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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"

28231 results found.

  1. GRB 210419C: RATIR Optical and NIR Upper Limits
  2. GRB 210419C: Montarrenti Observatory Upper Limit
  3. GRB 210419A: Swift/UVOT Upper Limits
  4. GRB 210419C: Enhanced Swift-XRT position
  5. GRB 210419A: Swift-BAT refined analysis
  6. GRB 210419A: Swift-XRT refined Analysis
  7. GRB 210419C: Swift detection of a burst
  8. GRB 210419A: Enhanced Swift-XRT position
  9. GRB 210419A: LCO Optical Upper Limit
  10. GRB 210419A: Swift detection of a burst
  11. GRB 210413B: Swift-XRT observations
  12. GRB 210413B: LOAO optical upper limit
  13. GRB 210411C: A very significant early X-ray afterglow
  14. GRB 210413A: GECAM detection
  15. GRB 210411C: Swift/UVOT Detection
  16. GRB 210411C: Swift-BAT refined analysis
  17. GRB 210411C: Swift-XRT refined Analysis
  18. GRB 210410A: MITSuME Akeno optical upper limits
  19. Swift GRB 210411C: Global MASTER-Net observations report
  20. GRB 210411C: LCO Optical Afterglow Candidate
  21. GRB 210411C: Enhanced Swift-XRT position
  22. GRB 210411D: BALROG localization (Fermi Trigger 639851475 / GRB 210411688)
  23. GRB 210411C: Swift detection of a burst with an optical counterpart
  24. GRB 210410A: Swift-BAT refined analysis
  25. GRB 210410A: Swift-XRT refined Analysis
  26. GRB 210410A: Fermi GBM detection
  27. GRB 210410A: Swift/UVOT Upper Limits
  28. GRB 210406A: Swift-XRT observations
  29. GRB 210410A: RATIR Optical and NIR Observations
  30. GRB 210409A: GECAM detection
  31. GRB 210410A: Fermi-LAT detection
  32. Swift Triggers 1042031 and 1042032 are not astrophysical events
  33. GRB 210406A: Mondy optical afterglow candidate
  34. GRB 210406B: Fermi GBM detection
  35. Konus-Wind detection of GRB 210406A
  36. GRB 210406A: Fermi GBM detection
  37. GRB 210406A: Mondy optical upper limit
  38. GRB 210406A: Konkoly Obs. optical upper limit
  39. GRB 210406A: A long GRB detected by INTEGRAL
  40. GRB 210402A: MASTER prompt and follow up optical observation
  41. GRB 210402A: Swift/UVOT Upper Limits
  42. GRB 210402A: Fermi GBM detection
  43. GRB 210402A: Further NOT optical observations
  44. GRB 210402A: Swift-BAT refined analysis
  45. GRB 210404.141: DDOTI Upper Limits
  46. GRB 210207B: Prompt and very late time observations with HCT.
  47. GRB 210401A: GECAM detection
  48. GRB 210402A: NOT optical afterglow candidate
  49. GRB 210403A: Swift-BAT refined analysis
  50. GRB 210402A: LBT observations
  51. GRB 210402A: DDOTI Upper Limits
  52. GRB 210402A: Swift-XRT refined Analysis
  53. GRB 210402A: Montarrenti Observatory upper limit
  54. GRB 210402A: NOT optical upper limits
  55. GRB 210402A: Swift detection of a burst
  56. GRB 210401A: Fermi GBM Final Real-time Localization
  57. GRB 210328A: GECAM detection
  58. GRB 210330A: GECAM detection
  59. GRB 210328A: BALROG localization (Fermi Trigger / GRB 210328865)
  60. GRB 210326A: Insight-HXMT/HE detection
  61. GRB 210323A: Insight-HXMT/HE detection
  62. GRB 210323A: MASTER optical observation
  63. GRB 210323A: Swift-BAT refined analysis
  64. GRB 210324C: BALROG localization (Fermi Trigger 638308803 / GRB 210324833)
  65. Short GRB 210323A: GTC Observations
  66. GRB 210323A: Swift/UVOT Upper Limits
  67. GRB 210323A: Classification and redshift estimation
  68. GRB 210323A: Kitab optical upper limit
  69. GRB 210323A: Fermi GBM detection
  70. GRB 210323A: Mondy optical observations, counterpart detection
  71. GRB 210318A: Swift/UVOT Upper Limits
  72. GRB 210323A: Swift-XRT refined Analysis
  73. GRB 210323A: Enhanced Swift-XRT position
  74. GRB 210323A: NOT optical afterglow candidate
  75. GRB 210323B: Swift/BAT-GUANO detection and possible arcminute localization
  76. GRB 210323A: Nanshan/NEXT optical upper limit
  77. GRB 210323A: Swift detection of a short burst
  78. GRB 210321A: Swift/UVOT Detection
  79. Konus-Wind detection of GRB 210321A
  80. GRB 210318B: Swift/UVOT Upper Limits
  81. GRB 210321A: CrAO optical upper limit
  82. GRB 210321A: Swift-BAT refined analysis
  83. IceCube 135113_19489408.amon: Swift-XRT observations
  84. GRB 210321A: Mondy optical observations
  85. GRB 210321A: Swift-XRT refined Analysis
  86. GRB 210321A: Redshift from OSIRIS/GTC
  87. GRB 210321A: NOT optical afterglow detection and redshift limit
  88. MAXI GRB210320.89: Global MASTER-Net observations report
  89. GRB 210321A: Enhanced Swift-XRT position
  90. GRB 210321A: DDOTI Afterglow Confirmation
  91. GRB 210321A: Swift/UVOT Detection
  92. GRB 210321A: Swift-XRT observations
  93. GRB 210321A: Swift detection of a burst
  94. GRB 210318B: MITSuME Okayama optical upper limits
  95. GRB 201216C: VIRT optical observations
  96. GRB 200524A: Redshift from Gemini-North
  97. GRB 210318A: Swift-BAT refined analysis
  98. GRB 210318A: Swift-XRT refined Analysis
  99. GRB 210318A: Enhanced Swift-XRT position
  100. GRB 210318B: Fermi GBM detection

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