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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"

28254 results found.

  1. GRB 261026B: NuSTAR detection of prompt emission
  2. GRB 261024D: NuSTAR detection of prompt emission
  3. GRB 261024C: NuSTAR detection of prompt emission
  4. GRB 261026A: Ondrejov D50 optical limit
  5. GRB 261026A: ULL-ASTRO-MASTER optical detection with LCO 40-cm telescope at Haleakalā Observatory
  6. GRB 261026A: J-band observations by the SYSU 80cm infrared telescope
  7. SVOM GRB261026.26: Global MASTER-Net observations report
  8. GRB 261026A: WINTER J-band observations
  9. GRB 261019A: SVOM/GRM observation
  10. Fermi GRB 261026B: Global MASTER-Net observations report
  11. GRB 261026A: SVOM/VT optical observation from VHF data
  12. GRB 261026A: KAIT optical observations
  13. GRB 261026A: SVOM/COLIBRÍ (FM-GFT) optical observations
  14. GRB 261024A: NuSTAR detection of prompt emission
  15. GRB 261026A: SVOM detection of a burst
  16. EP261025a: J-band upper limit with WINTER
  17. EP261023a: J-band upper limit with WINTER
  18. EP 261025a: COLIBRÍ optical upper limit
  19. EP261025a: Einstein Probe detection of a fast X-ray transient
  20. EP261023a: J band upper limit by SYSU 80cm infrared telescope
  21. EP261015a: VST optical observations
  22. GRB 261024A: BALROG localization (Fermi Trigger 814551785 / GRB 261024683)
  23. EP261023a: Mondy optical upper limit
  24. EP261015a: MAO/AZT-22 optical observations
  25. EP261015a: VLA non-detection
  26. EP261023a: NOT optical counterpart candidate
  27. EP261023a: Einstein Probe detection of an X-ray transient
  28. The EP-WXT trigger 01709321472 is likely a flaring star
  29. IceCube-261020A: Upper limits from a search for additional neutrino events in IceCube
  30. NuSTAR 261020, a 830s hard X-ray transient
  31. EP261015a: GSP multiband optical follow-up observations
  32. GRB 261017A: SVOM/GRM observation
  33. EP261015a: Further optical observations with the 1.3m DFOT
  34. GRB 261020B: AstroSat CZTI detection of a short burst
  35. Fermi-LAT Gamma-ray Observations of IceCube-261020A
  36. EP261015a: AZT-20 Assy-Turgen optical observations
  37. GRB 261020A: Fermi GBM Observation
  38. GRB 261017A: SAO RAS optical upper limit
  39. GRB 260903A
  40. EP261015a: Follow-up with the 1.3m DFOT
  41. EP261015a: Terskol Zeiss-2000 optical upper limit
  42. EP261007b: Further EP-FXT follow-up observations
  43. GRB 261017A: COLIBRÍ optical upper limit
  44. GRB 261020A: MAXI GSC detection
  45. EP261015a: COLIBRÍ optical observations of a rebrightening
  46. GRB 261017A: Possible Swift/UVOT Detection
  47. GRB 261017A: Luminance-band upper limit from a 28cm telescope in Chengde
  48. GRB 261017A: R-band upper limit with the 1.3-m DFOT
  49. GRB 261017A: Swift-BAT refined analysis
  50. EP261015b: NOT Optical Observations
  51. GRB 261017A: J band upper limit by the SYSU 80cm infrared telescope
  52. EP261015c: refined analysis of the EP-FXT observation favors a stellar flare interpretation
  53. GRB 261017A : MITSuME Akeno optical upper limits
  54. GRB 261017A: Swift-XRT refined Analysis
  55. GRB 261017A: Nanshan/NEXT optical upper limit
  56. GRB 261017A: Enhanced Swift-XRT position
  57. GRB 261017A: Fermi GBM Observation
  58. GRB 261017A: Swift detection of a burst
  59. EP261015a: Tentative fading of the candidate optical counterpart from the NOT
  60. EP261015b: Refined analysis of EP-FXT observations
  61. EP261015b: J-band upper limit by the SYSU 80cm infrared telescope
  62. EP261015a: refined analysis of EP-FXT observations
  63. EP261015c: J-band upper limit with WINTER
  64. EP261015a: J-band upper limit with WINTER
  65. EP261006a / AT 2026aetp: Optical follow-up with the 1.3-m DFOT
  66. GRB 261011A: 1.3m DFOT optical upper limit
  67. GRB 261010A: Pan-STARRS z-band imaging and upper limit
  68. EP261015a: SVOM/VT optical observation
  69. GRB 261010A: VLA radio observations
  70. EP261015a: COLIBRÍ optical observations
  71. EP261015c: Einstein Probe detection of a fast X-ray transient
  72. EP261015b: Einstein Probe detection of an X-ray transient
  73. EP261015a: Einstein Probe detection of a fast X-ray transient
  74. EP261015a (WXT 11900947714): Possible optical counterpart from NOT and LCO
  75. GRB 261010A: LBT tentative near-infrared detection
  76. GRB 261011A: SAO RAS and AbAO optical observations
  77. GRB 261010A: Glowbug gamma-ray detection
  78. GRB 261008A: SVOM/GRM observation
  79. GRB 261009A: GECAM-B detection of a burst
  80. EP261006a : MeerKAT radio observations.
  81. IceCube-261012A: Upper limits from a search for additional neutrino events in IceCube
  82. GRB 261010A: a short minimum variability timescale and a distinct pulse evolution compatible with a merger origin
  83. Fermi-LAT Gamma-ray Observations of IceCube-261012A
  84. GRB 261010A: J-band upper limit by the SYSU 80cm infrared telescope
  85. GRB 261010A: Swift-XRT refined Analysis
  86. GRB 261011A: Swift-XRT refined Analysis
  87. GRB 261011A: Enhanced Swift-XRT position
  88. GRB 261010A: a Type I-L (merger-driven) GRB candidate
  89. GRB 261011A: Swift-BAT refined analysis
  90. GRB 261010A: 10.4m GTC spectroscopy of the galaxy 2" from the afterglow
  91. MAXI GRB261012.23: Global MASTER-Net observations report
  92. GRB 261011A: REM optical/NIR observations
  93. GRB 261011A: SOAR optical afterglow observations at ~17 hours
  94. EP261006a: 10 GHz VLA observations
  95. GRB 261011A: VLT/X-shooter redshift constraints
  96. GRB 261012A: MAXI GSC detection
  97. GRB 261010A: Swift-BAT refined analysis
  98. GRB 261011A : MITSuME Akeno optical afterglow candidate detection
  99. GRB 261011A: Optical followup from Sichuan South Observatory
  100. GRB 261011A: GMG Optical Observation

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