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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"

11113 results found.

  1. GRB 240824B: NOT optical upper limit
  2. GRB 240825A: 1.6m Mephisto multi-band detection
  3. GRB 240825A: AKO Optical Afterglow Detection
  4. GRB 240825A: Nanshan/HMT optical afterglow observations
  5. GRB 240825A: Fermi GBM Final Real-time Localization
  6. GRB 240824B: Swift-XRT afterglow detection
  7. GRB 240824B: Swift/BAT arcminute localization of a burst
  8. Fermi GRB 240824C: Global MASTER-Net observations report
  9. GRB 240824C: Fermi GBM Final Localization
  10. GRB 240821A: Swift/UVOT observations of the XRT sources.
  11. GRB 240824B: MAXI/GSC detection
  12. GRB 240824B: Fermi GBM Final Real-time Localization
  13. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  14. GRB 240821A: Colibri Optical Upper Limit
  15. GRB 240821A: Swift-XRT observations
  16. GRB 240821A: REM optical/NIR upper limits
  17. GRB 240821A: LCO optical observations
  18. GRB 240821A: JinShan optical upper limits
  19. GRB 240821A: GMG Optical Upper Limit
  20. Fermi GRB 240821A: Global MASTER-Net observations report
  21. GRB 240821A: Fermi GBM Observation
  22. Fermi trigger No 745964969: Global MASTER-Net observations report
  23. Fermi trigger No 745925274: Global MASTER-Net observations report
  24. GRB 240821A: Swift ToO observations
  25. Fermi trigger No 746019401: Global MASTER-Net observations report
  26. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  27. Fermi trigger No 745935375: Global MASTER-Net observations report
  28. GRB240821A: EIRSAT-1 GMOD Detection
  29. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  30. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  31. Fermi GRB 240821B: Global MASTER-Net observations report
  32. GRB 240821A: SVOM/GRM observation
  33. GRB 240821A: SVOM/GRM observation
  34. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  35. GRB 240821B: Fermi GBM Final Localization
  36. Fermi trigger No 745866488: Global MASTER-Net observations report
  37. GRB 240821A: BALROG localization (Fermi Trigger 745958167 / GRB 240821775)
  38. GRB 240821A : a likely short GRB detected by SVOM/ECLAIRs
  39. GRB 240821A: Fermi GBM Final Real-time Localization
  40. Fermi trigger No 745873283: Global MASTER-Net observations report
  41. Fermi trigger No 745871958: Global MASTER-Net observations report
  42. Fermi Gamma-ray Burst Monitor trigger 745811685 / 240820080 is not a GRB
  43. GRB 240820A: Fermi GBM Final Real-time Localization
  44. GRB 240814A: SVOM/GRM observation
  45. GRB 240814C: SVOM/GRM observation
  46. GRB 240817A: Fermi GBM Final Real-time Localization
  47. GRB 240814B: GRBAlpha detection
  48. Fermi trigger No 745501396: Global MASTER-Net observations report
  49. Fermi GRB 240814A: Global MASTER-Net observations report
  50. Fermi GRB 240814C: Global MASTER-Net observations report
  51. Fermi trigger No 745306088: Global MASTER-Net observations report
  52. GRB 240814C: Fermi GBM Final Real-time Localization
  53. Fermi GRB 240814B: Global MASTER-Net observations report
  54. GRB 240814B: Fermi GBM Final Real-time Localization
  55. GRB 240814A: Fermi GBM Final Real-time Localization
  56. Fermi trigger No 745220784: Global MASTER-Net observations report
  57. Konus-Wind detection of GRB 240810A
  58. Fermi Gamma-ray Burst Monitor trigger 745220784/240813240 is not a GRB
  59. GRB 240810A: SVOM/GRM observation
  60. Fermi Gamma-ray Burst Monitor trigger 240812940/745194848 is not a GRB
  61. Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
  62. Fermi Gamma-ray Burst Monitor trigger 240812917/745192855 is not a GRB
  63. GRB 240812D: Fermi GBM Final Real-time Localization
  64. GRB 240812C: Fermi GBM Final Real-time Localization
  65. IPN triangulation of GRB 240810A (short)
  66. Fermi Gamma-ray Burst Monitor trigger 745135620/240812255 is not a GRB
  67. Fermi GRB 240810A: Global MASTER-Net observations report
  68. Fermi Gamma-ray Burst Monitor trigger 240812094/745121685 is not a GRB
  69. GRB 240812A: Fermi GBM Final Real-time Localization
  70. Fermi trigger No 745057312: Global MASTER-Net observations report
  71. Fermi Gamma-ray Burst Monitor trigger 745050426/240811269 is not a GRB
  72. GRB 240810A: Fermi GBM Final Real-time Localization
  73. Konus-Wind detection of GRB 240807A (a counterpart of EP240807a)
  74. Fermi-LAT gamma-ray observations of IceCube-240808A
  75. IPN triangulation of GRB 240807A / EP 240807a
  76. GRB 240807A: SVOM/GRM observation
  77. EP240807a: STEP/T80S optical limits
  78. GRB 240807B: AstroSat CZTI detection of a short burst
  79. IceCube-240808A - IceCube observation of a high-energy neutrino candidate track-like event
  80. GRB 240801A: GRBAlpha detection
  81. GRB 240807B: Fermi GBM Final Localization
  82. GRB 240710B: VZLUSAT-2 detection
  83. GRB 240805A: ATCA Radio Upper Limits
  84. Fermi trigger No 744761058: Global MASTER-Net observations report
  85. EP240807a/GRB 240807A: EP-FXT detection of the X-ray emission
  86. GRB 240710A: VZLUSAT-2 detection
  87. GRB 240807A: Fermi GBM Final Localization
  88. Fermi trigger No 744629911: Global MASTER-Net observations report
  89. Konus-Wind detection of GRB 240805A
  90. GRB240805A: Fermi GBM Observation
  91. Fermi Gamma-ray Burst Monitor trigger 240806402/744629911 is not a GRB
  92. GRB 240624B: VZLUSAT-2 detection
  93. GRB 240619C: VZLUSAT-2 detection
  94. Fermi trigger No 744544656: Global MASTER-Net observations report
  95. GRB 240805A: SVOM/GRM observation
  96. Fermi GRB 240805A: Global MASTER-Net observations report
  97. Fermi Gamma-ray Burst Monitor trigger 744558410/240805574 is not a GRB
  98. GRB 240805A: Fermi-LAT detection
  99. GRB 240805A: INTEGRAL spectral analysis
  100. GRB 240805A: A long GRB detected by INTEGRAL

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