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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 210410A: Swift XRT localization
  2. Swift Triggers 1042031 and 1042032 are not astrophysical events
  3. GRB 210406A: Mondy optical afterglow candidate
  4. GRB 210406A: Swift ToO observations
  5. GRB 210402A: MASTER prompt and follow up optical observation
  6. GRB 210402A: Swift/UVOT Upper Limits
  7. GRB 210402A: Fermi GBM detection
  8. GRB 210402A: Further NOT optical observations
  9. GRB 210402A: Swift-BAT refined analysis
  10. GRB 210207B: Prompt and very late time observations with HCT.
  11. GRB 210402A: NOT optical afterglow candidate
  12. GRB 210402A: BOOTES-network early optical upper limit
  13. GRB 210403A: Swift-BAT refined analysis
  14. GRB 210402A: LBT observations
  15. GRB 210402A: DDOTI Upper Limits
  16. Swift GRB210403.35: Global MASTER-Net observations report
  17. GRB 210402A: Swift-XRT refined Analysis
  18. GRB 210403A: Swift detection of a burst
  19. GRB 210402A: Montarrenti Observatory upper limit
  20. GRB 210402A: NOT optical upper limits
  21. GRB 210402A: Swift detection of a burst
  22. Swift GRB210402.92: Global MASTER-Net observations report
  23. GRB 210323A: Insight-HXMT/HE detection
  24. GRB 210321A: OSN Upper Limit
  25. GRB 210323A: MASTER optical observation
  26. GRB 210323A: Swift-BAT refined analysis
  27. GRB 210323A: Gemini-North Optical Source Detection
  28. Short GRB 210323A: GTC Observations
  29. GRB 210312B: OSN Afterglow Observations
  30. GRB 210323B: Swift ToO observations
  31. Konus-Wind detection of GRB 210323A (short)
  32. GRB 210323A: Swift/UVOT Upper Limits
  33. GRB 210323A: Kitab optical upper limit
  34. GRB 210323A: Fermi GBM detection
  35. GRB 210323A: Mondy optical observations, counterpart detection
  36. GRB 210318A: Swift/UVOT Upper Limits
  37. GRB 210323A: Swift-XRT refined Analysis
  38. GRB 210323A: Enhanced Swift-XRT position
  39. GRB 210323A: NOT optical afterglow candidate
  40. Swift GRB 210323A: Global MASTER-Net observations report
  41. GRB 210323B: Swift/BAT-GUANO detection and possible arcminute localization
  42. GRB 210323A: Nanshan/NEXT optical upper limit
  43. GRB 210323A: Swift detection of a short burst
  44. GRB 210321A: Swift/UVOT Detection
  45. Konus-Wind detection of GRB 210321A
  46. GRB 210318B: Swift/UVOT Upper Limits
  47. GRB 210321A: DDOTI Position Correction
  48. GRB 210321A: CrAO optical upper limit
  49. GRB 210321A: Swift-BAT refined analysis
  50. IceCube 135113_19489408.amon: Swift-XRT observations
  51. GRB 210321A: Mondy optical observations
  52. GRB 210321A: Swift-XRT refined Analysis
  53. GRB 210321A: Redshift from OSIRIS/GTC
  54. GRB 210321A: NOT optical afterglow detection and redshift limit
  55. GRB 210321A: MASTER optical observation
  56. GRB 210321A: Enhanced Swift-XRT position
  57. GRB 210321A: DDOTI Afterglow Confirmation
  58. GRB 210321A: Swift/UVOT Detection
  59. GRB 210321A: Swift-XRT observations
  60. GRB 210321A: Swift detection of a burst
  61. GRB 210318B: MITSuME Okayama optical upper limits
  62. GRB 201216C: VIRT optical observations
  63. GRB 200524A: Redshift from Gemini-North
  64. GRB 210318A: Swift-BAT refined analysis
  65. GRB 210318A: Swift-XRT refined Analysis
  66. GRB 210318A: Enhanced Swift-XRT position
  67. Swift GRB210318.13: Global MASTER-Net observations report
  68. GRB 210318B: Fermi GBM detection
  69. GRB 210318B: Swift-BAT refined analysis
  70. Swift GRB 210318A: Global MASTER-Net observations report
  71. Konus-Wind detection of GRB 210318B
  72. GRB210318B: Swift detection of a burst
  73. GRB 210318A: Swift detection of a burst
  74. GRB 210306A: GIT optical follow-up
  75. GRB 210226A: GIT optical upper limit
  76. GRB 210312B: Redshift from OSIRIS/GTC
  77. GRB 210306A: HCT optical upper limit
  78. GRB 210312B: GTC photometry
  79. GRB210312B (Integral alert 9073): Candidate optical afterglow by Ondrejov D50
  80. GRB 210306A: LBT observations
  81. GRB 210306A: Tautenburg observations
  82. Konus-Wind detection of GRB 210308A
  83. Konus-Wind detection of GRB 210306A
  84. Konus-Wind detection of GRB 210305A
  85. GRB 210306A: Early Spectroscopy of the Optical Afterglow
  86. GRB 210306B: Fermi GBM detection
  87. GRB 210306A: Swift/UVOT Detection
  88. GRB 210306A: continued Mondy optical observations
  89. GRB 210308A: Mondy and AbAO optical observations
  90. GRB 210308A: Swift-BAT refined analysis
  91. GRB 210307A: Swift-BAT refined analysis
  92. GRB 210308A: Swift/UVOT Detection
  93. GRB 210307A: Swift/UVOT Upper Limits
  94. GRB 210305A: Fermi GBM observation
  95. Swift GRB 210308A: Global MASTER-Net observations report
  96. GRB 210308A: Fermi GBM detection
  97. GRB 210305A: Swift-XRT refined Analysis
  98. GRB 210307A: Swift-XRT refined Analysis
  99. GRB 210308A: Nanshan/NEXT optical upper limits
  100. GRB 210306A: Swift-XRT refined Analysis

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