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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"

36161 results found.

  1. GRB 251117A: Tiled Swift observations
  2. GRB 251117A: Fermi-LAT detection
  3. GRB 251116C: Swift/BAT arcminute localization of a burst
  4. GRB 251116B: SVOM/VT optical upper limit
  5. GRB 251116C: Swift-XRT observations
  6. GRB 251117A: Fermi GBM Final Localization Correction
  7. GRB 251116D: Glowbug gamma-ray detection
  8. EP251023a: Assy AZT-20 optical observations
  9. EP251023a: UAFO and AbAO optical observations
  10. GRB 251116D: AstroSat CZTI detection
  11. The EP-WXT trigger 01709247588: more evidence of flaring star from Mondy optical observations
  12. GRB 251116C: SVOM/VT optical upper limit
  13. GRB 251025B: further Mondy optical observations
  14. GRB 251111A: Mondy optical upper limit
  15. GRB 251116B: EP-FXT follow-up observation
  16. GRB 251116B: LCO optical upper limits
  17. GRB 251116C: LCO optical upper limits
  18. GRB 251116C: SVOM detection of a burst
  19. GRB 251116B: SVOM detection of a burst
  20. GRB 251116A: Fermi GBM Final Real-time Localization
  21. GRB 251115A: Tiled Swift observations
  22. GRB 251115A: Fermi-LAT detection
  23. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  24. Fermi GRB 251115A: Global MASTER-Net observations report
  25. GRB 251115A: Fermi GBM Final Real-time Localization
  26. GRB 251113A: Glowbug gamma-ray detection
  27. GRB 251113A: AstroSat CZTI detection
  28. GRB 251114B: Fermi GBM Final Real-time Localization
  29. GRB 251112A: Swift-BAT refined analysis
  30. Konus-Wind detection of GRB 251108C
  31. Konus-Wind detection of GRB 251103A
  32. IPN triangulation of GRB 251108C
  33. Fermi GRB 251114A: Global MASTER-Net observations report
  34. GRB 251114A: Fermi GBM Final Real-time Localization
  35. Fermi GRB 251113A: Global MASTER-Net observations report
  36. GRB 251113A: BALROG localization (Fermi Trigger 784748255 / GRB 251113734)
  37. GRB 251113A: Fermi GBM Final Real-time Localization
  38. GRB 251111A: SVOM/ECLAIRs refined analysis
  39. GRB 251025B: SVOM/ECLAIRs refined analysis
  40. Fermi Gamma-ray Burst Monitor trigger 784717756/251113381 is not a GRB
  41. GRB 251112A: Swift/UVOT Upper Limits
  42. GRB 251112A: Swift-XRT refined Analysis
  43. GRB 251108C: AstroSat CZTI detection
  44. GRB 251112B: MAXI/GSC detection
  45. Fermi Gamma-ray Burst Monitor trigger 784687703/251113034 is not a GRB
  46. Fermi Gamma-ray Burst Monitor trigger 784687099/251113027 is not a GRB
  47. GRB 251108B: Glowbug gamma-ray detection
  48. Swift Trigger 1413695: a possible GRB 251112A
  49. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  50. Fermi Gamma-ray Burst Monitor trigger 784653403/251112637 is not a GRB
  51. GRB 251106B: Glowbug gamma-ray detection of a likely short burst
  52. GRB 251111A: Swift-XRT afterglow detection
  53. GRB 251111A: SVOM/VT optical observations with X-band data
  54. GRB 251111A: Swift-XRT observations
  55. GRB 251111A: EP-FXT counterpart detection
  56. GRB 251013C: Chandra X-ray observations and jet break detection
  57. GRB 251111A: SVOM/VT optical observations with VHF data
  58. GRB 251111A: KAIT optical upper limit
  59. GRB 251111A: LCO optical observation
  60. GRB 251111A: SVOM/COLIBRÍ (FM-GFT) optical counterpart detection
  61. GRB 251111A: SVOM detection of a soft burst
  62. GRB 251103B: Swift-BAT refined analysis
  63. GRB 251106A: Swift/UVOT Upper Limits
  64. GRB 251105B: Insight-HXMT/HE detection
  65. GRB 251106B: Insight-HXMT detection
  66. GRB 251105A: AstroSat CZTI detection
  67. GRB 251108A: Fermi GBM Final Localization Correction
  68. GRB 251102B: SVOM/GRM observation
  69. Fermi Gamma-ray Burst Monitor trigger 784279167/251108305 is not a GRB
  70. IPN triangulation of GRB 251105B (possible sGRB with EE)
  71. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) fading of the optical counterpart
  72. GRB 251106B: SVOM/GRM observation of a short burst
  73. GRB 251106A: Swift-XRT afterglow detection
  74. GRB 251106A: Kilonova-Catcher optical upper limit
  75. Fermi GBM Sub-Threshold Detection of GRB 251106A
  76. GRB 251106A: Swift/BAT arcminute localization of a burst
  77. GRB 251106A: SVOM/COLIBRÍ (FM-GFT) detection of a likely optical counterpart
  78. GRB 251106A: MASTER optical observations
  79. GRB 251106A: SVOM detection of a burst
  80. GRB 251103B: AstroSat CZTI detection
  81. GRB 251025C: TERI Gamma-ray detection
  82. GRB 251016B: TERI Gamma-ray detection
  83. GRB 251016A: TERI Gamma-ray detection of a short burst
  84. GRB 250920C: TERI Gamma-ray detection
  85. Fermi Gamma-ray Burst Monitor trigger 784109140/251106337 is not a GRB
  86. GRB 251105A: Fermi GBM Observation
  87. GRB 251105C: Fermi GBM Final Localization Correction
  88. GRB 251105A: Swift/BAT-GUANO localization skymap of a burst
  89. GRB 251104A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  90. GRB 251105B: AstroSat CZTI detection of a short burst with extended emission
  91. GRB 251023A: SVOM/ECLAIRs detection of a burst through targeted search
  92. Fermi GBM Sub-Threshold Detection of GRB 251105B
  93. GRB 251103B: Swift/UVOT Upper Limits
  94. GRB 251105B: SVOM/GRM observation of a possible short burst with extended emission
  95. Fermi GRB 251105A: Global MASTER-Net observations report
  96. GRB 251105A: Fermi GBM Final Real-time Localization
  97. Fermi Gamma-ray Burst Monitor trigger 783986701/251104920 is not a GRB
  98. GRB 251103B: Fermi GBM observation
  99. GRB 251104A: SVOM detection of a burst
  100. GRB 251028A: Insight-HXMT/HE detection

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