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"

42579 results found.

  1. GRB 090807: Skynet/DSO Observations
  2. GRB 090915: GROND upper limits
  3. Swift-BAT temporarily off-line for a few days
  4. Short-Duration GRB 090916: Skynet/PROMPT Observations
  5. GRB 090915: SARA detection of afterglow candidate
  6. GRB 090912: optical observation
  7. GRB 090915: Swift/UVOT detection of an optical afterglow candidate
  8. GRB 090702: Skynet/GORT Observations
  9. GRB 090902B: Skynet/PROMPT Observations
  10. GRB 090916, Swift-BAT refined analysis
  11. GRB 090915: Swift-XRT detection of a fading X-ray counterpart
  12. GRB 090916: Swift detection of a short burst
  13. GRB 090915 Swift-BAT detection of a burst in ground analysis
  14. GRB 090827: Confirmation of the X-ray afterglow
  15. GRB 090912: Swift-XRT refined analysis
  16. GRB 090912, Swift-BAT refined analysis
  17. GRB 090912 optical upper limit
  18. GRB 090912: Enhanced Swift-XRT position
  19. GRB 090912: Swift detection of a burst
  20. GRB 090910: Fermi GBM detection
  21. GRB 090814A: Skynet/DSO & GORT Observations
  22. GRB 090823: Swift XRT confirmation of the X-ray afterglow
  23. GRB 090904B: GROND detection of the optical afterglow
  24. GRB 090831A: Suzaku WAM observation of the prompt emission
  25. GRB 090904A: Swift/UVOT Refined Analysis
  26. GRB 090904B: Swift/UVOT Refined Analysis
  27. GRB 090902B: Suzaku WAM observation of the prompt emission
  28. GRB 090829A: Suzaku WAM observation of the prompt emission
  29. GRB 090904B: Fermi GBM detection
  30. GRB 090904A: Swift-XRT refined analysis
  31. GRB 090904B: Swift XRT Refined Analysis
  32. GRB 090904B: MOA-II Optical observation
  33. GRB 090904A: Enhanced Swift XRT position
  34. GRB 090904B: Swift-BAT refined analysis
  35. GRB 090902B: VLA radio detection
  36. GRB 090904A: Swift-BAT refined analysis
  37. GRB 090904B: Enhanced Swift-XRT position
  38. GRB090904A: Correction to enhanced XRT position
  39. GRB 090904A: Enhanced Swift-XRT position
  40. GRB 090904A: NOT observations
  41. GRB 090902B: WSRT Radio Observation
  42. GRB090904B: REM observations
  43. GRB 090904B: Swift detection of a burst
  44. GRB 090904: Swift detection of a burst
  45. GRB 090902B: ROTSE-III Detection of Optical Afterglow
  46. GRB 090902B: Swift/UVOT refined analysis
  47. GRB090902B: Swift XRT refined analysis
  48. GRB 090902B: Faulkes Telescope North observations
  49. GRB 090902B: GROND NIR Afterglow Observations
  50. GRB 090902B: Gemini-N absorption redshift
  51. GRB 090902B: Fermi LAT and GBM refined analysis.
  52. GRB 090902B: Enhanced Swift-XRT position
  53. GRB 090902B: Optical afterglow candidate
  54. GRB090902B: Swift/UVOT observations
  55. GRB 090902B: Swift/XRT Afterglow Candidate
  56. GRB 090902B: Fermi LAT detection
  57. GRB 090902B: Fermi GBM detection of a bright burst
  58. GRB 090902: Fermi GBM detection
  59. GRB 090831A: IPN Triangulation
  60. GRB 090831C BAT refined analysis
  61. GRB 090831C: GROND upper limits
  62. Konus-Wind observations of GRB 090831A
  63. Swift Trigger 361477, called GRB090831B, is probably not real.
  64. GRB090831C: Swift/UVOT upper limits
  65. GRB 090831C: Swift XRT Refined Analysis
  66. GRB 090829B: Fermi GBM Detection
  67. GRB 090831C: Enhanced Swift-XRT position
  68. GRB 090831C: Swift detection of a burst
  69. GRB 090831: MAXI GSC detection
  70. GRB 090831B: Swift detection of a possible burst
  71. GRB 090831: Fermi GBM detection
  72. GRB090829: Fermi GBM Detection
  73. Konus-Wind observations of GRB 090827
  74. GRB 090827: Swift XRT and UVOT observations
  75. GRB 090827 Burst discovered in BAT ground analysis
  76. GRB 090826: Fermi GBM detection
  77. GRB 090828: Fermi GBM detection
  78. Fermi Gamma-ray Burst Monitor trigger 273123112 is not a GRB
  79. GRB 090817 - TLS Observations
  80. GRB090817: Keck/LRIS Spectroscopy
  81. GRB 090823: Swift XRT possible detection of the X-ray afterglow
  82. GRB 090823: Confirmation of Swift-BAT position by BAT Slew Survey
  83. GRB 090823 Correction to BAT position
  84. GRB 090817: No host galaxy, no supernova
  85. Konus-Wind observations of GRB 090823
  86. GRB 090823 Long burst with IPN triangulation and BAT position
  87. GRB 090817: Swift/UVOT Observations of a Possible Late-Time Brightening
  88. GRB 090820: detection of a strong burst by RT-2 on board CORONAS PHOTON
  89. GRB 090820B: Fermi GBM detection
  90. GRB 090817: Swift/UVOT Observations of a Host Galaxy Candidate
  91. GRB 090820: MASTER-Net optical polarization observations
  92. GRB 090820: Fermi GBM Detection of a bright burst.
  93. GRB 090817: aphotometry of USNO-B1.0 341-0096763
  94. GRB 090817: Liverpool Telescope Observations
  95. GRB 090817: optical upper limit
  96. GRB 090817: Confirmation of the X-ray afterglow
  97. GRB 090815C: Swift refined analysis
  98. GRB 090817: Fermi GBM observation
  99. GRB 090817: Swift/UVOT Upper Limits
  100. GRB 090812: Konus-Wind and Swift/BAT joint spectral analysis

Advanced

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