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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"

4002 results found.

  1. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  2. Fermi GRB 240825A: Global MASTER-Net observations report
  3. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  4. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  5. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  6. GECAM-B observation of a short burst from SGR 1E 1841-045 / Kes 73
  7. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  8. Fermi trigger No 745866488: Global MASTER-Net observations report
  9. Trigger 1249878: Swift detection of another burst from SGR 1E 1841-045 / Kes 73
  10. Trigger 1249653: Swift detection of SGR 1E 1841-045 / Kes 73
  11. GRB 240819A: X-ray follow-up observation with EP-FXT
  12. EP240816b: Liverpool Telescope optical follow-up observations
  13. EP EP240816b: Global MASTER-Net observations report
  14. Fermi GRB 240814C: Global MASTER-Net observations report
  15. Fermi trigger No 745306088: Global MASTER-Net observations report
  16. Fermi GRB 240814B: Global MASTER-Net observations report
  17. Fermi GRB 240810A: Global MASTER-Net observations report
  18. GRB 240809A: Swift detection of a burst with a bright optical counterpart
  19. EP EP240807a: Global MASTER-Net observations report
  20. EP EP240806a: Global MASTER-Net observations report
  21. Fermi trigger No 744761058: Global MASTER-Net observations report
  22. EP240807a/GRB 240807A: EP-FXT detection of the X-ray emission
  23. EP240806A: Liverpool Telescope optical follow-up observations
  24. Fermi trigger No 744629911: Global MASTER-Net observations report
  25. Konus-Wind detection of GRB 240802A (EP240802a)
  26. GRB 240805B: NUTTelA-TAO / BSTI Optical Limits
  27. Fermi trigger No 744544656: Global MASTER-Net observations report
  28. GRB 240802A: AstroSat CZTI detection of a long burst
  29. Fermi trigger No 744128417: Global MASTER-Net observations report
  30. Fermi trigger No 743953682: Global MASTER-Net observations report
  31. Fermi Gamma-ray Burst Monitor trigger 743953682/240729575 is not a GRB
  32. Fermi GRB 240727A: Global MASTER-Net observations report
  33. GRB 240718A: GRBAlpha detection
  34. GRB 240627A: GRBAlpha detection
  35. Fermi GRB 240726A: Global MASTER-Net observations report
  36. Fermi trigger No 743345551: Global MASTER-Net observations report
  37. Fermi trigger No 743219692: Global MASTER-Net observations report
  38. Swift GRB240720.02: Global MASTER-Net observations report
  39. Konus-Wind detection of GRB 240718A
  40. Fermi GRB 240718A: Global MASTER-Net observations report
  41. GRB 240718A: Fermi GBM Observation
  42. IceCube-Cascade 240714A: TRT optical observations on the EP/FXT positions
  43. GRB 240718A: Fermi-LAT Detection
  44. GRB 240718A: SVOM/GRM observation
  45. GRB 240718A: BALROG localization (Fermi Trigger 742976945 / GRB 240718270)
  46. GRB 240718A: Fermi GBM Final Real-time Localization
  47. IPN triangulation of GRB 240715A (short)
  48. JinShan confirmation of the EP-WXT source triggered on July 14th due to a flaring star
  49. GRB 240712A: Swift detection of a burst
  50. Fermi trigger No 742317942: Global MASTER-Net observations report
  51. LIGO/Virgo S240615dg: Swift XRT observations, 28 futher X-ray sources
  52. LIGO/Virgo/KAGRA S240629by: Coverage and upper limits from MAXI/GSC observations
  53. Fermi trigger No 741356809: Global MASTER-Net observations report
  54. Fermi GRB 240629A: Global MASTER-Net observations report
  55. Fermi Gamma-ray Burst Monitor trigger 741362867/240629589 is not a GRB
  56. GRB 240629A: BALROG localization (Fermi Trigger 741372837 / GRB 240629704)
  57. GRB 240629A: Fermi GBM Final Real-time Localization
  58. Fermi Gamma-ray Burst Monitor trigger 741356809/240629519 is not a GRB
  59. LIGO/Virgo/KAGRA S240629by: Identification of a GW compact binary merger candidate
  60. Konus-Wind detection of GRB 240619A
  61. Fermi trigger No 740949590: Global MASTER-Net observations report
  62. GRB 240529A: JinShan optical observations
  63. Fermi trigger No 740474239: Global MASTER-Net observations report
  64. LIGO/Virgo S240615dg: Swift XRT observations, 39 X-ray sources
  65. Fermi trigger No 740430582: Global MASTER-Net observations report
  66. Fermi GRB 240616A: Global MASTER-Net observations report
  67. Fermi trigger No 740166710: Global MASTER-Net observations report
  68. GRB 240612A: GRBAlpha detection
  69. Fermi GRB 240611A: Global MASTER-Net observations report
  70. GRB 240529A : MITSuME Akeno optical afterglow detection
  71. Fermi GRB 240604A: Global MASTER-Net observations report
  72. Fermi GRB 240605A: Global MASTER-Net observations report
  73. GRB 240529A: MASTER prompt OT detection
  74. Fermi GRB 240602A: Global MASTER-Net observations report
  75. The EP-WXT source triggered on June 1st is likely a flaring star
  76. GRB 240529A: AKO Optical Afterglow Follow-Up Observations
  77. GRB 240529A: optical photometry from Konkoly
  78. GRB 240529A: GROWTH-India optical follow-up
  79. GRB 240529A: AKO Optical Afterglow Detection
  80. GRB 240529A: J-band detections with WINTER
  81. GRB 240529A: Skynet Optical Observations
  82. LIGO/Virgo S240527fv: GRANDMA/FRAM-Auger Optical Observations
  83. GRB240529A: BOOTES-6/DPRT optical detection
  84. GRB 240529A: NOT optical observations
  85. GRB 240529A: AstroSat CZTI detection
  86. Swift GRB240529.12: Global MASTER-Net observations report
  87. Fermi GRB 240527A: Global MASTER-Net observations report
  88. LAT GRB240527.59: Global MASTER-Net observations report
  89. Fermi trigger No 738348224: Global MASTER-Net observations report
  90. Fermi trigger No 738330463: Global MASTER-Net observations report
  91. Fermi trigger No 737996942: Global MASTER-Net observations report
  92. GRB 240516B: AstroSat CZTI detection
  93. GRB 240516A: Swift-BAT refined analysis
  94. GRB 240502C: Zeiss-1000 at Koshka observations of GOTO24bao optical counterpart candidate
  95. GRB 240516A: GOTO optical upper limit
  96. GRB 240516A: Swift detection of a burst
  97. Fermi GRB 240514B: Global MASTER-Net observations report
  98. LAT GRB240513.31: Global MASTER-Net observations report
  99. Fermi GRB 240513B: Global MASTER-Net observations report
  100. Fermi trigger No 737277727: Global MASTER-Net observations report

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