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GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

21794 results found.

  1. GRB 251023B: Swift-UVOT Upper Limits
  2. Konus-Wind detection of GRB 251022A
  3. GRB 251027A: Swift-XRT observations
  4. EP251027.145: COLIBRÍ optical upper limits
  5. GRB 251022A: SVOM/GRM observation
  6. GRB 251026A/EP251026a: Einstein Probe detection of a fast X-ray transient
  7. GRB 251027A: LCO optical upper limit
  8. GRB 251027A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  9. GRB 251023B / EP251023b: Mondy optical upper limit
  10. GRB 251017A: INASAN-Kislovodsk optical observations
  11. GRB 251026A: Mondy optical upper limit
  12. GRB 251025B: Mondy optical observations
  13. GRB 251025B: Kilonova-Catcher optical afterglow detection
  14. Konus-Wind detection of GRB 251016A (short/hard)
  15. GRB 251025B: VLT/MUSE spectroscopic redshift z = 2.003
  16. GRB 251027A: SVOM detection of a faint burst
  17. GRB 251026B: Tentative GOTO optical counterpart candidate
  18. EP251023a: Mondy optical observations
  19. GRB 251025B: MAO/AZT-22 optical observations
  20. LIGO/Virgo/KAGRA S251026bn: Identification of a GW compact binary merger candidate
  21. GRB 251025B: OHP/T193 optical detection
  22. GRB 251025B: J-band detection with WINTER
  23. GRB 251026A: SVOM/C-GFT upper limit
  24. IceCube-251025A: DDOTI Optical Upper Limit
  25. GRB 251026A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  26. GRB 251026A: SVOM detection of a long burst
  27. GRB 251025B: SVOM/COLIBRÍ (FM-GFT) strong rebrightening of the optical counterpart
  28. GRB 251023A: SVOM/GRM observation
  29. GRB 251025B: ULL-ASTRO-MASTER optical counterpart detection with IAC80 telescope at Teide Observatory
  30. Konus-Wind detection of GRB 251016B
  31. GRB 251025B: GROWTH-India Telescope optical observations
  32. GRB 251024A: Swift/UVOT Upper Limits
  33. GRB 251025B: Swift-XRT afterglow detection
  34. GRB 251025A (sb25102501): stellar flare confirmed
  35. GRB 251025B: SVOM/VT optical observations with VHF data
  36. GRB 251025B: MASTER OT detection
  37. GRB 251025B: SVOM/C-GFT optical counterpart detection
  38. GRB 251025B: SVOM detection of a burst
  39. GRB 251025A (sb25102501): Likely a stellar flare by SVOM/VT
  40. GRB 251025A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  41. GRB 251025A: SVOM/VT VHF optical upper limit
  42. GRB 251025A: SVOM detection of a faint burst
  43. GRB 251003A: VLA Detection
  44. GRB 251024A: Enhanced Swift-XRT position
  45. GRB 251024A: LCOGT Optical Afterglow Detection
  46. GRB 251022A: KAIT optical observations
  47. GRB 251024A: Swift detection of a burst
  48. GRB 251023B / EP251023b: COLIBRÍ Confirmation of the Fading Nature of the Optical Candidate
  49. GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
  50. EP251023a: MAO/AZT-22 optical observations
  51. EP251023b/GRB 251023B: JinShan optical observation
  52. GRB 251022A: Swift-XRT detection of GOTO25iym
  53. EP251023b/GRB 251023B : Einstein Probe detection of a fast X-ray transient
  54. GRB 251022A: GROWTH-India Telescope optical observations
  55. GRB 251023C: Swift/BAT-GUANO localization skymap of a burst
  56. EP251023a: GROWTH-India Telescope optical observations
  57. GRB 251022A: Fermi GBM Observation
  58. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  59. EP251023a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm telescope at Teide Observatory
  60. GRB 251023B / EP#01709247298: COLIBRÍ optical counterpart candidate
  61. IPN triangulation of GRB 251016B
  62. EP251023a: COLIBRÍ optical observations
  63. GRB 251013C: further SAO RAS optical observations
  64. GRB 251022A: COLIBRÍ optical observations
  65. GRB 251013C: ISON-Castelgrande observatory optical observations
  66. GRB 251022A: MASTER OT detection
  67. GRB 251022A: DDOTI Optical Detection
  68. EP251021b/GRB 251021A: SVOM/VT optical candidate
  69. EP251023a: NOT optical counterpart detection
  70. EP251023a: Einstein Probe detection of an X-ray transient
  71. EP/WXT 01709247295: GOTO optical afterglow candidate.
  72. GRB 251022A: GOTO optical counterpart detection
  73. EP251021b: Einstein Probe detection of a fast X-ray transient
  74. GRB 251016A: SVOM/ECLAIRs refined analysis
  75. LIGO/Virgo/KAGRA S251021u: Identification of a GW compact binary merger candidate
  76. Fermi-LAT gamma-ray observations of IceCube-251018A
  77. GRB 251017A : RAPAS follow-up observations
  78. GRB 251017A: COLIBRÍ optical observations of a late plateau
  79. IceCube-251018A: DDOTI Optical Upper Limit
  80. GRB 251018A: BOOTES-5 and BOOTES-7 early optical detections
  81. GRB 251018A: Enhanced Swift-XRT position
  82. LIGO/Virgo/KAGRA S251018bi: Identification of a GW compact binary merger candidate
  83. GRB 251016A: Swift-XRT afterglow detection
  84. GRB 251017A: Swift/UVOT Detection
  85. GRB 251016A: Swift/UVOT Detection
  86. GRB 251018A: Swift/UVOT Detection
  87. GRB 251016A: VLT/FORS2 Optical Observation
  88. GRB 251017A: COLIBRÍ photometric redshift
  89. GRB 251018A: MASTER OT detection
  90. GRB 251018A: TRT optical afterglow detection
  91. GRB 251018A: Swift detection of a burst with an optical counterpart
  92. GRB 251017A: J-band detection with WINTER
  93. GRB 251013C: Liverpool Telescope observations
  94. GRB 251013C: Leavitt Observatory optical photometry
  95. GRB 251017A: JinShan observations of the optical afterglow
  96. GRB 251017A : MITSuME Akeno optical afterglow candidate detection
  97. GRB 251017A: Enhanced Swift-XRT position
  98. GRB 251017A: COLIBRÍ Early Afterglow Detection
  99. GRB 251017A: BOOTES-5/JGT early optical afterglow detection
  100. GRB 251017A: Swift detection of a burst with an optical counterpart

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