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"
  1. GRB 090621A: Swift-BAT refined analysis
  2. GRB 090621B: Swift detection of a short hard burst
  3. GRB 090621: Swift/UVOT Upper Limits
  4. GRB 090621: Swift-XRT Team refined analysis
  5. GRB090618: Spectrum and photometry from 6.0m BTA
  6. GRB 090618: BOAO V-band Observation
  7. GRB 090621: Swift detection of a burst
  8. GRB 090618: ZTSh optical observations
  9. GRB 090618 : WSRT radio detection
  10. GRB090618, underlying supernova search
  11. GRB090618: OAA-OAUV Optical observations
  12. GRB 090618: Fermi GBM observation
  13. GRB 090618, Swift-BAT refined spectral analysis
  14. VLA radio detection of GRB 090618
  15. GRB 090618 15GHz radio detection
  16. GRB090618 - Continued optical monitoring and light curve break
  17. GRB 090618: Swift-BAT refined analysis
  18. GRB 090618: SARA observations
  19. GRB090618: Swift-XRT team refined analysis
  20. GRB090618: Swift/UVOT bright afterglow detection
  21. GRB 090618: SDSS host detection
  22. Swift XRT observations of GRB 090531A
  23. GRB 090618: AGILE observations
  24. GRB 090617: Fermi GBM detection
  25. GRB 090618: LOAO R-band Observation
  26. GRB 090618: Enhanced Swift-XRT position
  27. GRB 090618 Faulkes Telescope North observations
  28. Optical observations of GRB 090618
  29. GRB 090618: Lick/KAST Spectroscopy
  30. GRB 090618: OA behavior from KAIT
  31. GRB 090618: planned XMM-Newton observation
  32. GRB 090618: ROTSE-III Detection of Optical Counterpart
  33. GRB 090618: KAIT optical afterglow
  34. GRB090618: P60 Optical Afterglow
  35. GRB 090618: Swift detection of a bright burst with optical afterglow
  36. GRB 090616: Fermi GBM detection
  37. GRB 090612: Fermi GBM detection
  38. GRB 090610C: Fermi GBM detection
  39. GRB 090610B: Fermi GBM detection
  40. GRB 090610: Fermi GBM detection
  41. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  42. GRB 090602: Suzaku WAM observation of the prompt emission
  43. GRB 090424: WSRT Radio Observations
  44. GRB 090423: WSRT Radio Observations
  45. RXTE Discovery of Pulsations from SGR 0418+5729
  46. GRB 090531B: Fermi GBM detection
  47. Konus-RF observation of SGR burst 090605A
  48. Discovery of a new soft gamma repeater source, SGR 0418+5729
  49. GRB 090608: Fermi GBM detection
  50. GRB 090606: Fermi GBM detection
  51. GRB 090607: XRT Team Refined Analysis
  52. GRB 090607: Swift/UVOT Upper Limits
  53. GRB 090607: Swift-BAT refined analysis of the SHB
  54. GRB 090607: GRAS001 optical observations
  55. GRB 090607: Faulkes Telescope North observations
  56. GRB 090607: Swift detection of a burst
  57. Ignore GCN/Swift-BAT Lightcurve Notices for trigger 353567
  58. GRB 090530B: Suzaku WAM observation of the prompt emission
  59. GRB 090530: Further NOT optical observations
  60. GRB 090530: RTT150 Optical Observation
  61. GRB 090602: Fermi GBM detection
  62. GRB 090529A: RTT150 Optical Observations
  63. GMRT observation of GRB 090424 afterglow
  64. GRB 090528: Suzaku WAM observation of the prompt emission
  65. GRB090529: Further NOT optical observations
  66. GRB 090531b, SMARTS optical/IR observations
  67. GRB 090531B: GROND observation
  68. GRB 090528B: Suzaku WAM observation of the prompt emission
  69. GRB 090530: Early RAPTOR Optical Observations
  70. GRB090529B: ROVOR Upper Limits
  71. GRB 090531A: SARA upper limit
  72. GRB 090531B: Swift/BAT spectral lag results
  73. GRB 090529C: Fermi GBM detection
  74. GRB 090529B: Fermi GBM detection
  75. GRB 090530B: Fermi GBM detection
  76. Corrections to GRB 090531B Swift/UVOT Upper Limits
  77. GRB 090531B, RIMOTS optical upper limits
  78. GRB 090531B: Swift/UVOT Upper Limits
  79. GRB 090528B: MASTER-II Kourovka optical limit
  80. GRB 090529: MITSuME optical observation
  81. GRB 090530: GRT Optical Observation
  82. GRB 090531B: Swift-BAT refined analysis
  83. Initial Swift/UVOT observations of GRB 090531B
  84. GRB 090531B: Swift-XRT candidate afterglow position
  85. GRB 090531B: ROTSE-III Optical Limits
  86. GRB 090531B: Swift detection of a burst
  87. GRB 090531: Swift-BAT refined analysis
  88. GRB090530: R-band Observation
  89. GRB 090530: break in light curve
  90. GRB 090529: VLT spectroscopic redshift
  91. GRB 090531: GROND upper limits
  92. GRB 090531: P60 Observations
  93. GRB 090531: Swift detection of a burst
  94. GRB 090529: NOT optical observations
  95. GRB 090530: NOT optical observations
  96. GRB090530: Swift XRT refined analysis
  97. GRB090530: Swift/UVOT afterglow detection
  98. GRB 090529: Swift-XRT refined analysis
  99. GRB 090529: OSN optical observations
  100. GRB 090528B: Fermi GBM detection

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