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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"

11533 results found.

  1. Fermi trigger No 755485387: Global MASTER-Net observations report
  2. GRB 241207B: Fermi GBM Observation
  3. GRB 241209A: BOOTES-7 and 2.2m CAHA early optical upper limits
  4. GRB 241209D: Fermi GBM Observation
  5. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  6. GRB 241209D: COLIBRÍ detection of the afterglow
  7. GRB 241209A: COLIBRÍ Optical Upper Limit
  8. Fermi GRB 241209D: Global MASTER-Net observations report
  9. GRB 241209A: Fermi GBM Observation
  10. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  11. GRB 241209A: GRANDMA/TAROT upper limit
  12. Fermi GRB 241209C: Global MASTER-Net observations report
  13. Fermi GRB 241209E: Global MASTER-Net observations report
  14. GRB 241209E: Fermi GBM Final Real-time Localization
  15. GRB 241209A: REM optical/NIR observations
  16. GRB 241209C: AstroSat CZTI detection
  17. GRB 241209D: Fermi GBM Final Real-time Localization
  18. GRB 241209A: VLT/X-shooter spectroscopy
  19. GRB 241209A: VLT optical observations
  20. Fermi GRB 241209A: Global MASTER-Net observations report
  21. GRB 241209C: Fermi GBM Final Real-time Localization
  22. GRB 241209A: GOTO optical upper limits
  23. GRB 241209A: Swift detection of a short burst
  24. GRB 241209A: Fermi GBM Final Real-time Localization
  25. Fermi GRB 241207B: Global MASTER-Net observations report
  26. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  27. Fermi Gamma-ray Burst Monitor trigger 755277791/241207641 is not a GRB
  28. GRB 241201A: AstroSat CZTI detection
  29. GRB 241206A: DDOTI Upper Limit on the Afterglow
  30. Fermi trigger No 755225799: Global MASTER-Net observations report
  31. GRB 241207B: Fermi GBM Final Real-time Localization
  32. Fermi trigger No 755277791: Global MASTER-Net observations report
  33. Fermi GRB 241207A: Global MASTER-Net observations report
  34. GRB 241206A: Fermi GBM observation
  35. GRB 241207A: Fermi GBM Final Real-time Localization
  36. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  37. Fermi GRB 241206A: Global MASTER-Net observations report
  38. GRB 241206A: Fermi GBM Final Real-time Localization
  39. GRB 241204A: COLIBRÍ Optical Upper Limit
  40. GRB 241204A: DDOTI Upper Limits on the Afterglow
  41. GRB 241204A: Fermi GBM Observation
  42. Fermi GRB 241204A: Global MASTER-Net observations report
  43. GRB 241130A: CALET Gamma-Ray Burst Monitor detection
  44. GRB 241201A: GRBAlpha detection
  45. GRB 241204A: Fermi-LAT detection
  46. EP241202b: Upper limits from Fermi-GBM Observations
  47. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  48. Konus-Wind detection of GRB 241130A
  49. IPN triangulation of GRB 241130A
  50. GRB 241130A: EIRSAT-1 GMOD Detection
  51. GRB 241130A: Fermi GBM Detection
  52. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  53. GRB241201B: Fermi GBM Final Localization
  54. GRB241201B: Fermi GBM Final Localization
  55. Fermi GRB 241201A: Global MASTER-Net observations report
  56. GRB 241201A: BALROG localization (Fermi Trigger 754757764 / GRB 241201622)
  57. GRB 241130A: Fermi GBM Final Real-time Localization
  58. GRB 241130A: Fermi GBM Final Real-time Localization
  59. GRB 241201A: Fermi GBM Final Real-time Localization
  60. Fermi trigger No 754701230: Global MASTER-Net observations report
  61. SVOM/GRM observation of a short burst from soft gamma repeater Kes 73
  62. Fermi-LAT gamma-ray observations of IceCube-241127A
  63. GRB 241129A: Fermi GBM Final Real-time Localization
  64. Fermi trigger No 754492985: Global MASTER-Net observations report
  65. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  66. IceCube-241127A: IceCube observation of a high-energy neutrino candidate track-like event
  67. GRB 241026A: radio detection with the VLA
  68. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  69. GRB 241120A: GRBAlpha detection
  70. Konus-Wind detection of GRB 241117A
  71. GRB 241105A: ATCA radio detection
  72. IPN triangulation of GRB 241117A
  73. GRB 241026A: VIRT Optical Upper Limit
  74. GRB 241025A: VIRT Optical Upper Limit
  75. Konus-Wind detection of GRB 241120A
  76. GRB241120A: OHP/T193 optical observations
  77. GRB 241120A: CALET Gamma-Ray Burst Monitor detection
  78. GRB 241120A: Mondy and AbAO optical observations
  79. GRB 241120A: Fermi GBM Observation
  80. GRB241120A: a long GRB detected by INTEGRAL
  81. GRB 241120A: Fermi GBM Final Real-time Localization
  82. GRB 241115A: CALET Gamma-Ray Burst Monitor detection
  83. GRB 241119A: Fermi GBM Final Real-time Localization
  84. GRB 241115a: PRIME near-infrared upper limits
  85. GRB 241117A: Swift/BAT-GUANO localization skymap of a burst
  86. GRB 241115B: Fermi GBM Observation
  87. Fermi GRB 241118A: Global MASTER-Net observations report
  88. GRB 241118A: Fermi GBM Final Real-time Localization
  89. GRB 241117A: SVOM/GRM observation of a short burst with extended emission
  90. GRB 241117A: Fermi GBM Detection
  91. Fermi GRB 241117B: Global MASTER-Net observations report
  92. GRB 241117B: Fermi GBM Final Real-time Localization
  93. GRB 241115B: Swift/BAT-GUANO localization skymap of a long burst
  94. Fermi GRB 241117A: Global MASTER-Net observations report
  95. GRB 241117A: Fermi GBM Final Real-time Localization
  96. GRB 241115C: Fermi GBM Observation
  97. GRB 241115A: Fermi GBM Observation
  98. GRB 241115C: Swift/BAT-GUANO localization skymap of a burst
  99. Fermi GRB 241115B: Global MASTER-Net observations report
  100. GRB 241115B: Fermi GBM Final Real-time Localization

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