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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

11532 results found.

  1. GRB 240825A: SAO RAS optical observations
  2. GRB 240825A: TNG optical photometry and spectroscopy
  3. GRB 240824B: Ondrejov D50 optical limit
  4. GRB 240825A: KAIT optical observations
  5. GRB 240825A: PRIME near-infrared detection
  6. Konus-Wind detection of GRB 240825A (bright/long)
  7. GRB 240825A: Fermi GBM Observation
  8. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  9. GRB 240825A: AKO Optical Follow-Up Observations
  10. GRB 240825A: AstroSat CZTI detection of the long bright burst
  11. SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
  12. GRB 240825A: REM detection of the optical/NIR afterglow
  13. GRB 240825A: VLT/X-shooter redshift
  14. GRB 240825A: SVOM/C-GFT optical observations
  15. GRB 240825A: Montarrenti Observatory optical observations
  16. GRB 240825A: Fermi-LAT detection
  17. GRB 240824B: KAIT optical upper limit
  18. GRB 240824B: Fermi GBM Observation
  19. Fermi GRB 240825A: Global MASTER-Net observations report
  20. GRB 240824B: NOT optical upper limit
  21. GRB 240825A: 1.6m Mephisto multi-band detection
  22. GRB 240825A: AKO Optical Afterglow Detection
  23. GRB 240825A: Nanshan/HMT optical afterglow observations
  24. GRB 240825A: Fermi GBM Final Real-time Localization
  25. GRB 240824B: Swift-XRT afterglow detection
  26. GRB 240824B: Swift/BAT arcminute localization of a burst
  27. Fermi GRB 240824C: Global MASTER-Net observations report
  28. GRB 240824C: Fermi GBM Final Localization
  29. GRB 240821A: Swift/UVOT observations of the XRT sources.
  30. GRB 240824B: MAXI/GSC detection
  31. GRB 240824B: Fermi GBM Final Real-time Localization
  32. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  33. GRB 240821A: Colibri Optical Upper Limit
  34. GRB 240821A: Swift-XRT observations
  35. GRB 240821A: REM optical/NIR upper limits
  36. GRB 240821A: LCO optical observations
  37. GRB 240821A: JinShan optical upper limits
  38. GRB 240821A: GMG Optical Upper Limit
  39. Fermi GRB 240821A: Global MASTER-Net observations report
  40. GRB 240821A: Fermi GBM Observation
  41. Fermi trigger No 745964969: Global MASTER-Net observations report
  42. Fermi trigger No 745925274: Global MASTER-Net observations report
  43. GRB 240821A: Swift ToO observations
  44. Fermi trigger No 746019401: Global MASTER-Net observations report
  45. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  46. Fermi trigger No 745935375: Global MASTER-Net observations report
  47. GRB240821A: EIRSAT-1 GMOD Detection
  48. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  49. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  50. Fermi GRB 240821B: Global MASTER-Net observations report
  51. GRB 240821A: SVOM/GRM observation
  52. GRB 240821A: SVOM/GRM observation
  53. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  54. GRB 240821B: Fermi GBM Final Localization
  55. Fermi trigger No 745866488: Global MASTER-Net observations report
  56. GRB 240821A: BALROG localization (Fermi Trigger 745958167 / GRB 240821775)
  57. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  58. GRB 240821A: Fermi GBM Final Real-time Localization
  59. Fermi trigger No 745873283: Global MASTER-Net observations report
  60. Fermi trigger No 745871958: Global MASTER-Net observations report
  61. Fermi Gamma-ray Burst Monitor trigger 745811685 / 240820080 is not a GRB
  62. GRB 240820A: Fermi GBM Final Real-time Localization
  63. GRB 240814A: SVOM/GRM observation
  64. GRB 240814C: SVOM/GRM observation
  65. GRB 240817A: Fermi GBM Final Real-time Localization
  66. GRB 240814B: GRBAlpha detection
  67. Fermi trigger No 745501396: Global MASTER-Net observations report
  68. Fermi GRB 240814A: Global MASTER-Net observations report
  69. Fermi GRB 240814C: Global MASTER-Net observations report
  70. Fermi trigger No 745306088: Global MASTER-Net observations report
  71. GRB 240814C: Fermi GBM Final Real-time Localization
  72. Fermi GRB 240814B: Global MASTER-Net observations report
  73. GRB 240814B: Fermi GBM Final Real-time Localization
  74. GRB 240814A: Fermi GBM Final Real-time Localization
  75. Fermi trigger No 745220784: Global MASTER-Net observations report
  76. Konus-Wind detection of GRB 240810A
  77. Fermi Gamma-ray Burst Monitor trigger 745220784/240813240 is not a GRB
  78. GRB 240810A: SVOM/GRM observation
  79. Fermi Gamma-ray Burst Monitor trigger 240812940/745194848 is not a GRB
  80. Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
  81. Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
  82. GRB 240812D: Fermi GBM Final Real-time Localization
  83. GRB 240812C: Fermi GBM Final Real-time Localization
  84. IPN triangulation of GRB 240810A (short)
  85. Fermi Gamma-ray Burst Monitor trigger 745135620/240812255 is not a GRB
  86. Fermi GRB 240810A: Global MASTER-Net observations report
  87. Fermi Gamma-ray Burst Monitor trigger 240812094/745121685 is not a GRB
  88. GRB 240812A: Fermi GBM Final Real-time Localization
  89. Fermi trigger No 745057312: Global MASTER-Net observations report
  90. Fermi Gamma-ray Burst Monitor trigger 745050426/240811269 is not a GRB
  91. GRB 240810A: Fermi GBM Final Real-time Localization
  92. Konus-Wind detection of GRB 240807A (a counterpart of EP240807a)
  93. Fermi-LAT gamma-ray observations of IceCube-240808A
  94. IPN triangulation of GRB 240807A / EP 240807a
  95. GRB 240807A: SVOM/GRM observation
  96. EP240807a: STEP/T80S optical limits
  97. GRB 240807B: AstroSat CZTI detection of a short burst
  98. IceCube-240808A - IceCube observation of a high-energy neutrino candidate track-like event
  99. GRB 240801A: GRBAlpha detection
  100. GRB 240807B: Fermi GBM Final Localization

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