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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"

37763 results found.

  1. Fermi Gamma-ray Burst Monitor trigger 717299390/230925076 is not a GRB
  2. Fermi Gamma-ray Burst Monitor trigger 230925241/717313591 is not a GRB
  3. GRB 230812B: r'-band observations from MISTRAL at Observatoire de Haute-Provence
  4. GRB 230921A: Fermi GBM Final Real-time Localization
  5. GRB 230918B: VLT/X-shooter classification of AT 2023tbf (GOTO23aky) as a dwarf nova
  6. IPN triangulation of GRB 230919A (short)
  7. GRB 230919A: Fermi GBM Observation
  8. Correction to Fermi GBM Statement for Trigger 716527670/230916144
  9. Fermi GBM Statement for Trigger 716527670/230916144
  10. GRB 230919A: Swift/BAT-GUANO detection of a possibly short burst outside the coded FOV
  11. GRB 230812B : optical observations from MISTRAL at Observatoire de Haute-Provence
  12. GRB 230919A: AstroSat CZTI detection
  13. AT2023sva: redshift from OSIRIS+/GTC of the ZTF afterglow
  14. GRB 230918B: GOTO detection of a fast-rising transient in the GBM localisation region
  15. GRB 230919A: Fermi GBM Final Real-time Localization
  16. Detection of self-absorbed radio emission from GRB 230812B with the JVLA + uGMRT
  17. GRB 230918B: Fermi GBM Final Real-time Localization
  18. GRB 230918A (short): Glowbug gamma-ray detection
  19. GRB 230916B: Glowbug gamma-ray detection
  20. AT 2023sva: NOT observations of the ZTF candidate afterglow
  21. ZTF and SEDM Observations of the Candidate Optical Afterglow AT 2023sva
  22. GRB 230915A: Fermi GBM observation
  23. GRB 230812B: Radio observations with the uGMRT
  24. GRB 230918A: Fermi GBM Final Real-time Localization
  25. GRB 230917A: AstroSat CZTI detection
  26. GRB 230915B: Glowbug gamma-ray detection
  27. GRB 230916A: NuSTAR Discovery of Prompt Emission from a Potential GRB
  28. GRB 230911A: Fermi GBM Observation
  29. Fermi trigger No 716572242: Global MASTER-Net observations report
  30. Fermi trigger No 716544961: Global MASTER-Net observations report
  31. Fermi-LAT gamma-ray observations of IceCube-230914A
  32. GRB 230915A: Swift/BAT-GUANO detection of a burst
  33. LIGO/Virgo/KAGRA S230914ak: Upper limits from Swift/BAT-GUANO
  34. GRB 230911D: GRBAlpha detection
  35. Swift Trigger 1192233 is not a GRB
  36. GRB 230906A: optical counterpart
  37. GRB 230911A: Swift-XRT afterglow detection
  38. Fermi trigger No 716449174: Global MASTER-Net observations report
  39. GRB 230913A: CALET Gamma-Ray Burst Monitor detection
  40. Fermi trigger No 716419312: Global MASTER-Net observations report
  41. GRB 230913A: Glowbug gamma-ray detection
  42. GRB 230812B: Bad Time Intervals for Fermi GBM data
  43. IceCube-230914A - IceCube observation of a high-energy neutrino candidate track-like event
  44. GRB 230913A: Fermi GBM Observation
  45. Swift Trigger 1191904 is not a GRB
  46. GRB 230911A: Swift ToO observations
  47. GRB 230913A: Swift/BAT-GUANO arcminute localization of a burst
  48. Fermi GRB 230913A: Global MASTER-Net observations report
  49. GRB 230911A: GOTO optical counterpart candidate
  50. GRB 230913A: Fermi GBM Final Real-time Localization
  51. GRB 230908A: CALET Gamma-Ray Burst Monitor detection
  52. GRB 230911D: NuSTAR Detection of Prompt Emission
  53. GRB 230911B: AstroSat CZTI detection
  54. GRB 230911C: Swift-XRT refined Analysis
  55. GRB 230911C: Swift-BAT refined analysis
  56. GRB230911C: BOOTES-6/DPRT optical upper limit
  57. GRB 230906A: Chandra detection of the X-ray afterglow
  58. Swift GRB 230911C: Global MASTER-Net observations report
  59. GRB 230911D: Fermi GBM observation
  60. IPN triangulation of GRB 230911D (long)
  61. GRB 230911D: Fermi-LAT detection
  62. GRB230911C: LCOGT Optical Upper Limits
  63. GRB 230911C: Swift/UVOT Upper Limits
  64. GRB 230911B: GRBAlpha and VZLUSAT-2 joint detection
  65. Fermi trigger No 716145795: Global MASTER-Net observations report
  66. GRB 230911C: GOTO optical upper limits
  67. GRB 230908A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  68. GRB 230911B: correction to the KW GCN 34659
  69. Konus-Wind detection of GRB 230811D
  70. GRB 230911C: Enhanced Swift-XRT position
  71. GRB 230911D: BALROG localization (Fermi Trigger 716111594/ GRB 230911329)
  72. GRB 230911D: Fermi GBM Final Localization
  73. GRB 230911C: Swift detection of a burst
  74. Fermi GRB 230911B: Global MASTER-Net observations report
  75. GRB 230911B: Fermi GBM Final Real-time Localization
  76. GRB 230911A: Fermi GBM Final Real-time Localization
  77. GRB 230906A: BlackGEM upper limits
  78. GRB 230903A: TESS observations of optical emission
  79. GRB 230906A: AstroSat CZTI detection
  80. GRB 230910A: Fermi GBM Final Real-time Localization
  81. GRB 230908A: GRBAlpha detection
  82. GRB 230908A: AstroSat CZTI detection
  83. Glowbug gamma-ray detection GRB 230905B
  84. GRB 230906A: Swift/UVOT Upper Limits
  85. GRID detection of GRB 230827A
  86. GRB 230818A: radio observation with the VLA
  87. GRB 230205A: LBT spectroscopy of two host galaxy candidates
  88. GRB 230906A: Swift-XRT observations
  89. Konus-Wind detection of GRB 230906A (short)
  90. IPN triangulation of GRB 230906A (short)
  91. GRB 230906A: Swift ToO observations
  92. GRB 230905B: AstroSat CZTI detection
  93. Fermi GRB 230906A: Global MASTER-Net observations report
  94. GRB 230812B: Chandra late-time detection of the X-ray afterglow
  95. GRB 230906A: Fermi GBM Final Localizationn
  96. GRB 230905B: GECAM-C detection of a long burst
  97. GRB 230905A: Fermi GBM Final Real-time Localization
  98. GRB 230903A: Swift-XRT refined Analysis
  99. GRB 230903A: Enhanced Swift-XRT position
  100. GRB 230903A: VLT/X-shooter optical observations

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