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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"

28277 results found.

  1. GRB 261029A: SVOM/VT optical observation
  2. GRB 261029A / AT2026ahaw: r- and i-band optical follow-up with the PKU 60cm Telescope
  3. GRB 261029A : AstroSat CZTI detection
  4. GRB 261029A: SVOM/C-GFT optical observations
  5. EP261010a: Xinglong optical follow-up
  6. GRB 261029A: EP-FXT follow-up observation
  7. GRB 261029A: LCO optical observations (correction to GCN 46082)
  8. GRB 261029A: SVOM/COLIBRÍ (FM-GFT) optical observations
  9. GRB 261029A: LCO optical observations
  10. GRB261029A: Early infrared detection with MDM/MIRAGE
  11. GRB 261029A: KAIT optical observations
  12. GRB 261029A: TRT optical observations
  13. EP261006a / AT 2026aetp: Xinglong 2.16-m optical follow-up
  14. EP261025a: EP-FXT follow-up observations
  15. GRB 261028B / MAXI J1609-487: MAXI GSC detection
  16. GRB 261021A: Glowbug gamma-ray detection
  17. GRB261026A: Infrared detection with MDM/MIRAGE
  18. GRB 261026A: SAO RAS optical observations
  19. EP Alert 261026.29: Global MASTER-Net observations report
  20. GRB 261026A: EP-FXT follow-up observation
  21. GRB 261024A: SVOM/GRM observation
  22. GRB 261026A: Upper Limit with 60cm Panzhihua Telescope
  23. EP 261025a: J-band upper limit with MIRAGE
  24. GRB 261024D: Glowbug gamma-ray detection
  25. GRB 261026B: NuSTAR detection of prompt emission
  26. GRB 261024D: NuSTAR detection of prompt emission
  27. GRB 261024C: NuSTAR detection of prompt emission
  28. GRB 261026A: Ondrejov D50 optical limit
  29. GRB 261026A: ULL-ASTRO-MASTER optical detection with LCO 40-cm telescope at Haleakalā Observatory
  30. GRB 261026A: J-band observations by the SYSU 80cm infrared telescope
  31. SVOM GRB261026.26: Global MASTER-Net observations report
  32. GRB 261026A: WINTER J-band observations
  33. GRB 261019A: SVOM/GRM observation
  34. Fermi GRB 261026B: Global MASTER-Net observations report
  35. GRB 261026A: SVOM/VT optical observation from VHF data
  36. GRB 261026A: KAIT optical observations
  37. GRB 261026A: SVOM/COLIBRÍ (FM-GFT) optical observations
  38. GRB 261024A: NuSTAR detection of prompt emission
  39. GRB 261026A: SVOM detection of a burst
  40. EP261025a: J-band upper limit with WINTER
  41. EP261023a: J-band upper limit with WINTER
  42. EP 261025a: COLIBRÍ optical upper limit
  43. EP261025a: Einstein Probe detection of a fast X-ray transient
  44. EP261023a: J band upper limit by SYSU 80cm infrared telescope
  45. EP261015a: VST optical observations
  46. GRB 261024A: BALROG localization (Fermi Trigger 814551785 / GRB 261024683)
  47. EP261023a: Mondy optical upper limit
  48. EP261015a: MAO/AZT-22 optical observations
  49. EP261015a: VLA non-detection
  50. EP261023a: NOT optical counterpart candidate
  51. EP261023a: Einstein Probe detection of an X-ray transient
  52. The EP-WXT trigger 01709321472 is likely a flaring star
  53. IceCube-261020A: Upper limits from a search for additional neutrino events in IceCube
  54. NuSTAR 261020, a 830s hard X-ray transient
  55. EP261015a: GSP multiband optical follow-up observations
  56. GRB 261017A: SVOM/GRM observation
  57. EP261015a: Further optical observations with the 1.3m DFOT
  58. GRB 261020B: AstroSat CZTI detection of a short burst
  59. Fermi-LAT Gamma-ray Observations of IceCube-261020A
  60. EP261015a: AZT-20 Assy-Turgen optical observations
  61. GRB 261020A: Fermi GBM Observation
  62. GRB 261017A: SAO RAS optical upper limit
  63. GRB 260903A
  64. EP261015a: Follow-up with the 1.3m DFOT
  65. EP261015a: Terskol Zeiss-2000 optical upper limit
  66. EP261007b: Further EP-FXT follow-up observations
  67. GRB 261017A: COLIBRÍ optical upper limit
  68. GRB 261020A: MAXI GSC detection
  69. EP261015a: COLIBRÍ optical observations of a rebrightening
  70. GRB 261017A: Possible Swift/UVOT Detection
  71. GRB 261017A: Luminance-band upper limit from a 28cm telescope in Chengde
  72. GRB 261017A: R-band upper limit with the 1.3-m DFOT
  73. GRB 261017A: Swift-BAT refined analysis
  74. EP261015b: NOT Optical Observations
  75. GRB 261017A: J band upper limit by the SYSU 80cm infrared telescope
  76. EP261015c: refined analysis of the EP-FXT observation favors a stellar flare interpretation
  77. GRB 261017A : MITSuME Akeno optical upper limits
  78. GRB 261017A: Swift-XRT refined Analysis
  79. GRB 261017A: Nanshan/NEXT optical upper limit
  80. GRB 261017A: Enhanced Swift-XRT position
  81. GRB 261017A: Fermi GBM Observation
  82. GRB 261017A: Swift detection of a burst
  83. EP261015a: Tentative fading of the candidate optical counterpart from the NOT
  84. EP261015b: Refined analysis of EP-FXT observations
  85. EP261015b: J-band upper limit by the SYSU 80cm infrared telescope
  86. EP261015a: refined analysis of EP-FXT observations
  87. EP261015c: J-band upper limit with WINTER
  88. EP261015a: J-band upper limit with WINTER
  89. EP261006a / AT 2026aetp: Optical follow-up with the 1.3-m DFOT
  90. GRB 261011A: 1.3m DFOT optical upper limit
  91. GRB 261010A: Pan-STARRS z-band imaging and upper limit
  92. EP261015a: SVOM/VT optical observation
  93. GRB 261010A: VLA radio observations
  94. EP261015a: COLIBRÍ optical observations
  95. EP261015c: Einstein Probe detection of a fast X-ray transient
  96. EP261015b: Einstein Probe detection of an X-ray transient
  97. EP261015a: Einstein Probe detection of a fast X-ray transient
  98. EP261015a (WXT 11900947714): Possible optical counterpart from NOT and LCO
  99. GRB 261010A: LBT tentative near-infrared detection
  100. GRB 261011A: SAO RAS and AbAO optical observations

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