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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"

32544 results found.

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

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