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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

12082 results found.

  1. EP260210a: Mondy optical upper limits
  2. Konus-Wind detection of GRB 260212A
  3. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  4. EP260214b: Optical upper limit with Kinder observations
  5. EP260214a: Optical upper limits with Kinder observations
  6. EP260214b: EP-FXT follow-up observation
  7. EP260214a: COLIBRÍ optical upper limits
  8. EP260214a: refined analysis of the EP-FXT observation
  9. EP260214b: Einstein Probe detection of a fast X-ray transient
  10. EP260214a: Einstein Probe detection of an X-ray transient
  11. GRB 260212A: AstroSat CZTI detection
  12. EP260213a: Optical upper limits with Kinder observations
  13. EP260213a: Mondy R-band optical upper limit
  14. EP260213a: NUTTelA-TAO Early Optical Limits
  15. EP260213a: refined analysis of the EP-FXT observation
  16. EP260213a: Einstein Probe detection of a fast X-ray transient
  17. GRB 260211A: GOTO optical upper limit
  18. Konus-Wind detection of GRB 260207B
  19. GRB260131A/B: 3.6m DOT Optical Observations
  20. GRB 260211A: SVOM/COLIBRÍ (FM-GFT) optical upper limits
  21. GRB 260211A: SVOM detection of a burst
  22. Konus-Wind detection of GRB 260209B
  23. Konus-Wind detection of GRB 260127B
  24. EP260210a: Global MASTER-Net observations report
  25. EP260210a: refined analysis of the EP-FXT observation
  26. EP260209a: Einstein Probe detection of a fast X-ray transient
  27. EP260210a: Optical upper limits with Kinder observations
  28. GRB 260208C: AstroSat CZTI detection
  29. EP260210a: COLIBRÍ optical upper limit
  30. EP260210a: Einstein Probe detection of an X-ray transient
  31. GRB 260207B: AstroSat CZTI detection
  32. GRB 260208B: AstroSat CZTI detection of a bright long burst
  33. Fermi GRB 260209A: Global MASTER-Net observations report
  34. GRB 260208A: Mondy optical observations
  35. GRB 260208A: 1.3m DFOT optical detection
  36. GRB 260208B: EP-FXT observation
  37. Fermi GRB 260208C: Global MASTER-Net observations report
  38. GRB 260208B: Fermi-LAT detection
  39. GRB 260208A: Fermi-LAT detection
  40. Fermi trigger No 792135758: Global MASTER-Net observations report
  41. GRB 260206A (or XRB from 4U 0513-40): MAXI/GSC detection
  42. GRB 260204A: Swift-XRT observations
  43. GRB 260204A : MASTER Global robotic net optical observations
  44. GRB 260204A: SVOM detection of a burst
  45. GRB 260121A: 239Alferov CubeSat detection
  46. Konus-Wind detection of GRB 260121A
  47. GRB 260131A/B: GTC/OSIRIS+ redshift confimation
  48. GRB 260131A/B: EP/FXT X-ray afterglow detection
  49. Konus-Wind detection of GRB 260128A / EP260128a
  50. Konus-Wind detection of GRB 260131A/B
  51. GRB 260131A/B: GOTO candidate optical counterpart consistent with the MAXI localisation
  52. EP260131a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  53. GRB 260131B: MAXI/GSC detection
  54. GRB 260127B: AstroSat CZTI detection
  55. GRB 260130A: Fermi GBM Detection
  56. EP260131a: Einstein Probe detection of an X-ray transient
  57. GRB 260127B: Fermi GBM Detection
  58. GRB 260130A: Fermi GBM Final Real-time Localization
  59. EP260128a: J band upper limit by SYSU 80cm infrared telescope
  60. GRB 260127A: Swift-BAT refined analysis
  61. GRB 260128B: SVOM detection of a burst through offline search
  62. IPN triangulation of GRB 260127B (short)
  63. GRB 260127A: INASAN-Kislovodsk, SAO RAS, and Terskol K-800 optical observations
  64. EP260128a: refined analysis of the EP-WXT and autonomous EP-FXT observations
  65. EP260128a: Einstein Probe detection of an X-ray transient
  66. Fermi GRB 260127A: Global MASTER-Net observations report
  67. GRB 260127A: Swift-XRT refined Analysis
  68. GRB 260127B: GOTO candidate optical counterpart
  69. Fermi GRB 260127B: Global MASTER-Net observations report
  70. GRB 260127B: Fermi GBM Final Real-time Localization
  71. GRB 260127A: Swift detection of a burst
  72. EP260126a: Optical upper limit with Kinder observations
  73. EP260126a: Einstein Probe detection of a fast X-ray transient
  74. Fermi-LAT Gamma-ray Observations of IceCube-260125A
  75. Konus-Wind detection of GRB 260120B
  76. GRB 260120A: AstroSat CZTI detection
  77. GRB 260122B: Swift-BAT refined analysis
  78. GRB 260120B: AstroSat CZTI detection
  79. EP260119a: Assy AZT-20 optical observations
  80. EP260119a: Mondy and SAO RAS optical upper limits
  81. Fermi GRB 260120C: Global MASTER-Net observations report
  82. GRB 260120B: Swift-XRT refined Analysis
  83. GRB 260120B: Fermi GBM Observation
  84. SVOM GRB260121.06: Global MASTER-Net observations report
  85. GRB 260120C: Fermi GBM Final Real-time Localization
  86. GRB 260101A: 239Alferov CubeSat detection
  87. EP260116a: COLIBRÍ observations of a tentative optical rebrightening
  88. Swift GRB260120B: Global MASTER-Net observations report
  89. GRB 260120B: Fermi GBM Final Real-time Localization
  90. Fermi trigger No 790601190: Global MASTER-Net observations report
  91. Fermi trigger No 790570272: Global MASTER-Net observations report
  92. GRB 260120A: Fermi GBM Final Real-time Localization
  93. EP260119a: update of EP-FXT follow-up observation
  94. SVOM GRB260119.90: Global MASTER-Net observations report
  95. EP260116a: COLIBRÍ detection of a fading optical source
  96. EP260119a: Global MASTER-Net observations report
  97. GRB 260117A: ZTSh optical upper limit
  98. EP260119a: COLIBRÍ optical counterpart candidate
  99. EP260119a: preliminary result from the EP-FXT observation
  100. GRB 260110A: SVOM detection of a burst through offline search

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