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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"

26128 results found.

  1. GRB210410A: Candidate optical afterglow by Ondrejov D50
  2. GRB 210410A: Swift XRT localization
  3. Swift Triggers 1042031 and 1042032 are not astrophysical events
  4. GRB 210406A: Mondy optical afterglow candidate
  5. GRB 210406A: Swift ToO observations
  6. GRB 210402A: MASTER prompt and follow up optical observation
  7. GRB 210402A: Swift/UVOT Upper Limits
  8. GRB 210402A: Fermi GBM detection
  9. GRB 210402A: Further NOT optical observations
  10. GRB 210402A: Swift-BAT refined analysis
  11. GRB 210207B: Prompt and very late time observations with HCT.
  12. GRB 210402A: NOT optical afterglow candidate
  13. GRB 210402A: BOOTES-network early optical upper limit
  14. GRB 210403A: Swift-BAT refined analysis
  15. GRB 210402A: LBT observations
  16. GRB 210402A: DDOTI Upper Limits
  17. Swift GRB210403.35: Global MASTER-Net observations report
  18. GRB 210402A: Swift-XRT refined Analysis
  19. GRB 210403A: Swift detection of a burst
  20. GRB 210402A: Montarrenti Observatory upper limit
  21. GRB 210402A: NOT optical upper limits
  22. GRB 210402A: Swift detection of a burst
  23. Swift GRB210402.92: Global MASTER-Net observations report
  24. GRB 210323A: Insight-HXMT/HE detection
  25. GRB 210321A: OSN Upper Limit
  26. GRB 210323A: MASTER optical observation
  27. GRB 210323A: Swift-BAT refined analysis
  28. GRB 210323A: Gemini-North Optical Source Detection
  29. Short GRB 210323A: GTC Observations
  30. GRB 210312B: OSN Afterglow Observations
  31. GRB 210323B: Swift ToO observations
  32. Konus-Wind detection of GRB 210323A (short)
  33. GRB 210323A: Swift/UVOT Upper Limits
  34. GRB 210323A: Kitab optical upper limit
  35. GRB 210323A: Fermi GBM detection
  36. GRB 210323A: Mondy optical observations, counterpart detection
  37. GRB 210318A: Swift/UVOT Upper Limits
  38. GRB 210323A: Swift-XRT refined Analysis
  39. GRB 210323A: Enhanced Swift-XRT position
  40. GRB 210323A: NOT optical afterglow candidate
  41. Swift GRB 210323A: Global MASTER-Net observations report
  42. GRB 210323B: Swift/BAT-GUANO detection and possible arcminute localization
  43. GRB 210323A: Nanshan/NEXT optical upper limit
  44. GRB 210323A: Swift detection of a short burst
  45. GRB 210321A: Swift/UVOT Detection
  46. Konus-Wind detection of GRB 210321A
  47. GRB 210318B: Swift/UVOT Upper Limits
  48. GRB 210321A: DDOTI Position Correction
  49. GRB 210321A: CrAO optical upper limit
  50. GRB 210321A: Swift-BAT refined analysis
  51. IceCube 135113_19489408.amon: Swift-XRT observations
  52. GRB 210321A: Mondy optical observations
  53. GRB 210321A: Swift-XRT refined Analysis
  54. GRB 210321A: Redshift from OSIRIS/GTC
  55. GRB 210321A: NOT optical afterglow detection and redshift limit
  56. GRB 210321A: MASTER optical observation
  57. GRB 210321A: Enhanced Swift-XRT position
  58. GRB 210321A: DDOTI Afterglow Confirmation
  59. GRB 210321A: Swift/UVOT Detection
  60. GRB 210321A: Swift-XRT observations
  61. GRB 210321A: Swift detection of a burst
  62. GRB 210318B: MITSuME Okayama optical upper limits
  63. GRB 201216C: VIRT optical observations
  64. GRB 200524A: Redshift from Gemini-North
  65. GRB 210318A: Swift-BAT refined analysis
  66. GRB 210318A: Swift-XRT refined Analysis
  67. GRB 210318A: Enhanced Swift-XRT position
  68. Swift GRB210318.13: Global MASTER-Net observations report
  69. GRB 210318B: Fermi GBM detection
  70. GRB 210318B: Swift-BAT refined analysis
  71. Swift GRB 210318A: Global MASTER-Net observations report
  72. Konus-Wind detection of GRB 210318B
  73. GRB210318B: Swift detection of a burst
  74. GRB 210318A: Swift detection of a burst
  75. GRB 210306A: GIT optical follow-up
  76. GRB 210226A: GIT optical upper limit
  77. GRB 210312B: Redshift from OSIRIS/GTC
  78. GRB 210306A: HCT optical upper limit
  79. GRB 210312B: GTC photometry
  80. GRB210312B (Integral alert 9073): Candidate optical afterglow by Ondrejov D50
  81. GRB 210306A: LBT observations
  82. GRB 210306A: Tautenburg observations
  83. Konus-Wind detection of GRB 210308A
  84. Konus-Wind detection of GRB 210306A
  85. Konus-Wind detection of GRB 210305A
  86. GRB 210306A: Early Spectroscopy of the Optical Afterglow
  87. GRB 210306B: Fermi GBM detection
  88. GRB 210306A: Swift/UVOT Detection
  89. GRB 210306A: continued Mondy optical observations
  90. GRB 210308A: Mondy and AbAO optical observations
  91. GRB 210308A: Swift-BAT refined analysis
  92. GRB 210307A: Swift-BAT refined analysis
  93. GRB 210308A: Swift/UVOT Detection
  94. GRB 210307A: Swift/UVOT Upper Limits
  95. GRB 210305A: Fermi GBM observation
  96. Swift GRB 210308A: Global MASTER-Net observations report
  97. GRB 210308A: Fermi GBM detection
  98. GRB 210305A: Swift-XRT refined Analysis
  99. GRB 210307A: Swift-XRT refined Analysis
  100. GRB 210308A: Nanshan/NEXT optical upper limits

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