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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"

32690 results found.

  1. The EP-WXT trigger 01709250693/GRB 251230A: Las Cumbres detection of the optical counterpart
  2. EP251229a: Global MASTER-Net observations report
  3. GRB 251226A: Glowbug gamma-ray detection
  4. GRB 251222A/EP251222b: 1.6m Mephisto optical followup
  5. GRB 251129A: redshift correction and SN detection at z = 0.505 with GTC
  6. Fermi GRB 251228A: Global MASTER-Net observations report
  7. GRB 251226A: SVOM/GRM observation
  8. IceCube-251225A: Upper limits from a search for additional neutrino events in IceCube
  9. GRB 251222A: NUTTelA-TAO Early Measurements
  10. GRB 251222A/EP251222b: Optical detection with Kinder observations
  11. EP251222a: Optical upper limit with Kinder observations
  12. GRB 251221A: Swift-BAT refined analysis
  13. GRB 251222A/EP251222b: FTW optical and NIR observations
  14. EP251222a: FTW optical and NIR observations
  15. GRB 251205A: Kilonova-Catcher optical afterglow detection
  16. GRB 251222A: AbAO optical observations
  17. GRB 251222A / EP251222b: Kilonova-Catcher optical afterglow detection
  18. GRB 251129A / EP251129a: VLA detection of a radio counterpart
  19. EP251222a: VLT/FORS2 spectroscopic redshift z = 0.505
  20. GRB 251222A: ZTSH BVRI optical observations
  21. GRB 251222A: SVOM/COLIBRÍ (FM-GFT) optical observations
  22. GRB 251222A: Continued 1.3m DFOT optical observation
  23. EP251220a: 3.6m DOT optical afterglow detection
  24. GRB 251222A: Fermi GBM Observation
  25. EP251220a: CrAO ZTSh optical observations
  26. EP251221a: PRIME upper limit
  27. EP251222a: Global MASTER-Net observations report
  28. GRB 251222A / EP251222b: GECAM-B observation
  29. EP251221a: Liverpool Telescope upper limits
  30. EP251222a: refined analysis of the EP-WXT and EP-FXT observations
  31. EP251222b/GRB 251222A: refined analysis of the EP-WXT and EP-FXT observations
  32. Konus-Wind detection of GRB 251222A / EP251222b
  33. GRB 251222A / EP251222b: LCO detection of the optical counterpart
  34. EP251222a: NTT/ULTRACAM optical observations
  35. EP251222a: GOTO optical upper limit
  36. GRB 251222A / EP251222b: GOTO optical counterpart detection
  37. GRB 251222A / EP251222b: LCO optical observations
  38. GRB 251222A: 1.3m DFOT optical detection
  39. GRB251221A: 7DT optical upper limits
  40. EP251222a: GSP Optical Counterpart Detection
  41. GRB 251222A / EP251222b: VLT/X-shooter spectroscopic redshift z = 3.171
  42. GRB 251222A / EP251222b: SVOM/VT optical rebrightening
  43. EP251222b/GRB 251222A: SVOM/GRM observation
  44. EP251222b/GRB 251222A: Einstein Probe detection of an X-ray transient
  45. EP251221a: Global MASTER-Net observations report
  46. GRB 251222A: PRIME near-infrared detection
  47. EP251221a: NOT optical upper limit
  48. GRB 251222A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  49. GRB 251222A: NOT optical observations
  50. IceCube-251218A: No Candidate Transients from the Zwicky Transient Facility
  51. IPN triangulation of GRB 251220B (short)
  52. GRB 251222A: Swift ToO observations
  53. GRB 251222A: SVOM/VT optical candidate
  54. GRB 251222A: SVOM detection of a long burst
  55. EP251220a: PRIME upper limit
  56. EP251220a: VLT/FORS2 spectroscopic redshift z = 2.375
  57. GRB 251221A: PRIME near-infrared observation
  58. EP251220a: NOT optical observations
  59. EP251220a: FTW optical and NIR observations
  60. GRB 251221A: UAFO and Mondy optical upper limit
  61. GRB 251221A: Swift/UVOT Upper Limits
  62. GRB 251221A: Fermi GBM Observation
  63. EP251220a: EP-FXT follow-up observation
  64. GRB 251220B: SVOM/GRM observation of a short burst
  65. EP251220a: COLIBRÍ confirmation of fading and photometric redshift upper limit of z < 3.4
  66. EP 251220a: GOTO optical counterpart detection
  67. GRB 251221A: COLIBRÍ detection of the optical counterpart
  68. EP 251220a: COLIBRÍ detection of the optical counterpart
  69. EP251220a: Global MASTER-Net observations report
  70. GRB 251219A: SVOM/GRM observation of a short burst
  71. Fermi-LAT Gamma-ray Observations of IceCube-251218A
  72. IceCube-251218A: Upper limits from a search for additional neutrino events in IceCube
  73. IceCube-251218A: COLIBRÍ optical upper limits
  74. GRB 251214B: VIRT Optical Upper Limit
  75. Fermi GRB 251217A: Global MASTER-Net observations report
  76. GRB 251215A: Swift/UVOT Upper LImits
  77. GRB 251215A: Fermi GBM Observation
  78. Fermi GRB 251216A: Global MASTER-Net observations report
  79. GRB 251202A/EP251202a: Koshka optical upper limit
  80. GRB 251214B: Mondy optical upper limit
  81. GRB 251215A: COLIBRÍ optical upper limit
  82. EP251214b: KAIT optical upper limit
  83. Fermi GRB 251215A: Global MASTER-Net observations report
  84. EP251214a: Optical upper limit with Kinder observations
  85. GRB 251214B: 1.6m Mephisto observations with newly installed mosaic cameras
  86. GRB 251215A: Glowbug gamma-ray detection
  87. GRB 251214B: UAFO optical upper limit
  88. GRB 251214B: VLT/X-shooter observations
  89. GRB 251213A: GRID-10B observation
  90. GRB 251214B: Swift-BAT refined analysis
  91. GRB 251202A: radio detection with the VLA
  92. EP251214b: Global MASTER-Net observations report
  93. EP251214b : Einstein Probe detection of a fast X-ray transient
  94. EP251214b : Einstein Probe detection of a fast X-ray transient
  95. GRB 251214B: AbAO optical observations
  96. GRB 251214B: LCO detection of the optical counterpart
  97. GRB 251209A: GECAM-B observation of a long burst
  98. GRB 251214D: GECAM-B observation of a long burst
  99. GRB 251214B: Fermi GBM Observation
  100. GRB 251209A: Insight-HXMT/HE detection

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