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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"

19670 results found.

  1. GRB 250101A: Swift detection of a burst with an optical counterpart
  2. Swift GRB250101.56: Global MASTER-Net observations report
  3. EP241217a: VLA Radio Detection

  4. GRB 241229A: EP-FXT X-ray afterglow confirmation
  5. GRB 241228B: Multiband optical monitoring with 1.6m Mephisto
  6. GRB 241229B: SVOM/GRM observation
  7. EP241217A: J band upper limit by SYSU 80cm telescope
  8. GRB 241228B: SAO RAS optical observations
  9. GRB 241229B: SVOM/VT optical candidate
  10. GRB 241229A: Swift-XRT observations
  11. Konus-Wind detection of GRB 241228A
  12. GRB 241229A: EP-FXT afterglow candidates
  13. GRB 240606B: 7DT Optical upper limits
  14. GRB 241229B: Swift-BAT refined analysis
  15. GRB241229B: UVOT upper limits
  16. GRB 241228B: D50 optical detection
  17. GRB 241228B: Fermi GBM Observation
  18. GRB 241228B: Swift-XRT afterglow detection
  19. GRB 241229B: Fermi GBM Observation
  20. GRB 241229A: Swift ToO observations
  21. GRB 241229B: Swift-XRT refined Analysis
  22. Swift GRB 241229B: Global MASTER-Net observations report
  23. GRB 241228A: NOT optical upper limits
  24. GRB 241228A: Swift-BAT refined analysis
  25. GRB 241228B: Swift/BAT-GUANO localization skymap of a burst
  26. GRB 241229B: Swift detection of a burst
  27. GRB 241228A: Fermi GBM Observation
  28. Swift GRB 241228A: Global MASTER-Net observations report
  29. GRB 241226A: Swift/BAT-GUANO localization skymap of a burst
  30. GRB 241228A: GROWTH-India telescope optical upper limit
  31. GRB 241228B: Swift ToO observations
  32. GRB 241228A: Swift-XRT refined Analysis
  33. GRB 241228A: Swift/UVOT Upper Limits
  34. GRB 241228A: Enhanced Swift-XRT position
  35. GRB 241228A: Swift detection of a burst
  36. GRB 241223A: Swift-XRT observations
  37. GRB241113A: 7DT Optical upper limits
  38. GRB 241223A: GOTO optical observations summary
  39. GRB 241223A: Swift ToO observations
  40. GRB 241218A: Mondy AZT-33IK optical upper limit
  41. GRB 241218A: Swift/UVOT Upper Limits
  42. EP241217a: optical upper limit with the Liverpool Telescope
  43. GRB 241209B: EP-FXT afterglow detection
  44. GRB 241218A: NOT optical upper limits
  45. GRB 241218A: Swift-BAT refined analysis
  46. EP241217a: refined EP-WXT analysis and EP-FXT follow-up observations
  47. GRB 241217A: refined SVOM/MXT data analysis. Long lasting X-ray emission.
  48. GRB 241218A: REM optical upper limit
  49. GRB 241217A/EP241217b: REM optical/NIR upper limits
  50. EP241217a: REM optical/NIR upper limits
  51. GRB 241218a: Liverpool Telescope optical follow-up
  52. GRB 241217a: Liverpool Telescope optical follow-up
  53. GRB 241218A: Swift-XRT refined Analysis
  54. GRB 241209A: ATCA radio follow-up observations
  55. GRB 241218A: LCOGT Optical Upper Limit
  56. GRB 241218A: Enhanced Swift-XRT position
  57. GRB 241218A: Swift detection of a burst
  58. GRB 241217A : SVOM/VT optical afterglow detection
  59. GRB 241217A: Swift-XRT afterglow detection
  60. EP241217a: Swift-XRT Detection
  61. GRB 241214A: GRBAlpha detection
  62. GRB 241213A (EP241213a): GRBAlpha detection
  63. GRB 241209D: GRBAlpha detection
  64. GRB 241213A: Swift-BAT refined analysis
  65. GRB 241214A: Swift/BAT-GUANO localization skymap of a burst
  66. Konus-Wind detection of GRB 241213A (EP 241213a)
  67. GRB 241212A: Swift-XRT observations
  68. GRB 241213B: Swift-XRT observations
  69. GRB 241209D: CALET Gamma-Ray Burst Monitor detection
  70. GRB 241213A: SVOM/VT optical candidate
  71. GRB 241213B: Tiled Swift observations
  72. GRB 241213A: Swift/UVOT Upper Limits
  73. GRB 241213A: Swift-XRT refined Analysis
  74. GRB 241212A: Swift ToO observations
  75. GRB 241213A: LCOGT Optical Upper Limits
  76. EP241213a: EP detection of An X-ray Transient
  77. GRB 241213A: REM optical/NIR upper limits
  78. GRB 241213A: Enhanced Swift-XRT position
  79. Swift GRB 241213A: Global MASTER-Net observations report
  80. GRB 241213A: Swift detection of a burst
  81. GRB 241209A: Chandra X-ray Detection
  82. Konus-Wind detection of GRB 241209B
  83. GRB 241209B: GRBAlpha detection
  84. GRB 241129A: Fermi GBM Observation
  85. GRB 241209B: Swift/BAT-GUANO localization skymap of a burst
  86. GRB 241209D: REM optical/NIR upper limits
  87. Konus-Wind detection of GRB 241209D
  88. GRB 241209B: Swift-XRT afterglow detection
  89. GRB 241209C: Fermi GBM Observation
  90. GRB 241209A: Swift-XRT refined Analysis
  91. GRB 241209D: AstroSat CZTI detection
  92. GRB 241209A: EP-FXT follow-up observations
  93. GRB 241209B: SVOM/VT afterglow detection
  94. GRB 241207B: Fermi GBM Observation
  95. GRB 241209A: BOOTES-7 and 2.2m CAHA early optical upper limits
  96. GRB 241209D: Swift-XRT refined Analysis
  97. GRB 241209D: Fermi GBM Observation
  98. GRB 241209A: VLT/HAWK-I near-IR counterpart candidate
  99. GRB 241209D: COLIBRÍ detection of the afterglow
  100. GRB 241209A: COLIBRÍ Optical Upper Limit

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