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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"

28253 results found.

  1. EP251230a / GRB 251230A: refined analysis of the EP-WXT and EP-FXT observations
  2. GRB 251230A: Swift/UVOT detection
  3. GRB251230A: 7DT optical upper limits
  4. GRB 251230A: GOTO optical upper limit
  5. EP251229a: NOT optical upper limits
  6. GRB 251230A / EP251230a: SVOM/VT optical observation
  7. EP251229a: refined analysis of the EP-WXT and EP-FXT observations
  8. GRB 251230A: Enhanced Swift-XRT position
  9. GRB 251230A: Early optical counterpart detection by LCO.
  10. EP-WXT trigger 01709250662 Mephisto and 50cm telescope follow-up
  11. EP251230a / GRB 251230A: Einstein Probe detection of an X-ray transient
  12. LIGO/Virgo/KAGRA S251112cm: Candidates from the NSF-DOE Vera C. Rubin Observatory
  13. Swift GRB 251230A: Global MASTER-Net observations report
  14. EP251229a: Global MASTER-Net observations report
  15. EP251229a: Einstein Probe detection of an X-ray transient
  16. GRB 251230A: Swift detection of a burst with a bright optical counterpart
  17. GRB 251226A: Glowbug gamma-ray detection
  18. GRB 251222A/EP251222b: 1.6m Mephisto optical followup
  19. Fermi GRB 251228A: Global MASTER-Net observations report
  20. GRB 251226A: SVOM/GRM observation
  21. GRB 251226A: GECAM-B detection
  22. SVOM GRB251227.07: Global MASTER-Net observations report
  23. IceCube-251225A: Upper limits from a search for additional neutrino events in IceCube
  24. IceCube Alert 251225.84: Global MASTER-Net observations report
  25. GRB 251222A/EP251222b: Optical detection with Kinder observations
  26. EP251222a: Optical upper limit with Kinder observations
  27. GRB 251221A: Swift-BAT refined analysis
  28. GRB 251205A: Kilonova-Catcher optical afterglow detection
  29. GRB 251222A: AbAO optical observations
  30. GRB 251222A / EP251222b: Kilonova-Catcher optical afterglow detection
  31. GRB 251222A: ZTSH BVRI optical observations
  32. GRB 251222A: SVOM/COLIBRÍ (FM-GFT) optical observations
  33. GRB 251222A: Continued 1.3m DFOT optical observation
  34. EP251220a: 3.6m DOT optical afterglow detection
  35. GRB 251222A: Fermi GBM Observation
  36. EP251220a: CrAO ZTSh optical observations
  37. EP251221a: PRIME upper limit
  38. EP251222a: Global MASTER-Net observations report
  39. EP251221a: Liverpool Telescope upper limits
  40. EP251222a: refined analysis of the EP-WXT and EP-FXT observations
  41. EP251222b/GRB 251222A: refined analysis of the EP-WXT and EP-FXT observations
  42. GRB 251222A: Swift-XRT afterglow detection
  43. GRB 251222A / EP251222b: LCO detection of the optical counterpart
  44. EP251222a: NTT/ULTRACAM optical observations
  45. GRB 251222A / EP251222b: GOTO optical counterpart detection
  46. GRB 251222A / EP251222b: LCO optical observations
  47. GRB 251222A: 1.3m DFOT optical detection
  48. GRB251221A: 7DT optical upper limits
  49. EP251222a: GSP Optical Counterpart Detection
  50. EP251222b/GRB 251222A: Einstein Probe detection of an X-ray transient
  51. EP251222a: Einstein Probe detection of an X-ray transient
  52. EP251221a: Global MASTER-Net observations report
  53. GRB 251222A: PRIME near-infrared detection
  54. EP251221a: NOT optical upper limit
  55. GRB 251222A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  56. IceCube-251218A: No Candidate Transients from the Zwicky Transient Facility
  57. IPN triangulation of GRB 251220B (short)
  58. GRB 251222A: BALROG localization (Fermi Trigger / GRB 251222712)
  59. GRB 251222A: SVOM/VT optical candidate
  60. GRB 251222A: SVOM detection of a long burst
  61. SVOM GRB251222A: Global MASTER-Net observations report
  62. EP251220a: PRIME upper limit
  63. GRB 251221A: PRIME near-infrared observation
  64. GRB 251221A: UAFO and Mondy optical upper limit
  65. GRB 251221A: Swift-XRT refined Analysis
  66. EP251221a: Einstein Probe detection of a fast X-ray transient
  67. GRB 251221A: Swift/UVOT Upper Limits
  68. GRB 251221A: Enhanced Swift-XRT position
  69. GRB 251221A: Fermi GBM Observation
  70. GRB 251220B: SVOM/GRM observation of a short burst
  71. EP251220a: COLIBRÍ confirmation of fading and photometric redshift upper limit of z < 3.4
  72. EP 251220a: GOTO optical counterpart detection
  73. GRB 251221A: COLIBRÍ detection of the optical counterpart
  74. EP 251220a: COLIBRÍ detection of the optical counterpart
  75. GRB 251221A: Swift detection of a burst
  76. Swift GRB251221A: Global MASTER-Net observations report
  77. EP251220a: Global MASTER-Net observations report
  78. EP251220a: EP detection of a fast X-ray transient
  79. SVOM GRB251220.98: Global MASTER-Net observations report
  80. GRB 251219A: SVOM/GRM observation of a short burst
  81. GRB 251219A: GECAM-B detection of a possible magnetar X-ray burst from SGR 1830-0645
  82. Fermi-LAT Gamma-ray Observations of IceCube-251218A
  83. GRB 251220A: MAXI/GSC detection
  84. GRB 251215A: Swift-XRT afterglow detection
  85. IceCube-251218A: Upper limits from a search for additional neutrino events in IceCube
  86. IceCube-251218A: COLIBRÍ optical upper limits
  87. SVOM GRB251219.11: Global MASTER-Net observations report
  88. IceCube Alert 251218.85: Global MASTER-Net observations report
  89. GRB 251214B: VIRT Optical Upper Limit
  90. Fermi trigger No 787736968: Global MASTER-Net observations report
  91. Fermi GRB 251217A: Global MASTER-Net observations report
  92. GRB 251215A: Swift/UVOT Upper LImits
  93. GRB 251215A: Fermi GBM Observation
  94. Fermi GRB 251216A: Global MASTER-Net observations report
  95. GRB 251202A/EP251202a: Koshka optical upper limit
  96. GRB 251214B: Mondy optical upper limit
  97. GRB 251215A: COLIBRÍ optical upper limit
  98. EP251214b: KAIT optical upper limit
  99. GRB 251215A: Swift-XRT observations
  100. Fermi GRB 251215A: Global MASTER-Net observations report

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