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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').
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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"

32752 results found.

  1. GRB 251025C: SVOM/GRM observation
  2. GRB 251028A: GECAM-B detection
  3. GRB 251028A: SVOM/GRM observation
  4. IceCube-251025A: Two Transient Candidates from the Zwicky Transient Facility
  5. GRB 251028A: Fermi GBM Observation
  6. GRB 251026B: SOAR Classification of GOTO25jgl/SN2025absf as a Type Ia supernova
  7. GRB 251022A: Swift-XRT confirmation of fading
  8. GRB 251026B: LBT near-infrared observations
  9. GRB 250926B: VZLUSAT-2 detection
  10. GRB 250926A: VZLUSAT-2 detection
  11. GRB 250925A: VZLUSAT-2 detection
  12. GRB 251026A/EP251026a: SVOM/VT optical counterpart
  13. GRB 251026A/EP251026a: EP-FXT follow-up observation
  14. GRB 251028B: Fermi/GBM observation
  15. GRB 251028B: Swift/BAT-GUANO localization skymap of a burst
  16. GRB 251028B: Glowbug gamma-ray detection
  17. GRB 251028A: Glowbug gamma-ray detection
  18. GRB 251028B: CALET Gamma-Ray Burst Monitor detection
  19. Fermi GRB 251028B: Global MASTER-Net observations report
  20. GRB 251025B: GROWTH-India Telescope continued multiband optical observations and rebrightening
  21. GRB251026B: PRIME H-band upper limit
  22. GRB251025B: 3.6m DOT Optical Observations
  23. SVOM trigger sb25102702/GRB 251027A is not a GRB
  24. IceCube-251025A: Upper limits from a search for additional neutrino events in IceCube
  25. GRB 251025B: Swift-XRT confirmation of fading
  26. GRB 251013C : 3.4-m telescope of Iranian National Observatory (INO340) optical observations
  27. GRB 251026B: Swift-XRT observations of GOTO25jgl/AT2025absf
  28. GRB 251025C: Glowbug gamma-ray detection
  29. Fermi-LAT Gamma-ray Observations of IceCube-251025A
  30. GRB 251023B: Swift-UVOT Upper Limits
  31. Konus-Wind detection of GRB 251022A
  32. GRB 251022A: SVOM/GRM observation
  33. GRB 251026B: Swift ToO observations
  34. GRB 251026A/EP251026a: Einstein Probe detection of a fast X-ray transient
  35. GRB 251027A: LCO optical upper limit
  36. GRB 251027A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  37. GRB 251017A: Mondy AZT-33IK and Koshka Zeiss-1000 optical observations
  38. GRB 251023B / EP251023b: Mondy optical upper limit
  39. GRB 251017A: INASAN-Kislovodsk optical observations
  40. GRB 251026A: Mondy optical upper limit
  41. GRB 251025B: Mondy optical observations
  42. GRB 251025B: Kilonova-Catcher optical afterglow detection
  43. Konus-Wind detection of GRB 251016A (short/hard)
  44. GRB 251025B: VLT/MUSE spectroscopic redshift z = 2.003
  45. GRB 251026B: Tentative GOTO optical counterpart candidate
  46. GRB 251025C: AstroSat CZTI detection
  47. EP251023a: Mondy optical observations
  48. GRB 251025C: CALET Gamma-Ray Burst Monitor detection
  49. GRB 251025B: MAO/AZT-22 optical observations
  50. LIGO/Virgo/KAGRA S251026bn: Updated Sky localization
  51. Fermi GRB 251026B: Global MASTER-Net observations report
  52. Fermi GRB 251025C: Global MASTER-Net observations report
  53. LIGO/Virgo/KAGRA S251026bn: Identification of a GW compact binary merger candidate
  54. GRB 251026A: Swift-XRT observations
  55. GRB 251025B: OHP/T193 optical detection
  56. GRB 251025B: J-band detection with WINTER
  57. GRB 251026A: SVOM/C-GFT upper limit
  58. IceCube-251025A: DDOTI Optical Upper Limit
  59. GRB 251026A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  60. GRB 251025B: SVOM/VT optical bump
  61. GRB 251025B: SVOM/COLIBRÍ (FM-GFT) strong rebrightening of the optical counterpart
  62. GRB 251023A: SVOM/GRM observation
  63. GRB 251025B: ULL-ASTRO-MASTER optical counterpart detection with IAC80 telescope at Teide Observatory
  64. Konus-Wind detection of GRB 251016B
  65. GRB 251025B: GROWTH-India Telescope optical observations
  66. GRB 251024A: Swift/UVOT Upper Limits
  67. GRB 251025B: Swift-XRT afterglow detection
  68. GRB 251024A: Swift-BAT refined analysis
  69. GRB 251025A (sb25102501): stellar flare confirmed
  70. GRB 251025B: SVOM/VT optical observations with VHF data
  71. GRB 251025B: MASTER OT detection
  72. GRB 251025B: SVOM/C-GFT optical counterpart detection
  73. GRB 251025A (sb25102501): Likely a stellar flare by SVOM/VT
  74. GRB 251025A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  75. GRB 251025A: SVOM/VT VHF optical upper limit
  76. GRB 251003A: VLA Detection
  77. GRB 251023C: Glowbug gamma-ray detection
  78. GRB 251024A: LCOGT Optical Afterglow Detection
  79. GRB 251022A: KAIT optical observations
  80. GRB 251023B / EP251023b: COLIBRÍ Confirmation of the Fading Nature of the Optical Candidate
  81. GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
  82. EP251023a: MAO/AZT-22 optical observations
  83. GRB 251023B: OHP/T193 optical observations
  84. EP251023a: OHP/T193 optical observations
  85. GRB 251023C: AstroSat CZTI detection
  86. EP251023b/GRB 251023B: JinShan optical observation
  87. GRB 251022A: Swift-XRT detection of GOTO25iym
  88. EP251023b: Global MASTER-Net observations report
  89. EP251023b/GRB 251023B : Einstein Probe detection of a fast X-ray transient
  90. GRB 251023C: CALET Gamma-Ray Burst Monitor detection
  91. GRB 251022A: GROWTH-India Telescope optical observations
  92. EP251023a: GROWTH-India Telescope optical observations
  93. GRB 251022A: Fermi GBM Observation
  94. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  95. GRB 251023A: Glowbug gamma-ray detection
  96. GRB 251023B: Glowbug gamma-ray detection
  97. EP251023a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm telescope at Teide Observatory
  98. EP251023a: Global MASTER-Net observations report
  99. GRB 251023B / EP#01709247298: COLIBRÍ optical counterpart candidate
  100. IPN triangulation of GRB 251016B

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