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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"

42968 results found.

  1. EP251222a: refined analysis of the EP-WXT and EP-FXT observations
  2. EP251222b/GRB 251222A: refined analysis of the EP-WXT and EP-FXT observations
  3. Konus-Wind detection of GRB 251222A / EP251222b
  4. GRB 251222A: Swift-XRT afterglow detection
  5. GRB 251222A / EP251222b: LCO detection of the optical counterpart
  6. EP251222a: NTT/ULTRACAM optical observations
  7. EP251222a: GOTO optical upper limit
  8. GRB 251222A / EP251222b: GOTO optical counterpart detection
  9. GRB 251222A / EP251222b: LCO optical observations
  10. GRB 251222A: 1.3m DFOT optical detection
  11. GRB251221A: 7DT optical upper limits
  12. EP251222a: GSP Optical Counterpart Detection
  13. GRB 251222A / EP251222b: VLT/X-shooter spectroscopic redshift z = 3.171
  14. GRB 251222A / EP251222b: SVOM/VT optical rebrightening
  15. EP251222b/GRB 251222A: SVOM/GRM observation
  16. EP251222b/GRB 251222A: Einstein Probe detection of an X-ray transient
  17. EP251222a: Einstein Probe detection of an X-ray transient
  18. The EP-WXT trigger 01709250397 is likely a flaring star
  19. EP251221a: Global MASTER-Net observations report
  20. GRB 251222A: PRIME near-infrared detection
  21. EP251221a: NOT optical upper limit
  22. GRB 251222A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  23. GRB 251222A: NOT optical observations
  24. IceCube-251218A: No Candidate Transients from the Zwicky Transient Facility
  25. IPN triangulation of GRB 251220B (short)
  26. GRB 251222A: Swift ToO observations
  27. GRB 251222A: BALROG localization (Fermi Trigger / GRB 251222712)
  28. GRB 251222A: SVOM/VT optical candidate
  29. GRB 251222A: SVOM detection of a long burst
  30. SVOM GRB251222A: Global MASTER-Net observations report
  31. GRB 251222A: Fermi GBM Final Real-time Localization
  32. EP251220a: PRIME upper limit
  33. EP251220a: VLT/FORS2 spectroscopic redshift z = 2.375
  34. GRB 251221A: PRIME near-infrared observation
  35. EP251220a: NOT optical observations
  36. EP251220a: FTW optical and NIR observations
  37. GRB 251221A: UAFO and Mondy optical upper limit
  38. GRB 251221A: Swift-XRT refined Analysis
  39. EP251221a: Einstein Probe detection of a fast X-ray transient
  40. GRB 251221A: Swift/UVOT Upper Limits
  41. GRB 251221A: Enhanced Swift-XRT position
  42. GRB 251221A: Fermi GBM Observation
  43. GRB 251221B: Fermi GBM Final Real-time Localization
  44. EP251220a: EP-FXT follow-up observation
  45. GRB 251220B: SVOM/GRM observation of a short burst
  46. EP251220a: COLIBRÍ confirmation of fading and photometric redshift upper limit of z < 3.4
  47. EP 251220a: GOTO optical counterpart detection
  48. GRB 251221A: COLIBRÍ detection of the optical counterpart
  49. EP 251220a: COLIBRÍ detection of the optical counterpart
  50. GRB 251221A: Swift detection of a burst
  51. Swift GRB251221A: Global MASTER-Net observations report
  52. GRB 251221A: Fermi GBM Final Real-time Localization
  53. EP251220a: Global MASTER-Net observations report
  54. EP251220a: EP detection of a fast X-ray transient
  55. SVOM GRB251220.98: Global MASTER-Net observations report
  56. GRB 251220B: Fermi GBM Final Real-time Localization
  57. GRB 251219A: SVOM/GRM observation of a short burst
  58. GRB 251219A: GECAM-B detection of a possible magnetar X-ray burst from SGR 1830-0645
  59. Fermi-LAT Gamma-ray Observations of IceCube-251218A
  60. GRB 251220A: MAXI/GSC detection
  61. GRB 251215A: Swift-XRT afterglow detection
  62. IceCube-251218A: Upper limits from a search for additional neutrino events in IceCube
  63. IceCube-251218A: COLIBRÍ optical upper limits
  64. SVOM GRB251219.11: Global MASTER-Net observations report
  65. IceCube-251218A - IceCube observation of a high-energy neutrino candidate track-like event
  66. IceCube Alert 251218.85: Global MASTER-Net observations report
  67. GRB 251214B: VIRT Optical Upper Limit
  68. Fermi trigger No 787736968: Global MASTER-Net observations report
  69. Fermi GRB 251217A: Global MASTER-Net observations report
  70. GRB 251217A: Fermi GBM Final Real-time Localization
  71. GRB 251215A: Swift/UVOT Upper LImits
  72. GRB 251215A: Fermi GBM Observation
  73. Fermi GRB 251216A: Global MASTER-Net observations report
  74. GRB 251202A/EP251202a: Koshka optical upper limit
  75. GRB 251214B: Mondy optical upper limit
  76. GRB 251215A: COLIBRÍ optical upper limit
  77. GRB 251216A: Fermi GBM Final Real-time Localization
  78. EP251214b: KAIT optical upper limit
  79. GRB 251215A: Swift-XRT observations
  80. Fermi GRB 251215A: Global MASTER-Net observations report
  81. EP251214a: Optical upper limit with Kinder observations
  82. GRB 251214B: 1.6m Mephisto observations with newly installed mosaic cameras
  83. GRB 251215A: Glowbug gamma-ray detection
  84. GRB 251214B: UAFO optical upper limit
  85. GRB 251214B: VLT/X-shooter observations
  86. GRB 251213A: GRID-10B observation
  87. GRB 251202A: radio detection with the VLA
  88. EP251214b: Global MASTER-Net observations report
  89. EP251214b : Einstein Probe detection of a fast X-ray transient
  90. EP251214b : Einstein Probe detection of a fast X-ray transient
  91. GRB 251214B: AbAO optical observations
  92. GRB 251214B: LCO detection of the optical counterpart
  93. GRB 251209A: GECAM-B observation of a long burst
  94. GRB 251214D: GECAM-B observation of a long burst
  95. GRB 251214B: Fermi GBM Observation
  96. GRB 251209A: Insight-HXMT/HE detection
  97. GRB 251215A: Swift ToO observations
  98. EP251214b (EP trigger 01709250023): LCO optical limits
  99. GRID detection of GRB 251213A
  100. GRB 251203B: AbAO optical observations

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