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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"

14929 results found.

  1. GRB 231108A: Fermi GBM Final Real-time Localization
  2. GRB 231106A: AstroSat CZTI detection
  3. GRB 231106A: CALET Gamma-Ray Burst Monitor detection
  4. GRB 231104A: FRAM-ORM optical limit
  5. GRB 231106A: Fermi GBM Final Real-time Localization
  6. GRB 231104A: 3.6m DOT optical upper limit
  7. GRB 231104B: Fermi GBM Final Real-time Localization
  8. GRB 231104A: AstroSat CZTI detection
  9. GRB 231104A: Fermi-LAT detection
  10. GRB 231104A: Swift detection of a bright burst
  11. GRB 231104A: Fermi GBM Final Real-time Localization
  12. GRB 231103A: Fermi GBM Final Real-time Localization
  13. IceCube-231103A - IceCube observation of a high-energy neutrino candidate track-like event
  14. GRB 231101A: Glowbug gamma-ray detection
  15. GRB 231024A: GRANDMA observations of AT2023vuc/GOTO23baj candidate
  16. New Swift-BAT/GUANO and IceCube Notices Available via GCN Kafka
  17. GRB 231101A: Fermi GBM Final Real-time Localization
  18. GRB 231030B: GRBAlpha detection
  19. GRB 231028B: VZLUSAT-2 detection
  20. GRB 231030B: Fermi GBM Detection
  21. GRB 231030B: AstroSat CZTI detection
  22. IPN triangulation of GRB 231020A
  23. GRB 231030B: Fermi GBM Final Real-time Localization
  24. LIGO/Virgo/KAGRA S231030av: Retraction of GW compact binary merger candidate
  25. GRB 231028A: CALET Gamma-Ray Burst Monitor detection
  26. GRB 231030A: Fermi GBM Final Real-time Localization
  27. GRID detection of GRB 231020A
  28. GRB 231028A: AstroSat CZTI detection
  29. GRB 231028A: Glowbug gamma-ray detection
  30. GRB 231028A: Fermi GBM Detection
  31. GRB 231028A: Swift detection of a burst
  32. GRB 231028A: Fermi GBM Final Real-time Localization
  33. IceCube-231027A - IceCube observation of a high-energy neutrino candidate track-like event
  34. GRB 231019A: Glowbug gamma-ray detection
  35. GRB 231025A: Swift/BAT-GUANO detection of a likely short burst
  36. GRB 231025A: Fermi GBM Final Localization
  37. GRB 231024A: X-shooter spectroscopy of AT2023vuc/GOTO23baj reveals a young supernova with flash ionisation features
  38. GRB 231020A: AstroSat CZTI detection
  39. GRB 231020B: AstroSat CZTI detection
  40. GRB 231024A: Fermi GBM Final Localization
  41. GRB 231018A: Swift/BAT-GUANO detection of a long burst outside the coded FOV
  42. GRB 231020A: Fermi GBM Detection
  43. GRID detection of GRB 231004A
  44. GRB 231019A: VZLUSAT-2 detection
  45. GRB 231018A: VZLUSAT-2 detection
  46. GRB 231020B: Fermi GBM Final Real-time Localization
  47. LIGO/Virgo/KAGRA S231020ba: Upper limits from Fermi-GBM Observations
  48. GRB 231015A: NuSTAR Detection of Prompt Emission
  49. GRB 231020A: Fermi GBM Final Real-time Localization
  50. GRB 231012A: Zwicky Transient Facility Follow-Up of a Fermi Short GRB (Trigger 705709044)
  51. GRB 231017A: 1.3m DFOT Optical upper limit
  52. GRB 231018A: GRBAlpha detection
  53. GRB 231018A: CALET Gamma-Ray Burst Monitor detection
  54. GRB 231018A: Glowbug gamma-ray detection
  55. Konus-Wind detection of GRB 231018A
  56. IPN triangulation of GRB 231018A
  57. GRB 230911C: ATCA detection of possible radio counterpart
  58. GRB 231019A: Fermi GBM Final Real-time Localization
  59. IC231004A: Classification of AT2023uqf/ZTF23abidzvf as a rapidly-evolving supernova with CSM interaction
  60. GRB 231017A: Las Cumbres optical upper limit
  61. GRB 231015A: Glowbug gamma-ray detection
  62. GRB 231015A: AstroSat CZTI detection
  63. GRB 231018A: Fermi GBM Detection
  64. GRB 231017A: Fermi GBM Detection
  65. GRB 231018A: Fermi GBM Final Real-time Localization
  66. GRB231017A: Fermi GBM Final Localization
  67. (correction) Discovery of an optical transient with strong flaring activity: a new blazar candidate in the Messier 31 field
  68. Discovery of an optical transient with strong flaring activity: a new blazar candidate in the Messier 31 field.
  69. IceCube-231014A - IceCube observation of a high-energy neutrino candidate track-like event
  70. GRB 231012A: Fermi GBM Final Real-time Localization
  71. GRB 231012A: Fermi GBM Final Real-time Localization
  72. GRB 231004A: Glowbug gamma-ray detection
  73. IceCube-231004A: No significant detection in HAWC
  74. GRB 231004A: CALET Gamma-Ray Burst Monitor detection
  75. IceCube-231004A - IceCube observation of a high-energy neutrino candidate track-like event
  76. GRB 231004A: Fermi GBM Final Real-time Localization
  77. GRB 231003A: Fermi GBM Final Real-time Localization
  78. GRB 230827B: 10.4m GTC spectroscopic redshift
  79. GRB 230930A: Fermi GBM Final Real-time Localization
  80. NuEm-230927A: Swift-XRT follow-up
  81. Konus-Wind detection of GRB 230919A
  82. LIGO/Virgo/KAGRA S230917af: Zwicky Transient Facility observations
  83. GRB 230921A: Fermi GBM Final Real-time Localization
  84. IPN triangulation of GRB 230919A (short)
  85. GRB 230919A: Swift/BAT-GUANO detection of a possibly short burst outside the coded FOV
  86. GRB 230919A: AstroSat CZTI detection
  87. GRB 230918B: GOTO detection of a fast-rising transient in the GBM localisation region
  88. GRB 230919A: Fermi GBM Final Real-time Localization
  89. Detection of self-absorbed radio emission from GRB 230812B with the JVLA + uGMRT
  90. GRB 230918B: Fermi GBM Final Real-time Localization
  91. GRB 230918A (short): Glowbug gamma-ray detection
  92. GRB 230916B: Glowbug gamma-ray detection
  93. ZTF and SEDM Observations of the Candidate Optical Afterglow AT 2023sva
  94. LIGO/Virgo/KAGRA S230918aq: Retraction of GW compact binary merger candidate
  95. GRB 230918A: Fermi GBM Final Real-time Localization
  96. GRB 230917A: AstroSat CZTI detection
  97. GRB 230915B: Glowbug gamma-ray detection
  98. LIGO/Virgo/KAGRA S230904n: Correction of the coordinates of the ZTF candidate counterpart
  99. GRB 230915A: Swift/BAT-GUANO detection of a burst
  100. GRB 230911D: GRBAlpha detection

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