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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"

11109 results found.

  1. Fermi Gamma-ray Burst Monitor trigger 744459130/240804425 is not a GRB
  2. Fermi trigger No 744278264: Global MASTER-Net observations report
  3. GRB 240801B: AstroSat CZTI Updated classification - likely a solar flare
  4. Fermi GBM trigger 744179961 / 240801194 can not be confirmed as a GRB
  5. Fermi trigger No 744204856: Global MASTER-Net observations report
  6. GRB 240801B: AstroSat CZTI detection of a bright long burst
  7. Fermi GRB 240801A: Global MASTER-Net observations report
  8. GRB 240801A: Fermi GBM Final Real-time Localization
  9. GRB 240731A: Fermi GBM Final Localization
  10. Fermi trigger No 744128417: Global MASTER-Net observations report
  11. Fermi trigger No 744083370: Global MASTER-Net observations report
  12. GRB 240731A: AstroSat CZTI detection
  13. Fermi Gamma-ray Burst Monitor trigger 744061103/240730818 is not a GRB
  14. Fermi GRB 240730B: Global MASTER-Net observations report
  15. GRB 240730B: Fermi GBM Final Real-time Localization
  16. Fermi trigger No 743953682: Global MASTER-Net observations report
  17. Fermi Gamma-ray Burst Monitor trigger 743953682/240729575 is not a GRB
  18. GRB 240727B: Swift-XRT observations
  19. Fermi GRB 240727A: Global MASTER-Net observations report
  20. Fermi trigger No 743868421: Global MASTER-Net observations report
  21. Fermi Gamma-ray Burst Monitor trigger 743868421/240728588 is not a GRB
  22. GRB 240727D: Correction to the GRB name in GCN 36958
  23. GRB 240727A: Fermi GBM Final Real-time Localization
  24. GRB 240718A: GRBAlpha detection
  25. GRB 240710B: GRBAlpha detection
  26. Fermi GRB 240726A: Global MASTER-Net observations report
  27. GRB 240727B: Fermi GBM Observation
  28. GRB 240727B: Swift ToO observations
  29. GRB 240727B: Swift/BAT-GUANO arcminute localization of a long burst
  30. GRB 240726A: SVOM/GRM observation
  31. GRB 240727B: AstroSat CZTI detection
  32. GRB 240726A: AstroSat CZTI detection of a short burst
  33. GRB 240726A: Fermi GBM Final Real-time Localization
  34. Fermi-LAT gamma-ray observations of IceCube-240725A
  35. IceCube-240725A - IceCube observation of a high-energy neutrino candidate track-like event
  36. Fermi trigger No 743418632: Global MASTER-Net observations report
  37. Fermi trigger No 743315411: Global MASTER-Net observations report
  38. Fermi trigger No 743345551: Global MASTER-Net observations report
  39. Fermi-LAT gamma-ray observations of IceCube-240721A
  40. Fermi Gamma-ray Burst Monitor trigger 743271526/240721680 is not a GRB
  41. Fermi trigger No 743219692: Global MASTER-Net observations report
  42. IceCube-240721A - IceCube observation of a high-energy neutrino candidate track-like event
  43. Fermi Gamma-ray Burst Monitor trigger 743243582/240721356 (GRB 240721A) is not a GRB
  44. GRB 240721A: Fermi GBM Final Real-time Localization
  45. Fermi GRB 240720A: Global MASTER-Net observations report
  46. GRB 240720A: AstroSat CZTI detection
  47. GRB 240720A: Fermi GBM observation
  48. Konus-Wind detection of GRB 240718A
  49. GRB 240713A: SVOM/GRM observation
  50. Fermi GRB 240718A: Global MASTER-Net observations report
  51. GRB 240718A: Fermi GBM Observation
  52. GRB 240718A: Fermi-LAT Detection
  53. GRB 240718A: SVOM/GRM observation
  54. GRB 240718A: BALROG localization (Fermi Trigger 742976945 / GRB 240718270)
  55. GRB 240718A: Fermi GBM Final Real-time Localization
  56. Fermi-LAT gamma-ray observations of IceCube-cascade-240714A
  57. GRB 240715A: Swift/UVOT observations of the XRT sources.
  58. GRB 240715A: GECAM-C detection of a short burst
  59. Konus-Wind detection of GRB 240715A
  60. GRB 240715A: TRT optical upper limit on one Swift/XRT candidate
  61. SVOM/GRM In-Flight Trigger of GRB 240715A
  62. GRB 240713A: LAST optical upper limit
  63. Fermi GRB 240715A: Global MASTER-Net observations report
  64. GRB 240713A: optical upper limits from the INAF Asiago Observatory
  65. GRB 240715A: Fermi GBM Observation
  66. GRB240715A: GRANDMA Optical Upper Limits
  67. IPN triangulation of GRB 240715A (short)
  68. GRB 240715A: Fermi GBM Final Real-time Localization
  69. GRB 240713A: J-band upper limit from WINTER
  70. GRB 240713A: NOT optical upper limits on three EP/FXT candidates
  71. GRB 240713A: JinShan optical upper limits
  72. GRB 240713A: OHP/T120 optical upper limit
  73. GRB240713A: X-ray follow-up observation with EP-FXT
  74. Fermi Sub-threshold Observation of GRB240713A
  75. Fermi Gamma-ray Burst Monitor trigger 742413075/240711744 is not a GRB
  76. GRB 240711A: Fermi GBM Final Real-time Localization
  77. Fermi trigger No 742405878: Global MASTER-Net observations report
  78. Fermi trigger No 742317942: Global MASTER-Net observations report
  79. Fermi GRB 240710A: Global MASTER-Net observations report
  80. GRB 240710A: Fermi GBM Final Real-time Localization
  81. Fermi Gamma-ray Burst Monitor trigger 741911057/240705933 is not a GRB
  82. GRB 240705A: Fermi GBM Final Real-time Localization
  83. IPN triangulation of GRB 240628B (short)
  84. IPN triangulation of GRB 240627A
  85. GRB 240619A: Host galaxy redshift from VLT/X-shooter
  86. The first three GRBs detected by SVOM: GRB 240627B, GRB 240629A and GRB 240702A
  87. GRB 240702A: BALROG localization (Fermi Trigger / GRB 240702885)
  88. Fermi GRB 240702A: Global MASTER-Net observations report
  89. GRB 240702A: Fermi GBM Final Real-time Localization
  90. Fermi Gamma-ray Burst Monitor trigger 741448122/240630575 is not a GRB
  91. Fermi trigger No 741448122: Global MASTER-Net observations report
  92. LIGO/Virgo/KAGRA S240629by: Upper limits from Fermi-GBM Observations
  93. Fermi trigger No 741356809: Global MASTER-Net observations report
  94. Fermi GRB 240629A: Global MASTER-Net observations report
  95. Fermi Gamma-ray Burst Monitor trigger 741362867/240629589 is not a GRB
  96. Fermi Gamma-ray Burst Monitor trigger 741288821/240628732 is not a GRB
  97. GRB 240629A: BALROG localization (Fermi Trigger 741372837 / GRB 240629704)
  98. GRB 240629A: Fermi GBM Final Real-time Localization
  99. Fermi Gamma-ray Burst Monitor trigger 741356809/240629519 is not a GRB
  100. Fermi trigger No 741296200: Global MASTER-Net observations report

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