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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"

5152 results found.

  1. EP260223a: EP-FXT follow-up observation
  2. GRB 260223A: COLIBRÍ optical afterglow decay confirmation
  3. EP260223a: COLIBRÍ optical upper limits
  4. GRB 260223A: SVOM/VT optical observation
  5. EP260221a: Optical upper limit with Kinder observations
  6. GRB 260223A: DDOTI Optical Candidate
  7. Fermi GRB 260223A: Global MASTER-Net observations report
  8. IceCube Alert 260217A: Global MASTER-Net observations report
  9. GRB 260206A: probable hard X-ray burst from 4U 0513-40
  10. EP260214b: LCO optical counterpart detection
  11. EP260214b: VLT/X-shooter spectroscopic redshift z = 1.208
  12. GRB 260212A: GECAM-B observation
  13. GRB 260211A - SVOM/ECLAIRs refined analysis
  14. GRB 260210A: SVOM/GRM observation
  15. Fermi GBM Sub-Threshold Detection of GRB 260211A
  16. GRB 260211A: SVOM detection of a burst
  17. Konus-Wind detection of GRB 260209B
  18. Konus-Wind detection of GRB 260127B
  19. EP260210a: Global MASTER-Net observations report
  20. EP260210a: refined analysis of the EP-FXT observation
  21. GRB 260208B: AstroSat CZTI detection of a bright long burst
  22. Fermi GRB 260209A: Global MASTER-Net observations report
  23. Fermi GRB 260208D: Global MASTER-Net observations report
  24. Fermi GRB 260208A: Global MASTER-Net observations report
  25. GRB 260131A/B: Mondy and Terskol optical observations
  26. GRB 260206A: Swift-XRT observations
  27. Fermi trigger No 792135758: Global MASTER-Net observations report
  28. GRB 260206A (or XRB from 4U 0513-40): MAXI/GSC detection
  29. GRB 251230A: MeerLICHT afterglow detection
  30. GRB 260131A: NOT spectroscopic redshift z = 1.434
  31. EP260131a: COLIBRÍ observations of slow optical fading
  32. Fermi GRB 260130A: Global MASTER-Net observations report
  33. Fermi GRB 260129A: Global MASTER-Net observations report
  34. IceCube-260125A: Upper limits from a search for additional neutrino events in IceCube
  35. GRB 260127A: COLIBRÍ optical observations
  36. GRB 260125A: GOTO candidate optical counterpart
  37. GRB 260120A: AstroSat CZTI detection
  38. SVOM GRB260121.06: Global MASTER-Net observations report
  39. GRB 260120B: Swift detection of a burst
  40. EP260119a: Liverpool Telescope optical follow-up observations
  41. EP260119a: Global MASTER-Net observations report
  42. IceCube-260115A: Upper limits from a search for additional neutrino events in IceCube
  43. EP260116a: Einstein Probe detection of an X-ray transient
  44. Fermi GRB 260115A: Global MASTER-Net observations report
  45. GRB 251222A: radio detection with the VLA
  46. GRB 260114A: VLT/HAWK-I near-infrared upper limits
  47. GRB 260114A: Swift-XRT refined Analysis
  48. GRB 260109A: Fermi GBM Final Real-time Localization
  49. Fermi GRB 260107A: Global MASTER-Net observations report
  50. Fermi GRB 260105B: Global MASTER-Net observations report
  51. Fermi GRB 260104B: Global MASTER-Net observations report
  52. GRB 260104A: Swift-XRT refined Analysis
  53. GRB 260101A: Swift-XRT refined Analysis
  54. GRB 251230A/EP251230a: Optical upper limit with Kinder observations
  55. GRB 251230A: Swift-XRT refined Analysis
  56. EP251230a / GRB 251230A: refined analysis of the EP-WXT and EP-FXT observations
  57. EP251229a: Global MASTER-Net observations report
  58. GRB 251230A: Swift detection of a burst with a bright optical counterpart
  59. Fermi GRB 251228A: Global MASTER-Net observations report
  60. SVOM GRB251227.07: Global MASTER-Net observations report
  61. IceCube-251225A: Upper limits from a search for additional neutrino events in IceCube
  62. IceCube Alert 251225.84: Global MASTER-Net observations report
  63. EP251222a: Optical upper limit with Kinder observations
  64. GRB 251222A/EP251222b: FTW optical and NIR observations
  65. EP251222a: VLT/FORS2 spectroscopic redshift z = 0.505
  66. EP251222a: Global MASTER-Net observations report
  67. GRB 251222A: Swift-XRT afterglow detection
  68. IPN triangulation of GRB 251220B (short)
  69. GRB 251221A: Swift-XRT refined Analysis
  70. GRB 251221A: Fermi GBM Observation
  71. GRB 251221A: Swift detection of a burst
  72. GRB 251221A: Fermi GBM Final Real-time Localization
  73. GRB 251220A: MAXI/GSC detection
  74. Fermi GRB 251217A: Global MASTER-Net observations report
  75. Fermi GRB 251215A: Global MASTER-Net observations report
  76. EP251214a: Optical upper limit with Kinder observations
  77. GRB 251209A: GECAM-B observation of a long burst
  78. GRB 251214D: GECAM-B observation of a long burst
  79. GRB 251209A: Insight-HXMT/HE detection
  80. GRB 251214B: Swift-XRT refined Analysis
  81. GRB 251214D: AstroSat CZTI detection of a long burst
  82. Fermi trigger No 787396657: Global MASTER-Net observations report
  83. GRB 251214B: SVOM/C-GFT optical observations
  84. Fermi GRB 251214A: Global MASTER-Net observations report
  85. EP251212a: Global MASTER-Net observations report
  86. IceCube-251210A: No Candidate Transients from the Zwicky Transient Facility
  87. GRB 251209A: NuSTAR detection of prompt emission
  88. GRB 251209A: Fermi GBM observation
  89. GRB 251209A: AstroSat CZTI detection
  90. EP251124a: Mondy optical upper limit
  91. GRB 251209A: Fermi GBM Final Real-time Localization
  92. GRB 251203A: SVOM/GRM observation
  93. GRB 251202A / EP251202a: Liverpool Telescope optical follow-up observations
  94. GRB 251202A / EP251202a: SVOM/VT optical observation
  95. Fermi GRB 251202B: Global MASTER-Net observations report
  96. GRB 251202A: Swift-XRT afterglow detection
  97. GRB 251201B: Swift-XRT refined Analysis
  98. EP251118a: Mondy, CrAO, Assy and SAO RAS/Zeiss-1000 optical observations
  99. GRB 251201B: Fermi GBM Final Real-time Localization
  100. EP251130A: Optical observation from 1.3m DFOT

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