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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"

28251 results found.

  1. GRB 230919A: Fermi GBM Final Real-time Localization
  2. LIGO/Virgo S230917af: Swift XRT observations, 6 X-ray sources
  3. Detection of self-absorbed radio emission from GRB 230812B with the JVLA + uGMRT
  4. GRB 230918B: Fermi GBM Final Real-time Localization
  5. GRB 230918A (short): Glowbug gamma-ray detection
  6. GRB 230916B: Glowbug gamma-ray detection
  7. AT 2023sva: NOT observations of the ZTF candidate afterglow
  8. ZTF and SEDM Observations of the Candidate Optical Afterglow AT 2023sva
  9. LIGO/Virgo/KAGRA S230918aq: Retraction of GW compact binary merger candidate
  10. GRB 230812B: Radio observations with the uGMRT
  11. GRB 230918A: Fermi GBM Final Real-time Localization
  12. GRB 230917A: AstroSat CZTI detection
  13. GRB 230915B: Glowbug gamma-ray detection
  14. GRB 230911A: Fermi GBM Observation
  15. LIGO/Virgo/KAGRA S230904n: Correction of the coordinates of the ZTF candidate counterpart
  16. GRB 230915A: Swift/BAT-GUANO detection of a burst
  17. GRB 230911D: GRBAlpha detection
  18. GRB 230906A: optical counterpart
  19. GRB 230911A: Swift-XRT afterglow detection
  20. GRB 230913A: CALET Gamma-Ray Burst Monitor detection
  21. GRB 230913A: Glowbug gamma-ray detection
  22. IceCube-230914A - IceCube observation of a high-energy neutrino candidate track-like event
  23. LIGO/Virgo/KAGRA S230904n: One ZTF candidate counterpart to coincident neutrino event
  24. GRB 230911A: Swift ToO observations
  25. GRB 230913A: Swift/BAT-GUANO arcminute localization of a burst
  26. GRB 230913A: Fermi GBM Final Real-time Localization
  27. GRB 230908A: CALET Gamma-Ray Burst Monitor detection
  28. GRB 230911D: NuSTAR Detection of Prompt Emission
  29. GRB 230911B: AstroSat CZTI detection
  30. GRB 230911C: Swift-XRT refined Analysis
  31. GRB230911C: BOOTES-6/DPRT optical upper limit
  32. GRB 230906A: Chandra detection of the X-ray afterglow
  33. IPN triangulation of GRB 230911D (long)
  34. GRB 230911D: Fermi-LAT detection
  35. GRB230911C: LCOGT Optical Upper Limits
  36. GRB 230911C: Swift/UVOT Upper Limits
  37. GRB 230911B: GRBAlpha and VZLUSAT-2 joint detection
  38. GRB 230911C: GOTO optical upper limits
  39. GRB 230908A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  40. GRB 230911B: correction to the KW GCN 34659
  41. Konus-Wind detection of GRB 230811D
  42. GRB 230911C: Enhanced Swift-XRT position
  43. GRB 230911D: Fermi GBM Final Localization
  44. GRB 230911C: Swift detection of a burst
  45. GRB 230911B: Fermi GBM Final Real-time Localization
  46. GRB 230911A: Fermi GBM Final Real-time Localization
  47. GRB 230906A: BlackGEM upper limits
  48. GRB 230903A: TESS observations of optical emission
  49. GRB 230906A: AstroSat CZTI detection
  50. GRB 230910A: Fermi GBM Final Real-time Localization
  51. GRB 230908A: GRBAlpha detection
  52. GRB 230908A: AstroSat CZTI detection
  53. Glowbug gamma-ray detection GRB 230905B
  54. GRB 230906A: Swift/UVOT Upper Limits
  55. GRID detection of GRB 230827A
  56. GRB 230906A: Swift-XRT observations
  57. Konus-Wind detection of GRB 230906A (short)
  58. IPN triangulation of GRB 230906A (short)
  59. GRB 230906A: Swift ToO observations
  60. GRB 230905B: AstroSat CZTI detection
  61. Swift Attitude Control Affecting Some UVOT Images
  62. GRB 230812B: Chandra late-time detection of the X-ray afterglow
  63. GRB 230906A: Fermi GBM Final Localizationn
  64. GRB 230905B: GECAM-C detection of a long burst
  65. GRB 230905A: Fermi GBM Final Real-time Localization
  66. GRB 230903A: Swift-XRT refined Analysis
  67. GRB 230903A: Enhanced Swift-XRT position
  68. GRB 230903A: VLT/X-shooter optical observations
  69. GRB 230904C: Fermi GBM Final Localization
  70. GRB 230903A: Fermi GBM detection
  71. GRB 230904A: Fermi GBM Final Real-time Localization
  72. GRB 230903A: LCOGT Optical Upper Limits
  73. GRB 230903A: Swift detection of a burst
  74. GRB 230903A: Fermi GBM Final Real-time Localization
  75. GRB 230827B: Glowbug gamma-ray detection
  76. GRB 230827A: Glowbug gamma-ray detection
  77. GRB 230826A: Glowbug gamma-ray detection
  78. GRB 230827B: Swift-XRT afterglow detection
  79. LIGO/Virgo/KAGRA S230830b: Retraction of GW compact binary merger candidate
  80. GRB 230812B: Spectroscopic detection of the associated SN 2023pel.
  81. GRB 230827B: Swift ToO observations
  82. GRB 230827B: CALET Gamma-Ray Burst Monitor detection
  83. GRB 230828A: AstroSat CZTI detection
  84. GRB 230828A: GRBAlpha detection
  85. GRB 230827A: VZLUSAT-2 detection
  86. GRB 230827A: Swift/BAT-GUANO detection of a burst outside the coded FOV
  87. GRB 230826A: VZLUSAT-2 detection
  88. GRB 230827B: VZLUSAT-2 detection
  89. GRB 230827B / GRB 230827256: Fermi GBM Observation
  90. GRB 230827A: GRBAlpha detection
  91. Subject: GRB230826A: Swift/UVOT upper limits
  92. GRB 230827.256 : GIT optical follow-up of ZTF23abaanxz/AT2023qxj
  93. GRB 230827A: Fermi GBM Final Real-time Localization
  94. AT 2023qxj: ZTF discovery of the likely afterglow of Fermi GRB 230827256
  95. GRB 230826A: GRBAlpha detection
  96. GRB 230826A: Enhanced Swift-XRT position
  97. GRB 230826A: Swift-XRT refined Analysis
  98. GRB 230826A: Mondy optical observations
  99. GRB 230826A: Swift detection of a burst
  100. GRB 230826A: Fermi GBM Final Real-time Localization

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