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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"

21526 results found.

  1. GRB 221016A: Fermi GBM observation
  2. GRB 221009A: A type I BdHN of exceptional energetics
  3. GRB 221016A: Enhanced Swift-XRT position
  4. GRB 221016A: LCOGT Optical Afterglow Detection
  5. GRB 221016A: Swift detection of a burst
  6. Swift GRB221016.99: Global MASTER-Net observations report
  7. GRB 221009A: Faulkes Telescope North continued optical afterglow follow-up
  8. GRB 221009A: continued Assy optical afterglow observations, possible SN evidence
  9. GRB 221009A: LEIA X-ray Afterglow Detection
  10. GRB 221009A: ATCA radio spectrum
  11. GRB 221009A: Armchair Energetics
  12. GRB 221009A: Fermi LAT data rate effects due to extremely high flux
  13. GRB 221009A: Large Binocular Telescope Observatory optical afterglow detection
  14. GRB 221009A: Pan-STARRS optical photometry
  15. MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946
  16. GRB 221009A: continued REM optical/NIR observations and evidence for an achromatic steepening in the afterglow light curve
  17. GRB 221009A: HEBS detection
  18. GRB 221009A: Gamma-ray Detection by SIRI-2
  19. GRB221009A: Detection as sudden ionospheric disturbances (SID)
  20. GRB 221009A: search for neutrinos with KM3NeT
  21. GRB221009A: LCOGT Continued Observations - Optical Upper Limits
  22. GRB 221009A/Swift J1913.1+1946: low-frequency ASKAP observations
  23. GRB 221006A: Swift-XRT afterglow detection
  24. GRB 221009A: MITSuME Okayama optical observation
  25. GRB 221009A: Sayan observatory 1.6-m telescope observations
  26. GRB 221009A/Swift J1913.1+1946: SMA observations
  27. GRB 221009A/Swift J1913.1+1946: eMERLIN observations
  28. INTEGRAL detection of a burst from SGR J1935+2154
  29. GRB 221009A: NuSTAR Detection
  30. GRB 221009A: LCOGT Optical Afterglow Detection
  31. GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
  32. GRB 221009A (Swift J1913.1+1946): Swift-BAT refined analysis
  33. GRB 221009A: 10.4m GTC spectroscopic redshift confirmation
  34. GRB 221009A: Detection by GRBAlpha
  35. GRB 221009A: Sintez-Newton/CrAO optical observations
  36. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  37. GRB 221006A: Swift ToO observations
  38. Swift/XRT discovery of multiple dust-scattering X-ray rings around GRB 221009A
  39. GRB 221009A (Swift J1913.1+1946): iTelescope optical observation
  40. LHAASO observed GRB 221009A with more than 5000 VHE photons up to around 18 TeV
  41. GRB 221009A: Continued Swift/XRT observations
  42. GRB 221009A/Swift J1913.1+1946: Assy optical afterglow observation
  43. GRB 221009A/Swift J1913.1+1946: Lick/Nickel telescope optical observations
  44. GRB 221009A: Lulin SLT-40cm optical observations
  45. Swift J1913.1+1946: New Photometry
  46. GRB 221009A: Upper limits from a neutrino search with IceCube
  47. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  48. GRB221009A/Swift J1913.1+1946: SRG/ART-XC observation
  49. GRB 221009A / Swift J1913.1+1946: GIT detection of the optical afterglow
  50. GRB221009A/Swift J1913.1+1946: Solar Orbiter STIX measurements
  51. GRB221009A/Swift J1913.1+1946: INTEGRAL SPI/ACS observations
  52. GRB 221009A: Fermi-LAT refined analysis
  53. GRB 221009A (Swift J1913.1+1946): AGILE/GRID detection
  54. GRB 221009: Swift/UVOT Detection
  55. GRB221009A/Swift J1913.1+1946: ATA follow-up observations
  56. GRB 221009A or Swift J1913.1+1946: PRIME near-infrared detection
  57. GRB 221009A/Swift J1913.1+1946: AMI-LA observations
  58. GRB 221009A: Swift-XRT refined Analysis
  59. GRB 221009A (Swift J1913.1+1946): AGILE/MCAL detection
  60. Swift J1913.1+1946: Early Optical Photometry
  61. GRB 221009A: Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy
  62. GRB 221009A (Swift J1913.1+1946): MeerLICHT observations
  63. GRB 221009A (Swift J1913.1+1946): Mondy optical observations
  64. GRB 221009A BOOTES-2/TELMA and OSN optical detections
  65. Swift J1913.1+1946 : Pre-discovery limits from ZTF
  66. GRB 221009A: Fermi GBM observation
  67. IPN triangulation of extremely bright GRB 221009A
  68. Swift J1913.1+1946: Optical photometry
  69. Swift J1913.1+1946: Liverpool Telescope imaging and spectroscopy
  70. GRB 221009A or Swift J1913.1+1946: Fermi-LAT detection
  71. GRB 221009A: Fermi GBM detection of an extraordinarily bright GRB
  72. GRB 221009A: Swift detected transient may be GRB
  73. Swift GRB221009.59: Global MASTER-Net OT detection
  74. GRB 221008A: Swift-XRT observations
  75. Swift J1913.1+1946 a new bright hard X-ray and optical transient
  76. GRB 221008A: Tiled Swift observations
  77. GRB 221006A: Swift-XRT observations
  78. GRB 221006A: Tiled Swift observations
  79. GRB 220930A: MITSuME Akeno optical upper limits
  80. GRB 220930A: AbAO Optical Upper Limit
  81. Konus-Wind detection of GRB 220930A
  82. GRB 220930A: AstroSat CZTI detection
  83. GRB 220930A: Swift-BAT refined analysis
  84. GRB 220930A: Swift-XRT refined Analysis
  85. GRB 220930A: LCOGT Optical Upper Limits
  86. GRB 220930A: Swift/UVOT Upper Limits
  87. GRB 220930A: Enhanced Swift-XRT position
  88. Swift GRB 220930A: Global MASTER-Net observations report
  89. GRB 220930A: BOOTES-5/JGT early optical upper limit
  90. GRB 220930A: Prompt enhanced Swift-XRT position
  91. GRB 220930A: COATLI Upper Limits
  92. GRB 220930A: Swift detection of a burst
  93. IPN triangulation of GRB 220927A (long)
  94. GRB 220924A: Fermi GBM detection
  95. Swift Trigger 1125354 (GRB 220926A) is not a GRB
  96. Swift GRB220926.34: Global MASTER-Net observations report
  97. Swift GRB 220926A: Global MASTER-Net observations report
  98. GRB 220926A: Swift detection of a burst
  99. GRB 220924A: Swift/BAT-GUANO detection outside the coded FOV
  100. Swift GRB220923.47: Global MASTER-Net observations report

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