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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"

32569 results found.

  1. EP260110a: Global MASTER-Net observations report
  2. Fermi GRB 260111A: Global MASTER-Net observations report
  3. EP260110a: KAIT optical upper limit
  4. EP260110a: refined analysis of the EP-WXT and EP-FXT observations
  5. EP 260110a: COLIBRÍ optical observations
  6. EP260110a: SVOM/C-GFT upper limit
  7. EP260110a: BOOTES-5/JGU optical upper limit
  8. GRB 260109C: LCO optical upper limits
  9. GRB 260109C: Kilonova-Catcher optical upper limit
  10. EP260105b / GRB 260105C : Fermi-GBM Sub-Threshold Detection
  11. GRB 260104A: Swift-BAT refined analysis
  12. GRB 260101A: Swift-BAT refined analysis
  13. Swift GRB 251230A: Global MASTER-Net OT detection
  14. Fermi GRB 260107A: Global MASTER-Net observations report
  15. GRB 260102A: AbAO optical observations
  16. EP260105b/EP-WXT trigger 01709251028: Einstein Probe detection of an X-ray transient
  17. Fermi GRB 260105A: Global MASTER-Net observations report
  18. EP260105a: FTW optical observations
  19. EP260104a: FTW optical observations
  20. GRB 260105A: SVOM/GRM observation
  21. GRB 260105B: SVOM/GRM observation
  22. FRB 20251229A: COLIBRÍ optical upper limits
  23. Fermi GRB 260105B: Global MASTER-Net observations report
  24. EP260105a: SVOM/VT optical upperlimit
  25. EP260105a: refined analysis of the EP-WXT and EP-FXT observations
  26. EP260105a: LCO Optical Upper limit
  27. EP260104a: Global MASTER-Net observations report
  28. GRB 260101A: COLIBRÍ optical upper limits
  29. EP260105a: Global MASTER-Net observations report
  30. GRB 260103A: Insight-HXMT/HE detection
  31. GRB 260104A: COLIBRÍ optical upper limits
  32. Fermi GRB 260104B: Global MASTER-Net observations report
  33. Swift GRB 260104A: Global MASTER-Net observations report
  34. GRB 251230A/EP-WXT trigger 01709250693: Mephisto optical upper limits
  35. GRB 260101A: Swift/UVOT Detection
  36. GRB 260103A: GECAM-B observation of a burst
  37. Fermi-LAT Gamma-ray Observations of IceCube-251225A
  38. GRB 260101A: COLIBRÍ optical observations
  39. Fermi GBM Sub-Threshold Detection of GRB 260102A
  40. GRB 260102A: EP-FXT follow-up observation
  41. EP260101a: Global MASTER-Net observations report
  42. GRB 260102A: LCO optical upper limits
  43. GRB 260102A: Swift-XRT observations
  44. GRB 260102A: SVOM/COLIBRÍ (FM-GFT) optical observations
  45. GRB 251230A / EP251230a: GECAM-B detection
  46. GRB 260102A: SVOM/VT optical counterpart
  47. GRB 251230A / EP251230a: Insight-HXMT/HE detection
  48. GRB 260102A: Swift ToO observations
  49. GRB 260101A: Fermi GBM Observation
  50. EP260101a: refined analysis of the EP-WXT and EP-FXT observations
  51. GRB 260101A: GECAM-B detection
  52. GRB 260101A: NOT spectroscopic observations
  53. GRB 260101A: SVOM/GRM observation
  54. Swift GRB 260101A: Global MASTER-Net observations report
  55. GRB 260101A: OSIRIS+ redshift z = 2.623 for the new year burst
  56. GRB 260101A: LCO detection of the optical counterpart
  57. GRB 251230A / EP251230a: SVOM/VT optical continued observations and upper limit
  58. GRB 251230A: GRANDMA/TAROT Early Detection
  59. GRB 251230A / EP251230a: further NOT optical observations revealing shallower decay or possible rebrightening
  60. GRB 251230A/EP251230a: Optical upper limit with Kinder observations
  61. EP251229a: Optical upper limit with Kinder observations
  62. GRB 251230A: 1.3m DFOT optical upper limit
  63. GRB 251222A: Mondy Optical Observations
  64. EP251230a / GRB 251230A: refined analysis of the EP-WXT and EP-FXT observations
  65. GRB 251230A: Swift/UVOT detection
  66. GRB251230A: 7DT optical upper limits
  67. GRB 251230A / EP251230a: NOT observations and spectroscopic redshift upper limit z < 2.2
  68. EP251229a: BOOTES-2 early optical upper limit
  69. GRB 251230A: GOTO optical upper limit
  70. EP251229a: NOT optical upper limits
  71. GRB 251230A / EP251230a: SVOM/VT optical observation
  72. EP251229a: refined analysis of the EP-WXT and EP-FXT observations
  73. GRB 251230A: Early optical counterpart detection by LCO.
  74. EP-WXT trigger 01709250662 Mephisto and 50cm telescope follow-up
  75. GRB 251230A: Optical Observations via Virtual Telescope Project, Italy
  76. EP251230a / GRB 251230A: Einstein Probe detection of an X-ray transient
  77. GRB 251230A/EP#01709250693 (likely EP251230a): FTW optical and NIR observations
  78. LIGO/Virgo/KAGRA S251112cm: Candidates from the NSF-DOE Vera C. Rubin Observatory
  79. Swift GRB 251230A: Global MASTER-Net observations report
  80. The EP-WXT trigger 01709250693/GRB 251230A: Las Cumbres detection of the optical counterpart
  81. EP251229a: Global MASTER-Net observations report
  82. GRB 251226A: Glowbug gamma-ray detection
  83. GRB 251222A/EP251222b: 1.6m Mephisto optical followup
  84. GRB 251129A: redshift correction and SN detection at z = 0.505 with GTC
  85. Fermi GRB 251228A: Global MASTER-Net observations report
  86. GRB 251226A: SVOM/GRM observation
  87. IceCube-251225A: Upper limits from a search for additional neutrino events in IceCube
  88. GRB 251222A: NUTTelA-TAO Early Measurements
  89. GRB 251222A/EP251222b: Optical detection with Kinder observations
  90. EP251222a: Optical upper limit with Kinder observations
  91. GRB 251221A: Swift-BAT refined analysis
  92. GRB 251222A/EP251222b: FTW optical and NIR observations
  93. EP251222a: FTW optical and NIR observations
  94. GRB 251205A: Kilonova-Catcher optical afterglow detection
  95. GRB 251222A: AbAO optical observations
  96. GRB 251222A / EP251222b: Kilonova-Catcher optical afterglow detection
  97. GRB 251129A / EP251129a: VLA detection of a radio counterpart
  98. EP251222a: VLT/FORS2 spectroscopic redshift z = 0.505
  99. GRB 251222A: ZTSH BVRI optical observations
  100. GRB 251222A: SVOM/COLIBRÍ (FM-GFT) optical observations

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