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 100802A: XRT refined analysis
  2. GRB 100802A: Swift/UVOT Possible Optical Afterglow
  3. GRB 100728A: Suzaku WAM observation of the prompt emission
  4. GRB 100802A: Enhanced Swift-XRT position
  5. GRB 100802A: Swift-BAT refined analysis
  6. GRB 100802A: Liverpool Telescope observations
  7. GRB 100802A: ROTSE-III Optical Limits
  8. GRB 100802A: Possible Swift/UVOT Detection of Optical Afterglow
  9. GRB 100802A: Swift detection of a burst
  10. GRB 100725B: TELMA optical observation
  11. GRB 100728B: Swift/UVOT Observations (correction to GCN 11028)
  12. GRB 100728B: Swift/UVOT Observations (correction)
  13. GRB 100728B - NOT optical observation
  14. GRB 100728B: Swift/UVOT Observations
  15. GRB 100728B: Lick Observations
  16. GRB 100728B: Continued KAIT observations
  17. GRB 100728B, Swift-BAT refined analysis
  18. GRB 100728B: Swift-XRT Refined Analysis
  19. Konus-Wind observation of GRB 100728A
  20. GRB 100728A: GROND Detection of the NIR Afterglow Candidate
  21. GRB 100727A: Swift/UVOT Upper Limits
  22. GRB 100728A, Swift-BAT refined analysis
  23. GRB 100728B: Enhanced Swift-XRT position
  24. GRB 100728A: Swift/UVOT Upper Limits
  25. GRB 100728B: Fermi GBM observation
  26. GRB 100728A: Swift-XRT refined analysis
  27. GRB 100728B: GROND Detection of the NIR Afterglow
  28. GRB 100728B: optical detection
  29. GRB 100728B: Skynet/PROMPT Detections (correction)
  30. GRB 100728B: KAIT optical afterglow detection (correction)
  31. GRB 100728B: Swift detection of a burst with an optical counterpart
  32. GRB 100728A: Skynet/PROMPT Detections
  33. GRB 100728A: KAIT optical afterglow detection
  34. GRB 100728A: Fermi GBM observation
  35. GRB 100728A: Enhanced Swift-XRT position
  36. GRB 100728A: Swift detection of a burst
  37. GRB 100727A: Swift XRT refined analysis
  38. GRB 100727A: Fermi GBM observation
  39. GRB 100727A, Swift-BAT refined analysis
  40. GRB 100727A: Enhanced Swift-XRT position
  41. GRB100727A: MOA optical upper limit
  42. GRB 100727A: Swift detection of a burst
  43. GRB100725B: MITSuME optical upper limits
  44. GRB 100724B: AGILE/GRID analysis
  45. GRB 100724B: Suzaku WAM observation of the prompt emission
  46. GRB 100724B: gamma-ray detection by AGILE
  47. GRB 100725B: Swift-BAT refined analysis
  48. GRB 100725B: refined XRT analysis
  49. GRB 100725A: GROND upper limits
  50. GRB 100725B: Swift/UVOT Upper Limits
  51. GRB 100725A: Swift/UVOT Upper Limits
  52. GRB 100725A: Swift-BAT refined analysis
  53. GRB 100725A: Swift XRT refined analysis
  54. GRB 100725B: Enhanced Swift-XRT position
  55. GRB 100725A: Enhanced Swift-XRT position
  56. GRB100725B: Faulkes Telescope North observations
  57. GRB 100725B: Swift detection of a burst
  58. GRB100725A Faulkes Telescope South observations
  59. Konus-Wind observation of GRB 100724B
  60. GRB 100725A: Prompt enhanced Swift-XRT position
  61. GRB 100725A: Swift detection of a burst
  62. GRB 100724B: Fermi LAT and GBM analysis
  63. GRB 100724B: Fermi GBM detection
  64. GRB 100724A: Swift/BAT spectral lag results
  65. GRB 100724A: Swift XRT refined analysis
  66. GRB 100724A: Enhanced Swift-XRT position
  67. GRB 100724A: Swift/UVOT observations
  68. GRB 100724A: Swift-BAT refined analysis
  69. GRB 100724A: X-shooter redshift
  70. GRB 100724A: fading afterglow seen with GROND
  71. GRB 100724A, GROND detection of an afterglow candidate
  72. GRB 100724A: Swift detection of a burst
  73. GRB 100614A: 10.4-m GTC deep-optical limit
  74. GRB 100722A: Fermi GBM detection
  75. GRB 100718A: MASTER-Net optical prompt and alert observations
  76. GRB 100719A: Swift-BAT refined analysis
  77. GRB 100719A: Swift detection of a burst
  78. GRB 100713A: optical observation in Maidanak
  79. GRB 100713A: further inspection of TNG images
  80. GRB 100713A: Swift XRT refined analysis
  81. GRB 100713A : IRSF/SIRIUS NIR upper limits
  82. Fermi GBM trigger 300794561 (100714419) is not a GRB
  83. GRB100713A: Swift/UVOT observations
  84. GRB 100713A: GROND upper limits
  85. GRB 100713A: optical upper limit
  86. GRB 100713A: TNG optical observations
  87. GRB 100713A: TELMA and 1.5m OSN optical observations
  88. GRB100713A: Swift X-ray afterglow detection
  89. GRB 100713A: a long GRB detected by INTEGRAL
  90. GRB 100707A: Suzaku WAM observation of the prompt emission
  91. Fermi GBM trigger 300370702 (100709513) is not a GRB
  92. Konus-Wind observation of GRB 100707A
  93. IPN triangulation of GRB 100707A
  94. GRB 100628A: Keck/LRIS Spectroscopy of Host Galaxy Candidate
  95. GRB 100707A: Fermi LAT detection
  96. GRB 100707A: Fermi GBM detection
  97. GRB 100628A: Near-IR sources coincident with the possible X-ray afterglow
  98. GRB 100628A: Chandra observations
  99. GRB 100628A: Swift XRT/UVOT refined analysis
  100. Tentative redshift of GRB100704A from Swift-XRT data

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