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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').
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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"

12178 results found.

  1. GRB 251208D: Swift-XRT observations
  2. GRB 251208B: Fermi-LAT detection
  3. GRB 251206A: SVOM detection of a burst through offline search
  4. GRB 251205A: Swift-XRT refined Analysis
  5. Konus-Wind detection of GRB 251118A
  6. Swift GRB251205A: Global MASTER-Net observations report
  7. GRB 251203A: SVOM/GRM observation
  8. GRB 251203A: AstroSat CZTI detection
  9. GRB 251203C: EP-FXT follow-up observation
  10. GRB 251203B: Swift-XRT observations
  11. GRB 251203B: confirmation of a stellar flare by BOOTES-2
  12. GRB 251203B: SVOM detection of a burst
  13. EP251130a: MAO/AZT-22 optical observations
  14. EP251202a / GRB251202A: AstroSat CZTI detection
  15. Fermi GRB 251202B: Global MASTER-Net observations report
  16. GRB 251129B: AstroSat CZTI detection
  17. GRB 251201B: Swift/UVOT Detection
  18. GRB 251122A/EP251122a: CrAO ZTSh optical observations
  19. Fermi-LAT Gamma-ray Observations of IceCube-251130A
  20. EP251202a/GRB 251202A: refined analysis of the EP-WXT observations
  21. GRB 251202A: Swift-XRT afterglow detection
  22. EP251129a/GRB 251129A: NOWT Detection
  23. GRB 251126A: SVOM/VT optical observation
  24. EP251202a/GRB 251202A: Einstein Probe detection of an X-ray transient
  25. GRB 251201B: Swift-XRT refined Analysis
  26. EP251118a: Mondy, CrAO, Assy and SAO RAS/Zeiss-1000 optical observations
  27. GRB 251130B: AstroSat CZTI detection
  28. EP251130a: Optical detections with Kinder observations
  29. GRB 251201A: MAXI/GSC detection
  30. EP251130a: Swift-XRT counterpart detection
  31. EP251130a: Einstein Probe detection of an X-ray transient
  32. EP251129a/GRB 251129A: EP-FXT follow-up observations
  33. GRB 251128A: AstroSat CZTI detection
  34. GRB 251129A: Swift-XRT afterglow detection
  35. EP251129a: Global MASTER-Net observations report
  36. EP251129a/GRB 251129A : Einstein Probe detection of an X-ray transient
  37. GRB 251126A: TShAO, Mondy, and AbAO optical observations
  38. GRB 251128A: Swift/BAT-GUANO localization skymap of a burst
  39. GRB 251126A: further SAO RAS optical observations
  40. GRB 251126A: Mondy and SAO RAS optical observations
  41. GRB 251126A: Swift-XRT refined Analysis
  42. Fermi GRB 251127A: Global MASTER-Net observations report
  43. Swift GRB 251126A: Global MASTER-Net observations report
  44. GRB 251126A: Swift detection of a burst
  45. GRB 251125B: COLIBRÍ further observations and photometric redshift upper limit of z < 3
  46. Fermi GRB 251125B : MASTER OT J155558.56+581224.1 optical counterpart discovery
  47. Fermi GRB 251125B: Global MASTER-Net observations report
  48. GRB 251125B: Fermi GBM Final Real-time Localization
  49. Fermi GRB 251125A: Global MASTER-Net observations report
  50. EP251124a: Swift-XRT observations
  51. LIGO/Virgo/KAGRA S251112cm: AT 2025adht Kinder follow-up observations
  52. EP251124a: Optical upper limit with Kinder observations
  53. EP251118A: 6 GHz VLA Detection
  54. LIGO/Virgo/KAGRA S251105aj: EP-FXT follow-up observations and preliminary results on SVOM J2320.0-2901
  55. EP251124a: Einstein Probe detection of an X-ray transient
  56. GRB 251122A/EP251122a: Additional, deeper LCO optical r band upper limit
  57. EP251122a / GRB 251122A: optical counterpart candidate with Kinder observations
  58. GRB 251122A / EP251122a: SVOM detection of a long burst
  59. EP251122a: Einstein Probe detection of an X-ray transient
  60. EP251118a: Continued Optical Detection with Kinder observations
  61. GRB 251121A: Swift/BAT-GUANO localization skymap of a short burst
  62. GRB 251115A: Fermi GBM Observation
  63. EP251118A: 1.3m DFOT optical afterglow detection
  64. GRB 251118A: Glowbug gamma-ray detection
  65. GRB 251118A: Fermi GBM Observation
  66. GRB 251118A: Swift-XRT afterglow detection
  67. GRB 251103A: SVOM/ECLAIRs and SVOM/GRM joint refined analysis
  68. EP251118a: Optical detection with Kinder observations
  69. EP251118a / GRB 251118C: SVOM/VT optical observation
  70. GRB 251118A: NuSTAR detection of bright prompt emission
  71. Konus-Wind detection of GRB 251118C (EP251118a)
  72. GRB 251116D: SVOM/GRM observation of a long GRB
  73. EP251118a: Global MASTER-Net observations report
  74. EP251118a: preliminary result of EP-FXT follow-up observation
  75. LAT GRB251118.86: Global MASTER-Net observations report
  76. GRB 251118A: Fermi-LAT detection
  77. GRB 251118A: BALROG localization (Fermi Trigger 785190695 / GRB 251118855)
  78. GRB 251118A: Fermi GBM Final Real-time Localization
  79. GRB 251013C: Koshka, SAO RAS, Mondy, and CrAO optical observations, possible SN detection
  80. GRB 251117A: Swift/BAT-GUANO localization skymap of a short burst
  81. GRB 251117A: Fermi-LAT detection
  82. LAT GRB251117.51: Global MASTER-Net observations report
  83. GRB 251116C: Swift/BAT arcminute localization of a burst
  84. LIGO/Virgo/KAGRA S251112cm: J-GEM follow-up observations
  85. GRB 251116C: Swift-XRT observations
  86. EP251023a: Assy AZT-20 optical observations
  87. GRB 251116D: AstroSat CZTI detection
  88. GRB 251025B: further Mondy optical observations
  89. SVOM GRB251116C: Global MASTER-Net observations report
  90. GRB 251116C: SVOM detection of a burst
  91. GRB 251115A: Fermi-LAT detection
  92. Fermi GRB 251115A: Global MASTER-Net observations report
  93. LIGO/Virgo/KAGRA S251112cm: NED Galaxies in the 4-Update Localization Volume
  94. GRB 251115A: Fermi GBM Final Real-time Localization
  95. GRB 251113A: AstroSat CZTI detection
  96. GRB 251114B: Fermi GBM Final Real-time Localization
  97. Konus-Wind detection of GRB 251108C
  98. Konus-Wind detection of GRB 251103A
  99. LIGO/Virgo/KAGRA S251112cm: ATLAS targeted observations of the skymap
  100. LIGO/Virgo/KAGRA S251112cm: Swift XRT observations, 20 X-ray sources

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