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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"

24555 results found.

  1. LIGO/Virgo/KAGRA S230819ax: Updated Sky localization
  2. LIGO/Virgo/KAGRA S230819ax: Identification of a GW compact binary merger candidate
  3. Fermi GRB 230818A: Global MASTER-Net observations report
  4. Fermi trigger No 713974668: Global MASTER-Net observations report
  5. GRB 230818A: Swift detection of a burst
  6. GRB 230818A: Fermi GBM Final Real-time Localization
  7. Swift GRB230818.98: Global MASTER-Net observations report
  8. Swift GRB230818.98: Global MASTER-Net OT detection
  9. GRB 230816A: Swift-BAT refined analysis
  10. GRB 230816A: SVOM/C-GFT optical detection
  11. Fermi GRB 230817A: Global MASTER-Net observations report
  12. GRB 230817A: BALROG localization (Fermi Trigger 713966581 / GRB 230817502)
  13. GRB 230817A: Fermi GBM Final Real-time Localization
  14. Swift GRB230816.80: Global MASTER-Net observations report
  15. IPN triangulation of GRB 230815B
  16. Swift GRB230816.67: Global MASTER-Net observations report
  17. GRB 230815A: Swift-BAT refined analysis
  18. GRB 230815B: GECAM-B and GECAM-C detection of a burst
  19. GRB 230815A: Swift-XRT refined Analysis
  20. GRB 230812B: iTelescope optical upper limit
  21. GRB 230815A: Fermi GBM detection
  22. Swift GRB 230815A: Global MASTER-Net observations report
  23. Fermi GRB 230814A: Global MASTER-Net observations report
  24. GRB 230815A: Swift detection of a burst
  25. LIGO/Virgo/KAGRA S230814ah: Identification of a GW compact binary merger candidate
  26. GRB 230812B: Upper limits from a neutrino search with IceCube
  27. LIGO/Virgo/KAGRA S230814r: Updated Sky localization
  28. GRB 230812B: GRANDMA further observations of ZTF23aaxeacr candidate afterglow
  29. GRB 230814A: BALROG localization (Fermi Trigger 713732101 / GRB 230814788)
  30. GRB 230814A: Fermi GBM Final Real-time Localization
  31. GRB 230812B: GIT optical follow-up
  32. GRB 230812B: Leavitt Observatory optical observations
  33. GRB 230812B: rest-frame energetics from Konus-Wind observation
  34. LIGO/Virgo/KAGRA S230814r: Identification of a GW compact binary merger candidate
  35. GRB 230812B: Redshift from OSIRIS+/GTC
  36. LIGO/Virgo/KAGRA S230812aj: two counterpart neutrino candidates from IceCube neutrino searches
  37. GRB 230812B: Detected Optical Afterglow Candidate
  38. Konus-Wind detection of GRB 230812B
  39. GRB230812B: AGILE/MCAL detection
  40. GRB 230812B: GECAM-C observation of a very bright burst
  41. GRB 230812B: Swift-XRT afterglow detection
  42. GRB 230812B: Zwicky Transient Facility Identifies Optical Afterglow Candidate of a Fermi GRB (Trigger 713559497)
  43. GRB 230812B: KAIT Optical Afterglow Candidate
  44. GRB 230812B: Improved Swift/XRT localization
  45. GRB 230812B: Preliminary Swift/XRT localization
  46. GRB 230812B: Fermi-LAT detection
  47. GRB 230812B: Fermi GBM Observation of a very bright burst
  48. LAT GRB230812.79: Global MASTER-Net observations report
  49. Fermi GRB 230812B: Global MASTER-Net observations report
  50. GRB 230812B: Fermi GBM detection of an extremely bright GRB
  51. GRB 230812B: Fermi GBM Final Real-time Localization
  52. Fermi trigger No 713525317: Global MASTER-Net observations report
  53. GRB 230812A: Fermi GBM Final Real-time Localization
  54. LIGO/Virgo/KAGRA S230811n: Updated Sky localization
  55. GRB 230808A: Fermi GBM Detection
  56. LIGO/Virgo/KAGRA S230811n: Identification of a GW compact binary merger candidate
  57. GRB 230805B: Swift-BAT refined analysis
  58. LIGO/Virgo/KAGRA S230810af: Retraction of GW compact binary merger candidate
  59. GRB 230808A: Swift/BAT-GUANO detection of a burst
  60. Fermi trigger No 713136868: Global MASTER-Net observations report
  61. GRB 230808B: Fermi GBM Final Real-time Localization
  62. Fermi trigger No 713205976: Global MASTER-Net observations report
  63. GRB 230808A: Fermi GBM Final Real-time Localization
  64. GRB 230805B : MITSuME Akeno optical upper limits
  65. LIGO/Virgo/KAGRA S230808i: Identification of a GW unmodeled transient candidate
  66. LIGO/Virgo/KAGRA S230807f: Updated Sky localization and EM Bright Classification
  67. Fermi GRB 230807A: Global MASTER-Net observations report
  68. Fermi trigger No 713134237: Global MASTER-Net observations report
  69. GRB 230807A: Fermi GBM Final Real-time Localization
  70. LIGO/Virgo/KAGRA S230807f: Identification of a GW compact binary merger candidate
  71. LIGO/Virgo/KAGRA S230805x: Upper limits from Swift/BAT-GUANO
  72. Konus-Wind detection of GRB 230803A
  73. GRB 230805B: Fermi GBM observation
  74. GRB 230805B : OHP/T193 optical upper limit
  75. LIGO/Virgo/KAGRA S230806ak: Updated Sky localization and EM Bright Classification
  76. GRB 230806A: Fermi GBM Final Localization
  77. LIGO/Virgo/KAGRA S230806ak: Identification of a GW compact binary merger candidate
  78. Fermi trigger No 712991593: Global MASTER-Net observations report
  79. Fermi trigger No 712987357: Global MASTER-Net observations report
  80. Fermi GRB 230805A: Global MASTER-Net observations report
  81. Fermi trigger No 712927418: Global MASTER-Net observations report
  82. Swift GRB 230805B: Global MASTER-Net observations report
  83. LIGO/Virgo/KAGRA S230805x: Updated Sky localization
  84. GRB 230805A: Fermi GBM Final Real-time Localization
  85. LIGO/Virgo/KAGRA S230805x: Identification of a GW compact binary merger candidate
  86. LIGO/Virgo/KAGRA S230802aq: Updated Sky localization and EM Bright Classification
  87. GRB 230802A: Fermi GBM observation
  88. GRB 230802A: Swift-BAT refined analysis
  89. GRB 230804A: Fermi GBM Final Real-time Localization
  90. Fermi trigger No 712798043: Global MASTER-Net observations report
  91. IPN triangulation of GRB 230803A
  92. LIGO/Virgo/KAGRA S230802aq: AstroSat CZTI non-detection and upper limits
  93. Fermi trigger No 712718833: Global MASTER-Net observations report
  94. GRB 230803A: Fermi GBM Final Real-time Localization
  95. Fermi trigger No 712713532: Global MASTER-Net observations report
  96. Fermi trigger No 712651827: Global MASTER-Net observations report
  97. GRB 230802B: Fermi GBM Final Localization
  98. Swift GRB 230802A: Global MASTER-Net observations report
  99. LIGO/Virgo/KAGRA S230802aq: Upper limits from Fermi-GBM Observations
  100. LIGO/Virgo S230802aq: No counterpart candidates in INTEGRAL SPI-ACS prompt observation

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