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"

42777 results found.

  1. GRB061210: Radio Observations
  2. GRB061201, VLT optical decay: correction
  3. GRB 061126: a GRB detected off-axis by INTEGRAL
  4. GRB 061202: Suzaku WAM observation of the prompt emission
  5. GRB 061210: Swift-BAT detection of a short burst
  6. Optical Afterglow observations of GRB 061126
  7. GRB061126: optical observations
  8. GRB 060926: MASTER: discovery of the optical flare
  9. Corrections for Swift/UVOT Exposure Times for GRBs 061110B and 061121
  10. GRB 061201: UVOT Observations of a Fading Optical Afterglow
  11. GRB 061202: TORTOREM optical upper limits
  12. GRB 061201: VLT optical decay
  13. GRB 061201: SOAR Confirmation of Candidate Afterglow
  14. GRB061126 : NMSU 1.0m observations
  15. GRB 061202: Swift XRT refined analysis
  16. GRB061202: FRAM early follow-up limit
  17. GRB061202 optical limit by "Pi of the Sky"
  18. Konus-Wind observation of GRB 061201
  19. GRB061202: optical/NIR observations with REM
  20. GRB061202: Swift/UVOT Upper Limits
  21. GRB 061202, Swift-BAT refined analysis
  22. GRB 061202: Swift detection of a burst
  23. GRB 061201: Swift XRT Team refined analysis
  24. GRB 061201: VLT optical observations
  25. GRB 061201: Initial UVOT Observations
  26. GRB 061201, Swift-BAT refined analysis of the SHB
  27. GRB 061201: Swift detection of a short hard burst
  28. GRB 061201: Coincidence with a Galaxy Cluster
  29. GRB 061122: GETS observation
  30. GRB 061121, SMARTS optical/IR observations
  31. INT+WFC observations of GRB 061126
  32. GRB 061126: Possible Jet Break
  33. GRB 061121: Second Epoch ATCA Radio Observations
  34. GRB 061126: RAPTOR Optical Detection During Gamma-Ray Emission
  35. Swift XRT on-board boresight update
  36. GRB 061121: ATCA & WSRT Radio Observations
  37. GRB061121: optical observations
  38. GRB 061126: Early Super-LOTIS Observations
  39. GRB 061126: optical observation
  40. RHESSI Spectrum of GRB061126
  41. GRB 061126: Tautenburg afterglow observations
  42. GRB061126: Optical afterglow observations from MIRO
  43. GRB061126: Optical afterglow observations from MIRO
  44. GRB 061126 : SDSS Pre-Burst Observations
  45. GRB 061126: Swift-XRT refined analysis
  46. GRB 061126: Swift/UVOT Observations
  47. GRB 061126: SARA Observations
  48. GRB 061126: Early Detection of the IR Afterglow
  49. GRB 061126: Faulkes Telescope North Optical Observations
  50. GRB 061126: Swift/UVOT Afterglow Detection
  51. GRB 061126: XRT position
  52. GRB 061126: Swift detection of a burst
  53. GRB 061121: MDM Continued Monitoring
  54. GRB 061121: MDM Continuing Optical Decay
  55. GRB061121: optical observations
  56. GRB 061122: Candidate Optical Afterglow
  57. GRB 061121: Ep,i - Eiso correlation
  58. GRB 061121: MDM Optical Decay
  59. GRB061122: Swift/UVOT Optical Observations
  60. GRB061121: P60 Observations
  61. Radio detection of GRB 061121
  62. GRB061122: Swift-XRT position
  63. Konus-Wind observation of GRB 061122
  64. GRB 061121: MDM Optical Observations
  65. GRB 061121 declared "Burst of Interest" by Swift team
  66. RHESSI Spectrum of GRB061121
  67. Konus-Wind and Konus-A observations of GRB 061121
  68. INTEGRAL results on GRB 061122
  69. Swift-BAT trigger 239987 is not a GRB
  70. GRB 061122A: a long GRB detected by INTEGRAL
  71. GRB 061121: Swift/UVOT Observations
  72. GRB 061121: Swift-XRT Team Refined Analysis
  73. GRB 061121, Swift-BAT refined analysis
  74. GRB 061121 : Planned XMM-Newton observation
  75. GRB 061121: Optical observation at the KANATA 1.5m telescope
  76. GRB 061121: Faulkes Telescope North Optical Observation
  77. GRB061121: Spectroscopic Redshift
  78. GRB061121: Keck spectroscopic observations
  79. GRB 061121: Swift detection of a bright burst with an optical counterpart
  80. GRB 060605: NIR Observations
  81. GRB 050915B: optical afterglow
  82. GRB 060111B: Swift UVOT Refined Magnitudes
  83. Swift-BAT triggers 238544 and 238546 are not GRBs
  84. GRB 061110A: refined R-band analysis
  85. GRB 061110B: NIR Observations
  86. Swift TOO observations of GRB061110A
  87. GRB 061110A - VLT tentative redshift
  88. GRB 061110B: Swift XRT refined analysis
  89. GRB 061110B, Swift-BAT refined analysis
  90. GRB 061110B: VLT redshift
  91. GRB061110B: Optical observations at Crni Vrh
  92. GRB 061110B: NOT optical observations
  93. GRB 061110A: Swift XRT refined analysis
  94. GRB 061110B: Swift/XRT position
  95. GRB 061110A, Swift-BAT refined analysis
  96. GRB 061110B: TAROT Calern observatory optical observations
  97. GRB 061110B: Swift detection of a burst
  98. GRB 061110: NOT observations
  99. GRB 061110: Candidate confirmed
  100. GRB 061110 : Optical afterglow candidate

Advanced

Download all Circulars as a .tar.gz archive (updated once a day):
Questions or comments?
Contact GCN directly.
Have you found a bug in GCN?
Open an issue.
Want to contribute code to GCN?
Get involved on GitHub.

gcn.nasa.gov

A service of the Astrophysics Science Division at NASA Goddard Space Flight Center

Looking for U.S. government information and services? Visit USA.gov