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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"

31734 results found.

  1. GRB 230911B: GRBAlpha and VZLUSAT-2 joint detection
  2. GRB 230911C: GOTO optical upper limits
  3. GRB 230908A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  4. GRB 230911B: correction to the KW GCN 34659
  5. Konus-Wind detection of GRB 230811D
  6. GRB 230911C: Swift detection of a burst
  7. Fermi GRB 230911B: Global MASTER-Net observations report
  8. GRB 230906A: BlackGEM upper limits
  9. GRB 230903A: TESS observations of optical emission
  10. GRB 230906A: AstroSat CZTI detection
  11. GRB 230908A: GRBAlpha detection
  12. Glowbug gamma-ray detection GRB 230905B
  13. GRB 230906A: Swift/UVOT Upper Limits
  14. GRID detection of GRB 230827A
  15. GRB 230818A: radio observation with the VLA
  16. GRB 230205A: LBT spectroscopy of two host galaxy candidates
  17. GRB 230906A: Swift-XRT observations
  18. Konus-Wind detection of GRB 230906A (short)
  19. IPN triangulation of GRB 230906A (short)
  20. GRB 230906A: Swift ToO observations
  21. GRB 230905B: AstroSat CZTI detection
  22. Fermi GRB 230906A: Global MASTER-Net observations report
  23. GRB 230812B: Chandra late-time detection of the X-ray afterglow
  24. LIGO/Virgo/KAGRA S230904n: Updated Sky localization and EM Bright Classification
  25. GRB 230903A: VLT/X-shooter optical observations
  26. GRB 230903A: Swift-BAT refined analysis
  27. Fermi GRB 230903A: Global MASTER-Net observations report
  28. GRB 230903A: Fermi GBM detection
  29. GRB 230904B is not a GRB
  30. Fermi GRB 230904A: Global MASTER-Net observations report
  31. LIGO/Virgo/KAGRA S230904n: Identification of a GW compact binary merger candidate
  32. GRB 230903A: LCOGT Optical Upper Limits
  33. LIGO/Virgo/KAGRA S230831e: Updated Sky localization
  34. LIGO/Virgo/KAGRA S230831e: Identification of a GW compact binary merger candidate
  35. GRB 230827B: Glowbug gamma-ray detection
  36. GRB 230827A: Glowbug gamma-ray detection
  37. GRB 230826A: Glowbug gamma-ray detection
  38. GRB 230827B: Swift-XRT afterglow detection
  39. LIGO/Virgo/KAGRA S230715bw: Reissue of Retraction of GW compact binary merger candidate
  40. LIGO/Virgo/KAGRA S230820bq: Updated Sky localization
  41. GRB 230812B: Spectroscopic detection of the associated SN 2023pel.
  42. GRB 230827B: Swift ToO observations
  43. LIGO/Virgo/KAGRA S230814ah: Updated Sky localization
  44. GRB 230827A: Fermi GBM Observation
  45. GRB 230827B: CALET Gamma-Ray Burst Monitor detection
  46. GRB 230826A: Swift-BAT refined analysis
  47. GRB 230828A: AstroSat CZTI detection
  48. GRB 230827A: VZLUSAT-2 detection
  49. GRB 230827A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  50. GRB 230826A: VZLUSAT-2 detection
  51. GRB 230827B: VZLUSAT-2 detection
  52. GRB 230827B / GRB 230827256: Fermi GBM Observation
  53. GRB 230827A: GRBAlpha detection
  54. Subject: GRB230826A: Swift/UVOT upper limits
  55. GRB 230827.256: AKO Optical follow-up of ZTF23abaanxz (AT 2023qxj)
  56. Fermi GRB 230827A: Global MASTER-Net observations report
  57. Swift J1727.8-1613 (GRB 230824A): Osservatorio Astronomico "Nastro Verde" optical observations
  58. GRB 230827.256 : GIT optical follow-up of ZTF23abaanxz/AT2023qxj
  59. Swift J1727.8-1613 (GRB 230824A): Montarrenti Observatory photometric observations
  60. GRB 230826A: GRBAlpha detection
  61. GRB 230826A: Fermi GBM Observation
  62. Swift J1727.8-1613 (GRB 230824A): Leavitt Observatory optical observations
  63. GRB 230826A: Mondy optical observations
  64. Swift J1727.8-1613 (GRB 230824A): GAD Observatory La Spezia - optical observations
  65. GRB 230826A: Swift detection of a burst
  66. Swift J1727.8-1613 (GRB 230824A): Bassano Bresciano Observatory optical observations
  67. GRB 230824A: AKO Photometric Follow-up Observations
  68. GRB 230818B: CALET Gamma-Ray Burst Monitor detection
  69. Trigger 1187225: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  70. Swift J1727.8-1613 (GRB 230824A): Skynet Optical Observations
  71. Trigger 1187207: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  72. Trigger 1187203: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  73. GRB 230812B: radio detection with the VLA
  74. NICER detection of Swift J1727.8-1613 (GRB 230824A)
  75. LIGO/Virgo/KAGRA S230825k: Updated Sky localization
  76. Trigger 1187142: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  77. LIGO/Virgo/KAGRA S230825k: Identification of a GW compact binary merger candidate
  78. MAXI/GSC detection of Swift J1727.8-1613 (GRB 230824A)
  79. GRB 230824A: AKO Optical Afterglow Candidate
  80. Trigger 1186982: Swift detection of Swift J1727.8-1613 (AKA GRB 230824A)
  81. IBAS trigger 10375 is not a GRB
  82. GRB 230824A is likely a Galactic Transient: Swift J1727.8-1613
  83. LIGO/Virgo/KAGRA S230824r: Updated Sky localization
  84. LIGO/Virgo/KAGRA S230824r: Identification of a GW compact binary merger candidate
  85. GRB 230822A: Fermi GBM Observation
  86. GRB 230822A: Swift/BAT-GUANO detection of a burst
  87. IceCube-230823A: Event likely due to background
  88. GRB 230818B: VZLUSAT-2 detection
  89. GRB 230818B: AstroSat CZTI detection
  90. GRID detection of GRB 230818A
  91. LIGO/Virgo/KAGRA S230822bm: Updated Sky localization
  92. LIGO/Virgo/KAGRA S230822bm: Identification of a GW compact binary merger candidate
  93. GRB 230812B: Assy optical observations, possible SN rise
  94. GRB 230815A: ATCA detection of radio counterpart
  95. GRB 230812B: SAO RAS RC-500 and Zeiss-1000 observations
  96. GRB 230818A: Swift-BAT refined analysis
  97. GRB 20230818A: GIT optical upper limit
  98. Konus-Wind detection of GRB 230818A
  99. Swift triggers 1186294-1186304 are not astrophysical transients
  100. GRB 230812B : GRANDMA/Kilonova-Catcher optical afterglow detection and upper limits

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