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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"

18511 results found.

  1. GRB 261029A / AT 2026ahaw: Optical upper limits from the PKU 60cm Telescope
  2. GRB 261024D: SVOM/GRM observation
  3. GRB 261026A: Mondy, SAO RAS and Terskol optical observations
  4. GRB 261029A : SVOM/GWAC-F60 observations
  5. The EP-WXT trigger 01709321980 is likely a flaring star
  6. GRB 261029A: WFST optical observations
  7. GRB 261029A: ULL-ASTRO-MASTER observations with LCO 1-m telescope at Siding Spring Observatory
  8. GRB 261029A: Ondrejov D50 optical observations, possible rebrightening
  9. GRB 261029A: Optical detection with 60cm Panzhihua Telescope
  10. GRB261029A: Infrared fading detected with MDM/MIRAGE
  11. GRB 261029A: SVOM/VT optical observation
  12. GRB 261029A / AT2026ahaw: r- and i-band optical follow-up with the PKU 60cm Telescope
  13. GRB 261029A: SVOM/C-GFT optical observations
  14. EP261010a: Xinglong optical follow-up
  15. GRB 261029A: EP-FXT follow-up observation
  16. GRB 261029A: LCO optical observations (correction to GCN 46082)
  17. GRB 261029A: SVOM/COLIBRÍ (FM-GFT) optical observations
  18. GRB 261029A: LCO optical observations
  19. GRB261029A: Early infrared detection with MDM/MIRAGE
  20. GRB 261029A: KAIT optical observations
  21. GRB 261029A: TRT optical observations
  22. EP261006a / AT 2026aetp: Xinglong 2.16-m optical follow-up
  23. EP261025a: EP-FXT follow-up observations
  24. GRB261026A: Infrared detection with MDM/MIRAGE
  25. GRB 261026A: SAO RAS optical observations
  26. The EP-WXT trigger 01709321750 is likely a flaring star
  27. GRB 261026A: EP-FXT follow-up observation
  28. GRB 261024A: SVOM/GRM observation
  29. GRB 261026A: Upper Limit with 60cm Panzhihua Telescope
  30. EP 261025a: J-band upper limit with MIRAGE
  31. GRB 261026A: Ondrejov D50 optical limit
  32. GRB 261026A: ULL-ASTRO-MASTER optical detection with LCO 40-cm telescope at Haleakalā Observatory
  33. GRB 261026A: J-band observations by the SYSU 80cm infrared telescope
  34. GRB 261026A: WINTER J-band observations
  35. GRB 261019A: SVOM/GRM observation
  36. GRB 261026A: KAIT optical observations
  37. GRB 261026A: SVOM/COLIBRÍ (FM-GFT) optical observations
  38. GRB 261026A: SVOM detection of a burst
  39. EP261025a: J-band upper limit with WINTER
  40. EP261023a: J-band upper limit with WINTER
  41. EP 261025a: COLIBRÍ optical upper limit
  42. EP261025a: Einstein Probe detection of a fast X-ray transient
  43. EP261023a: J band upper limit by SYSU 80cm infrared telescope
  44. EP261015a: VST optical observations
  45. EP261023a: Mondy optical upper limit
  46. EP261015a: MAO/AZT-22 optical observations
  47. EP261015a: VLA non-detection
  48. EP261023a: NOT optical counterpart candidate
  49. EP261023a: Einstein Probe detection of an X-ray transient
  50. The EP-WXT trigger 01709321472 is likely a flaring star
  51. EP261015a: GSP multiband optical follow-up observations
  52. GRB 261017A: SVOM/GRM observation
  53. EP261015a: Further optical observations with the 1.3m DFOT
  54. EP261015a: AZT-20 Assy-Turgen optical observations
  55. GRB 261017A: SAO RAS optical upper limit
  56. EP261015a: Follow-up with the 1.3m DFOT
  57. EP261015a: Terskol Zeiss-2000 optical upper limit
  58. EP261007b: Further EP-FXT follow-up observations
  59. GRB 261017A: COLIBRÍ optical upper limit
  60. EP261015a: COLIBRÍ optical observations of a rebrightening
  61. GRB 261017A: Possible Swift/UVOT Detection
  62. GRB 261017A: Luminance-band upper limit from a 28cm telescope in Chengde
  63. GRB 261017A: R-band upper limit with the 1.3-m DFOT
  64. EP261015b: NOT Optical Observations
  65. GRB 261017A: J band upper limit by the SYSU 80cm infrared telescope
  66. EP261015c: refined analysis of the EP-FXT observation favors a stellar flare interpretation
  67. GRB 261017A : MITSuME Akeno optical upper limits
  68. GRB 261017A: Swift-XRT refined Analysis
  69. GRB 261017A: Nanshan/NEXT optical upper limit
  70. GRB 261017A: Enhanced Swift-XRT position
  71. GRB 261017A: Swift detection of a burst
  72. EP261015a: Tentative fading of the candidate optical counterpart from the NOT
  73. EP261015b: Refined analysis of EP-FXT observations
  74. EP261015b: J-band upper limit by the SYSU 80cm infrared telescope
  75. EP261015a: refined analysis of EP-FXT observations
  76. EP261015c: J-band upper limit with WINTER
  77. EP261015a: J-band upper limit with WINTER
  78. EP261006a / AT 2026aetp: Optical follow-up with the 1.3-m DFOT
  79. GRB 261011A: 1.3m DFOT optical upper limit
  80. GRB 261010A: Pan-STARRS z-band imaging and upper limit
  81. EP261015a: SVOM/VT optical observation
  82. EP261015a: COLIBRÍ optical observations
  83. EP261015c: Einstein Probe detection of a fast X-ray transient
  84. EP261015b: Einstein Probe detection of an X-ray transient
  85. EP261015a: Einstein Probe detection of a fast X-ray transient
  86. EP261015a (WXT 11900947714): Possible optical counterpart from NOT and LCO
  87. The EP-WXT trigger 01709321333 is likely a flaring star
  88. GRB 261010A: LBT tentative near-infrared detection
  89. GRB 261011A: SAO RAS and AbAO optical observations
  90. GRB 261008A: SVOM/GRM observation
  91. EP261006a : MeerKAT radio observations.
  92. GRB 261011A: GECAM-B observation
  93. GRB 261010A: J-band upper limit by the SYSU 80cm infrared telescope
  94. GRB 261011A: Swift-XRT refined Analysis
  95. GRB 261011A: Enhanced Swift-XRT position
  96. GRB 261010A: 10.4m GTC spectroscopy of the galaxy 2" from the afterglow
  97. GRB 261011A: REM optical/NIR observations
  98. GRB 261011A: SOAR optical afterglow observations at ~17 hours
  99. EP261006a: 10 GHz VLA observations
  100. GRB 261011A: VLT/X-shooter redshift constraints

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