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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.

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subject:"Swift"
body:"GRB"
submitter:"Judith Racusin"

19615 results found.

  1. Konus-Wind detection of GRB 250615A / EP250615a
  2. GRB 250615A / EP250615a: AstroSat CZTI detection
  3. GRB 250615A: COLIBRÍ optical upper limit
  4. GRB 250615A: DDOTI Optical Upper Limit
  5. GRB 250615A: Swift/UVOT Upper Limits
  6. GRB 250615A: Swift-XRT refined Analysis
  7. GRB 250615A: Enhanced Swift-XRT position
  8. GRB 250615A: Prompt enhanced Swift-XRT position
  9. GRB 250615A: Swift detection of a burst
  10. Swift GRB 250615A: Global MASTER-Net observations report
  11. sb25061207: Mephisto optical upper limits
  12. sb25061218: Swift-XRT observations
  13. sb25061207: EP-FXT follow-up observation and afterglow candidate
  14. sb25061207: Swift-XRT observations
  15. GRB 250610B: Swift-XRT refined Analysis
  16. EP250610a: continuous follow-up observations with EP-FXT
  17. GRB 250612A: Swift detection of a burst or new Galactic transient Swift J1643.6-3854
  18. Swift GRB250612.04: Global MASTER-Net observations report
  19. GRB 250610B: Swift/UVOT Detection
  20. EP250610A: Swift/UVOT Upper limits
  21. GRB 250610B: EP-FXT follow-up observation and afterglow counterpart
  22. GRB 250610B: Swift-XRT counterpart detection
  23. GRB 250610B: SVOM/VT optical counterpart
  24. EP250610a: refined analysis of the EP-WXT and EP-FXT observations
  25. GRB 250605A: Swift-BAT refined analysis
  26. EP250610a: SVOM/VT optical upper limit
  27. EP250610a: REM optical/NIR observations
  28. GRB 250609A: Fermi GBM Observation
  29. EP250610a: Swift-XRT counterpart detection
  30. GRB 250609A: Swift/BAT-GUANO localization skymap of a likely short burst
  31. GRB 250605A: Swift/UVOT Upper Limits
  32. GRB 250527C: CrAO Optical Upper Limit
  33. GRB 250605A: SVOM/VT optical upper limit
  34. GRB 250605A: Swift-XRT refined Analysis
  35. GRB 250605A: Enhanced Swift-XRT position
  36. GRB 250605A: LT optical observations
  37. GRB 250605A: Swift detection of a burst
  38. Swift GRB250605.79: Global MASTER-Net observations report
  39. Konus-Wind detection of GRB 250601A
  40. IPN triangulation of GRB 250404B
  41. IPN triangulation of GRB 250529A
  42. GRB 250601A: PRIME H band upper limit.
  43. GRB 250601A: PRIME J band upper limit.
  44. GRB 250601A: VLT/FORS2 Optical Observation
  45. GRB 250601A: Fermi GBM Observation
  46. GRB 250603A: Swift/UVOT Upper Limits
  47. GRB 250603A: Swift-XRT refined Analysis
  48. GRB 250603A: Enhanced Swift-XRT position
  49. GRB 250603A: Swift-XRT position and confirmation of GRB nature
  50. Swift GRB250603.05: Global MASTER-Net observations report
  51. GRB 250603A: Swift detection of a burst or new Galactic transient Swift J0839.7-3916
  52. GRB 250530C: Swift-BAT refined analysis
  53. GRB 250601A: EP-FXT follow-up observation and afterglow candidates
  54. GRB 250601A: Swift/XRT candidate afterglow
  55. GRB 250601A: Swift-XRT observations
  56. GRB 250601A: Swift/BAT-GUANO arcminute localization of a likely short burst
  57. GRB 250601A: Swift ToO observations
  58. EP#01709177494: SVOM/VT optical observations
  59. EP#01709177494: Swift-XRT counterpart detection of known source
  60. GRB 250530C: BOOTES-7 optical upper limit
  61. GRB 250530C: Swift-XRT refined Analysis
  62. GRB 250530A: TNG detection of a NIR source inside the Swift/XRT error circle
  63. Swift GRB 250530C: Global MASTER-Net observations report
  64. GRB 250530C: Enhanced Swift-XRT position
  65. GRB 250530C: Swift detection of a burst
  66. GRB 250530A: EP-FXT counterpart detection
  67. GRB 250530A: SVOM/VT optical upper limit
  68. GRB 250530A: Swift-XRT counterpart detection
  69. GRB 250527D: CALET Gamma-Ray Burst Monitor detection
  70. GRB 250527C: Swift/UVOT Upper Limits
  71. GRB 250527D: Swift/BAT-GUANO localization skymap of a burst
  72. GRB 250527B: Swift-XRT observations
  73. GRB 250520A: Swift-BAT refined analysis
  74. GRB 250527C: Swift ToO observations
  75. GRB 250527C: Swift/BAT-GUANO arcminute localization of a burst
  76. GRB 250527B: Tiled Swift observations
  77. GRB 250520A: GRBAlpha detection
  78. GRB 250521B: SVOM/VT optical upper limit
  79. The EP-WXT trigger 01709176612: refined analysis of the EP-FXT observation
  80. GRB 250521B: EP-FXT follow-up observation and afterglow candidates
  81. EP#01709176612: Swift-XRT counterpart detection of flaring star
  82. GRB 250520A: CALET Gamma-Ray Burst Monitor detection
  83. GRB 250521B: Swift ToO observations
  84. Konus-Wind detection of GRB 250520A (short/hard)
  85. GRB 250520A: Swift/UVOT Upper Limits
  86. IPN triangulation of GRB 250516B
  87. GRB 250520A: J-band observations with WINTER
  88. GRB 250520A: Swift-XRT refined Analysis
  89. GRB 250520A: REM optical/NIR early observations
  90. GRB 250520A:SVOM/VT optical candidate
  91. GRB 250520A: COLIBRÍ optical upper limit
  92. GRB 250520A: DDOTI Optical Upper Limit
  93. GRB 250520A: AstroSat CZTI detection of a short burst
  94. GRB 250520A: SVOM/GRM observation
  95. GRB 250520A: Enhanced Swift-XRT position
  96. GRB 250520A: GOTO optical upper limit
  97. GRB 250520A: Prompt enhanced Swift-XRT position
  98. GRB 250520A: Swift detection of a burst
  99. Swift GRB 250520A: Global MASTER-Net observations report
  100. EP250427a/GRB250427A: VLA Detection of Radio Counterpart

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