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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"

27277 results found.

  1. EP240702a: EP-WXT detection of a fast X-ray transient
  2. LIGO/Virgo/KAGRA S240627by: Upper limits from Swift/BAT-GUANO
  3. Fermi Gamma-ray Burst Monitor trigger 741448122/240630575 is not a GRB
  4. GRB 240627A: CALET Gamma-Ray Burst Monitor detection
  5. Fermi trigger No 741448122: Global MASTER-Net observations report
  6. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  7. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  8. Fermi trigger No 741356809: Global MASTER-Net observations report
  9. Fermi GRB 240629A: Global MASTER-Net observations report
  10. Fermi Gamma-ray Burst Monitor trigger 741362867/240629589 is not a GRB
  11. Fermi Gamma-ray Burst Monitor trigger 741288821/240628732 is not a GRB
  12. GRB 240629A: BALROG localization (Fermi Trigger 741372837 / GRB 240629704)
  13. GRB 240629A: Fermi GBM Final Real-time Localization
  14. Fermi Gamma-ray Burst Monitor trigger 741356809/240629519 is not a GRB
  15. Fermi trigger No 741296200: Global MASTER-Net observations report
  16. Fermi trigger No 741251380: Global MASTER-Net observations report
  17. IPN triangulation of GRB 240619C
  18. GRB 240628A: BALROG localization (Fermi Trigger 741288821 / GRB 240628732)
  19. GRB 240627A: AstroSat CZTI detection
  20. Fermi trigger No 741211696: Global MASTER-Net observations report
  21. EP240626a: KAIT optical upper limit
  22. EP240625a: GRANDMA Optical Upper Limits
  23. EP240626a: EP-FXT detection of the X-ray emission
  24. GRB 240624A: Swift-BAT refined analysis
  25. EP240626a: BOOTES-7 optical upper limit
  26. EP240626a: EP-WXT detection of a fast X-ray transient
  27. Fermi GRB 240625B: Global MASTER-Net observations report
  28. GRB 240624B: CALET Gamma-Ray Burst Monitor detection
  29. GRB 240625B: Fermi GBM Final Real-time Localization
  30. GRB 240625A: Fermi GBM Observation
  31. EP240625a: NOT optical counterpart candidate
  32. EP240625a: EP-FXT detection of the X-ray emission
  33. GRB 240625A: Fermi GBM Final Real-time Localization
  34. EP240625a: EP-WXT detection of a fast X-ray transient
  35. GRB240624A: Fermi GBM Observation
  36. LIGO/Virgo/KAGRA S240622h: Upper limits from Swift/BAT-GUANO
  37. LIGO/Virgo/KAGRA S240621dy: Upper limits from Swift/BAT-GUANO
  38. LIGO/Virgo/KAGRA S240618ah: Upper limits from Swift/BAT-GUANO
  39. Swift GRB 240624A: Global MASTER-Net observations report
  40. Fermi GRB 240624A: Global MASTER-Net observations report
  41. GRB 240624B: Fermi GBM Final Real-time Localization
  42. Fermi trigger No 740949590: Global MASTER-Net observations report
  43. LIGO/Virgo/KAGRA S240624cd: Retraction of GW unmodeled transient candidate
  44. GRB 240624A: Fermi GBM Final Real-time Localization
  45. GRB 240624A: Swift detection of a burst
  46. LIGO/Virgo/KAGRA S240623dg: Retraction of GW compact binary merger candidate
  47. EP240618a: NOT further optical observations
  48. Fermi trigger No 740744838: Global MASTER-Net observations report
  49. EP240618a: NOT optical counterpart candidate
  50. EP240618a: GSP optical upper limit
  51. IPN triangulation of GRB 240615A (short)
  52. GRB 240619A: CALET Gamma-Ray Burst Monitor detection
  53. GRB 240619A: Fermi GBM Observation
  54. Fermi GBM Sub-Threshold Detection of GRB 240619C
  55. GRB 240619A: GOTO candidate optical afterglow
  56. EP240618a: GRANDMA Optical Upper Limits
  57. EP240618a: TRT optical upper limit
  58. Fermi trigger No 740474239: Global MASTER-Net observations report
  59. Fermi GRB 240619A: Global MASTER-Net observations report
  60. EP240617a: STEP/T80S optical limits
  61. LIGO/Virgo S240615dg: GRANDMA/FRAM-CTA-N Observations
  62. EP240618a: OHP/T193 MISTRAL i' and Y band upper limits
  63. EP240618a: BOOTES-6/DPRT optical upper limit
  64. Fermi Gamma-ray Burst Monitor trigger 740474239/240619304 is not a GRB
  65. GRB 240619B: Fermi GBM Final Real-time Localization
  66. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  67. Fermi trigger No 740430582: Global MASTER-Net observations report
  68. GRB240615A: 1.3m DFOT optical upper limit
  69. GRB 240619A: BALROG localization (Fermi Trigger 740461416 / GRB 240619155)
  70. GRB 240619A: Fermi GBM Final Real-time Localization
  71. EP240617a: BOOTES-6/DPRT optical upper limit
  72. EP240617a: EP-WXT detection of a fast X-ray transient
  73. EP240618a: EP-WXT detection of a fast X-ray transient and EP-FXT quick follow-up
  74. LIGO/Virgo/KAGRA S240615ea: Upper limits from Swift/BAT-GUANO
  75. LIGO/Virgo/KAGRA S240615dg: Upper limits from Swift/BAT-GUANO
  76. GRB 240615A: J-band upper limits from WINTER
  77. GRB 240615A: Fermi GBM Observation
  78. GRB 240615A: GECAM detection
  79. Fermi trigger No 740221779: Global MASTER-Net observations report
  80. Fermi GRB 240616A: Global MASTER-Net observations report
  81. GRB 240615A: GOTO optical upper limits
  82. Fermi trigger No 740166710: Global MASTER-Net observations report
  83. GRB 240616A: Fermi GBM Final Real-time Localization
  84. GRB 240615A: Swift/BAT-GUANO arcminute localization of a short burst
  85. GRB 240615A: Fermi GBM Final Real-time Localization
  86. GRB 240613A: Fermi GBM Final Real-time Localization
  87. Fermi GRB 240612B: Global MASTER-Net observations report
  88. Fermi GRB 240612A: Global MASTER-Net observations report
  89. GRB 240612B: Fermi GBM Final Real-time Localization
  90. GRB 240612A: Fermi GBM Final Real-time Localization
  91. GRB 240607A: GECAM detection of a bright long burst
  92. Fermi GRB 240611A: Global MASTER-Net observations report
  93. GRB 240611A: Fermi GBM Final Real-time Localization
  94. EXO 0748-676: Swift-BAT refined analysis
  95. GRB 240529A: LBT optical detection and late temporal decay
  96. GRB 240529A : MITSuME Akeno optical afterglow detection
  97. Trigger 1236151: Swift detection of EXO 0748-676
  98. Fermi GRB 240610A: Global MASTER-Net observations report
  99. GRB 240610A: Fermi GBM Final Real-time Localization
  100. IPN triangulation of GRB 240607A

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