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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"

27774 results found.

  1. GRB 230802B: AstroSat CZTI detection
  2. GRB 230802A: Fermi GBM observation
  3. GRB 230802A: Swift-BAT refined analysis
  4. GRB 230804A: Fermi GBM Final Real-time Localization
  5. IPN triangulation of GRB 230803A
  6. GRB 230802A: Swift/UVOT Upper Limits
  7. GRB 230803A: AstroSat CZTI detection
  8. LIGO/Virgo/KAGRA S230802aq: AstroSat CZTI non-detection and upper limits
  9. GRB 230803A: Fermi GBM Final Real-time Localization
  10. GRB 230802B: Fermi GBM Final Localization
  11. Swift GRB 230802A: Global MASTER-Net observations report
  12. GRB 230802A: BOOTES-5/JGT optical upper limit
  13. LIGO/Virgo/KAGRA S230802aq: Upper limits from Fermi-GBM Observations
  14. GRB 230802A: Swift-XRT refined Analysis
  15. GRB 230802A: Enhanced Swift-XRT position
  16. GRB 230802A: Swift detection of a burst
  17. LIGO/Virgo/KAGRA S230731an: Upper limits from Swift/BAT-GUANO
  18. LIGO/Virgo/KAGRA S230731an: AstroSat CZTI non-detection and upper limits
  19. GRB 230731A: Fermi GBM Final Real-time Localization
  20. GRB 230723A: Detection of candidate millimeter-band radiation by SPT-3G
  21. GRB 230728A: Swift-BAT refined analysis
  22. GRB 230723B: Swift-BAT refined analysis
  23. GRB 230723B: MITSuME Ishigaki optical observation
  24. GRB 230728A: BOOTES-1 optical upper limit
  25. GRB 230728A: Fermi GBM Observation
  26. GRB 230728A: LCOGT Optical Upper Limit
  27. GRB 230728A: Swift/UVOT Upper Limits
  28. GRB 230728A: Swift-XRT refined Analysis
  29. GRB 230728A: Enhanced Swift-XRT position
  30. GRB 230728A: NOT optical observations and possible host galaxy
  31. GRB 230727A: AstroSat CZTI detection
  32. GRB 230728A: Swift detection of a burst
  33. Swift GRB230728.12: Global MASTER-Net observations report
  34. GRB 230727A: Swift/BAT-GUANO detection of a burst
  35. IceCube-230727A - IceCube observation of a high-energy neutrino candidate track-like event
  36. GRB 230727A: Fermi GBM Final Real-time Localization
  37. GRB 230723B: Further CAHA observations and host galaxy detection
  38. Konus-Wind detection of GRB 230723A
  39. GRB 230723B: MITSuME Akeno optical afterglow candidate detection
  40. IceCube-230724A - IceCube observation of a high-energy neutrino candidate track-like event
  41. IBAS trigger number 10337: not a real GRB
  42. IceCube-230725A - IceCube observation of a high-energy neutrino candidate track-like event
  43. GRB 230723B: GAD Observatory, La Spezia, Italy upper limit
  44. IPN triangulation of GRB 230723A (short)
  45. GRB 230725B: Fermi GBM Final Real-time Localization
  46. GRB 230725A: Fermi GBM Final Real-time Localization
  47. GRB 230723B: Leavitt Observatory upper limit
  48. GRB 230723B: Osservatorio Astronomico Nastro Verde upper limit
  49. GRB 230723B: Montarrenti Observatory upper limit
  50. GRB 230723B: Bassano Bresciano Observatory upper limit
  51. GRB 230723B: Fermi GBM observation
  52. GRB 230723B: Swift-XRT refined Analysis
  53. GRB 230724A: Fermi GBM Final Real-time Localization
  54. GRB 230723B: Swift/UVOT Upper Limits
  55. Swift GRB 230723B: Global MASTER-Net observations report
  56. Swift-XRT position for GRB 230723B
  57. GRB 230723A: AGILE/MCAL detection
  58. GRB 230723B: Swift-XRT observations
  59. GRB 230723B: Swift detection of a burst
  60. GRB 230723A: Fermi GBM Final Real-time Localization
  61. Swift GRB230720.30: Global MASTER-Net observations report
  62. IPN triangulation of GRB 230715D
  63. Swift Trigger 1180063 is not a GRB
  64. Swift Trigger 1180060 is not a GRB
  65. Swift Trigger 1180055 is not a GRB
  66. GRB 230718A: Final Localization Correction
  67. GRB 230718A: Fermi GBM Final Real-time Localization
  68. IPN triangulation of GRB 230712C (short)
  69. IPN triangulation of GRB 230712A (short)
  70. GRB 230717A: Fermi GBM Final Real-time Localization
  71. LIGO/Virgo/KAGRA S230715bw: Retraction of GW compact binary merger candidate
  72. GRB 230715A: Fermi GBM Final Real-time Localization
  73. IceCube-230707A : MAXI upper limit and NICER follow-up observation of Swift J1753.5-0127
  74. GRB 230713A: Fermi GBM Final Real-time Localization
  75. GRB 230709B: CALET Gamma-Ray Burst Monitor detection
  76. GRB 230703A: CALET Gamma-Ray Burst Monitor detection
  77. GRB 230709C: Swift/BAT-GUANO detection of a short burst outside the coded FOV
  78. IceCube-230708A: Upper limits from Swift/BAT-GUANO
  79. GRB 230712B: Fermi GBM Final Localization
  80. GRB 230707A: Swift/BAT-GUANO position correction
  81. GRB 230712A: Fermi GBM Final Real-time Localization
  82. GRB 230709C: GRBAlpha detection
  83. GRB 230709B: GRBAlpha detection
  84. GRB 230709C: Fermi GBM Detection
  85. GRB 230709C: Fermi GBM Final Localization
  86. GRB 230707B: Fermi GBM Observation
  87. GRB 230710A: Fermi GBM Final Real-time Localization
  88. IceCube-230707A: No candidates detected by Swift-XRT
  89. Swift Trigger 1178410 is not an astrophysical event
  90. GRB 230709C: AstroSat CZTI detection
  91. GRB 230707B: CALET Gamma-Ray Burst Monitor detection
  92. Swift Trigger 1178410: possible GRB 230709A
  93. GRB 230628C: GRID Detection
  94. IceCube-230708A - IceCube observation of a high-energy neutrino candidate track-like event
  95. GRB 230707B: Swift/BAT-GUANO detection of a burst outside the coded FOV
  96. GRB 230707A: Swift-XRT observations
  97. IceCube-230707B - IceCube observation of a high-energy neutrino candidate track-like event
  98. GRB 230707B: Fermi GBM Final Real-time Localization
  99. IceCube-230707A - IceCube observation of a high-energy neutrino candidate track-like event
  100. GRB 230707A: Fermi GBM Detection

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