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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"

28237 results found.

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

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