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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"

37301 results found.

  1. GRB 241209A: Fermi GBM Observation
  2. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  3. GRB 241209A: GRANDMA/TAROT upper limit
  4. GRB 241209B: BOOTES-5 optical upper limit
  5. Swift GRB 241209D: Global MASTER-Net observations report
  6. Fermi GRB 241209C: Global MASTER-Net observations report
  7. Fermi GRB 241209E: Global MASTER-Net observations report
  8. GRB 241209E: Fermi GBM Final Real-time Localization
  9. GRB 241209B: Swift ToO observations
  10. GRB 241209A: REM optical/NIR observations
  11. GRB 241209D: Enhanced Swift-XRT position
  12. GRB 241209C: AstroSat CZTI detection
  13. GRB 241209D: Swift detection of a burst
  14. GRB 241209D: Fermi GBM Final Real-time Localization
  15. GRB 241209A: VLT/X-shooter spectroscopy
  16. GRB 241209A: Enhanced Swift-XRT position
  17. GRB 241114B: cubesat Avion detection
  18. GRB 241209A: VLT optical observations
  19. Fermi GRB 241209A: Global MASTER-Net observations report
  20. GRB 241209C: Fermi GBM Final Real-time Localization
  21. GRB 241209A: GOTO optical upper limits
  22. GRB 241209A: Prompt enhanced Swift-XRT position
  23. GRB 241209B: SVOM/ECLAIRs and GRM detection of a long burst
  24. GRB 241209A: Swift detection of a short burst
  25. GRB 241209A: Fermi GBM Final Real-time Localization
  26. Fermi GRB 241207B: Global MASTER-Net observations report
  27. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  28. Fermi Gamma-ray Burst Monitor trigger 755277791/241207641 is not a GRB
  29. GRB 241201A: AstroSat CZTI detection
  30. GRB 241206A: DDOTI Upper Limit on the Afterglow
  31. GRB 241207C: MASTER optical observations
  32. GRB 241207C: Tiled Swift observations
  33. GRB 241207C: MAXI/GSC detection
  34. GRB 241207B: Fermi GBM Final Real-time Localization
  35. Fermi GRB 241207A: Global MASTER-Net observations report
  36. EP241206a: EP detection of a fast X-ray transient
  37. GRB 241206A: Fermi GBM observation
  38. GRB 241206C: SVOM/GRM observation of a likely short burst
  39. GRB 241207A: Fermi GBM Final Real-time Localization
  40. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  41. GRB 241206B: SVOM/MXT observations: a probable flare from the QSO 1ES 1959+650
  42. GRB 241206B: GWAC-F50A optical upper limit
  43. GRB 241206B: SVOM/ECLAIRs detection of a long soft transient
  44. Fermi GRB 241206A: Global MASTER-Net observations report
  45. GRB 241206A: Fermi GBM Final Real-time Localization
  46. EP241201a: 1.6m Mephisto Optical Upper Limits
  47. GRB 241204A: COLIBRÍ Optical Upper Limit
  48. EP241202b: KAIT optical upper limit
  49. LIGO/Virgo/KAGRA S241125n: gamma-ray upper limits from joint observations by the LST-1 and MAGIC telescopes
  50. GRB 241204A: DDOTI Upper Limits on the Afterglow
  51. GRB 241204A: Fermi GBM Observation
  52. Fermi GRB 241204A: Global MASTER-Net observations report
  53. GRB 241130A: CALET Gamma-Ray Burst Monitor detection
  54. GRB 241128A : RAPAS follow-up observations
  55. GRB 241201A: GRBAlpha detection
  56. GRB 241204A: Fermi-LAT detection
  57. EP241202b: Upper limits from Fermi-GBM Observations
  58. IceCube-241127A: No transient candidates from the Zwicky Transient Facility
  59. EP241202b: Kinder optical counterpart candidate
  60. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  61. GRB 241113B : RAPAS follow-up observation
  62. Konus-Wind detection of GRB 241130A
  63. EP241202b: EP detection of a fast X-ray transient
  64. IPN triangulation of GRB 241130A
  65. GRB 241130A: EIRSAT-1 GMOD Detection
  66. GRB 241128A: Swift/UVOT Upper Limits
  67. GRB 241130A: Fermi GBM Detection
  68. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  69. EP241201a: Kinder optical counterpart candidate
  70. LIGO/Virgo/KAGRA S241102br: GRAWITA wide-field optical observations
  71. GRB 241127B: detection of a long GRB by SVOM/ECLAIRs
  72. GRB241201B: Fermi GBM Final Localization
  73. GRB241201B: Fermi GBM Final Localization
  74. Fermi GRB 241201A: Global MASTER-Net observations report
  75. GRB 241201A: BALROG localization (Fermi Trigger 754757764 / GRB 241201622)
  76. GRB 241130A: Fermi GBM Final Real-time Localization
  77. GRB 241130A: Fermi GBM Final Real-time Localization
  78. EP241126a: 1.6m Mephisto Optical Upper Limits
  79. GRB 241201A: Fermi GBM Final Real-time Localization
  80. IPN triangulation of GRB 241128B
  81. Konus-Wind detection of GRB 241114B
  82. GRB 241128A: AbAO optical upper limit
  83. GRB 241128C: SVOM/GRM observation
  84. GRB 241128B: SVOM/GRM observation
  85. GRB 241128A: Swift-BAT refined analysis
  86. GRB 241127A: Swift-BAT refined analysis
  87. GRB 241127A: PRIME near-infrared detection
  88. GRB 241128A: Mondy optical observations
  89. GRB 241128A: GRANDMA and Kilonova-Catcher Optical Afterglow Detections and Upperlimits
  90. Swift GRB 241128A: Global MASTER-Net observations report
  91. GRB 241128A: Swift-XRT refined Analysis
  92. GRB 241129A: Fermi GBM Final Real-time Localization
  93. GRB 241128A: Enhanced Swift-XRT position
  94. GRB 241128A: NOT optical observations
  95. GRB 241128A: LCO optical detection
  96. GRB 241128A: 1.5m OSN optical afterglow detection
  97. GRB 241128A: Swift-XRT afterglow detection
  98. GRB 241128A: Swift detection of a burst
  99. GRB 241127A: GRANDMA and Kilonova-Catcher optical afterglow detections
  100. GRB 241127A: Swift/UVOT Detection

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