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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"

11630 results found.

  1. GRB 251118A: NuSTAR detection of bright prompt emission
  2. GRB 251117A: Swift-XRT observations
  3. GRB 251117A: Insight-HXMT/HE detection
  4. GRB 251118A: Fermi-LAT detection
  5. GRB 251118A: Swift ToO observations
  6. Fermi GRB 251118B: Global MASTER-Net observations report
  7. GRB 251118B: Fermi GBM Final Real-time Localization
  8. LIGO/Virgo/KAGRA S251112cm: Upper limits from Glowbug gamma-ray observations
  9. GRB 251118A: BALROG localization (Fermi Trigger 785190695 / GRB 251118855)
  10. GRB 251117A: FTW Observations of Swift candidate X-ray sources
  11. GRB 251118A: Fermi GBM Final Real-time Localization
  12. GRB 251117A: AstroSat CZTI detection
  13. GRB 251114B: Insight-HXMT/HE detection
  14. GRB 251114B: GECAM-B detection of a short burst
  15. GRB 251117A: Fermi GBM observation
  16. GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
  17. GRB 251115A: Swift-XRT observations
  18. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  19. GRB 251117A: SVOM/GRM observation of a short burst
  20. GRB 251117A: Tiled Swift observations
  21. GRB 251117A: Fermi-LAT detection
  22. GRB 251117A: Fermi GBM Final Localization Correction
  23. GRB 251116A: Fermi GBM Final Real-time Localization
  24. GRB 251115A: Tiled Swift observations
  25. GRB 251115A: Fermi-LAT detection
  26. GRB 251013C: joint SVOM/ECLAIRs-GRM refined analysis
  27. Fermi GRB 251115A: Global MASTER-Net observations report
  28. GRB 251115A: Fermi GBM Final Real-time Localization
  29. GRB 251113A: Glowbug gamma-ray detection
  30. GRB 251113A: AstroSat CZTI detection
  31. GRB 251114B: Fermi GBM Final Real-time Localization
  32. Fermi trigger No 784717756: Global MASTER-Net observations report
  33. Konus-Wind detection of GRB 251103A
  34. Fermi GRB 251114A: Global MASTER-Net observations report
  35. GRB 251114A: Fermi GBM Final Real-time Localization
  36. Fermi GRB 251113A: Global MASTER-Net observations report
  37. GRB 251113A: BALROG localization (Fermi Trigger 784748255 / GRB 251113734)
  38. GRB 251113A: Fermi GBM Final Real-time Localization
  39. Fermi Gamma-ray Burst Monitor trigger 784717756/251113381 is not a GRB
  40. Fermi Gamma-ray Burst Monitor trigger 784687703/251113034 is not a GRB
  41. Fermi Gamma-ray Burst Monitor trigger 784687099/251113027 is not a GRB
  42. LIGO/Virgo/KAGRA S251112cm: Upper limits from Fermi-GBM Observations
  43. Fermi trigger No 784621743: Global MASTER-Net observations report
  44. Fermi Gamma-ray Burst Monitor trigger 784653403/251112637 is not a GRB
  45. GRB 251013C: Chandra X-ray observations and jet break detection
  46. GRB 251105B: Insight-HXMT/HE detection
  47. GRB 251105A: AstroSat CZTI detection
  48. GRB 251108A: Fermi GBM Final Localization Correction
  49. Fermi trigger No 784329591: Global MASTER-Net observations report
  50. Fermi trigger No 784279167: Global MASTER-Net observations report
  51. GRB 251102B: SVOM/GRM observation
  52. Fermi Gamma-ray Burst Monitor trigger 784279167/251108305 is not a GRB
  53. IPN triangulation of GRB 251105B (possible sGRB with EE)
  54. GRB 251106A: Kilonova-Catcher optical upper limit
  55. Fermi GBM Sub-Threshold Detection of GRB 251106A
  56. GRB 251103B: AstroSat CZTI detection
  57. GRB 251025C: TERI Gamma-ray detection
  58. GRB 251016B: TERI Gamma-ray detection
  59. GRB 251016A: TERI Gamma-ray detection of a short burst
  60. GRB 250920C: TERI Gamma-ray detection
  61. Fermi trigger No 784034269: Global MASTER-Net observations report
  62. Fermi Gamma-ray Burst Monitor trigger 784109140/251106337 is not a GRB
  63. GRB 251105A: Fermi GBM Observation
  64. GRB 251105C: Fermi GBM Final Localization Correction
  65. GRB 251105A: Swift/BAT-GUANO localization skymap of a burst
  66. GRB 251105B: AstroSat CZTI detection of a short burst with extended emission
  67. GRB 251023A: SVOM/ECLAIRs detection of a burst through targeted search
  68. Fermi GBM Sub-Threshold Detection of GRB 251105B
  69. Fermi GRB 251105A: Global MASTER-Net observations report
  70. GRB 251105A: Fermi GBM Final Real-time Localization
  71. Fermi Gamma-ray Burst Monitor trigger 783986701/251104920 is not a GRB
  72. GRB 251103B: Fermi GBM observation
  73. GRB 251028A: Insight-HXMT/HE detection
  74. GRB 251103A: WFST optical observations
  75. GRB 251103A: OHP/T193 optical observations
  76. GRB 251103A: Xinglong 2.16m optical detection
  77. GRB 251103A: Insight-HXMT detection
  78. GRB 251103A: KAIT optical observations
  79. GRB 251103B: Nanshan/HMT optical upper limit
  80. GRB 251013C: 7DT detection and Medium-band SED of Afterglow
  81. GRB 251103A: Swift/BAT-GUANO arcminute localization of a burst
  82. GRB 251103B: MITSuME Akeno optical upper limits
  83. Fermi GRB 251103A: Global MASTER-Net observations report
  84. GRB 251103A: J-band detection with WINTER
  85. GRB 251103B: GROWTH-India Telescope optical upper limits
  86. GRB 251103A: Kilonova-Catcher optical afterglow detection
  87. GRB 251103B: Fermi GBM Final Real-time Localization
  88. GRB 251103A: Fermi GBM Observation
  89. GRB 251103A: SVOM/GRM observation
  90. GRB 251103A: SVOM/COLIBRÍ (FM-GFT) optical observations
  91. GRB 251103A: GOTO optical afterglow detection
  92. GRB 251102A: AstroSat CZTI detection
  93. GRB 251103A: NOT spectroscopic redshift z = 0.76
  94. GRB 251103A: Fermi GBM Final Localization
  95. GRB 251102B: Fermi GBM Final Real-time Localization
  96. Fermi GRB 251102A: Global MASTER-Net observations report
  97. GRB 251102A: Fermi GBM Final Real-time Localization
  98. GRB 251031A: Fermi GBM Observation
  99. GRB 251031A: Swift/BAT-GUANO localization skymap of a burst
  100. Konus-Wind detection of GRB 251028A

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