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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"

23608 results found.

  1. GRB 260421B: Kilonova-Catcher optical afterglow detection
  2. The EP-WXT trigger 01709258652: Mondy optical observations
  3. GRB 260421B: SVOM/ECLAIRs refined analysis
  4. EP260416a: ZTSh R band observations
  5. GRB 260419A: AstroSat CZTI detection
  6. GRB 260421B: J-band upper limit with WINTER
  7. GRB 260421B: LCO optical counterpart detection
  8. GRB 260421A: AstroSat CZTI detection
  9. GRB 260412A: SVOM/ECLAIRs refined analysis
  10. GRB 260415A: CALET Gamma-Ray Burst Monitor detection
  11. GRB 260415B: CALET Gamma-Ray Burst Monitor detection
  12. GRB 260421B: BOOTES-7 early optical afterglow detection
  13. GRB 260421B: SVOM/COLIBRÍ (FM-GFT) optical detection of a candidate counterpart
  14. GRB 260421B: TRT optical counterpart detection
  15. EP260321a: VLA radio follow-up
  16. EP260416a: Optical follow-up observations with Kinder
  17. EP-WXT trigger 01709260303: KAIT optical observations
  18. EP260416a: 1.5m OSN and 2.2m CAHA optical monitoring
  19. EP260416a: Ondrejov D50 optical detection
  20. Konus-Wind detection of GRB 260411B
  21. GRB 260417A: AstroSat CZTI detection
  22. IPN triangulation of GRB 260411B
  23. EP260324a / AT2026hir: Further multiband optical follow-up with the PKU 60cm Telescope
  24. EP260417a: TRT optical counterpart detection
  25. EP260416a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  26. EP-WXT trigger 01709259586: KAIT optical observations
  27. EP260416a: KAIT optical upper limit
  28. EP260416a: COLIBRÍ confirmation of the optical rebrightening
  29. GRB 260415B: Glowbug gamma-ray detection
  30. GRB 260411B: Glowbug gamma-ray detection
  31. EP260416a: COLIBRÍ optical counterpart candidate
  32. COLIBRI optical observations of the transient GOTO26djh/AT2026jpw
  33. EP260416a: Einstein Probe detection of an X-ray transient
  34. GOTO discovery of fast-fading transient GOTO26djh/AT2026jpw, a candidate orphan afterglow
  35. GRB 260414A: Glowbug gamma-ray detection
  36. EP260321a: CMO SAI J,K observations
  37. GRB 260412A: Insight-HXMT/HE detection
  38. GRB 260410A: Glowbug gamma-ray detection of a short burst
  39. Konus-Wind detection of GRB 260410A (short/hard)
  40. GRB 260410A: CALET Gamma-Ray Burst Monitor detection
  41. GRB 260412A: GECAM-B observation of a long burst
  42. GRB 260411B: COLIBRÍ optical observations
  43. GRB 260411B: Ondrejov D50 optical afterglow detection
  44. GRB 260409A: Insight-HXMT/HE detection
  45. GRB 260411B: GOTO optical counterpart candidate
  46. GRB 260410A: COLIBRÍ optical upper limit
  47. EP-WXT01709259790: Optical Upper limits with kinder observations
  48. The EP-WXT trigger 01709259790 is likely a flaring star
  49. EP-WXT01709259790: Xinglong optical upper limit
  50. GRB 260310A/AT2026fgk: Kilonova-Catcher SN peak identification
  51. GRB 260407A: GECAM-A detection
  52. GRB 260407A: Insight-HXMT/HE detection
  53. EP260409a: COLIBRÍ optical upper limits
  54. GRB 260407A: CALET Gamma-Ray Burst Monitor detection
  55. EP260321a: VLA radio detection
  56. GRB 260407A: Glowbug gamma-ray detection
  57. GRB 260402A: SVOM/ECLAIRs refined analysis
  58. GRB 260310A: Continued VLA Multi-frequency Radio Observations
  59. GRB 260310A / AT2026fgk: X-ray rebrightening
  60. EP260402a / GRB 260402A: Mephisto optical upper limits
  61. EP-WXT01709259586: Xinglong optical upper limit
  62. EP260403a: Mephisto optical upper limits
  63. EP260402a/GRB 260402A: Xinglong optical upper limit
  64. EP260321a: Upper limits from VLA radio observations
  65. EP260405a / EP-WXT 11900672904: COLIBRÍ optical upper limits
  66. EP260324A / AT 2026hir: COLIBRÍ further optical observations
  67. GRB 260330B: SVOM/ECLAIRs refined analysis
  68. EP260403a: LCO optical observations of the counterpart
  69. GRB 260310A/AT2026fgk: Kilonova-Catcher long term optical monitoring
  70. EP260403a: LCO optical counterpart detection
  71. EP260403a: COLIBRÍ optical counterpart candidate
  72. GRB 260403A: AstroSat CZTI detection
  73. GRB 260402C: AstroSat CZTI detection of a long burst
  74. EP260324A / AT 2026hir: COLIBRÍ optical observations
  75. GRB 260402A: WINTER J-band upper limit
  76. GRB 260402A: Kilonova-Catcher optical upper limit
  77. GRB 260402A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  78. GRB 260402A: SVOM detection of a burst
  79. GRB 260401A: Fermi GBM Observation
  80. GRB 260401A: CALET Gamma-Ray Burst Monitor detection
  81. GRB 260401A: MAXI/GSC detection
  82. EP260329b: Mondy and Assy-Turgen optical upper limits
  83. EP260321a :Xinglong optical observations
  84. EP260327a: Xinglong optical upper limit
  85. EP260329b: GOTO detection of optical counterpart
  86. Konus-Wind detection of GRB 260320A
  87. Konus-Wind detection of GRB 260316B
  88. GRB 260321A: SVOM/ECLAIRs refined analysis
  89. EP260329b: J-band upper limits with WINTER
  90. EP260329a: J-band upper limit with WINTER
  91. GRB 260330A: Glowbug gamma-ray detection
  92. GRB 260310A: VLA Multi-frequency Radio Observations
  93. EP260329a: COLIBRÍ optical upper limit
  94. EP260329a: NOT optical counterpart candidate
  95. GRB 260327A: Insight-HXMT/HE detection
  96. EP260329b: Optical follow-up with Kinder observations
  97. EP 260329b: COLIBRÍ optical observations
  98. EP260329a: Optical upper limit with Kinder observations
  99. EP260329b: LCO optical observations of the counterpart
  100. EP-WXT trigger 01709259209: TRT optical counterpart detection

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