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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"

32728 results found.

  1. GRB 251221A: Fermi GBM Observation
  2. EP251220a: EP-FXT follow-up observation
  3. GRB 251220B: SVOM/GRM observation of a short burst
  4. EP251220a: COLIBRÍ confirmation of fading and photometric redshift upper limit of z < 3.4
  5. EP 251220a: GOTO optical counterpart detection
  6. GRB 251221A: COLIBRÍ detection of the optical counterpart
  7. EP 251220a: COLIBRÍ detection of the optical counterpart
  8. EP251220a: Global MASTER-Net observations report
  9. GRB 251219A: SVOM/GRM observation of a short burst
  10. Fermi-LAT Gamma-ray Observations of IceCube-251218A
  11. IceCube-251218A: Upper limits from a search for additional neutrino events in IceCube
  12. IceCube-251218A: COLIBRÍ optical upper limits
  13. GRB 251214B: VIRT Optical Upper Limit
  14. Fermi GRB 251217A: Global MASTER-Net observations report
  15. GRB 251215A: Swift/UVOT Upper LImits
  16. GRB 251215A: Fermi GBM Observation
  17. Fermi GRB 251216A: Global MASTER-Net observations report
  18. GRB 251202A/EP251202a: Koshka optical upper limit
  19. GRB 251214B: Mondy optical upper limit
  20. GRB 251215A: COLIBRÍ optical upper limit
  21. EP251214b: KAIT optical upper limit
  22. Fermi GRB 251215A: Global MASTER-Net observations report
  23. EP251214a: Optical upper limit with Kinder observations
  24. GRB 251214B: 1.6m Mephisto observations with newly installed mosaic cameras
  25. GRB 251215A: Glowbug gamma-ray detection
  26. GRB 251214B: UAFO optical upper limit
  27. GRB 251214B: VLT/X-shooter observations
  28. GRB 251213A: GRID-10B observation
  29. GRB 251214B: Swift-BAT refined analysis
  30. GRB 251202A: radio detection with the VLA
  31. EP251214b: Global MASTER-Net observations report
  32. EP251214b : Einstein Probe detection of a fast X-ray transient
  33. EP251214b : Einstein Probe detection of a fast X-ray transient
  34. GRB 251214B: AbAO optical observations
  35. GRB 251214B: LCO detection of the optical counterpart
  36. GRB 251209A: GECAM-B observation of a long burst
  37. GRB 251214D: GECAM-B observation of a long burst
  38. GRB 251214B: Fermi GBM Observation
  39. GRB 251209A: Insight-HXMT/HE detection
  40. GRB 251215A: Swift ToO observations
  41. EP251214b (EP trigger 01709250023): LCO optical limits
  42. GRID detection of GRB 251213A
  43. GRB 251203B: AbAO optical observations
  44. GRB 251215A: Swift/BAT-GUANO arcminute localization of a burst
  45. GRB 251214B: GECAM-B observation of a long burst
  46. GRB 251213A: SVOM/GRM observation
  47. EP251214a: KAIT optical upper limit
  48. GRB 251213A: AstroSat CZTI detection
  49. GRB 251214A: AstroSat CZTI detection
  50. GRB 251214B: Swift/UVOT Detection
  51. GRB 251214B: COLIBRÍ observations of the afterglow
  52. EP251214a: EP-FXT non-detection and upper limit
  53. GRB 251214A: GECAM-B observation of a likely long burst
  54. GRB 251214B: 1.3m DFOT optical detection
  55. EP251214a: Global MASTER-Net observations report
  56. GRB 251214B: Xinglong-2.16m optical observation
  57. GRB 251214B : MASTER optical afterglow detection
  58. GRB 251214B: SVOM/C-GFT optical observations
  59. EP251214a: COLIBRÍ optical upper limit
  60. Swift GRB 251214B: Global MASTER-Net observations report
  61. EP251214a: EP-WXT detection of an X-ray transient possibly associated with GRB 251214A
  62. Fermi GRB 251214A: Global MASTER-Net observations report
  63. EP251212a: Global MASTER-Net observations report
  64. EP251212a: KAIT optical upper limit
  65. EP251212a / GRB 251212A: AstroSat CZTI detection
  66. EP251212a: EP-FXT follow-up observation
  67. GRB 251211B: AstroSat CZTI detection
  68. IceCube-251210A: No Candidate Transients from the Zwicky Transient Facility
  69. GRB 251209A: NuSTAR detection of prompt emission
  70. EP251212a : COLIBRÍ optical upper limit
  71. EP251212a: Einstein Probe detection of an X-ray transient
  72. Fermi-LAT Gamma-ray Observations of IceCube-251210A
  73. IceCube-251210A: Upper limits from a search for additional neutrino events in IceCube
  74. Fermi GRB 251211B: Global MASTER-Net observations report
  75. IceCube-251210A: DDOTI Optical Upper Limit
  76. GRB 251209A: Fermi GBM observation
  77. GRB 251205A: 1.3m DFOT optical upper limit
  78. GRB 251209A: AstroSat CZTI detection
  79. EP251124a: Mondy optical upper limit
  80. GRB 251129A/EP251129a: AbAO and Mondy optical observations
  81. EP251130a: Mondy and AbAO optical observations
  82. GRB 251208A: AstroSat CZTI detection
  83. Fermi GBM Sub-Threshold Detection of GRB 251205A
  84. GRB 251208A: Glowbug gamma-ray detection
  85. GRB 251208B: COLIBRÍ optical upper limits
  86. EP251118a / GRB 251118C: VLT/MUSE redshift confirmation
  87. GRB 251208C: GECAM-B observation of a short burst
  88. GRB 251208A: GECAM-B observation of a short burst
  89. Fermi GRB 251209A: Global MASTER-Net observations report
  90. Fermi GRB 251208C: Global MASTER-Net observations report
  91. GRB 251206A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  92. GRB 251208B: Swift-XRT afterglow detection
  93. GRB 251208D: LAST optical upper limit
  94. GRB 251208D: LCO analysis of the XRT sources
  95. GRB 251208B: Fermi GBM Observation
  96. GRB 251208B: GROWTH-India Telescope optical upper limits
  97. GRB 251205A: J-band detection with WINTER
  98. GRB 251208D: Swift-XRT observations
  99. GRB 251208A: SVOM/GRM observation of a short burst
  100. GRB 251208C: SVOM/GRM observation of a short burst

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