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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"

32580 results found.

  1. GRB 251222A/EP251222b: Optical detection with Kinder observations
  2. EP251222a: Optical upper limit with Kinder observations
  3. GRB 251221A: Swift-BAT refined analysis
  4. GRB 251222A/EP251222b: FTW optical and NIR observations
  5. EP251222a: FTW optical and NIR observations
  6. GRB 251205A: Kilonova-Catcher optical afterglow detection
  7. GRB 251222A: AbAO optical observations
  8. GRB 251222A / EP251222b: Kilonova-Catcher optical afterglow detection
  9. GRB 251129A / EP251129a: VLA detection of a radio counterpart
  10. EP251222a: VLT/FORS2 spectroscopic redshift z = 0.505
  11. GRB 251222A: ZTSH BVRI optical observations
  12. GRB 251222A: SVOM/COLIBRÍ (FM-GFT) optical observations
  13. GRB 251222A: Continued 1.3m DFOT optical observation
  14. EP251220a: 3.6m DOT optical afterglow detection
  15. GRB 251222A: Fermi GBM Observation
  16. EP251220a: CrAO ZTSh optical observations
  17. EP251221a: PRIME upper limit
  18. EP251222a: Global MASTER-Net observations report
  19. GRB 251222A / EP251222b: GECAM-B observation
  20. EP251221a: Liverpool Telescope upper limits
  21. EP251222a: refined analysis of the EP-WXT and EP-FXT observations
  22. EP251222b/GRB 251222A: refined analysis of the EP-WXT and EP-FXT observations
  23. Konus-Wind detection of GRB 251222A / EP251222b
  24. GRB 251222A / EP251222b: LCO detection of the optical counterpart
  25. EP251222a: NTT/ULTRACAM optical observations
  26. EP251222a: GOTO optical upper limit
  27. GRB 251222A / EP251222b: GOTO optical counterpart detection
  28. GRB 251222A / EP251222b: LCO optical observations
  29. GRB 251222A: 1.3m DFOT optical detection
  30. GRB251221A: 7DT optical upper limits
  31. EP251222a: GSP Optical Counterpart Detection
  32. GRB 251222A / EP251222b: VLT/X-shooter spectroscopic redshift z = 3.171
  33. GRB 251222A / EP251222b: SVOM/VT optical rebrightening
  34. EP251222b/GRB 251222A: SVOM/GRM observation
  35. EP251222b/GRB 251222A: Einstein Probe detection of an X-ray transient
  36. EP251221a: Global MASTER-Net observations report
  37. GRB 251222A: PRIME near-infrared detection
  38. EP251221a: NOT optical upper limit
  39. GRB 251222A: Calapai Observatory, Massa S. Giorgio (Messina), optical observation.
  40. GRB 251222A: NOT optical observations
  41. IceCube-251218A: No Candidate Transients from the Zwicky Transient Facility
  42. IPN triangulation of GRB 251220B (short)
  43. GRB 251222A: Swift ToO observations
  44. GRB 251222A: SVOM/VT optical candidate
  45. GRB 251222A: SVOM detection of a long burst
  46. EP251220a: PRIME upper limit
  47. EP251220a: VLT/FORS2 spectroscopic redshift z = 2.375
  48. GRB 251221A: PRIME near-infrared observation
  49. EP251220a: NOT optical observations
  50. EP251220a: FTW optical and NIR observations
  51. GRB 251221A: UAFO and Mondy optical upper limit
  52. GRB 251221A: Swift/UVOT Upper Limits
  53. GRB 251221A: Fermi GBM Observation
  54. EP251220a: EP-FXT follow-up observation
  55. GRB 251220B: SVOM/GRM observation of a short burst
  56. EP251220a: COLIBRÍ confirmation of fading and photometric redshift upper limit of z < 3.4
  57. EP 251220a: GOTO optical counterpart detection
  58. GRB 251221A: COLIBRÍ detection of the optical counterpart
  59. EP 251220a: COLIBRÍ detection of the optical counterpart
  60. EP251220a: Global MASTER-Net observations report
  61. GRB 251219A: SVOM/GRM observation of a short burst
  62. Fermi-LAT Gamma-ray Observations of IceCube-251218A
  63. IceCube-251218A: Upper limits from a search for additional neutrino events in IceCube
  64. IceCube-251218A: COLIBRÍ optical upper limits
  65. GRB 251214B: VIRT Optical Upper Limit
  66. Fermi GRB 251217A: Global MASTER-Net observations report
  67. GRB 251215A: Swift/UVOT Upper LImits
  68. GRB 251215A: Fermi GBM Observation
  69. Fermi GRB 251216A: Global MASTER-Net observations report
  70. GRB 251202A/EP251202a: Koshka optical upper limit
  71. GRB 251214B: Mondy optical upper limit
  72. GRB 251215A: COLIBRÍ optical upper limit
  73. EP251214b: KAIT optical upper limit
  74. Fermi GRB 251215A: Global MASTER-Net observations report
  75. EP251214a: Optical upper limit with Kinder observations
  76. GRB 251214B: 1.6m Mephisto observations with newly installed mosaic cameras
  77. GRB 251215A: Glowbug gamma-ray detection
  78. GRB 251214B: UAFO optical upper limit
  79. GRB 251214B: VLT/X-shooter observations
  80. GRB 251213A: GRID-10B observation
  81. GRB 251214B: Swift-BAT refined analysis
  82. GRB 251202A: radio detection with the VLA
  83. EP251214b: Global MASTER-Net observations report
  84. EP251214b : Einstein Probe detection of a fast X-ray transient
  85. EP251214b : Einstein Probe detection of a fast X-ray transient
  86. GRB 251214B: AbAO optical observations
  87. GRB 251214B: LCO detection of the optical counterpart
  88. GRB 251209A: GECAM-B observation of a long burst
  89. GRB 251214D: GECAM-B observation of a long burst
  90. GRB 251214B: Fermi GBM Observation
  91. GRB 251209A: Insight-HXMT/HE detection
  92. GRB 251215A: Swift ToO observations
  93. EP251214b (EP trigger 01709250023): LCO optical limits
  94. GRID detection of GRB 251213A
  95. GRB 251203B: AbAO optical observations
  96. GRB 251215A: Swift/BAT-GUANO arcminute localization of a burst
  97. GRB 251214B: GECAM-B observation of a long burst
  98. GRB 251213A: SVOM/GRM observation
  99. EP251214a: KAIT optical upper limit
  100. GRB 251213A: AstroSat CZTI detection

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