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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"

28247 results found.

  1. SVOM GRB261026.26: Global MASTER-Net observations report
  2. GRB 261026A: WINTER J-band observations
  3. GRB 261019A: SVOM/GRM observation
  4. Fermi GRB 261026B: Global MASTER-Net observations report
  5. GRB 261026A: SVOM/VT optical observation from VHF data
  6. GRB 261026A: KAIT optical observations
  7. GRB 261026A: SVOM/COLIBRÍ (FM-GFT) optical observations
  8. GRB 261024A: NuSTAR detection of prompt emission
  9. GRB 261026A: SVOM detection of a burst
  10. EP261025a: J-band upper limit with WINTER
  11. EP261023a: J-band upper limit with WINTER
  12. EP 261025a: COLIBRÍ optical upper limit
  13. EP261025a: Einstein Probe detection of a fast X-ray transient
  14. EP261023a: J band upper limit by SYSU 80cm infrared telescope
  15. EP261015a: VST optical observations
  16. GRB 261024A: BALROG localization (Fermi Trigger 814551785 / GRB 261024683)
  17. EP261023a: Mondy optical upper limit
  18. EP261015a: MAO/AZT-22 optical observations
  19. EP261015a: VLA non-detection
  20. EP261023a: NOT optical counterpart candidate
  21. EP261023a: Einstein Probe detection of an X-ray transient
  22. The EP-WXT trigger 01709321472 is likely a flaring star
  23. IceCube-261020A: Upper limits from a search for additional neutrino events in IceCube
  24. NuSTAR 261020, a 830s hard X-ray transient
  25. EP261015a: GSP multiband optical follow-up observations
  26. GRB 261017A: SVOM/GRM observation
  27. EP261015a: Further optical observations with the 1.3m DFOT
  28. GRB 261020B: AstroSat CZTI detection of a short burst
  29. Fermi-LAT Gamma-ray Observations of IceCube-261020A
  30. EP261015a: AZT-20 Assy-Turgen optical observations
  31. GRB 261020A: Fermi GBM Observation
  32. GRB 261017A: SAO RAS optical upper limit
  33. GRB 260903A
  34. EP261015a: Follow-up with the 1.3m DFOT
  35. EP261015a: Terskol Zeiss-2000 optical upper limit
  36. EP261007b: Further EP-FXT follow-up observations
  37. GRB 261017A: COLIBRÍ optical upper limit
  38. GRB 261020A: MAXI GSC detection
  39. EP261015a: COLIBRÍ optical observations of a rebrightening
  40. GRB 261017A: Possible Swift/UVOT Detection
  41. GRB 261017A: Luminance-band upper limit from a 28cm telescope in Chengde
  42. GRB 261017A: R-band upper limit with the 1.3-m DFOT
  43. GRB 261017A: Swift-BAT refined analysis
  44. EP261015b: NOT Optical Observations
  45. GRB 261017A: J band upper limit by the SYSU 80cm infrared telescope
  46. EP261015c: refined analysis of the EP-FXT observation favors a stellar flare interpretation
  47. GRB 261017A : MITSuME Akeno optical upper limits
  48. GRB 261017A: Swift-XRT refined Analysis
  49. GRB 261017A: Nanshan/NEXT optical upper limit
  50. GRB 261017A: Enhanced Swift-XRT position
  51. GRB 261017A: Fermi GBM Observation
  52. GRB 261017A: Swift detection of a burst
  53. EP261015a: Tentative fading of the candidate optical counterpart from the NOT
  54. EP261015b: Refined analysis of EP-FXT observations
  55. EP261015b: J-band upper limit by the SYSU 80cm infrared telescope
  56. EP261015a: refined analysis of EP-FXT observations
  57. EP261015c: J-band upper limit with WINTER
  58. EP261015a: J-band upper limit with WINTER
  59. EP261006a / AT 2026aetp: Optical follow-up with the 1.3-m DFOT
  60. GRB 261011A: 1.3m DFOT optical upper limit
  61. GRB 261010A: Pan-STARRS z-band imaging and upper limit
  62. EP261015a: SVOM/VT optical observation
  63. GRB 261010A: VLA radio observations
  64. EP261015a: COLIBRÍ optical observations
  65. EP261015c: Einstein Probe detection of a fast X-ray transient
  66. EP261015b: Einstein Probe detection of an X-ray transient
  67. EP261015a: Einstein Probe detection of a fast X-ray transient
  68. EP261015a (WXT 11900947714): Possible optical counterpart from NOT and LCO
  69. GRB 261010A: LBT tentative near-infrared detection
  70. GRB 261011A: SAO RAS and AbAO optical observations
  71. GRB 261010A: Glowbug gamma-ray detection
  72. GRB 261008A: SVOM/GRM observation
  73. GRB 261009A: GECAM-B detection of a burst
  74. EP261006a : MeerKAT radio observations.
  75. IceCube-261012A: Upper limits from a search for additional neutrino events in IceCube
  76. GRB 261010A: a short minimum variability timescale and a distinct pulse evolution compatible with a merger origin
  77. Fermi-LAT Gamma-ray Observations of IceCube-261012A
  78. GRB 261010A: J-band upper limit by the SYSU 80cm infrared telescope
  79. GRB 261010A: Swift-XRT refined Analysis
  80. GRB 261011A: Swift-XRT refined Analysis
  81. GRB 261011A: Enhanced Swift-XRT position
  82. GRB 261010A: a Type I-L (merger-driven) GRB candidate
  83. GRB 261011A: Swift-BAT refined analysis
  84. GRB 261010A: 10.4m GTC spectroscopy of the galaxy 2" from the afterglow
  85. MAXI GRB261012.23: Global MASTER-Net observations report
  86. GRB 261011A: REM optical/NIR observations
  87. GRB 261011A: SOAR optical afterglow observations at ~17 hours
  88. EP261006a: 10 GHz VLA observations
  89. GRB 261011A: VLT/X-shooter redshift constraints
  90. GRB 261012A: MAXI GSC detection
  91. GRB 261010A: Swift-BAT refined analysis
  92. GRB 261011A : MITSuME Akeno optical afterglow candidate detection
  93. GRB 261011A: Optical followup from Sichuan South Observatory
  94. GRB 261011A: GMG Optical Observation
  95. GRB 261011A: Liverpool Telescope optical observations
  96. GRB 261011A: J-band observations by the SYSU 80cm infrared telescope
  97. GRB 261010A: NOT confirmation of the optical afterglow
  98. GRB 261010A: Fermi GBM Observation
  99. GRB 261011A: continued LCO optical observations
  100. EP261007b: Global MASTER-Net observations report

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