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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').
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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"

20502 results found.

  1. EP260623a: SVOM/VT optical observations
  2. EP260623a: TRT optical observations
  3. EP260623a: REM optical/NIR afterglow detection
  4. EP 260623a: COLIBRÍ optical observations
  5. EP260623a: Las Cumbres discovery of the optical counterpart
  6. EP260623a: Einstein Probe detection of an X-ray transient
  7. GRB 260614B: EP-FXT follow-up observation
  8. GRB 260618C: SVOM/ECLAIRs detection of a possible burst through on-ground search
  9. EP260618a: Liverpool Telescope optical observations
  10. GRB 260618B: LCO optical observations
  11. EP260618a: JinShan optical observations
  12. GRB 260616B/EP260616a: SVOM/GRM detection of a burst
  13. IceCube-Cascade 260618A: Upper limits from a search for additional neutrino events in IceCube
  14. GRB 260619A: TRT optical counterpart confirmation
  15. GRB 260610B: Further GRANDMA Optical Observations and re-brightening detection
  16. GRB 260610B: VLT/FORS2 spectroscopic observation suggests the non-thermal nature of the optical rebrightening
  17. Fermi-LAT Gamma-ray Observations of IceCube-260610A
  18. GRB 260619A: SVOM/COLIBRÍ (FM-GFT) optical counterpart candidate
  19. Konus-Wind detection of GRB 260617A
  20. GRB 260616A: AstroSat CZTI detection
  21. GRB 260616A: SVOM/GRM observation
  22. EP260618a: OHP/T193 optical observations
  23. GRB 260610B/AT2026owq: 1.3m DFOT optical rebrightening detection
  24. GRB 260619A: Kilonova-Catcher optical upper limit
  25. EP260618a: LCO optical counterpart confirmation
  26. EP260618a: COLIBRÍ optical counterpart candidate
  27. IceCube-260610A: Upper limits from a search for additional neutrino events in IceCube
  28. EP260618a: EP-WXT detection of an X-ray transient
  29. GRB 260610B: AbAO optical observations
  30. GRB 260616C: GECAM-B observation of a burst
  31. Konus-Wind detection of GRB 260616A
  32. EP260616a/GRB260616B: COLIBRÍ optical upper limit
  33. GRB 260610B / AT2026owq: SAO RAS optical observations of possible re-brightening
  34. GRB 260610B / AT 2026owq: COLIBRÍ further observations and confirmation of the rebrigthening
  35. EP260616a: EP-WXT detection of a fast X-ray transient
  36. GRB 260614B: SVOM/ECLAIRs refined analysis
  37. GRB 260610B: Terskol optical observations
  38. GRB 260610B: SVOM/GRM observation
  39. GRB 260614B: SVOM/VT optical candidate from VHF data
  40. GRB 260614B: SVOM detection of a burst
  41. GRB 260611B: SVOM/GRM detection
  42. GRB 260603C: AstroSat CZTI detection
  43. GRB 260610B: further Liverpool Telescope optical observations
  44. GRB 260610B / AT2026owq: GRANDMA optical observations
  45. GRB 260610B / AT2026owq: further SAO RAS optical observations
  46. EP260605a: COLIBRÍ optical upper limits
  47. GRB 260610b: Liverpool Telescope optical observations
  48. EP260610b: Liverpool Telescope optical upper limits
  49. The EP-WXT trigger 01709269176: SVOM/C-GFT confirmation of a stellar flare
  50. GRB 260610B / AT2026owq: SAO RAS optical observations
  51. GRB 260610B: optical counterpart shows spectroscopic redshift of z=0.473
  52. EP260610b: refined analysis of the EP-WXT and follow-up EP-FXT observations
  53. GRB 260610B / AT 2026owq: COLIBRÍ optical observations
  54. GRB 260610B / AT2026owq: Early ATLAS observations
  55. GRB 260610B: TRT optical observation
  56. EP260610a: refined analysis of the EP-WXT and follow-up EP-FXT observations
  57. EP260610b: COLIBRÍ optical observations
  58. GRB 260610B: DDOTI optical observations
  59. EP260610b: MAO/AZT-22 optical observations
  60. EP260610b: NOT optical observation
  61. EP260610b: SVOM/VT optical confirmation with blue color
  62. GRB 260515A: SOAR optical observations
  63. EP260610a: SVOM/VT optical upper limits
  64. EP260610b: Einstein Probe detection of an X-ray transient
  65. EP260610a: COLIBRÍ optical upper limits
  66. EP260610a: Einstein Probe detection of a fast X-ray transient
  67. Konus-Wind detection of GRB 260604C
  68. GRB 260604C: AstroSat CZTI detection
  69. GRB 260604C: SVOM/ECLAIRs refined analysis
  70. GRB 260608A: SVOM/ECLAIRs refined analysis
  71. Konus-Wind detection of GRB 260607B
  72. GRB 260604C: further SAO RAS optical observations
  73. GRB 260607A / GOTO26fqf / AT2026ong: COLIBRÍ optical observations
  74. GRB 260604C: SVOM/COLIBRÍ (FM-GFT) colour evolution and confirmation of the late rebrightening
  75. GRB 260604C: SVOM/C-GFT upper limit
  76. GRB 260607B: AstroSat CZTI detection
  77. EP260605a: EP-FXT follow-up observation
  78. GRB 260607A: TRT optical observations
  79. GRB 260604A: SVOM/GRM detection
  80. GRB 260604C: Mondy optical observations: evidence of a possible brightening
  81. GRB 260604C: Simeiz Zeiss-1000 optical observations of the afterglow
  82. GRB 260604C: OPD1.6m - GRANDMA observations - detection
  83. GRB 260604C: 6 GHz VLA observations
  84. GRB 260604C: SAO RAS optical observations
  85. GRB 260604B: SVOM/GRM detection
  86. GRB260603A: SVOM/ECLAIRs refined analysis
  87. EP260605a: Einstein Probe detection of a fast X-ray transient
  88. EP260603a: COLIBRÍ optical upper limit
  89. GRB 260604C: LCO optical upper limit
  90. EP260602d: EP-FXT follow-up observation
  91. EP260602c: EP-FXT follow-up observation
  92. GRB 260601B / EP260601a: AstroSat CZTI detection
  93. GRB 260527A/EP260527a: 6 GHz VLA observations
  94. GRB 260604C: Kilonova-Catcher optical afterglow detection
  95. GRB 260604C: SVOM/COLIBRÍ (FM-GFT) optical observations
  96. GRB 260604C: Jinshan optical observations
  97. EP260602d: J-band upper limit with WINTER
  98. EP260602b: J-band upper limit with WINTER
  99. GRB 260604C: LAST detection of optical counterpart candidate
  100. GRB 260604C: SVOM detection of a long burst

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