Skip to main content
New! Browse Circulars by Event, Advanced Search, Sample Codes, Schema Release. 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"

24167 results found.

  1. GRB 090621C: Fermi GBM detection
  2. GRB 090621: Fermi GBM observation
  3. GRB 090620: Fermi GBM detecion
  4. GRB 090621B: Swift/UVOT Upper Limits
  5. GRB 090621B: Swift-BAT refined analysis
  6. GRB 090621B: Swift-XRT refined analysis
  7. GRB 090621B: RTT150 optical observations
  8. GRB 090621A: Swift-BAT refined analysis
  9. GRB 090621B: Swift detection of a short hard burst
  10. GRB 090621: Swift/UVOT Upper Limits
  11. GRB 090621: Swift-XRT Team refined analysis
  12. GRB 090618: BOAO V-band Observation
  13. GRB 090621: Swift detection of a burst
  14. GRB 090618: Fermi GBM observation
  15. GRB 090618, Swift-BAT refined spectral analysis
  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. Swift XRT observations of GRB 090531A
  22. GRB 090618: AGILE observations
  23. GRB 090617: Fermi GBM detection
  24. GRB 090618: LOAO R-band Observation
  25. GRB 090618 Faulkes Telescope North observations
  26. Optical observations of GRB 090618
  27. GRB 090618: OA behavior from KAIT
  28. GRB 090618: ROTSE-III Detection of Optical Counterpart
  29. GRB090618: P60 Optical Afterglow
  30. GRB 090618: Swift detection of a bright burst with optical afterglow
  31. GRB 090616: Fermi GBM detection
  32. GRB 090612: Fermi GBM detection
  33. GRB 090610C: Fermi GBM detection
  34. GRB 090610B: Fermi GBM detection
  35. GRB 090610: Fermi GBM detection
  36. SGR 0418+5729 Fermi/GBM Detection of Pulsations
  37. GRB 090602: Suzaku WAM observation of the prompt emission
  38. GRB 090531B: Fermi GBM detection
  39. Discovery of a new soft gamma repeater source, SGR 0418+5729
  40. GRB 090608: Fermi GBM detection
  41. GRB 090606: Fermi GBM detection
  42. GRB 090607: XRT Team Refined Analysis
  43. GRB 090607: Swift/UVOT Upper Limits
  44. GRB 090607: Swift-BAT refined analysis of the SHB
  45. GRB 090607: Faulkes Telescope North observations
  46. GRB 090607: Swift detection of a burst
  47. Ignore GCN/Swift-BAT Lightcurve Notices for trigger 353567
  48. GRB 090530B: Suzaku WAM observation of the prompt emission
  49. GRB 090530: RTT150 Optical Observation
  50. GRB 090602: Fermi GBM detection
  51. GRB 090529A: RTT150 Optical Observations
  52. GRB 090528: Suzaku WAM observation of the prompt emission
  53. GRB 090531B: GROND observation
  54. GRB 090528B: Suzaku WAM observation of the prompt emission
  55. GRB 090530: Early RAPTOR Optical Observations
  56. GRB090529B: ROVOR Upper Limits
  57. GRB 090531B: Swift/BAT spectral lag results
  58. GRB 090529C: Fermi GBM detection
  59. GRB 090529B: Fermi GBM detection
  60. GRB 090530B: Fermi GBM detection
  61. Corrections to GRB 090531B Swift/UVOT Upper Limits
  62. GRB 090531B, RIMOTS optical upper limits
  63. GRB 090531B: Swift/UVOT Upper Limits
  64. GRB 090530: GRT Optical Observation
  65. GRB 090531B: Swift-BAT refined analysis
  66. Initial Swift/UVOT observations of GRB 090531B
  67. GRB 090531B: Swift-XRT candidate afterglow position
  68. GRB 090531B: ROTSE-III Optical Limits
  69. GRB 090531B: Swift detection of a burst
  70. GRB 090531: Swift-BAT refined analysis
  71. GRB 090530: break in light curve
  72. GRB 090531: GROND upper limits
  73. GRB 090531: P60 Observations
  74. GRB 090531: Swift detection of a burst
  75. GRB090530: Swift XRT refined analysis
  76. GRB090530: Swift/UVOT afterglow detection
  77. GRB 090529: Swift-XRT refined analysis
  78. GRB 090528B: Fermi GBM detection
  79. GRB 090528: Fermi GBM detection
  80. GRB 090530: Swift-BAT refined analysis
  81. GRB 090530: PAIRITEL NIR Detections
  82. GRB 090530A: ROTSE-III Detection of Optical Counterpart
  83. GRB 090530: Swift detection of a burst with an optical counterpart
  84. GRB090529: UVOT/Swift detection of a brightening optical afterglow
  85. GRB 090529: Swift-BAT refined analysis
  86. GRB 090529: Preliminary Swift/UVOT Upper Limit
  87. GRB 090529: Xinglong TNT optical observation
  88. GRB 090529: Swift detection of a burst
  89. GRB 090520D: Fermi GBM detection
  90. GRB 090520C: Fermi GBM detection
  91. GRB 090520B: Fermi GBM detection
  92. GRB090518B optical limit by "Pi of the Sky"
  93. GRB 090522 : Fermi GBM detection
  94. GRB 090524: Fermi GBM detection
  95. GRB 090516A: Konus-Wind and Swift/BAT joint spectral analysis
  96. GRB 090513B: Fermi GBM detection
  97. GRB 090518: Fermi GBM detection
  98. GRB 090516C: Fermi GBM detection
  99. GRB 090520 Swift-BAT detection of a burst in ground analysis
  100. GRB 090516: Fermi GBM observation

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