSat CZTI detection
  55. GRB 251213A: GECAM-B detection
  56. GRB 251214B: Swift/UVOT Detection
  57. GRB 251215A: Fermi GBM Final Real-time Localization
  58. GRB 251214B: COLIBRÍ observations of the afterglow
  59. EP251214a: EP-FXT non-detection and upper limit
  60. GRB 251214B: 1.3m DFOT optical detection
  61. GRB 251214B: Enhanced Swift-XRT position
  62. GRB 251214B: Xinglong-2.16m optical observation
  63. GRB 251214C: Fermi GBM Final Localization
  64. GRB 251214B : MASTER optical afterglow detection
  65. GRB 251214B: Swift detection of a burst with an optical counterpart
  66. GRB 251214B: Fermi GBM Final Real-time Localization
  67. EP251214a: EP-WXT detection of an X-ray transient possibly associated with GRB 251214A
  68. GRB 251214A: Fermi GBM Final Real-time Localization
  69. EP251212a / GRB 251212A: AstroSat CZTI detection
  70. EP251212a: EP-FXT follow-up observation
  71. GRB 251211B: AstroSat CZTI detection
  72. GRB 251209A: NuSTAR detection of prompt emission
  73. EP251212a: Einstein Probe detection of an X-ray transient
  74. GRB 251211B: Fermi GBM Final Real-time Localization
  75. GRB 251211A: Fermi GBM Final Real-time Localization
  76. GRB 251205A: 1.3m DFOT optical upper limit
  77. GRB 251209A: AstroSat CZTI detection
  78. IceCube-251210A - IceCube observation of a high-energy neutrino candidate track-like event
  79. GRB 251129A/EP251129a: AbAO and Mondy optical observations
  80. EP251130a: Mondy and AbAO optical observations
  81. GRB 251208A: AstroSat CZTI detection
  82. Fermi GBM Sub-Threshold Detection of GRB 251205A
  83. GRB 251208A: Glowbug gamma-ray detection
  84. GRB 251208B: COLIBRÍ optical upper limits
  85. EP251118a / GRB 251118C: VLT/MUSE redshift confirmation
  86. GRB 251208B: Swift-XRT afterglow detection
  87. GRB 251209A: Fermi GBM Final Real-time Localization
  88. GRB 251208D: LCO analysis of the XRT sources
  89. GRB 251208B: GROWTH-India Telescope optical upper limits
  90. GRB 251205A: J-band detection with WINTER
  91. GRB 251208D: Swift-XRT observations
  92. GRB 251208B: Swift ToO observations
  93. GRB 251208B: Fermi-LAT detection
  94. GRB 251208B: Swift/BAT-GUANO arcminute localization of a burst
  95. GRB 251208D: SVOM possible detection of a faint burst
  96. GRB 251206A: SVOM detection of a burst through offline search
  97. GRB 251208C: Fermi GBM Final Real-time Localization
  98. GRB 251205A : MITSuME Akeno optical afterglow candidate detection
  99. GRB 251208B: Fermi GBM Final Real-time Localization
  100. GRB 251208A: Fermi GBM Final Real-time Localization

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