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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"

26122 results found.

  1. GRB 230906A: Swift-XRT observations
  2. IPN triangulation of GRB 230906A (short)
  3. GRB 230906A: Swift ToO observations
  4. Swift Attitude Control Affecting Some UVOT Images
  5. GRB 230812B: Chandra late-time detection of the X-ray afterglow
  6. GRB 230903A: Swift-XRT refined Analysis
  7. GRB 230903A: Enhanced Swift-XRT position
  8. GRB 230903A: VLT/X-shooter optical observations
  9. GRB 230903A: Swift-BAT refined analysis
  10. GRB 230903A: Fermi GBM detection
  11. GRB 230903A: LCOGT Optical Upper Limits
  12. GRB 230903A: Swift detection of a burst
  13. Swift GRB230903.72: Global MASTER-Net observations report
  14. GRB 230827A: Glowbug gamma-ray detection
  15. GRB 230826A: Glowbug gamma-ray detection
  16. GRB 230827B: Swift-XRT afterglow detection
  17. GRB 230827B: Swift ToO observations
  18. GRB 230827A: Fermi GBM Observation
  19. GRB 230826A: Swift-BAT refined analysis
  20. Swift Trigger 1188089 is not a GRB
  21. GRB 230827A: VZLUSAT-2 detection
  22. GRB 230827A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  23. GRB 230826A: VZLUSAT-2 detection
  24. GRB 230827B / GRB 230827256: Fermi GBM Observation
  25. Subject: GRB230826A: Swift/UVOT upper limits
  26. Swift J1727.8-1613 (GRB 230824A): Osservatorio Astronomico "Nastro Verde" optical observations
  27. GRB 230827.256 : GIT optical follow-up of ZTF23abaanxz/AT2023qxj
  28. AT 2023qxj: ZTF discovery of the likely afterglow of Fermi GRB 230827256
  29. Swift J1727.8-1613 (GRB 230824A): Montarrenti Observatory photometric observations
  30. GRB 230826A: GRBAlpha detection
  31. GRB 230826A: Fermi GBM Observation
  32. Swift J1727.8-1613 (GRB 230824A): Leavitt Observatory optical observations
  33. GRB 230826A: Enhanced Swift-XRT position
  34. GRB 230826A: Swift-XRT refined Analysis
  35. GRB 230826A: Mondy optical observations
  36. Swift J1727.8-1613 (GRB 230824A): GAD Observatory La Spezia - optical observations
  37. GRB 230826A: Swift detection of a burst
  38. Swift GRB230826.81: Global MASTER-Net observations report
  39. Swift J1727.8-1613 (GRB 230824A): Bassano Bresciano Observatory optical observations
  40. GRB 230824A: AKO Photometric Follow-up Observations
  41. LIGO/Virgo/KAGRA S230825k: Upper limits from Swift/BAT-GUANO
  42. Swift GRB230825.85: Global MASTER-Net observations report
  43. Trigger 1187225: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  44. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  45. Trigger 1187207: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  46. Trigger 1187203: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  47. Swift GRB230825.75: Global MASTER-Net observations report
  48. Swift Trigger 1187199 is not an astrophysical event
  49. Fermi Gamma-ray Burst Monitor trigger 714618399/230825046 is not a GRB
  50. NICER detection of Swift J1727.8-1613 (GRB 230824A)
  51. Trigger 1187142: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  52. MAXI/GSC detection of Swift J1727.8-1613 (GRB 230824A)
  53. GRB 230824A: AKO Optical Afterglow Candidate
  54. Trigger 1186982: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  55. GRB 230824A is likely a Galactic Transient: Swift J1727.8-1613
  56. GRB 230824A: Swift detection of a burst
  57. Swift GRB230824.58: Global MASTER-Net observations report
  58. Swift GRB230824.10: Global MASTER-Net observations report
  59. Swift Trigger 1186908 is not a GRB
  60. GRB 230822A: Fermi GBM Observation
  61. LIGO/Virgo/KAGRA S230822bm: Upper limits from Swift/BAT-GUANO
  62. GRB 230822A: Swift/BAT-GUANO detection of a burst
  63. GRID detection of GRB 230818A
  64. GRB 230815A: ATCA detection of radio counterpart
  65. Swift GRB230821.64: Global MASTER-Net observations report
  66. GRB 230818A: Swift-BAT refined analysis
  67. Swift Trigger 1186391 is not a GRB
  68. Swift Trigger 1186390 is not a GRB
  69. Konus-Wind detection of GRB 230818A
  70. Swift Trigger 1186386 is not a GRB
  71. Swift triggers 1186294-1186304 are not astrophysical transients
  72. GRB 230812B : GRANDMA/Kilonova-Catcher optical afterglow detection and upper limits
  73. Swift GRB230820.81: Global MASTER-Net observations report
  74. Swift GRB230820.80: Global MASTER-Net observations report
  75. Swift GRB230820.82: Global MASTER-Net observations report
  76. Swift Triggers 1186280 and 1186291 are not GRBs
  77. GRB 230818A: Fermi GBM Observation
  78. GRB 230812B: GIT Confirmation of SN rise
  79. GRB 230818A: Nickel and KAIT telescope optical observations
  80. GRB 230818A: SAO RAS 6-m telescope spectroscopy
  81. GRB 230818A: AKO Upper Limit
  82. GRB 230818A: AstroSat CZTI detection
  83. GRB 230818A: Leavitt Observatory upper limit
  84. GRB 230818A: Swift-XRT refined Analysis
  85. GRB 230818A: Bassano Bresciano Observatory optical observations
  86. GRB 230818A: KGO RC-25 optical observations
  87. GRB 230818A: Swift/UVOT Detection
  88. GRB 230818A: NOT photometry and spectroscopy
  89. GRB 230818A: Enhanced Swift-XRT position
  90. GRB 230818A: GOTO optical afterglow detection
  91. GRB 230818A: Swift detection of a burst
  92. Swift GRB230818.98: Global MASTER-Net observations report
  93. Swift GRB230818.98: Global MASTER-Net OT detection
  94. GRB 230816A: Swift-BAT refined analysis
  95. GRB 230816A: SVOM/C-GFT optical detection
  96. GRB 230816A: Swift-XRT refined Analysis
  97. GRB 230816A: Osservatorio Astronomico "Nastro Verde" optical observations
  98. GRB 230812B: NOEMA detection
  99. GRB 230815A: VLT/HAWK-I near-infrared afterglow detection
  100. GRB 230812B: optical photometry from Konkoly

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