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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"

11557 results found.

  1. GRB 241209A: ATCA radio follow-up observations
  2. EP241217A: Non-detection from Fermi-GBM Observations
  3. GRB 241209D: GRBAlpha detection
  4. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  5. GRB 241209D: CALET Gamma-Ray Burst Monitor detection
  6. GRB 241212A: Fermi GBM detection
  7. GRB241212A: OHP/T193 optical observations
  8. GRB 241212A : SVOM/C-GFT optical upper limit at early phase
  9. GRB 241212A : SVOM/VT bright optical afterglow
  10. GRB 241212A: AstroSat CZTI detection
  11. GRB 241207A: TSHAO Zeiss-1000 optical observations
  12. GRB 241212A: SVOM detection of a bright long burst
  13. GRB 241212A: Fermi GBM Final Real-time Localization
  14. GRB 241207A: EIRSAT-1 GMOD Detection
  15. GRB 241209A: Redshift of the likely host galaxy z = 0.784 from OSIRIS+/GTC
  16. GRB 241211A: Fermi GBM Final Real-time Localization
  17. GRB 241129A: Fermi GBM Observation
  18. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  19. GRB 241209D: REM optical/NIR upper limits
  20. Konus-Wind detection of GRB 241209D
  21. GRB 241209C: Fermi GBM Observation
  22. Fermi Gamma-ray Burst Monitor trigger 755485387 / 241210044 is not a GRB
  23. GRB 241209D: AstroSat CZTI detection
  24. GRB 241209A: EP-FXT follow-up observations
  25. Fermi trigger No 755485387: Global MASTER-Net observations report
  26. GRB 241207B: Fermi GBM Observation
  27. GRB 241209A: BOOTES-7 and 2.2m CAHA early optical upper limits
  28. GRB 241209D: Fermi GBM Observation
  29. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  30. GRB 241209D: COLIBRÍ detection of the afterglow
  31. GRB 241209A: COLIBRÍ Optical Upper Limit
  32. Fermi GRB 241209D: Global MASTER-Net observations report
  33. GRB 241209A: Fermi GBM Observation
  34. GRB 241209C: Swift/BAT-GUANO localization skymap of a burst
  35. GRB 241209A: GRANDMA/TAROT upper limit
  36. Fermi GRB 241209C: Global MASTER-Net observations report
  37. Fermi GRB 241209E: Global MASTER-Net observations report
  38. GRB 241209E: Fermi GBM Final Real-time Localization
  39. GRB 241209A: REM optical/NIR observations
  40. GRB 241209C: AstroSat CZTI detection
  41. GRB 241209D: Fermi GBM Final Real-time Localization
  42. GRB 241209A: VLT/X-shooter spectroscopy
  43. GRB 241209A: VLT optical observations
  44. Fermi GRB 241209A: Global MASTER-Net observations report
  45. GRB 241209C: Fermi GBM Final Real-time Localization
  46. GRB 241209A: GOTO optical upper limits
  47. GRB 241209A: Swift detection of a short burst
  48. GRB 241209A: Fermi GBM Final Real-time Localization
  49. Fermi GRB 241207B: Global MASTER-Net observations report
  50. GRB 241207B: Swift/BAT-GUANO localization skymap of a short burst
  51. Fermi Gamma-ray Burst Monitor trigger 755277791/241207641 is not a GRB
  52. GRB 241201A: AstroSat CZTI detection
  53. GRB 241206A: DDOTI Upper Limit on the Afterglow
  54. Fermi trigger No 755225799: Global MASTER-Net observations report
  55. GRB 241207B: Fermi GBM Final Real-time Localization
  56. Fermi trigger No 755277791: Global MASTER-Net observations report
  57. Fermi GRB 241207A: Global MASTER-Net observations report
  58. GRB 241206A: Fermi GBM observation
  59. GRB 241207A: Fermi GBM Final Real-time Localization
  60. GRB 241206A: Swift/BAT-GUANO localization skymap of a burst
  61. Fermi GRB 241206A: Global MASTER-Net observations report
  62. GRB 241206A: Fermi GBM Final Real-time Localization
  63. GRB 241204A: COLIBRÍ Optical Upper Limit
  64. GRB 241204A: DDOTI Upper Limits on the Afterglow
  65. GRB 241204A: Fermi GBM Observation
  66. Fermi GRB 241204A: Global MASTER-Net observations report
  67. GRB 241130A: CALET Gamma-Ray Burst Monitor detection
  68. GRB 241201A: GRBAlpha detection
  69. GRB 241204A: Fermi-LAT detection
  70. EP241202b: Upper limits from Fermi-GBM Observations
  71. Fermi-GBM Sub-Threshold Detection of GRB 241128A
  72. Konus-Wind detection of GRB 241130A
  73. IPN triangulation of GRB 241130A
  74. GRB 241130A: EIRSAT-1 GMOD Detection
  75. GRB 241130A: Fermi GBM Detection
  76. GRB 241129A: Swift/BAT-GUANO localization skymap of a burst
  77. GRB241201B: Fermi GBM Final Localization
  78. GRB241201B: Fermi GBM Final Localization
  79. Fermi GRB 241201A: Global MASTER-Net observations report
  80. GRB 241201A: BALROG localization (Fermi Trigger 754757764 / GRB 241201622)
  81. GRB 241130A: Fermi GBM Final Real-time Localization
  82. GRB 241130A: Fermi GBM Final Real-time Localization
  83. GRB 241201A: Fermi GBM Final Real-time Localization
  84. Fermi trigger No 754701230: Global MASTER-Net observations report
  85. SVOM/GRM observation of a short burst from soft gamma repeater Kes 73
  86. Fermi-LAT gamma-ray observations of IceCube-241127A
  87. GRB 241129A: Fermi GBM Final Real-time Localization
  88. Fermi trigger No 754492985: Global MASTER-Net observations report
  89. LIGO/Virgo/KAGRA S241125n: Preliminary flux estimate and spectral analysis of the Swift/BAT-GUANO candidate counterpart
  90. IceCube-241127A: IceCube observation of a high-energy neutrino candidate track-like event
  91. GRB 241026A: radio detection with the VLA
  92. LIGO/Virgo/KAGRA S241125n: Upper limits from Fermi-GBM Observations
  93. GRB 241120A: GRBAlpha detection
  94. Konus-Wind detection of GRB 241117A
  95. GRB 241105A: ATCA radio detection
  96. IPN triangulation of GRB 241117A
  97. GRB 241026A: VIRT Optical Upper Limit
  98. GRB 241025A: VIRT Optical Upper Limit
  99. Konus-Wind detection of GRB 241120A
  100. GRB241120A: OHP/T193 optical observations

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