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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').
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"

32546 results found.

  1. GRB 230911D: NuSTAR Detection of Prompt Emission
  2. GRB 230911B: AstroSat CZTI detection
  3. GRB 230911C: Swift-BAT refined analysis
  4. LIGO/Virgo/KAGRA S230911ae: Updated Sky localization
  5. GRB 230906A: Chandra detection of the X-ray afterglow
  6. Swift GRB 230911C: Global MASTER-Net observations report
  7. GRB 230911D: Fermi GBM observation
  8. IPN triangulation of GRB 230911D (long)
  9. GRB 230911D: Fermi-LAT detection
  10. GRB230911C: LCOGT Optical Upper Limits
  11. LIGO/Virgo/KAGRA S230911ae: Identification of a GW compact binary merger candidate
  12. GRB 230911C: Swift/UVOT Upper Limits
  13. GRB 230911B: GRBAlpha and VZLUSAT-2 joint detection
  14. GRB 230911C: GOTO optical upper limits
  15. GRB 230908A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  16. GRB 230911B: correction to the KW GCN 34659
  17. Konus-Wind detection of GRB 230811D
  18. GRB 230911C: Swift detection of a burst
  19. Fermi GRB 230911B: Global MASTER-Net observations report
  20. GRB 230906A: BlackGEM upper limits
  21. GRB 230903A: TESS observations of optical emission
  22. GRB 230906A: AstroSat CZTI detection
  23. GRB 230908A: GRBAlpha detection
  24. Glowbug gamma-ray detection GRB 230905B
  25. GRB 230906A: Swift/UVOT Upper Limits
  26. GRID detection of GRB 230827A
  27. GRB 230818A: radio observation with the VLA
  28. GRB 230205A: LBT spectroscopy of two host galaxy candidates
  29. GRB 230906A: Swift-XRT observations
  30. Konus-Wind detection of GRB 230906A (short)
  31. IPN triangulation of GRB 230906A (short)
  32. GRB 230906A: Swift ToO observations
  33. GRB 230905B: AstroSat CZTI detection
  34. Fermi GRB 230906A: Global MASTER-Net observations report
  35. GRB 230812B: Chandra late-time detection of the X-ray afterglow
  36. LIGO/Virgo/KAGRA S230904n: Updated Sky localization and EM Bright Classification
  37. GRB 230903A: VLT/X-shooter optical observations
  38. GRB 230903A: Swift-BAT refined analysis
  39. Fermi GRB 230903A: Global MASTER-Net observations report
  40. GRB 230903A: Fermi GBM detection
  41. GRB 230904B is not a GRB
  42. Fermi GRB 230904A: Global MASTER-Net observations report
  43. LIGO/Virgo/KAGRA S230904n: Identification of a GW compact binary merger candidate
  44. GRB 230903A: LCOGT Optical Upper Limits
  45. LIGO/Virgo/KAGRA S230831e: Updated Sky localization
  46. LIGO/Virgo/KAGRA S230831e: Identification of a GW compact binary merger candidate
  47. GRB 230827B: Glowbug gamma-ray detection
  48. GRB 230827A: Glowbug gamma-ray detection
  49. GRB 230826A: Glowbug gamma-ray detection
  50. GRB 230827B: Swift-XRT afterglow detection
  51. LIGO/Virgo/KAGRA S230715bw: Reissue of Retraction of GW compact binary merger candidate
  52. LIGO/Virgo/KAGRA S230820bq: Updated Sky localization
  53. GRB 230812B: Spectroscopic detection of the associated SN 2023pel.
  54. GRB 230827B: Swift ToO observations
  55. LIGO/Virgo/KAGRA S230814ah: Updated Sky localization
  56. GRB 230827A: Fermi GBM Observation
  57. GRB 230827B: CALET Gamma-Ray Burst Monitor detection
  58. GRB 230826A: Swift-BAT refined analysis
  59. GRB 230828A: AstroSat CZTI detection
  60. GRB 230827A: VZLUSAT-2 detection
  61. GRB 230827A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  62. GRB 230826A: VZLUSAT-2 detection
  63. GRB 230827B: VZLUSAT-2 detection
  64. GRB 230827B / GRB 230827256: Fermi GBM Observation
  65. GRB 230827A: GRBAlpha detection
  66. Subject: GRB230826A: Swift/UVOT upper limits
  67. GRB 230827.256: AKO Optical follow-up of ZTF23abaanxz (AT 2023qxj)
  68. Fermi GRB 230827A: Global MASTER-Net observations report
  69. Swift J1727.8-1613 (GRB 230824A): Osservatorio Astronomico "Nastro Verde" optical observations
  70. GRB 230827.256 : GIT optical follow-up of ZTF23abaanxz/AT2023qxj
  71. Swift J1727.8-1613 (GRB 230824A): Montarrenti Observatory photometric observations
  72. GRB 230826A: GRBAlpha detection
  73. GRB 230826A: Fermi GBM Observation
  74. Swift J1727.8-1613 (GRB 230824A): Leavitt Observatory optical observations
  75. GRB 230826A: Mondy optical observations
  76. Swift J1727.8-1613 (GRB 230824A): GAD Observatory La Spezia - optical observations
  77. GRB 230826A: Swift detection of a burst
  78. Swift J1727.8-1613 (GRB 230824A): Bassano Bresciano Observatory optical observations
  79. GRB 230824A: AKO Photometric Follow-up Observations
  80. GRB 230818B: CALET Gamma-Ray Burst Monitor detection
  81. Trigger 1187225: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  82. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  83. Trigger 1187207: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  84. Trigger 1187203: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  85. GRB 230812B: radio detection with the VLA
  86. NICER detection of Swift J1727.8-1613 (GRB 230824A)
  87. LIGO/Virgo/KAGRA S230825k: Updated Sky localization
  88. Trigger 1187142: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  89. LIGO/Virgo/KAGRA S230825k: Identification of a GW compact binary merger candidate
  90. MAXI/GSC detection of Swift J1727.8-1613 (GRB 230824A)
  91. GRB 230824A: AKO Optical Afterglow Candidate
  92. Trigger 1186982: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  93. IBAS trigger 10375 is not a GRB
  94. GRB 230824A is likely a Galactic Transient: Swift J1727.8-1613
  95. LIGO/Virgo/KAGRA S230824r: Updated Sky localization
  96. LIGO/Virgo/KAGRA S230824r: Identification of a GW compact binary merger candidate
  97. GRB 230822A: Fermi GBM Observation
  98. GRB 230822A: Swift/BAT-GUANO detection of a burst
  99. IceCube-230823A: Event likely due to background
  100. GRB 230818B: VZLUSAT-2 detection

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