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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"

28241 results found.

  1. GRB 261026A: KAIT optical observations
  2. GRB 261026A: SVOM/COLIBRÍ (FM-GFT) optical observations
  3. GRB 261024A: NuSTAR detection of prompt emission
  4. GRB 261026A: SVOM detection of a burst
  5. EP261025a: J-band upper limit with WINTER
  6. EP261023a: J-band upper limit with WINTER
  7. EP 261025a: COLIBRÍ optical upper limit
  8. EP261025a: Einstein Probe detection of a fast X-ray transient
  9. EP261023a: J band upper limit by SYSU 80cm infrared telescope
  10. EP261015a: VST optical observations
  11. GRB 261024A: BALROG localization (Fermi Trigger 814551785 / GRB 261024683)
  12. EP261023a: Mondy optical upper limit
  13. EP261015a: MAO/AZT-22 optical observations
  14. EP261015a: VLA non-detection
  15. EP261023a: NOT optical counterpart candidate
  16. EP261023a: Einstein Probe detection of an X-ray transient
  17. The EP-WXT trigger 01709321472 is likely a flaring star
  18. IceCube-261020A: Upper limits from a search for additional neutrino events in IceCube
  19. NuSTAR 261020, a 830s hard X-ray transient
  20. EP261015a: GSP multiband optical follow-up observations
  21. GRB 261017A: SVOM/GRM observation
  22. EP261015a: Further optical observations with the 1.3m DFOT
  23. GRB 261020B: AstroSat CZTI detection of a short burst
  24. Fermi-LAT Gamma-ray Observations of IceCube-261020A
  25. EP261015a: AZT-20 Assy-Turgen optical observations
  26. GRB 261020A: Fermi GBM Observation
  27. GRB 261017A: SAO RAS optical upper limit
  28. GRB 260903A
  29. EP261015a: Follow-up with the 1.3m DFOT
  30. EP261015a: Terskol Zeiss-2000 optical upper limit
  31. EP261007b: Further EP-FXT follow-up observations
  32. GRB 261017A: COLIBRÍ optical upper limit
  33. GRB 261020A: MAXI GSC detection
  34. EP261015a: COLIBRÍ optical observations of a rebrightening
  35. GRB 261017A: Possible Swift/UVOT Detection
  36. GRB 261017A: Luminance-band upper limit from a 28cm telescope in Chengde
  37. GRB 261017A: R-band upper limit with the 1.3-m DFOT
  38. GRB 261017A: Swift-BAT refined analysis
  39. EP261015b: NOT Optical Observations
  40. GRB 261017A: J band upper limit by the SYSU 80cm infrared telescope
  41. EP261015c: refined analysis of the EP-FXT observation favors a stellar flare interpretation
  42. GRB 261017A : MITSuME Akeno optical upper limits
  43. GRB 261017A: Swift-XRT refined Analysis
  44. GRB 261017A: Nanshan/NEXT optical upper limit
  45. GRB 261017A: Enhanced Swift-XRT position
  46. GRB 261017A: Fermi GBM Observation
  47. GRB 261017A: Swift detection of a burst
  48. EP261015a: Tentative fading of the candidate optical counterpart from the NOT
  49. EP261015b: Refined analysis of EP-FXT observations
  50. EP261015b: J-band upper limit by the SYSU 80cm infrared telescope
  51. EP261015a: refined analysis of EP-FXT observations
  52. EP261015c: J-band upper limit with WINTER
  53. EP261015a: J-band upper limit with WINTER
  54. EP261006a / AT 2026aetp: Optical follow-up with the 1.3-m DFOT
  55. GRB 261011A: 1.3m DFOT optical upper limit
  56. GRB 261010A: Pan-STARRS z-band imaging and upper limit
  57. EP261015a: SVOM/VT optical observation
  58. GRB 261010A: VLA radio observations
  59. EP261015a: COLIBRÍ optical observations
  60. EP261015c: Einstein Probe detection of a fast X-ray transient
  61. EP261015b: Einstein Probe detection of an X-ray transient
  62. EP261015a: Einstein Probe detection of a fast X-ray transient
  63. EP261015a (WXT 11900947714): Possible optical counterpart from NOT and LCO
  64. GRB 261010A: LBT tentative near-infrared detection
  65. GRB 261011A: SAO RAS and AbAO optical observations
  66. GRB 261010A: Glowbug gamma-ray detection
  67. GRB 261008A: SVOM/GRM observation
  68. GRB 261009A: GECAM-B detection of a burst
  69. EP261006a : MeerKAT radio observations.
  70. IceCube-261012A: Upper limits from a search for additional neutrino events in IceCube
  71. GRB 261010A: a short minimum variability timescale and a distinct pulse evolution compatible with a merger origin
  72. Fermi-LAT Gamma-ray Observations of IceCube-261012A
  73. GRB 261010A: J-band upper limit by the SYSU 80cm infrared telescope
  74. GRB 261010A: Swift-XRT refined Analysis
  75. GRB 261011A: Swift-XRT refined Analysis
  76. GRB 261011A: Enhanced Swift-XRT position
  77. GRB 261010A: a Type I-L (merger-driven) GRB candidate
  78. GRB 261011A: Swift-BAT refined analysis
  79. GRB 261010A: 10.4m GTC spectroscopy of the galaxy 2" from the afterglow
  80. MAXI GRB261012.23: Global MASTER-Net observations report
  81. GRB 261011A: REM optical/NIR observations
  82. GRB 261011A: SOAR optical afterglow observations at ~17 hours
  83. EP261006a: 10 GHz VLA observations
  84. GRB 261011A: VLT/X-shooter redshift constraints
  85. GRB 261012A: MAXI GSC detection
  86. GRB 261010A: Swift-BAT refined analysis
  87. GRB 261011A : MITSuME Akeno optical afterglow candidate detection
  88. GRB 261011A: Optical followup from Sichuan South Observatory
  89. GRB 261011A: GMG Optical Observation
  90. GRB 261011A: Liverpool Telescope optical observations
  91. GRB 261011A: J-band observations by the SYSU 80cm infrared telescope
  92. GRB 261010A: NOT confirmation of the optical afterglow
  93. GRB 261010A: Fermi GBM Observation
  94. GRB 261011A: continued LCO optical observations
  95. EP261007b: Global MASTER-Net observations report
  96. GRB 261011A: GROWTH-India Telescope optical observations
  97. GRB 261011A: Luminance-band upper limit from a 28cm telescope in Chengde
  98. Swift GRB 261011A: Global MASTER-Net observations report
  99. GRB 261011A: Optical follow-up observations with Kinder
  100. GRB 261011A: SVOM/C-GFT optical observations

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