Skip to main content
New! CHIME and DSA-110 FRB Notices, IceCube Notices and Schema v6.1.1. 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"
  1. GRB 090320C: Fermi GBM Detection
  2. Fermi GBM and LAT detections of GRB 090323
  3. GRB 090320B: Fermi GBM detection.
  4. GRB 090319: Fermi GBM detection
  5. GRB 090320A: Fermi GBM detection
  6. Further 15GHz observations of GRB090313
  7. GRB 090313: WSRT Radio Detection
  8. X-shooter observations of GRB 090313
  9. A bright burst from AXP 1E 1547.0-5408/SGR J1550-5418
  10. GRB 090315: Suzaku WAM observation of the prompt emission
  11. GRB 090313: VLT spectroscopy
  12. GRB090313: radio detection with the VLA
  13. Konus-Wind observation of GRB 090315
  14. IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
  15. GRB 090313, SMARTS optical/IR observations
  16. Further radio observation of GRB 090313
  17. Further Swift/UVOT observations of GRB 090313
  18. GRB 090313: detection with CARMA in 3mm band
  19. GRB090305B: MASTER-net prompt optical short burst observations
  20. Radio detection of GRB090313
  21. GRB 090313: MITSuME Okayama observation
  22. GRB 090313: Additional Gemini-S photometry
  23. GRB 090313: WSRT Radio Observations
  24. GRB 090313: Light curve steepening
  25. GRB 090313: TAROT La Silla observatory optical detection
  26. GRB 090313: Gemini-S photometry
  27. GRB 090313: Zadko Telescope observations
  28. GRB 090313 - PAIRITEL NIR detections
  29. GRB 090313: Gemini-S redshift
  30. GRB 090313 optical observations
  31. GRB 090313: Ongoing plateau phase
  32. GRB 090313: Swift-XRT refined analysis
  33. GRB 090313: Swift/UVOT upper limits
  34. GRB 090313: Faulkes Telescope North observations
  35. GRB 090313: Sustained optical brightness (correction)
  36. GRB 090306B: Confirmation of the X-ray afterglow
  37. GRB 090313: Swift-BAT refined analysis
  38. GRB 090313: Sustained optical brightness
  39. GRB 090313: SDSS object underlying the optical afterglow position
  40. GRB 090313, GROND observations
  41. GRB 090309, Swift-BAT lag analysis
  42. GRB 090313: Swift detection of a burst
  43. GRB 090313: Swift detection of a burst
  44. GRB 090313 OA candidate
  45. Swift trigger 346250 is probably not a burst
  46. GRB090310: Fermi GBM detection
  47. GRB 090205: Zadko Telescope late-time observations
  48. GRB 090309A: GROND upper limits
  49. GRB 090307A: TAROT Calern observatory optical observations
  50. GRB 090309: Swift/UVOT Upper Limits
  51. GRB090305B: Fermi GBM detection
  52. GRB 090309B: Fermi GBM detection
  53. GRB 090309: Swift-XRT refined analysis
  54. GRB 090309: Enhanced Swift-XRT position
  55. GRB 090306B: INTEGRAL SPI-ACS light curve
  56. GRB 090309, Swift-BAT refined analysis
  57. GRB 090308: GROND observations
  58. GRB 090308: Gemini GMOS Observations
  59. GRB 090309: Swift detection of a burst
  60. GRB 090308B: Fermi GBM detection
  61. GRB 090308: Swift/UVOT Upper Limits
  62. GRB 090307B: Fermi GBM detection
  63. GRB 090306C: Fermi GBM detection
  64. GRB 090307: GROND Upper Limits
  65. GRB 090306B: GROND Upper Limits
  66. GRB 090305C: Suzaku WAM observation of the prompt emission
  67. GRB 090308: Swift-XRT refined analysis
  68. Radio observation of GRB 090201 with ATCA
  69. Radio observation of GRB 090117 with ATCA
  70. Radio observation of GRB 081226b with ATCA
  71. Radio observation of GRB 081226a with ATCA
  72. Radio observation of GRB 081007 with ATCA
  73. ATCA observation of SGR J1550-5418
  74. GRB 090308: Swift-BAT refined analysis
  75. GRB 090308: Swift detection of a burst
  76. GRB 090306B: Possible XRT afterglow
  77. GRB 090307: Swift-XRT afterglow confirmation and analysis
  78. GRB 090307: Swift-BAT refined analysis of trigger 345551
  79. GRB 090306B: Burst detection from Swift-BAT slew data
  80. Swift Trigger 345551 is probably not a GRB
  81. Swift-BAT trigger 345396 is not a GRB
  82. IPN localization of short GRB 090305C
  83. Fermi GBM trigger 090305784 is not a GRB
  84. GRB 090306: Swift detection of a possible burst
  85. GRB 090305: Swift/UVOT Upper Limits
  86. GRB 090305: Swift-XRT refined analysis
  87. GRB 090305, Swift-BAT refined analysis
  88. GRB 090227A: Suzaku WAM observation of the prompt emission
  89. GRB 090305: Magellan confirmation of the optical afterglow
  90. GRB090305: GMOS-S Candidate Optical Afterglow
  91. GRB 090305: Swift detection of a short burst
  92. GRB 090303: Fermi GBM detection
  93. GRB 090304: Fermi GBM detection
  94. GRB 090301A: Suzaku WAM observation of the prompt emission
  95. Konus-RF catches first GRB and SGR bursts
  96. GRB 090228B: Fermi GBM detection
  97. Konus-Wind observation of bright short GRB 090227B
  98. IPN localization of short bright GRB 090227B
  99. Konus-Wind observation of GRB 090301A
  100. GRB 090301A: Swift-BAT refined analysis

Advanced

Download all Circulars as a .tar.gz archive:
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