Skip to main content
Updates to LVK & CHIME Notices, Schema v7.2.3! See news and announcements

GCN Circulars

GCN Circulars are rapid astronomical bulletins submitted by and distributed to community members worldwide. They are used to share discoveries, observations, quantitative near-term predictions, requests for follow-up observations, or future observing plans related to high-energy, multi-messenger, and variable or transient astrophysical events. 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"

28090 results found.

  1. GRB 061218, Swift-BAT refined analysis
  2. GRB061217: VLT NIR observations
  3. GRB 061218, SMARTS optical/IR observations
  4. GRB 061218: REM prompt observations
  5. Swift triggers (#251863) on a possible burst
  6. GRB061217: Swift/UVOT refined analysis.
  7. GRB 061217: optical observations at Calar Alto
  8. GRB061217 - Swift/XRT refined analysis
  9. GRB 061217, Swift-BAT refined analysis
  10. GRB 061217: Magellan Observations
  11. GRB 061217: REM prompt observations
  12. GRB 061217: ROTSE-III Optical Limits
  13. GRB061210: Swift/UVOT observations
  14. GRB 061210: Swift XRT analysis - Possible counterparts
  15. GRB 061210: Gemini/GMOS Observations
  16. GRB 061126: Radio Observations
  17. GRB061210: Radio Observations
  18. GRB 061202: Suzaku WAM observation of the prompt emission
  19. GRB 061210, Swift-BAT refined analysis of the SHB
  20. Optical Afterglow observations of GRB 061126
  21. GRB 060926: MASTER: discovery of the optical flare
  22. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  23. GRB 061202: TORTOREM optical upper limits
  24. GRB 061201: VLT optical decay
  25. GRB 061201: SOAR Confirmation of Candidate Afterglow
  26. GRB061202: FRAM early follow-up limit
  27. GRB061202 optical limit by "Pi of the Sky"
  28. GRB061202: optical/NIR observations with REM
  29. GRB061202: Swift/UVOT Upper Limits
  30. GRB 061202, Swift-BAT refined analysis
  31. GRB 061202: Swift detection of a burst
  32. GRB 061201: VLT optical observations
  33. GRB 061201: Initial UVOT Observations
  34. GRB 061201, Swift-BAT refined analysis of the SHB
  35. GRB 061201: Swift detection of a short hard burst
  36. INT+WFC observations of GRB 061126
  37. Swift XRT on-board boresight update
  38. GRB 061126: optical observation
  39. GRB 061126: Tautenburg afterglow observations
  40. GRB061126: Optical afterglow observations from MIRO
  41. GRB061126: Optical afterglow observations from MIRO
  42. GRB 061126 : SDSS Pre-Burst Observations
  43. GRB 061126: Swift-XRT refined analysis
  44. GRB 061126: Swift/UVOT Observations
  45. GRB 061126, Swift-BAT refined analysis
  46. GRB 061126: Early Detection of the IR Afterglow
  47. GRB 061126: Swift/UVOT Afterglow Detection
  48. GRB 061122: Candidate Optical Afterglow
  49. GRB 061121: Ep,i - Eiso correlation
  50. GRB061122: Swift/UVOT Optical Observations
  51. GRB061121: P60 Observations
  52. Radio detection of GRB 061121
  53. GRB061122: Swift-XRT position
  54. INTEGRAL results on GRB 061122
  55. Swift-BAT trigger 239987 is not a GRB
  56. GRB 061121: Swift/UVOT Observations
  57. GRB 061121: Swift-XRT Team Refined Analysis
  58. GRB 061121, Swift-BAT refined analysis
  59. GRB061121, optical observation
  60. GRB 061121: Optical observation at the KANATA 1.5m telescope
  61. GRB 061121: ROTSE-III Confirmation of Optical Counterpart
  62. GRB 061121: Swift detection of a bright burst with an optical counterpart
  63. GRB 060605: NIR Observations
  64. GRB 050915B: optical afterglow
  65. Swift-BAT triggers 238544 and 238546 are not GRBs
  66. Swift/UVOT Upper Limits for GRB061110b
  67. Swift/UVOT Upper Limits for GRB061110a
  68. GRB 061110B, Swift-BAT refined analysis
  69. GRB061110B: Optical observations at Crni Vrh
  70. GRB 061110A: Swift XRT refined analysis
  71. GRB 061110A, Swift-BAT refined analysis
  72. GRB 061110B: TAROT Calern observatory optical observations
  73. GRB 061110B: Swift detection of a burst
  74. GRB 061110: Candidate confirmed
  75. GRB 061110 : Optical afterglow candidate
  76. GRB 061110: ROTSE-III Optical Limits
  77. GRB 061110: Swift detection of a burst
  78. GRB061110A - Optical Non-detection
  79. GRB 061109: optical observation
  80. GRB 061109: TAROT Calern observatory optical observations
  81. GRB 061027: TAROT La Silla observatory optical observations
  82. GRB 061028: Swift/XRT Astrometry Correction
  83. GRB 061102: Swift/UVOT Magnitude Upper Limits
  84. GRB 061102, XRT refined analysis
  85. GRB061102B: Super-LOTIS observations
  86. GRB 061028: Optical R passband observations
  87. GRB 061102B: Swift detection of a possible burst
  88. GRB 061102, Swift-BAT refined analysis
  89. GRB 061102: Swift detection of a burst
  90. GRB 061028: VLA Observation
  91. GRB 061004: Swift/XRT Astrometry Correction
  92. GRB 060801: Swift/XRT Astrometry Correction
  93. GRB 061028: Futher P200 Observations
  94. GRB 061028: P200 Observations
  95. GRB 061028: SARA upper limit
  96. GRB 061028: z band imaging
  97. GRB061028: XRT refined analysis
  98. GRB 061028: Swift/UVOT Observations
  99. GRB 061028, Swift-BAT refined analysis
  100. GRB 061028: TAROT Calern observatory optical observations

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Looking for U.S. government information and services? Visit USA.gov