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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"

19319 results found.

  1. EP260105a: FTW optical observations
  2. EP260104a: FTW optical observations
  3. GRB 260105B: BALROG localization (Fermi Trigger 789348101 / GRB 260105973)
  4. GRB 260105A: SVOM/GRM observation
  5. GRB 260105B: SVOM/GRM observation
  6. The EP-WXT trigger 01709251028 is likely a flaring star
  7. FRB 20251229A: COLIBRÍ optical upper limits
  8. Fermi GRB 260105B: Global MASTER-Net observations report
  9. EP260105a: SVOM/VT optical upperlimit
  10. GRB 260105B: Fermi GBM Final Real-time Localization
  11. GRB 260105A: Fermi GBM Final Real-time Localization
  12. FRB 20251229A: A potentially hyperactive repeating fast radio burst source
  13. EP260105a: refined analysis of the EP-WXT and EP-FXT observations
  14. EP260105a: LCO Optical Upper limit
  15. EP260104a: Global MASTER-Net observations report
  16. EP260104a: Einstein Probe detection of a fast X-ray transient
  17. GRB 260101A: COLIBRÍ optical upper limits
  18. EP260105a: Global MASTER-Net observations report
  19. EP260105a: Einstein Probe detection of an X-ray transient
  20. GRB 260103A: Insight-HXMT/HE detection
  21. GRB 260104A: COLIBRÍ optical upper limits
  22. GRB 260104C: Fermi GBM Final Real-time Localization
  23. Fermi GRB 260104B: Global MASTER-Net observations report
  24. Swift GRB 260104A: Global MASTER-Net observations report
  25. GRB 251230A/EP-WXT trigger 01709250693: Mephisto optical upper limits
  26. GRB 260104A: Swift-XRT refined Analysis
  27. GRB 260103A: GECAM-B observation of a burst
  28. GRB 260104B: Fermi GBM Final Localization
  29. GRB 260103A: SVOM/GRM observation of a possible GRB
  30. Fermi-LAT Gamma-ray Observations of IceCube-251225A
  31. GRB 260101A: COLIBRÍ optical observations
  32. SVOM GRB260103.08: Global MASTER-Net observations report
  33. GRB 260102B: Fermi GBM Final Real-time Localization
  34. SVOM GRB260102A: Global MASTER-Net observations report
  35. Fermi GBM Sub-Threshold Detection of GRB 260102A
  36. GRB 260102A: EP-FXT follow-up observation
  37. EP260101a: Global MASTER-Net observations report
  38. GRB 260102A: LCO optical upper limits
  39. GRB 260102A: Swift-XRT observations
  40. GRB 260102A: SVOM/COLIBRÍ (FM-GFT) optical observations
  41. Fermi Gamma-ray Burst Monitor trigger 789047602/260102495 is not a GRB
  42. GRB 260102A: SVOM/VT optical counterpart
  43. GRB 260101A: Fermi GBM Observation
  44. EP260101a: refined analysis of the EP-WXT and EP-FXT observations
  45. GRB 260102A: SVOM detection of a burst
  46. GRB 260101A: GECAM-B detection
  47. GRB 260101A: NOT spectroscopic observations
  48. GRB 260101A: SVOM/GRM observation
  49. GRB 260101A: Swift-XRT refined Analysis
  50. Swift GRB 260101A: Global MASTER-Net observations report
  51. EP260101a: Einstein Probe detection of an X-ray transient
  52. GRB 260101A: OSIRIS+ redshift z = 2.623 for the new year burst
  53. GRB 260101A: LCO detection of the optical counterpart
  54. GRB 260101A: Swift detection of a burst with an optical counterpart
  55. GRB 260101A: Fermi GBM Final Real-time Localization
  56. SVOM GRB251231.57: Global MASTER-Net observations report
  57. GRB 251230A: Swift-XRT refined Analysis
  58. GRB251230A: 7DT optical upper limits
  59. EP251229a: refined analysis of the EP-WXT and EP-FXT observations
  60. GRB 251230A: Enhanced Swift-XRT position
  61. GRB 251230A: Early optical counterpart detection by LCO.
  62. LIGO/Virgo/KAGRA S251112cm: Candidates from the NSF-DOE Vera C. Rubin Observatory
  63. Swift GRB 251230A: Global MASTER-Net observations report
  64. EP251229a: Global MASTER-Net observations report
  65. GRB 251230A: Swift detection of a burst with a bright optical counterpart
  66. GRB 251226A: Glowbug gamma-ray detection
  67. Fermi GRB 251228A: Global MASTER-Net observations report
  68. GRB 251226A: GECAM-B detection
  69. SVOM GRB251227.07: Global MASTER-Net observations report
  70. IceCube-251225A: Upper limits from a search for additional neutrino events in IceCube
  71. IceCube Alert 251225.84: Global MASTER-Net observations report
  72. GRB 251222A/EP251222b: Optical detection with Kinder observations
  73. GRB 251221A: Swift-BAT refined analysis
  74. GRB 251222A: AbAO optical observations
  75. GRB 251129A / EP251129a: VLA detection of a radio counterpart
  76. GRB 251222A: Fermi GBM Observation
  77. EP251222a: Global MASTER-Net observations report
  78. EP251221a: Liverpool Telescope upper limits
  79. GRB 251222A: Swift-XRT afterglow detection
  80. GRB 251222A / EP251222b: LCO detection of the optical counterpart
  81. GRB251221A: 7DT optical upper limits
  82. EP251222a: GSP Optical Counterpart Detection
  83. EP251221a: Global MASTER-Net observations report
  84. GRB 251222A: BALROG localization (Fermi Trigger / GRB 251222712)
  85. GRB 251222A: SVOM/VT optical candidate
  86. GRB 251222A: SVOM detection of a long burst
  87. SVOM GRB251222A: Global MASTER-Net observations report
  88. GRB 251221A: Swift-XRT refined Analysis
  89. EP251221a: Einstein Probe detection of a fast X-ray transient
  90. GRB 251221A: Fermi GBM Observation
  91. GRB 251221A: Swift detection of a burst
  92. Swift GRB251221A: Global MASTER-Net observations report
  93. EP251220a: Global MASTER-Net observations report
  94. SVOM GRB251220.98: Global MASTER-Net observations report
  95. GRB 251219A: GECAM-B detection of a possible magnetar X-ray burst from SGR 1830-0645
  96. Fermi-LAT Gamma-ray Observations of IceCube-251218A
  97. GRB 251220A: MAXI/GSC detection
  98. GRB 251215A: Swift-XRT afterglow detection
  99. IceCube-251218A: Upper limits from a search for additional neutrino events in IceCube
  100. IceCube-251218A: COLIBRÍ optical upper limits

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