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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"

23696 results found.

  1. SVOM GRB 240821A: optical afterglow discovery
  2. GRB 240821A: the second and third EP-FXT follow-up observations and afterglow candidates
  3. GRB 240824A: GIT optical upper limit
  4. GRB 240825A: TNG optical photometry and spectroscopy
  5. GRB 240825A: NUTTelA-TAO / BSTI Optical Limits
  6. GRB 240825A: GMG Continued Optical Observation on the Second Night
  7. GRB 240825A: KAIT optical observations
  8. Konus-Wind detection of GRB 240825A (bright/long)
  9. GRB 240825A : MISTRAL/T193 OHP optical follow-up of the afterglow
  10. GRB 240825A: Swift/UVOT Detection
  11. GRB 240825A: REM detection of the optical/NIR afterglow
  12. GRB 240825A: Swift-XRT refined Analysis
  13. GRB 240825A: Montarrenti Observatory optical observations
  14. GRB 240825A: MASTER optical counterpart observation
  15. GRB 240825A: LCO optical observations
  16. GRB 240824B: KAIT optical upper limit
  17. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  18. GRB 240824B: Fermi GBM Observation
  19. Fermi GRB 240825A: Global MASTER-Net observations report
  20. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  21. GRB 240825A: GMG Optical Observation
  22. Swift GRB 240825A: Global MASTER-Net observations report
  23. GRB 240825A: Swift detection of a burst with a bright optical counterpart
  24. GRB 240824A: Swift-BAT refined analysis
  25. GRB 240824B: Swift-XRT afterglow detection
  26. GRB 240824A: Swift-XRT observations
  27. Fermi GRB 240824C: Global MASTER-Net observations report
  28. GRB 240824A: Swift/UVOT Upper Limits
  29. GRB 240824B: MAXI/GSC detection
  30. GRB240824A: GRANDMA/TAROT-TCA Upper Limit
  31. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  32. GRB 240824A: KAIT optical upper limit
  33. GRB 240824A: Swift detection of a burst
  34. Swift GRB240824.04: Global MASTER-Net observations report
  35. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  36. GRB 240821A: Colibri Optical Upper Limit
  37. GRB 240821A: Swift-XRT observations
  38. GRB 240821A: REM optical/NIR upper limits
  39. GRB 240821A: LCO optical observations
  40. GRB 240821A: GMG Optical Upper Limit
  41. Fermi GRB 240821A: Global MASTER-Net observations report
  42. Fermi trigger No 745964969: Global MASTER-Net observations report
  43. Fermi trigger No 745925274: Global MASTER-Net observations report
  44. Fermi trigger No 746019401: Global MASTER-Net observations report
  45. Fermi trigger No 745935375: Global MASTER-Net observations report
  46. GRB240821A: EIRSAT-1 GMOD Detection
  47. GRB240821B: First GRB Detected by EIRSAT-1 GMOD
  48. GRB 240821A: EP-FXT follow-up observation and afterglow candidates
  49. Fermi GRB 240821B: Global MASTER-Net observations report
  50. EP240801a: Keck/LRIS spectroscopic redshift confirmation
  51. GRB 240821A: GRANDMA/LesMakes-T60 Upper Limit
  52. Fermi trigger No 745866488: Global MASTER-Net observations report
  53. Trigger 1249878: Swift detection of another burst from SGR 1E 1841-045 / Kes 73
  54. EP240820a: TRT optical upper limit
  55. EP240820a: EP detection of a fast X-ray transient
  56. GRB 240819A: KAIT optical upper limit
  57. Trigger 1249653: Swift detection of SGR 1E 1841-045 / Kes 73
  58. Fermi trigger No 745873283: Global MASTER-Net observations report
  59. Fermi trigger No 745871958: Global MASTER-Net observations report
  60. GRB 240819A: TRT optical upper limits on the Swift/XRT and EP/FXT sources
  61. GRB 240819A: X-ray follow-up observation with EP-FXT
  62. EP240816a: BOOTES-6/DPRT optical upper limit
  63. Integral GRB240816.79: Global MASTER-Net observations report
  64. IceCube-240721A: AT2023qqp and AT2024pge likely unrelated
  65. GRB 240805B: Osservatorio Astronomico Nastro Verde upper limit
  66. EP240816b: KAIT optical upper limit
  67. GRB 240814B: GRBAlpha detection
  68. Fermi trigger No 745501396: Global MASTER-Net observations report
  69. EP240816a: EP detection of a fast X-ray transient and follow-up observation
  70. EP EP240816b: Global MASTER-Net observations report
  71. EP240816b: TRT optical upper limit
  72. EP240816b: EP-WXT detection and EP-FXT follow-up observation of a fast X-ray transient
  73. Fermi GRB 240814A: Global MASTER-Net observations report
  74. Fermi GRB 240814C: Global MASTER-Net observations report
  75. Fermi trigger No 745306088: Global MASTER-Net observations report
  76. Fermi GRB 240814B: Global MASTER-Net observations report
  77. EP240802a: Kinder optical, SWIFT-UVOT, and SWIFT-XRT upper limits 6 days after the WXT detection
  78. Fermi trigger No 745220784: Global MASTER-Net observations report
  79. Konus-Wind detection of GRB 240811A
  80. Konus-Wind detection of GRB 240810A
  81. GRB 240809A : RAPAS follow-up observations
  82. IPN triangulation of GRB 240810A (short)
  83. GRB 240811A: Swift-BAT refined analysis
  84. GRB 240809A: Swift-BAT refined analysis
  85. GRB 240811A: Bassano Bresciano Observatory upper limit
  86. GRB 240811A: Swift/UVOT Upper Limits
  87. EP240801a: Assy-Turgen optical observations
  88. Fermi GRB 240810A: Global MASTER-Net observations report
  89. Konus-Wind detection of GRB 240809A
  90. Fermi trigger No 745057312: Global MASTER-Net observations report
  91. Swift GRB 240811A: Global MASTER-Net observations report
  92. Konus-Wind detection of GRB 240807A (a counterpart of EP240807a)
  93. GRB 240809A: Conclusive redshift from VLT
  94. GRB 240809A: KAIT optical observations
  95. GRB 240809B: MAXI/GSC detection
  96. GRB 240809A: Tentative redshift from NOT
  97. IPN triangulation of GRB 240807A / EP 240807a
  98. Swift GRB 240809A: Global MASTER-Net observations report
  99. GRB 240807A: SVOM/GRM observation
  100. EP240807a: STEP/T80S optical limits

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