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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"

19608 results found.

  1. GRB 221009A/Swift J1913.1+1946: eMERLIN observations
  2. INTEGRAL detection of a burst from SGR J1935+2154
  3. GRB 221009A: NuSTAR Detection
  4. GRB 221009A: LCOGT Optical Afterglow Detection
  5. GRB221009A: INTEGRAL detection of Hard X-ray emission up to 38 hours after trigger
  6. GRB 221009A (Swift J1913.1+1946): Swift-BAT refined analysis
  7. GRB 221009A: 10.4m GTC spectroscopic redshift confirmation
  8. GRB 221009A: Detection by GRBAlpha
  9. GRB 221009A: Sintez-Newton/CrAO optical observations
  10. GRB 221009A: Upper limits from HAWC 8 hours after trigger
  11. GRB 221006A: Swift ToO observations
  12. Swift/XRT discovery of multiple dust-scattering X-ray rings around GRB 221009A
  13. GRB 221009A (Swift J1913.1+1946): iTelescope optical observation
  14. LHAASO observed GRB 221009A with more than 5000 VHE photons up to around 18 TeV
  15. GRB 221009A: Continued Swift/XRT observations
  16. GRB 221009A/Swift J1913.1+1946: Assy optical afterglow observation
  17. GRB 221009A/Swift J1913.1+1946: Lick/Nickel telescope optical observations
  18. GRB 221009A: Lulin SLT-40cm optical observations
  19. Swift J1913.1+1946: New Photometry
  20. GRB 221009A: Upper limits from a neutrino search with IceCube
  21. GRB 221009A (Swift J1913.1+1946): Burke-Gaffney Observatory optical observations
  22. GRB221009A/Swift J1913.1+1946: SRG/ART-XC observation
  23. GRB 221009A / Swift J1913.1+1946: GIT detection of the optical afterglow
  24. GRB221009A/Swift J1913.1+1946: Solar Orbiter STIX measurements
  25. GRB221009A/Swift J1913.1+1946: INTEGRAL SPI/ACS observations
  26. GRB 221009A: Fermi-LAT refined analysis
  27. GRB 221009A (Swift J1913.1+1946): AGILE/GRID detection
  28. GRB 221009: Swift/UVOT Detection
  29. GRB221009A/Swift J1913.1+1946: ATA follow-up observations
  30. GRB 221009A or Swift J1913.1+1946: PRIME near-infrared detection
  31. GRB 221009A/Swift J1913.1+1946: AMI-LA observations
  32. GRB 221009A: Swift-XRT refined Analysis
  33. GRB 221009A (Swift J1913.1+1946): AGILE/MCAL detection
  34. Swift J1913.1+1946: Early Optical Photometry
  35. GRB 221009A: Nanshan/NEXT photometry and Xinglong-2.16m spectroscopy
  36. GRB 221009A (Swift J1913.1+1946): MeerLICHT observations
  37. GRB 221009A (Swift J1913.1+1946): Mondy optical observations
  38. GRB 221009A BOOTES-2/TELMA and OSN optical detections
  39. Swift J1913.1+1946 : Pre-discovery limits from ZTF
  40. GRB 221009A: Fermi GBM observation
  41. IPN triangulation of extremely bright GRB 221009A
  42. Swift J1913.1+1946: Optical photometry
  43. Swift J1913.1+1946: Liverpool Telescope imaging and spectroscopy
  44. GRB 221009A or Swift J1913.1+1946: Fermi-LAT detection
  45. GRB 221009A: Fermi GBM detection of an extraordinarily bright GRB
  46. GRB 221009A: Swift detected transient may be GRB
  47. Swift GRB221009.59: Global MASTER-Net OT detection
  48. GRB 221008A: Swift-XRT observations
  49. Swift J1913.1+1946 a new bright hard X-ray and optical transient
  50. GRB 221008A: Tiled Swift observations
  51. GRB 221006A: Swift-XRT observations
  52. GRB 221006A: Tiled Swift observations
  53. GRB 220930A: MITSuME Akeno optical upper limits
  54. GRB 220930A: AbAO Optical Upper Limit
  55. Konus-Wind detection of GRB 220930A
  56. GRB 220930A: AstroSat CZTI detection
  57. GRB 220930A: Swift-BAT refined analysis
  58. GRB 220930A: Swift-XRT refined Analysis
  59. GRB 220930A: LCOGT Optical Upper Limits
  60. GRB 220930A: Swift/UVOT Upper Limits
  61. GRB 220930A: Enhanced Swift-XRT position
  62. Swift GRB 220930A: Global MASTER-Net observations report
  63. GRB 220930A: BOOTES-5/JGT early optical upper limit
  64. GRB 220930A: Prompt enhanced Swift-XRT position
  65. GRB 220930A: COATLI Upper Limits
  66. GRB 220930A: Swift detection of a burst
  67. IPN triangulation of GRB 220927A (long)
  68. GRB 220924A: Fermi GBM detection
  69. Swift Trigger 1125354 (GRB 220926A) is not a GRB
  70. Swift GRB220926.34: Global MASTER-Net observations report
  71. Swift GRB 220926A: Global MASTER-Net observations report
  72. GRB 220926A: Swift detection of a burst
  73. GRB 220924A: Swift/BAT-GUANO detection outside the coded FOV
  74. Swift GRB220923.47: Global MASTER-Net observations report
  75. GRB 220921A: MeerLICHT afterglow observations
  76. GRB 220921A: Swift-XRT Observations
  77. GRB 220921A: Fermi-LAT detection
  78. GRB 220921A: Tiled Swift observations
  79. GRB 220909A: Fermi GBM observation
  80. GRB 220909A: Swift-XRT observations
  81. IPN triangulation of GRB 220905A
  82. GRB 220909A: Swift ToO observations
  83. GRB 220909A: Swift/BAT-GUANO candidate arcminute localization
  84. GRB 220907A: Swift-BAT refined analysis
  85. GRB 220831A: Gemini-South/GMOS detection of potential optical counterpart
  86. IPN triangulation of GRB 220903A (long)
  87. GRB 220907A: Fermi GBM observation
  88. GRB 220907A: Nanshan/NEXT optical upper limits
  89. GRB 220907A: Swift/UVOT Upper Limits
  90. GRB 220907A: Swift-XRT refined Analysis
  91. GRB 220831A: ATCA 5/9 GHz radio observations
  92. GRB 220907A: Swift-XRT position
  93. GRB 220907A: Swift detection of a burst
  94. Swift GRB220907.59: Global MASTER-Net observations report
  95. GRB 220831A: Swift-UVOT Upper Limits
  96. GRB 220831A: DECam detection of a possible optical counterpart
  97. GRB 220831A, VLT/HAWK-I near-infrared observations
  98. GRB 220831A: Fermi GBM observation
  99. GRB 220831A: Swift-XRT observations
  100. GRB 220831A: Swift ToO observations

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