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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"

4252 results found.

  1. GRB 240929A: SAO RAS, Mondy, and CrAO optical observations
  2. Fermi GRB 241002B: Global MASTER-Net observations report
  3. GRB 241001A: Swift-XRT observations
  4. GRB 240929A: GRBAlpha detection
  5. Fermi-LAT Gamma-ray Observations of IceCube-240929A
  6. SVOM/GRM detection of a burst from SGR Swift J1818.0-1607
  7. IceCube-240929A: Upper limits from a search for additional neutrino events in IceCube
  8. LIGO/Virgo/KAGRA S240930df: 1 counterpart neutrino candidate event from an IceCube neutrino search
  9. GRB 240929A : Leavitt Observatory optical upper limit
  10. Fermi GRB 240930B: Global MASTER-Net observations report
  11. Fermi GRB 240930A: Global MASTER-Net observations report
  12. Fermi trigger No 749339671: Global MASTER-Net observations report
  13. Fermi Gamma-ray Burst Monitor trigger 749339671/240929913 is not a GRB
  14. GRB 240929A long GRB detected by INTEGRAL
  15. GRB 240929A: BALROG localization (Fermi Trigger 749332209 / GRB 240929826)
  16. Fermi GRB 240929A: Global MASTER-Net observations report
  17. GRB 240929A: Fermi GBM Final Real-time Localization
  18. Integral GRB240929.83: Global MASTER-Net observations report
  19. IceCube-240929A - IceCube observation of a high-energy neutrino candidate track-like event
  20. Insight-HXMT ToO observations of X-ray bursts from SGR 1E 1841-045 / Kes 73
  21. EP240913a/GRB 240913C: 1.6m Mephisto observations
  22. EP240918a: SVOM/VT upper limit
  23. LIGO/Virgo/KAGRA S240920dw: Identification of a GW compact binary merger candidate
  24. GRB 240821A: radio observation with the VLA
  25. LIGO/Virgo/KAGRA S240915b: Identification of a GW compact binary merger candidate
  26. EP240913a: JinShan optical upper limits
  27. GRB 240914A : An intermediate duration GRB located on-board by SVOM/ECLAIRs.
  28. Fermi trigger No 747553301: Global MASTER-Net observations report
  29. GRB 240905B: GOTO optical upper limits
  30. GRB 240905E: Swift detection of a burst
  31. Fermi GRB 240905B: Global MASTER-Net observations report
  32. LIGO/Virgo/KAGRA S240902bq: Identification of a GW compact binary merger candidate
  33. Fermi trigger No 746923430: Global MASTER-Net observations report
  34. GRB 240828A: SAO RAS AS-500(2) optical observations
  35. GRB 240829B: GRBAlpha detection
  36. GRB 240828B: AbAO optical upper limit
  37. GRB 240828B: GRANDMA Optical Upper Limit
  38. GRB 240825A: MeerKAT detection
  39. GRB 240828B: SAO RAS optical upper limit
  40. GRB 240828A: SAO RAS optical observations
  41. Fermi trigger No 746587425: Global MASTER-Net observations report
  42. GRB 240829B: Fermi GBM Final Localization
  43. GRB 240629A: First GRB Detected by BurstCube
  44. GRB 240828A: KAIT Optical Afterglow Candidate
  45. Swift GRB240829.16: Global MASTER-Net observations report
  46. LAT GRB240828.62: Global MASTER-Net observations report
  47. Fermi trigger No 746438824: Global MASTER-Net observations report
  48. GRB 240825A: SAO RAS optical observations
  49. GRB 240824A: GIT optical upper limit
  50. SGR 1E 1841-045 / Kes 73: SVOM/GRM observation
  51. SGR 1E 1841-045 / Kes 73 (Trigger 1249878): Osservatorio Atronomico Nastro Verde optical upper limit
  52. Fermi GRB 240825A: Global MASTER-Net observations report
  53. SGR 1E 1841-045 / Kes 73 (Trigger 1249653) - Osservatorio Astronomico Nastro Verde upper limit
  54. SGR 1E 1841-045 / Kes 73: Leavitt Observatory optical upper limit
  55. SGR 1E 1841-045 / Kes 73: Montarrenti Observatory optical upper limits
  56. GECAM-B observation of a short burst from SGR 1E 1841-045 / Kes 73
  57. Fermi-GBM Observations of the reactivation of SGR 1E 1841-045 / Kes 73
  58. Fermi trigger No 745866488: Global MASTER-Net observations report
  59. Trigger 1249878: Swift detection of another burst from SGR 1E 1841-045 / Kes 73
  60. Trigger 1249653: Swift detection of SGR 1E 1841-045 / Kes 73
  61. GRB 240819A: X-ray follow-up observation with EP-FXT
  62. EP240816b: Liverpool Telescope optical follow-up observations
  63. EP EP240816b: Global MASTER-Net observations report
  64. Fermi GRB 240814C: Global MASTER-Net observations report
  65. Fermi trigger No 745306088: Global MASTER-Net observations report
  66. Fermi GRB 240814B: Global MASTER-Net observations report
  67. Fermi GRB 240810A: Global MASTER-Net observations report
  68. GRB 240809A: Swift detection of a burst with a bright optical counterpart
  69. EP EP240807a: Global MASTER-Net observations report
  70. EP EP240806a: Global MASTER-Net observations report
  71. Fermi trigger No 744761058: Global MASTER-Net observations report
  72. EP240807a/GRB 240807A: EP-FXT detection of the X-ray emission
  73. EP240806A: Liverpool Telescope optical follow-up observations
  74. Fermi trigger No 744629911: Global MASTER-Net observations report
  75. Konus-Wind detection of GRB 240802A (EP240802a)
  76. GRB 240805B: NUTTelA-TAO / BSTI Optical Limits
  77. Fermi trigger No 744544656: Global MASTER-Net observations report
  78. GRB 240802A: AstroSat CZTI detection of a long burst
  79. Fermi trigger No 744128417: Global MASTER-Net observations report
  80. Fermi trigger No 743953682: Global MASTER-Net observations report
  81. Fermi Gamma-ray Burst Monitor trigger 743953682/240729575 is not a GRB
  82. Fermi GRB 240727A: Global MASTER-Net observations report
  83. GRB 240718A: GRBAlpha detection
  84. GRB 240627A: GRBAlpha detection
  85. Fermi GRB 240726A: Global MASTER-Net observations report
  86. Fermi trigger No 743345551: Global MASTER-Net observations report
  87. Fermi trigger No 743219692: Global MASTER-Net observations report
  88. Swift GRB240720.02: Global MASTER-Net observations report
  89. Konus-Wind detection of GRB 240718A
  90. Fermi GRB 240718A: Global MASTER-Net observations report
  91. GRB 240718A: Fermi GBM Observation
  92. IceCube-Cascade 240714A: TRT optical observations on the EP/FXT positions
  93. GRB 240718A: Fermi-LAT Detection
  94. GRB 240718A: SVOM/GRM observation
  95. GRB 240718A: BALROG localization (Fermi Trigger 742976945 / GRB 240718270)
  96. GRB 240718A: Fermi GBM Final Real-time Localization
  97. IPN triangulation of GRB 240715A (short)
  98. JinShan confirmation of the EP-WXT source triggered on July 14th due to a flaring star
  99. GRB 240712A: Swift detection of a burst
  100. Fermi trigger No 742317942: Global MASTER-Net observations report

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