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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"

45699 results found.

  1. GRB 251023B: OHP/T193 optical observations
  2. EP251023a: OHP/T193 optical observations
  3. GRB 251023C: AstroSat CZTI detection
  4. EP251023b/GRB 251023B: JinShan optical observation
  5. GRB 251022A: Swift-XRT detection of GOTO25iym
  6. EP251023b: Global MASTER-Net observations report
  7. EP251023b/GRB 251023B : Einstein Probe detection of a fast X-ray transient
  8. GRB 251023C: CALET Gamma-Ray Burst Monitor detection
  9. GRB 251022A: GROWTH-India Telescope optical observations
  10. GRB 251023C: Swift/BAT-GUANO localization skymap of a burst
  11. EP251023a: GROWTH-India Telescope optical observations
  12. GRB 251022A: Fermi GBM Observation
  13. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  14. GRB 251023A: Glowbug gamma-ray detection
  15. GRB 251023B: Glowbug gamma-ray detection
  16. EP251023a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm telescope at Teide Observatory
  17. EP251023a: Global MASTER-Net observations report
  18. GRB 251023B / EP#01709247298: COLIBRÍ optical counterpart candidate
  19. IPN triangulation of GRB 251016B
  20. GRB 251023B: CALET Gamma-Ray Burst Monitor detection
  21. EP#01709247298: Swift-XRT counterpart detection
  22. EP251023a: COLIBRÍ optical observations
  23. GRB 251013C: further SAO RAS optical observations
  24. EP251023a: Keck/LRIS spectroscopic redshift z=2.232
  25. GRB 251022A: COLIBRÍ optical observations
  26. GRB 251013C: ISON-Castelgrande observatory optical observations
  27. GRB 251022A: MASTER OT detection
  28. GRB 251022A: DDOTI Optical Detection
  29. EP251021b/GRB 251021A: SVOM/VT optical candidate
  30. GRB 251023B / MAXI J0451+122: MAXI/GSC detection
  31. EP251023a: NOT optical counterpart detection
  32. Fermi GRB 251023A: Global MASTER-Net observations report
  33. EP251023a: GSP Optical Counterpart Detection
  34. EP251023a: Einstein Probe detection of an X-ray transient
  35. EP/WXT 01709247295: GOTO optical afterglow candidate.
  36. GRB 251022A: GOTO optical counterpart detection
  37. GRB 251023A: Fermi GBM Final Localization Correction
  38. GRB 251022A: Fermi-LAT detection
  39. GRB 251016B: Fermi GBM Detection
  40. GRB 251022A: Tiled Swift observations
  41. LAT GRB251022A: Global MASTER-Net observations report
  42. GRB 251022A: Fermi GBM Final Real-time Localization
  43. GRB 251021A/EP251021b: Fermi-GBM Sub-Threshold Detection
  44. EP251021b: BOOTES-7 optical upper limit
  45. EP251021b: Einstein Probe detection of a fast X-ray transient
  46. GRB 250911A: MAXI/GSC detection
  47. LIGO/Virgo/KAGRA S251021u: Updated Sky localization
  48. GRB 251016A: SVOM/ECLAIRs refined analysis
  49. LIGO/Virgo/KAGRA S251021u: Identification of a GW compact binary merger candidate
  50. LIGO/Virgo/KAGRA S251018bi: Updated Sky localization
  51. Fermi-LAT gamma-ray observations of IceCube-251018A
  52. GRB 251017A : RAPAS follow-up observations
  53. IceCube-251018A: Upper limits from a search for additional neutrino events in IceCube
  54. GRB 251017A: COLIBRÍ optical observations of a late plateau
  55. IceCube-251018A: DDOTI Optical Upper Limit
  56. GRB 251017A: Swift-BAT refined analysis
  57. GRB 251016A: Fermi GBM Observation
  58. GRB 251018A: Fermi GBM Observation
  59. GRB 251018A: BOOTES-5 and BOOTES-7 early optical detections
  60. GRB 251018A: Swift-XRT refined Analysis
  61. GRB 251018A: Enhanced Swift-XRT position
  62. Fermi trigger No 782500909: Global MASTER-Net observations report
  63. GRB 251016A: HXMT/HE detection
  64. IceCube-251018A: Global MASTER-Net observations report
  65. LIGO/Virgo/KAGRA S251018bi: Identification of a GW compact binary merger candidate
  66. GRB 251016A: Swift-XRT afterglow detection
  67. GRB 251017A: Swift/UVOT Detection
  68. GRB 251016A: Swift/UVOT Detection
  69. GRB 251018A: Swift/UVOT Detection
  70. IceCube-251018A - IceCube observation of a high-energy neutrino candidate track-like event
  71. IceCube-251018A - IceCube observation of a high-energy neutrino candidate track-like event (duplicate submission)
  72. GRB 251017A: VLT/MUSE spectroscopic redshift z = 4.327
  73. GRB 251016A: VLT/FORS2 Optical Observation
  74. GRB 251017A: COLIBRÍ photometric redshift
  75. GRB 251017A: Swift-XRT refined Analysis
  76. GRB 251018A: MASTER OT detection
  77. GRB 251018A: TRT optical afterglow detection
  78. Swift GRB 251018A: Global MASTER-Net observations report
  79. GRB 251018A: Swift detection of a burst with an optical counterpart
  80. GRB 251018A: Fermi GBM Final Real-time Localization
  81. GRB 251017A: SVOM/VT optical observation
  82. GRB 251011A: Fermi GBM Observation
  83. GRB 251017A: OHP/T193 i-band observations
  84. GRB 251013C: OHP/T193 third epoch optical observations and detected rebrightening
  85. LIGO/Virgo/KAGRA S251017di: Retraction of GW compact binary merger candidate
  86. GRB 251017A: J-band detection with WINTER
  87. GRB 251017A: Glowbug gamma-ray detection
  88. GRB 251013C: Liverpool Telescope observations
  89. GRB 251013C: Leavitt Observatory optical photometry
  90. Fermi GRB 251016B: Global MASTER-Net observations report
  91. GRB 251017A: JinShan observations of the optical afterglow
  92. Swift GRB 251017A: Global MASTER-Net observations report
  93. GRB 251017A : MITSuME Akeno optical afterglow candidate detection
  94. Swift Trigger 1404295 is not a GRB
  95. GRB 251016A: AstroSat CZTI detection of a short burst
  96. GRB 251017A: Enhanced Swift-XRT position
  97. GRB 251017A: COLIBRÍ Early Afterglow Detection
  98. GRB 251016B: AstroSat CZTI 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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