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"
  1. GRB 080523: Swift detection of a burst
  2. GRB 080515: NIR magnitude correction
  3. GRB 080515: KPNO 4m NIR afterglow detection
  4. GRB080521(?): detection of possible burst from BAT slew data and XRT ToO
  5. GRB 80516: Swift/UVOT Observations
  6. GRB 080515: Swift-XRT position and analysis
  7. GRB 080520, Swift-BAT refined analysis
  8. GRB 080514B: pseudo-z= 1.8 from prompt emission spectrum
  9. GRB 080514B: UVOT Observations
  10. GRB080520: Swift/UVOT observations
  11. GRB 080520: VLT redshift
  12. GRB 080520, GROND observations
  13. GRB 080520: Enhanced Swift-XRT position
  14. GRB 080520: Swift XRT Refined Analysis
  15. GRB 080520: Swift detection of a burst with optical afterglow
  16. GRB 080514B: Suzaku WAM observation of the prompt emission
  17. Konus-Wind observation of GRB 080514B
  18. GRB 080514B: second epoch Swift XRT data confirms the X-ray afterglow
  19. GRB 080503: Further HST imaging
  20. GRB 080517, Swift-BAT refined analysis
  21. GRB 080516, GROND further analysis
  22. GRB 080517: Swift-XRT refined analysis
  23. GRB 080514B: Further NIR observations
  24. GRB 080517: Enhanced Swift-XRT position
  25. GRB080517: Liverpool Telescope Optical Observations
  26. GRB 080517: Swift detection of a burst
  27. GRB 080516, GROND 2nd epoch observations
  28. GRB 080516, GROND observations
  29. GRB080430: optical observations
  30. GRB 080516, SMARTS optical/IR observations
  31. GRB 080516: Swift-XRT Team refined analysis
  32. GRB 080516, Swift-BAT refined analysis
  33. GRB 080516: Enhanced Swift-XRT position
  34. GRB 080514B: NOT observations
  35. GRB 080516: Swift detection of a burst
  36. Errartum: VLA upper limit on GRB 080507
  37. VLA upper limit on GRB 080705
  38. GRB 080514B : redshift estimation
  39. Konus-Wind observation of GRB 080513
  40. IPN triangulation of bright GRB 080513
  41. Swift-BAT refined analysis for Trigger 311603: Galactic source
  42. GRB 080515, Swift-BAT refined analysis
  43. GRB 080514B: KPNO 4m IR observations
  44. GRB 080514B: slow fading behaviour ?
  45. GRB 080514B: Swift-XRT analysis
  46. GRB 080514B, GROND observations
  47. GRB 080515: Swift detection of a burst
  48. GRB 080514B: Finding chart
  49. GRB 080514B: Afterglow candidate
  50. GRB 080514B: Watcher observations
  51. GRB 080430
  52. GRB 080514B: possible AGILE detection at E>50 MeV
  53. GRB 080514B: SuperAGILE/IPN GRB Localization
  54. procesure for GRB Circular
  55. Swift detection of a possible galactic transient
  56. GRB080514: REM NIR & Optical Observations
  57. Konus-Wind observation of GRB 080507
  58. GRB 080319B: Further HST observations and underlying host
  59. GRB 080506: NAYUTA Optical Observation
  60. GRB 080507: Suzaku WAM observation of the prompt emission
  61. GRB 080507: Swift XRT analysis confirms the X-ray afterglow
  62. GRB 080507: Keck photometry
  63. GRB 080507: E Pur Si Muove!
  64. GRB 080503: Chandra Observation of X-ray Rebrightening or Flattening
  65. GRB 080503: Hubble Space Telescope Imaging
  66. GRB080507: Swift/UVOT followup observations
  67. GRB 080507: Optical Afterglow
  68. GRB 080506:Optical observations from HCT
  69. GRB 080507: Swift-XRT position of a possible afterglow
  70. GRB 080506: VLA radio upper limit
  71. GRB 080507: GRB localization by SuperAGILE
  72. GRB 080506: TLS 2nd Epoch - possible light curve break
  73. GRB 080503: Fading in continued Gemini imaging
  74. GRB 080506: Swift XRT refined analysis
  75. GRB080506: Swift/UVOT observations
  76. GRB 080506, Swift-BAT refined analysis
  77. GRB080503, RIMOTS optical upper limit
  78. GRB 080506: Observations from NOT
  79. GRB 080506: optical observation from Ondrejov
  80. GRB 080506: TLS afterglow detection in VRIZ
  81. GRB 080506: Enhanced Swift-XRT position
  82. GRB 080506: Optical observation with KANATA/TRISPEC
  83. GRB 080506: Swift detection of a burst with optical afterglow
  84. GRB 080503: VLA radio upper limit
  85. GRB 080503: Observations from NOT
  86. GRB 080503: Slow-rise optical AG ?
  87. GRB 080430: TLS imaging one day after the GRB
  88. GRB 080503: No further optical rebrightening
  89. GRB 080503: Late-time Optical rebrightening (possible mini-SN) - correction
  90. GRB 080503: Late-time Optical rebrightening (possible mini-SN)
  91. GRB 080503, Swift-BAT lag and time-resolved spectral analysis
  92. GRB 080503: MITSuME Ishigakijima optical upper limits
  93. GRB080503: Swift/UVOT Upper Limits
  94. GRB080503 XRT refined analysis
  95. GRB 080503, Swift-BAT refined analysis
  96. GRB 080430
  97. GRB 080430
  98. GRB 080430
  99. GRB 080503: Enhanced Swift-XRT position
  100. GRB 080503: MITSuME Akeno optical upper limits

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