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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"

26127 results found.

  1. GRB 210606A: 1.5m OSN optical upper limit
  2. GECAM Sub-Threshold Detection of new magnetar Swift SGR J1555.2-5402
  3. GRB 210606A: Swift ToO observations
  4. Fermi GRB 210606A: DDOTI Upper Limits on the Afterglow
  5. GRB 210606A: Swift/BAT-GUANO detection and arcminute localization
  6. GRB 210605B: Swift ToO observations
  7. GRB 210605B: Swift/BAT-GUANO detection and arcminute localization
  8. Initial results of a NICER X-ray monitoring of the magnetar, Swift J1555.2-5402
  9. Fermi GBM Sub-Threshold Detection of new Swift SGR J1555.2-5402
  10. SGR J1555.2-5402: Swift-BAT refined analysis
  11. Swift J1555.2-5402: Swift XRT refined analysis of the new SGR
  12. NICER discovery of 3.86 s pulsations from a new magnetar: SGR J1555.2-5402
  13. Swift Detection of probable new Swift SGR J1555.2-5402
  14. Swift GRB210603.41: Global MASTER-Net observations report
  15. GRB 210529B: DDOTI Upper Limits on the Afterglow
  16. GRB 210528B: DDOTI Upper Limits on the Afterglow
  17. GRB 210527A: Swift-BAT refined analysis
  18. GRB 210527A: Swift/UVOT Observations
  19. GRB 210527A: GIT optical upper limit
  20. GRB 210527A: MITSuME Akeno optical upper limits
  21. Swift GRB 210527A: Global MASTER-Net observations report
  22. GRB 210527A: Swift-XRT refined Analysis
  23. GRB 210527A: RATIR Optical and NIR Observations
  24. GRB 210527A: Enhanced Swift-XRT position
  25. GRB 210527A: Swift-XRT observations
  26. GRB 210527A: Swift detection of a burst
  27. GRB 210306A: LBT observations of the likely host galaxy
  28. ZTF21aayokph (AT2021lfa): LBT optical observations
  29. Fermi GRB 210524B: DDOTI Upper Limits on the Afterglow
  30. IPN triangulation of GRB 210524A
  31. GRB 210520A: Swift-XRT observations
  32. GRB210413B: further Swift-XRT observations
  33. GRB 210520A: Tiled Swift observations
  34. GRB 210520A: Fermi-LAT detection
  35. GRB 210517A: KCT optical upper limit
  36. GRB 210518.889: DDOTI Upper Limits on the Afterglow
  37. Konus-Wind detection of GRB 210514A
  38. GRB 210517A: Swift-BAT refined analysis
  39. GRB 210517A: Swift-XRT refined Analysis
  40. GRB 210517A: Swift/UVOT Upper Limits
  41. GRB 210515C: Swift/UVOT Upper Limits
  42. GRB 210517A: VLT/X-shooter optical afterglow and redshift
  43. GRB 210517A: AGILE detection
  44. GRB 210514A: CALET Gamma-Ray Burst Monitor detection
  45. GRB 210517A: Enhanced Swift-XRT position
  46. Swift GRB 210517A: Global MASTER-Net observations report
  47. GRB 210517A: Swift detection of a burst
  48. GRB 210515C: LCO Optical Upper Limit
  49. GRB 210504A: LCO Optical Afterglow Detection
  50. GRB 210514A: Swift/UVOT Upper Limits
  51. GRB 210515C: Swift-XRT refined Analysis
  52. Swift GRB210515.83: Global MASTER-Net observations report
  53. GRB 210515C: Swift-BAT refined analysis
  54. GRB 210515C: Swift detection of a burst
  55. GRB 210514A: Swift-BAT refined analysis
  56. Swift GRB210514.71: Global MASTER-Net observations report
  57. GRB 210514A: Swift XRT light curve is fading
  58. GRB 210514A: Swift-XRT refined Analysis
  59. GRB 210514A: Enhanced Swift-XRT position
  60. GRB 210514A: update on the BAT trigger time and burst duration
  61. GRB 210514A: Swift detection of a burst
  62. GRB 210512.786: DDOTI Upper Limits on the Afterglow
  63. GRB210510A: Optical afterglow candidate from the Zwicky Transient Facility
  64. Short GRB 210323A: likely host galaxy detection
  65. GRB 210511B: DDOTI Upper Limits on the Afterglow
  66. IPN triangulation of GRB 210427A
  67. Fermi GRB 210510A: DDOTI Upper Limits on the Afterglow
  68. GRB 201228B: Swift/BAT-GUANO archival detection and arcminute localization
  69. GRB 200716A: Swift/BAT-GUANO archival detection and arcminute localization
  70. Swift trigger 1047857 is 4U 1700-377
  71. GRB 210509A: RATIR Optical and NIR Upper Limits
  72. GRB 210509A: Swift/UVOT Upper Limits
  73. GRB 210509A: Swift-XRT refined Analysis
  74. GRB 210509A: Swift-BAT refined analysis
  75. Swift GRB 210509A: Global MASTER-Net observations report
  76. GRB 210509A: Enhanced Swift-XRT position
  77. GRB 210509A: BOOTES-4/MET optical upper limit
  78. GRB 210509A: Swift-XRT observations
  79. GRB 210509A: Swift detection of a burst
  80. GRB 210506A: Swift/BAT-GUANO position retraction
  81. IPN triangulation of GRB 210506A
  82. GRB 210506A: Swift-XRT observations
  83. GRB 210506A: Nanshan/NEXT optical upper limit
  84. GRB 210506A: TNG NIR upper limits
  85. ZTF21aayokph (AT2021lfa): X-ray Detection with Swift/XRT
  86. GRB 210506A: Swift ToO observations
  87. GRB 210506A: Swift/BAT-GUANO detection and possible arcminute localization of a short hard burst
  88. GRB 210504A: Lowell Discovery Telescope optical observations
  89. ZTF21aayokph (AT2021lfa): Redshift from Gemini South
  90. GRB 210504A: VLT X-shooter redshift
  91. GRB 210504A: Swift-XRT refined Analysis
  92. GRB 210504A: Swift-BAT refined analysis
  93. ZTF and LT observations of ZTF21aayokph (AT2021lfa), a fast-fading red transient
  94. GRB 210504A: NOT optical afterglow detection
  95. GRB 210504A: MITSuME Akeno optical upper limits
  96. Fermi GRB 210503A: DDOTI Upper Limits on the Afterglow
  97. GRB 210504A: AST3-3 YaoAn Optical Upper Limit
  98. GRB 210504A: Swift/UVOT Detection
  99. GRB 210504A: BOOTES-4/MET optical upper limit
  100. Swift GRB210504.58: Global MASTER-Net observations report

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