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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"

19600 results found.

  1. GRB 251022A: Swift-XRT confirmation of fading
  2. GRB 251026A/EP251026a: SVOM/VT optical counterpart
  3. GRB 251028B: Fermi/GBM observation
  4. GRB 251028B: Swift/BAT-GUANO localization skymap of a burst
  5. GRB 251025B: GROWTH-India Telescope continued multiband optical observations and rebrightening
  6. GRB251026B: PRIME H-band upper limit
  7. GRB251025B: 3.6m DOT Optical Observations
  8. SVOM trigger sb25102702/GRB 251027A is not a GRB
  9. GRB 251013C : 3.4-m telescope of Iranian National Observatory (INO340) optical observations
  10. GRB 251026B: Swift-XRT observations of GOTO25jgl/AT2025absf
  11. EP251027.145: COLIBRÍ optical upper limits
  12. GRB 251022A: SVOM/GRM observation
  13. GRB 251026B: Swift ToO observations
  14. GRB 251026A/EP251026a: Einstein Probe detection of a fast X-ray transient
  15. GRB 251027A: LCO optical upper limit
  16. GRB 251027A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  17. GRB 251023B / EP251023b: Mondy optical upper limit
  18. GRB 251017A: INASAN-Kislovodsk optical observations
  19. GRB 251026A: Mondy optical upper limit
  20. GRB 251025B: Mondy optical observations
  21. GRB 251025B: Kilonova-Catcher optical afterglow detection
  22. GRB 251025B: VLT/MUSE spectroscopic redshift z = 2.003
  23. GRB 251026B: Tentative GOTO optical counterpart candidate
  24. GRB 251025C: AstroSat CZTI detection
  25. EP251023a: Mondy optical observations
  26. GRB 251025B: MAO/AZT-22 optical observations
  27. LIGO/Virgo/KAGRA S251026bn: Identification of a GW compact binary merger candidate
  28. GRB 251025B: J-band detection with WINTER
  29. GRB 251026A: SVOM/C-GFT upper limit
  30. IceCube-251025A: DDOTI Optical Upper Limit
  31. GRB 251026A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  32. GRB 251026A: SVOM detection of a long burst
  33. GRB 251025B: SVOM/COLIBRÍ (FM-GFT) strong rebrightening of the optical counterpart
  34. GRB 251023A: SVOM/GRM observation
  35. GRB 251025B: ULL-ASTRO-MASTER optical counterpart detection with IAC80 telescope at Teide Observatory
  36. GRB 251025B: GROWTH-India Telescope optical observations
  37. GRB 251024A: Swift/UVOT Upper Limits
  38. GRB 251025B: Swift-XRT afterglow detection
  39. GRB 251025A (sb25102501): stellar flare confirmed
  40. GRB 251025B: SVOM/VT optical observations with VHF data
  41. GRB 251025B: MASTER OT detection
  42. GRB 251025B: SVOM/C-GFT optical counterpart detection
  43. GRB 251025B: SVOM detection of a burst
  44. GRB 251025A (sb25102501): Likely a stellar flare by SVOM/VT
  45. GRB 251025A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  46. GRB 251025A: SVOM/VT VHF optical upper limit
  47. GRB 251025A: SVOM detection of a faint burst
  48. GRB 251024A: Enhanced Swift-XRT position
  49. GRB 251024A: LCOGT Optical Afterglow Detection
  50. GRB 251022A: KAIT optical observations
  51. GRB 251024A: Swift detection of a burst
  52. GRB 251023B / EP251023b: COLIBRÍ Confirmation of the Fading Nature of the Optical Candidate
  53. GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
  54. EP251023a: MAO/AZT-22 optical observations
  55. GRB 251023C: AstroSat CZTI detection
  56. EP251023b/GRB 251023B: JinShan optical observation
  57. GRB 251022A: Swift-XRT detection of GOTO25iym
  58. EP251023b/GRB 251023B : Einstein Probe detection of a fast X-ray transient
  59. GRB 251022A: GROWTH-India Telescope optical observations
  60. GRB 251023C: Swift/BAT-GUANO localization skymap of a burst
  61. EP251023a: GROWTH-India Telescope optical observations
  62. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  63. EP251023a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm telescope at Teide Observatory
  64. GRB 251023B / EP#01709247298: COLIBRÍ optical counterpart candidate
  65. IPN triangulation of GRB 251016B
  66. EP251023a: COLIBRÍ optical observations
  67. GRB 251013C: further SAO RAS optical observations
  68. GRB 251022A: COLIBRÍ optical observations
  69. GRB 251013C: ISON-Castelgrande observatory optical observations
  70. GRB 251022A: MASTER OT detection
  71. GRB 251022A: DDOTI Optical Detection
  72. EP251021b/GRB 251021A: SVOM/VT optical candidate
  73. EP251023a: NOT optical counterpart detection
  74. EP251023a: Einstein Probe detection of an X-ray transient
  75. GRB 251022A: Tiled Swift observations
  76. EP251021b: Einstein Probe detection of a fast X-ray transient
  77. LIGO/Virgo/KAGRA S251021u: Identification of a GW compact binary merger candidate
  78. Fermi-LAT gamma-ray observations of IceCube-251018A
  79. GRB 251017A : RAPAS follow-up observations
  80. GRB 251017A: COLIBRÍ optical observations of a late plateau
  81. IceCube-251018A: DDOTI Optical Upper Limit
  82. GRB 251018A: Enhanced Swift-XRT position
  83. IceCube-251018A: Global MASTER-Net observations report
  84. LIGO/Virgo/KAGRA S251018bi: Identification of a GW compact binary merger candidate
  85. GRB 251016A: Swift-XRT afterglow detection
  86. GRB 251017A: Swift/UVOT Detection
  87. GRB 251016A: Swift/UVOT Detection
  88. GRB 251018A: Swift/UVOT Detection
  89. GRB 251017A: VLT/MUSE spectroscopic redshift z = 4.327
  90. GRB 251016A: VLT/FORS2 Optical Observation
  91. GRB 251017A: COLIBRÍ photometric redshift
  92. GRB 251018A: MASTER OT detection
  93. GRB 251018A: TRT optical afterglow detection
  94. GRB 251018A: Swift detection of a burst with an optical counterpart
  95. GRB 251017A: J-band detection with WINTER
  96. GRB 251013C: Liverpool Telescope observations
  97. GRB 251013C: Leavitt Observatory optical photometry
  98. GRB 251017A: JinShan observations of the optical afterglow
  99. GRB 251017A : MITSuME Akeno optical afterglow candidate detection
  100. GRB 251017A: Enhanced Swift-XRT position

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