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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"

19625 results found.

  1. GRB 221009A: ATCA radio spectrum
  2. GRB 221009A: Armchair Energetics
  3. GRB 221009A: Fermi LAT data rate effects due to extremely high flux
  4. GRB 221009A: Large Binocular Telescope Observatory optical afterglow detection
  5. GRB 221009A: Pan-STARRS optical photometry
  6. MAXI/GSC refined analysis of the bright X-ray afterglow of GRB 221009A/Swift J1913.1+1946
  7. GRB 221009A: continued REM optical/NIR observations and evidence for an achromatic steepening in the afterglow light curve
  8. GRB 221009A: HEBS detection
  9. GRB 221009A: Gamma-ray Detection by SIRI-2
  10. GRB221009A: Detection as sudden ionospheric disturbances (SID)
  11. GRB 221009A: search for neutrinos with KM3NeT
  12. GRB221009A: LCOGT Continued Observations - Optical Upper Limits
  13. GRB 221009A/Swift J1913.1+1946: low-frequency ASKAP observations
  14. GRB 221006A: Swift-XRT afterglow detection
  15. GRB 221009A: MITSuME Okayama optical observation
  16. GRB 221009A: Sayan observatory 1.6-m telescope observations
  17. GRB 221009A/Swift J1913.1+1946: SMA observations
  18. GRB 221009A/Swift J1913.1+1946: eMERLIN observations
  19. INTEGRAL detection of a burst from SGR J1935+2154
  20. GRB 221009A: NuSTAR Detection
  21. GRB 221009A: LCOGT Optical Afterglow Detection
  22. GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
  23. GRB 221009A (Swift J1913.1+1946): Swift-BAT refined analysis
  24. GRB 221009A: 10.4m GTC spectroscopic redshift confirmation
  25. GRB 221009A: Detection by GRBAlpha
  26. GRB 221009A: Sintez-Newton/CrAO optical observations
  27. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  28. GRB 221006A: Swift ToO observations
  29. Swift/XRT discovery of multiple dust-scattering X-ray rings around GRB 221009A
  30. GRB 221009A (Swift J1913.1+1946): iTelescope optical observation
  31. LHAASO observed GRB 221009A with more than 5000 VHE photons up to around 18 TeV
  32. GRB 221009A: Continued Swift/XRT observations
  33. GRB 221009A/Swift J1913.1+1946: Assy optical afterglow observation
  34. GRB 221009A/Swift J1913.1+1946: Lick/Nickel telescope optical observations
  35. GRB 221009A: Lulin SLT-40cm optical observations
  36. Swift J1913.1+1946: New Photometry
  37. GRB 221009A: Upper limits from a neutrino search with IceCube
  38. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  39. GRB221009A/Swift J1913.1+1946: SRG/ART-XC observation
  40. GRB 221009A / Swift J1913.1+1946: GIT detection of the optical afterglow
  41. GRB221009A/Swift J1913.1+1946: Solar Orbiter STIX measurements
  42. GRB221009A/Swift J1913.1+1946: INTEGRAL SPI/ACS observations
  43. GRB 221009A: Fermi-LAT refined analysis
  44. GRB 221009A (Swift J1913.1+1946): AGILE/GRID detection
  45. GRB 221009: Swift/UVOT Detection
  46. GRB221009A/Swift J1913.1+1946: ATA follow-up observations
  47. GRB 221009A or Swift J1913.1+1946: PRIME near-infrared detection
  48. GRB 221009A/Swift J1913.1+1946: AMI-LA observations
  49. GRB 221009A: Swift-XRT refined Analysis
  50. GRB 221009A (Swift J1913.1+1946): AGILE/MCAL detection
  51. Swift J1913.1+1946: Early Optical Photometry
  52. GRB 221009A: Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy
  53. GRB 221009A (Swift J1913.1+1946): MeerLICHT observations
  54. GRB 221009A (Swift J1913.1+1946): Mondy optical observations
  55. GRB 221009A BOOTES-2/TELMA and OSN optical detections
  56. Swift J1913.1+1946 : Pre-discovery limits from ZTF
  57. GRB 221009A: Fermi GBM observation
  58. IPN triangulation of extremely bright GRB 221009A
  59. Swift J1913.1+1946: Optical photometry
  60. Swift J1913.1+1946: Liverpool Telescope imaging and spectroscopy
  61. GRB 221009A or Swift J1913.1+1946: Fermi-LAT detection
  62. GRB 221009A: Fermi GBM detection of an extraordinarily bright GRB
  63. GRB 221009A: Swift detected transient may be GRB
  64. Swift GRB221009.59: Global MASTER-Net OT detection
  65. GRB 221008A: Swift-XRT observations
  66. Swift J1913.1+1946 a new bright hard X-ray and optical transient
  67. GRB 221008A: Tiled Swift observations
  68. GRB 221006A: Swift-XRT observations
  69. GRB 221006A: Tiled Swift observations
  70. GRB 220930A: MITSuME Akeno optical upper limits
  71. GRB 220930A: AbAO Optical Upper Limit
  72. Konus-Wind detection of GRB 220930A
  73. GRB 220930A: AstroSat CZTI detection
  74. GRB 220930A: Swift-BAT refined analysis
  75. GRB 220930A: Swift-XRT refined Analysis
  76. GRB 220930A: LCOGT Optical Upper Limits
  77. GRB 220930A: Swift/UVOT Upper Limits
  78. GRB 220930A: Enhanced Swift-XRT position
  79. Swift GRB 220930A: Global MASTER-Net observations report
  80. GRB 220930A: BOOTES-5/JGT early optical upper limit
  81. GRB 220930A: Prompt enhanced Swift-XRT position
  82. GRB 220930A: COATLI Upper Limits
  83. GRB 220930A: Swift detection of a burst
  84. IPN triangulation of GRB 220927A (long)
  85. GRB 220924A: Fermi GBM detection
  86. Swift Trigger 1125354 (GRB 220926A) is not a GRB
  87. Swift GRB220926.34: Global MASTER-Net observations report
  88. Swift GRB 220926A: Global MASTER-Net observations report
  89. GRB 220926A: Swift detection of a burst
  90. GRB 220924A: Swift/BAT-GUANO detection outside the coded FOV
  91. Swift GRB220923.47: Global MASTER-Net observations report
  92. GRB 220921A: MeerLICHT afterglow observations
  93. GRB 220921A: Swift-XRT Observations
  94. GRB 220921A: Fermi-LAT detection
  95. GRB 220921A: Tiled Swift observations
  96. GRB 220909A: Fermi GBM observation
  97. GRB 220909A: Swift-XRT observations
  98. IPN triangulation of GRB 220905A
  99. GRB 220909A: Swift ToO observations
  100. GRB 220909A: Swift/BAT-GUANO candidate arcminute localization

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