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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"

19602 results found.

  1. GRB 221028A: Swift-XRT refined Analysis
  2. GRB 221028A: 1.3m DFOT Optical upper limit
  3. GRB 221028A, Swift-BAT refined analysis
  4. GRB 221027B: Swift-BAT refined analysis
  5. GRB 221029A: Swift/BAT-GUANO detection outside the coded FOV
  6. Trigger 1132968: Swift trigger is the Crab
  7. GRB 221028A: HCT optical upper limit
  8. GRB 221028A: AGILE detection
  9. GRB 221028A: MITSuME Okayama optical upper limits
  10. Swift GRB 221028A: Global MASTER-Net observations report
  11. GRB 221028A: BOOTES-4/MET optical upper limit
  12. GRB 221028A: GIT optical upper limit
  13. GRB 221027B: Swift/UVOT Upper Limits
  14. GRB 221028A: Swift detection of a burst
  15. GRB 221027B: FRAM-ORM and Ondrejov SBT optical limits
  16. Swift GRB 221027B: Global MASTER-Net observations report
  17. GRB 221027B: Swift-XRT refined Analysis
  18. GRB 221027B: BOOTES-1 optical upper limit
  19. GRB 221027B: Enhanced Swift-XRT position
  20. GRB 221027B: Swift detection of a burst
  21. Konus-Wind detection of GRB 221022B
  22. GRB 221024A: Mondy optical observations
  23. GRB 221027A: Fermi-LAT detection
  24. GRB 221024A: GRANDMA observations
  25. IPN triangulation of GRB 221022C (short)
  26. GRB 221024A: Swift-BAT refined analysis
  27. GRB 221009A: SARA-RM 1m Optical Afterglow Detection
  28. GRB 221024A: Swift/UVOT UV upper limits
  29. GRB 221022A: Swift-XRT observations
  30. GRB 221024A: Swift-XRT refined Analysis
  31. GRB 221022B: Detection by GRBAlpha
  32. GRB 221025A: Fermi-LAT detection
  33. IPN triangulation of GRB 221022B (long)
  34. GRB 221024A: GIT confirmation of the optical afterglow
  35. GRB 221024A: Enhanced Swift-XRT position
  36. GRB 221024A: D50 candidate afterglow
  37. GRB 221022B: AstroSat CZTI detection
  38. GRB 221022A: Fermi GBM detection
  39. GRB 221022A: Swift ToO observations
  40. GRB 221023A: Fermi-LAT detection
  41. GRB 221022B: Fermi GBM detection
  42. GRB 221021A: Fermi GBM observation
  43. GRB 221009A: Determination of the black holes mass and spin
  44. GRB 221024A: Swift detection of a burst
  45. GRB 221022A: Swift/BAT-GUANO detection
  46. GRB 221022B: Swift/BAT-GUANO detection outside the coded FOV
  47. GRB 221009A: optical observations, SN photometric evidence
  48. GRB 221021A: Swift/BAT-GUANO detection outside the coded FOV
  49. GRB 221017A: Swift-XRT observations
  50. Improved IPN localization for GRB 221009A (BepiColombo-MGNS light curve)
  51. GRB 221009A: BOAO NIR detections
  52. GRB 221009A X-ray light-curve and the indication of TeV light-curve
  53. GRB 221009A: Spectroscopic detection of emerging SN features
  54. GRB 221013B: Swift/BAT-GUANO detection
  55. AGILE detection of the 2022 October 17 burst from SGR J1935+2154 reported by Konus-Wind
  56. GRB 221009A: GRANDMA observations
  57. The probability of observing GRB 221009A at z = 0.151
  58. GRB 221017A: Swift ToO observations
  59. AGILE detection of short X-ray flaring activity contemporary to SGR J1935+2154 reported bursts
  60. GRB 221009A: Second epoch of NuSTAR data
  61. GRB 221016A: Swift-BAT refined analysis
  62. GRB 221016A: Swift/UVOT Detection
  63. GRB 221016A: Swift-XRT refined Analysis
  64. Konus-Wind detection of GRB 221016A
  65. GRB 221016A: Fermi GBM observation
  66. GRB 221009A: A type I BdHN of exceptional energetics
  67. GRB 221016A: Enhanced Swift-XRT position
  68. GRB 221016A: Swift detection of a burst
  69. Swift GRB221016.99: Global MASTER-Net observations report
  70. GRB 221009A: Faulkes Telescope North continued optical afterglow follow-up
  71. GRB 221009A: continued Assy optical afterglow observations, possible SN evidence
  72. GRB 221009A: LEIA X-ray Afterglow Detection
  73. GRB 221009A: ATCA radio spectrum
  74. GRB 221009A: Armchair Energetics
  75. GRB 221009A: Fermi LAT data rate effects due to extremely high flux
  76. GRB 221009A: Large Binocular Telescope Observatory optical afterglow detection
  77. GRB 221009A: Pan-STARRS optical photometry
  78. MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946
  79. GRB 221009A: continued REM optical/NIR observations and evidence for an achromatic steepening in the afterglow light curve
  80. GRB 221009A: HEBS detection
  81. GRB 221009A: Gamma-ray Detection by SIRI-2
  82. GRB221009A: Detection as sudden ionospheric disturbances (SID)
  83. GRB 221009A: search for neutrinos with KM3NeT
  84. GRB221009A: LCOGT Continued Observations - Optical Upper Limits
  85. GRB 221009A/Swift J1913.1+1946: low-frequency ASKAP observations
  86. GRB 221006A: Swift-XRT afterglow detection
  87. GRB 221009A: MITSuME Okayama optical observation
  88. GRB 221009A: Sayan observatory 1.6-m telescope observations
  89. GRB 221009A/Swift J1913.1+1946: SMA observations
  90. GRB 221009A/Swift J1913.1+1946: eMERLIN observations
  91. INTEGRAL detection of a burst from SGR J1935+2154
  92. GRB 221009A: NuSTAR Detection
  93. GRB 221009A: LCOGT Optical Afterglow Detection
  94. GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
  95. GRB 221009A (Swift J1913.1+1946): Swift-BAT refined analysis
  96. GRB 221009A: 10.4m GTC spectroscopic redshift confirmation
  97. GRB 221009A: Detection by GRBAlpha
  98. GRB 221009A: Sintez-Newton/CrAO optical observations
  99. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  100. GRB 221006A: Swift ToO observations

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