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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

12113 results found.

  1. GRB 251220B: Fermi GBM Final Real-time Localization
  2. GRB 251219A: GECAM-B detection of a possible magnetar X-ray burst from SGR 1830-0645
  3. Fermi-LAT Gamma-ray Observations of IceCube-251218A
  4. GRB 251220A: MAXI/GSC detection
  5. IceCube-251218A: Upper limits from a search for additional neutrino events in IceCube
  6. SVOM GRB251219.11: Global MASTER-Net observations report
  7. IceCube-251218A - IceCube observation of a high-energy neutrino candidate track-like event
  8. IceCube Alert 251218.85: Global MASTER-Net observations report
  9. Fermi GRB 251217A: Global MASTER-Net observations report
  10. Fermi GRB 251215A: Global MASTER-Net observations report
  11. EP251214a: Optical upper limit with Kinder observations
  12. EP251214b : Einstein Probe detection of a fast X-ray transient
  13. EP251214b : Einstein Probe detection of a fast X-ray transient
  14. EP251214b (EP trigger 01709250023): LCO optical limits
  15. GRB 251203B: AbAO optical observations
  16. GRB 251214B: Swift-XRT refined Analysis
  17. GRB 251214D: AstroSat CZTI detection of a long burst
  18. GRB 251213A: AstroSat CZTI detection
  19. GRB 251214A: AstroSat CZTI detection
  20. GRB 251214B : MASTER optical afterglow detection
  21. Swift GRB 251214B: Global MASTER-Net observations report
  22. GRB 251214B: Swift detection of a burst with an optical counterpart
  23. EP251214a: EP-WXT detection of an X-ray transient possibly associated with GRB 251214A
  24. EP251212a: Global MASTER-Net observations report
  25. EP251212a / GRB 251212A: AstroSat CZTI detection
  26. GRB 251211B: AstroSat CZTI detection
  27. Fermi-LAT Gamma-ray Observations of IceCube-251210A
  28. Fermi GRB 251211B: Global MASTER-Net observations report
  29. GRB 251211B: Fermi GBM Final Real-time Localization
  30. GRB 251209A: AstroSat CZTI detection
  31. GRB 251129A/EP251129a: AbAO and Mondy optical observations
  32. EP251130a: Mondy and AbAO optical observations
  33. GRB 251208A: AstroSat CZTI detection
  34. GRB 251208B: Swift-XRT afterglow detection
  35. GRB 251208B: Fermi GBM Observation
  36. GRB 251208D: Swift-XRT observations
  37. GRB 251208B: Fermi-LAT detection
  38. GRB 251206A: SVOM detection of a burst through offline search
  39. GRB 251205A: Swift-XRT refined Analysis
  40. Konus-Wind detection of GRB 251118A
  41. Swift GRB251205A: Global MASTER-Net observations report
  42. GRB 251203A: SVOM/GRM observation
  43. GRB 251203A: AstroSat CZTI detection
  44. GRB 251203C: EP-FXT follow-up observation
  45. GRB 251203B: Swift-XRT observations
  46. GRB 251203B: confirmation of a stellar flare by BOOTES-2
  47. GRB 251203B: SVOM detection of a burst
  48. EP251130a: MAO/AZT-22 optical observations
  49. EP251202a / GRB251202A: AstroSat CZTI detection
  50. Fermi GRB 251202B: Global MASTER-Net observations report
  51. GRB 251129B: AstroSat CZTI detection
  52. GRB 251201B: Swift/UVOT Detection
  53. GRB 251122A/EP251122a: CrAO ZTSh optical observations
  54. Fermi-LAT Gamma-ray Observations of IceCube-251130A
  55. EP251202a/GRB 251202A: refined analysis of the EP-WXT observations
  56. GRB 251202A: Swift-XRT afterglow detection
  57. EP251129a/GRB 251129A: NOWT Detection
  58. GRB 251126A: SVOM/VT optical observation
  59. EP251202a/GRB 251202A: Einstein Probe detection of an X-ray transient
  60. GRB 251201B: Swift-XRT refined Analysis
  61. EP251118a: Mondy, CrAO, Assy and SAO RAS/Zeiss-1000 optical observations
  62. GRB 251130B: AstroSat CZTI detection
  63. EP251130a: Optical detections with Kinder observations
  64. GRB 251201A: MAXI/GSC detection
  65. EP251130a: Swift-XRT counterpart detection
  66. EP251130a: Einstein Probe detection of an X-ray transient
  67. EP251129a/GRB 251129A: EP-FXT follow-up observations
  68. GRB 251128A: AstroSat CZTI detection
  69. GRB 251129A: Swift-XRT afterglow detection
  70. EP251129a: Global MASTER-Net observations report
  71. EP251129a/GRB 251129A : Einstein Probe detection of an X-ray transient
  72. GRB 251126A: TShAO, Mondy, and AbAO optical observations
  73. GRB 251128A: Swift/BAT-GUANO localization skymap of a burst
  74. GRB 251126A: further SAO RAS optical observations
  75. GRB 251126A: Mondy and SAO RAS optical observations
  76. GRB 251126A: Swift-XRT refined Analysis
  77. Fermi GRB 251127A: Global MASTER-Net observations report
  78. Swift GRB 251126A: Global MASTER-Net observations report
  79. GRB 251126A: Swift detection of a burst
  80. GRB 251125B: COLIBRÍ further observations and photometric redshift upper limit of z < 3
  81. Fermi GRB 251125B : MASTER OT J155558.56+581224.1 optical counterpart discovery
  82. Fermi GRB 251125B: Global MASTER-Net observations report
  83. GRB 251125B: Fermi GBM Final Real-time Localization
  84. Fermi GRB 251125A: Global MASTER-Net observations report
  85. EP251124a: Swift-XRT observations
  86. LIGO/Virgo/KAGRA S251112cm: AT 2025adht Kinder follow-up observations
  87. EP251124a: Optical upper limit with Kinder observations
  88. EP251118A: 6 GHz VLA Detection
  89. LIGO/Virgo/KAGRA S251105aj: EP-FXT follow-up observations and preliminary results on SVOM J2320.0-2901
  90. EP251124a: Einstein Probe detection of an X-ray transient
  91. GRB 251122A/EP251122a: Additional, deeper LCO optical r band upper limit
  92. EP251122a / GRB 251122A: optical counterpart candidate with Kinder observations
  93. GRB 251122A / EP251122a: SVOM detection of a long burst
  94. EP251122a: Einstein Probe detection of an X-ray transient
  95. EP251118a: Continued Optical Detection with Kinder observations
  96. GRB 251121A: Swift/BAT-GUANO localization skymap of a short burst
  97. GRB 251115A: Fermi GBM Observation
  98. EP251118A: 1.3m DFOT optical afterglow detection
  99. GRB 251118A: Glowbug gamma-ray detection
  100. GRB 251118A: Fermi GBM Observation

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