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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.

Advanced Search Examples (click to copy):

subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

42469 results found.

  1. GRB 251025B: GROWTH-India Telescope optical observations
  2. GRB 251024A: Swift/UVOT Upper Limits
  3. GRB 251025B: Swift-XRT afterglow detection
  4. GRB 251024A: Swift-BAT refined analysis
  5. IceCube Alert 251025.57: Global MASTER-Net observations report
  6. GRB 251024A: Swift-XRT refined Analysis
  7. GRB 251025A (sb25102501): stellar flare confirmed
  8. GRB 251025B: SVOM/VT optical observations with VHF data
  9. GRB 251025B: MASTER OT detection
  10. GRB 251025B: SVOM/C-GFT optical counterpart detection
  11. GRB 251025B: SVOM detection of a burst
  12. IceCube-251025A - IceCube observation of a high-energy neutrino candidate track-like event
  13. GRB 251025A (sb25102501): Likely a stellar flare by SVOM/VT
  14. GRB 251025A: SVOM/COLIBRÍ (FM-GFT) optical upper limit
  15. GRB 251025A: SVOM/VT VHF optical upper limit
  16. GRB 251025A: SVOM detection of a faint burst
  17. GRB 251003A: VLA Detection
  18. GRB 251024A: Enhanced Swift-XRT position
  19. GRB 251023C: Glowbug gamma-ray detection
  20. GRB 251024A: LCOGT Optical Afterglow Detection
  21. GRB 251022A: KAIT optical observations
  22. GRB 251024A: Swift detection of a burst
  23. Swift GRB 251024A: Global MASTER-Net observations report
  24. GRB 251023B / EP251023b: COLIBRÍ Confirmation of the Fading Nature of the Optical Candidate
  25. GRB 251022A: COLIBRÍ Further Multi-frequency Optical Observations
  26. EP251023a: MAO/AZT-22 optical observations
  27. GRB 251023B: OHP/T193 optical observations
  28. EP251023a: OHP/T193 optical observations
  29. GRB 251023C: AstroSat CZTI detection
  30. EP251023b/GRB 251023B: JinShan optical observation
  31. GRB 251022A: Swift-XRT detection of GOTO25iym
  32. EP251023b: Global MASTER-Net observations report
  33. EP251023b/GRB 251023B : Einstein Probe detection of a fast X-ray transient
  34. GRB 251022A: GROWTH-India Telescope optical observations
  35. GRB 251023C: Swift/BAT-GUANO localization skymap of a burst
  36. EP251023a: GROWTH-India Telescope optical observations
  37. GRB 251022A: Fermi GBM Observation
  38. GRB 251022A: Swift/BAT-GUANO localization skymap of a burst
  39. GRB 251023A: Glowbug gamma-ray detection
  40. GRB 251023B: Glowbug gamma-ray detection
  41. EP251023a: ULL-ASTRO-MASTER detection of the optical afterglow with LCO 40-cm telescope at Teide Observatory
  42. EP251023a: Global MASTER-Net observations report
  43. GRB 251023B / EP#01709247298: COLIBRÍ optical counterpart candidate
  44. EP#01709247298: Swift-XRT counterpart detection
  45. EP251023a: COLIBRÍ optical observations
  46. GRB 251013C: further SAO RAS optical observations
  47. EP251023a: Keck/LRIS spectroscopic redshift z=2.232
  48. GRB 251022A: COLIBRÍ optical observations
  49. GRB 251013C: ISON-Castelgrande observatory optical observations
  50. GRB 251022A: MASTER OT detection
  51. GRB 251022A: DDOTI Optical Detection
  52. EP251021b/GRB 251021A: SVOM/VT optical candidate
  53. GRB 251023B / MAXI J0451+122: MAXI/GSC detection
  54. EP251023a: NOT optical counterpart detection
  55. Fermi GRB 251023A: Global MASTER-Net observations report
  56. EP251023a: GSP Optical Counterpart Detection
  57. EP251023a: Einstein Probe detection of an X-ray transient
  58. EP/WXT 01709247295: GOTO optical afterglow candidate.
  59. GRB 251022A: GOTO optical counterpart detection
  60. GRB 251023A: Fermi GBM Final Localization Correction
  61. GRB 251022A: Fermi-LAT detection
  62. GRB 251016B: Fermi GBM Detection
  63. GRB 251022A: Tiled Swift observations
  64. LAT GRB251022A: Global MASTER-Net observations report
  65. GRB 251022A: Fermi GBM Final Real-time Localization
  66. GRB 251021A/EP251021b: Fermi-GBM Sub-Threshold Detection
  67. EP251021b: BOOTES-7 optical upper limit
  68. EP251021b: Einstein Probe detection of a fast X-ray transient
  69. GRB 250911A: MAXI/GSC detection
  70. GRB 251016A: SVOM/ECLAIRs refined analysis
  71. LIGO/Virgo/KAGRA S251021u: Identification of a GW compact binary merger candidate
  72. Fermi-LAT gamma-ray observations of IceCube-251018A
  73. GRB 251017A : RAPAS follow-up observations
  74. IceCube-251018A: Upper limits from a search for additional neutrino events in IceCube
  75. GRB 251017A: COLIBRÍ optical observations of a late plateau
  76. IceCube-251018A: DDOTI Optical Upper Limit
  77. GRB 251017A: Swift-BAT refined analysis
  78. GRB 251016A: Fermi GBM Observation
  79. GRB 251018A: Fermi GBM Observation
  80. GRB 251018A: BOOTES-5 and BOOTES-7 early optical detections
  81. GRB 251018A: Swift-XRT refined Analysis
  82. GRB 251018A: Enhanced Swift-XRT position
  83. Fermi trigger No 782500909: Global MASTER-Net observations report
  84. GRB 251016A: HXMT/HE detection
  85. IceCube-251018A: Global MASTER-Net observations report
  86. LIGO/Virgo/KAGRA S251018bi: Identification of a GW compact binary merger candidate
  87. GRB 251016A: Swift-XRT afterglow detection
  88. GRB 251017A: Swift/UVOT Detection
  89. GRB 251016A: Swift/UVOT Detection
  90. GRB 251018A: Swift/UVOT Detection
  91. IceCube-251018A - IceCube observation of a high-energy neutrino candidate track-like event
  92. GRB 251017A: VLT/MUSE spectroscopic redshift z = 4.327
  93. GRB 251016A: VLT/FORS2 Optical Observation
  94. GRB 251017A: COLIBRÍ photometric redshift
  95. GRB 251017A: Swift-XRT refined Analysis
  96. GRB 251018A: MASTER OT detection
  97. GRB 251018A: TRT optical afterglow detection
  98. Swift GRB 251018A: Global MASTER-Net observations report
  99. GRB 251018A: Swift detection of a burst with an optical counterpart
  100. GRB 251018A: Fermi GBM Final Real-time Localization

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