Skip to main content
New! BOOM Notices and Schema v7.0.0. 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 090518, Swift-BAT refined analysis
  2. GRB 090518B: Fermi GBM detection
  3. GRB 090516, RIMOTS optical upper limits
  4. GRB090513: Fermi GBM detection
  5. GRB090518 : Optical upper limit by MOA-II telescope
  6. GRB 090518: Swift-XRT refined analysis
  7. GRB 090518: Enhanced Swift-XRT position
  8. GRB 090518: Swift detection of a burst
  9. GRB 090515: Swift/BAT spectral lag results
  10. GRB 090516: Swift-BAT refined analysis
  11. GRB 090516: VLT spectrum (correction & update)
  12. GRB 090516: GROND OBSERVATIONS
  13. GRB 090516: VLT redshift
  14. GRB 090516 - Zadko Telescope observations
  15. GRB 090516: NOT optical observations
  16. GRB 090516: Swift XRT refined analysis
  17. GRB 090516: Swift/UVOT Observations
  18. GRB 090516: Enhanced Swift-XRT position
  19. GRB 090516: Faulkes Telescope South optical afterglow
  20. GRB 090516: Swift detection of a burst
  21. GRB 090515: VLA observations
  22. GRB 090515: Lick Upper Limits
  23. GRB 090515: ROVOR Upper Limit
  24. GRB 090515: MMT/MMIRS NIR Upper Limit
  25. GRB 090515: Swift/UVOT Observations
  26. GRB 090515: Swift-XRT refined analysis
  27. GRB 090515: Enhanced Swift-XRT position
  28. GRB 090509: Fermi GBM observation
  29. GRB 090515: Swift-BAT refined spectral analysis
  30. GRB 090515: Swift-BAT refined analysis
  31. GRB 090509 - Zadko Telescope observations
  32. GRB 090515: Gemini-N upper limit
  33. GRB 090515: WIYN NIR Upper Limit
  34. GRB 090515: Super-LOTIS Upper Limits
  35. GRB 090515: PAIRITEL Upper Limits
  36. GRB 090515: KAIT optical upper limits
  37. GRB 090515: ROTSE-III Optical Limits
  38. GRB 090515: Swift detection of a short burst
  39. GRB 090510: Suzaku WAM observation of the prompt emission
  40. GRB 090510, Radio limits
  41. GRB090510: VLT/FORS2 spectroscopic redshift
  42. GRB 090510: GROND observations
  43. GRB 090510: Swift/UVOT host galaxy candidates
  44. GRB 090510: Fermi-LAT follow-up analysis
  45. GRB 090509, further Swift-BAT refined analysis
  46. Fermi Gamma-ray Burst Monitor trigger 263649437 is not a GRB
  47. GRB 090510B: Fermi GBM detection
  48. GRB 090502: Fermi GBM detection
  49. GRB 090510: correction to GCN 9344
  50. Konus-Wind observation of GRB 090510
  51. AGILE detection of GRB 090510
  52. GRB 090510: UVOT refined analysis
  53. GRB 090510: Swift XRT refined analysis
  54. GRB 090510: correction to coordinates in GCN 9338
  55. GRB 090510: Enhanced Swift-XRT position
  56. GRB 090510: NOT afterglow confirmation
  57. GRB 090510: Swift-BAT refined analysis
  58. GRB 090510: Fermi GBM detection
  59. GRB 090509: Swift-BAT refined analysis
  60. Fermi LAT detection of GRB 090510
  61. GRB 090509, SMARTS optical/IR afterglow observations
  62. GRB 090510: Swift/UVOT Detection of a Candidate Optical Afterglow
  63. GRB 090510: Swift detection of a short hard burst
  64. GRB 090408: optical upper limit
  65. GRB 090418A: optical observation
  66. GRB 090509: GROND further analysis and redshift limit
  67. GRB 090509: REM NIR afterglow
  68. GRB 090509: GROND afterglow candidate
  69. GRB 090509: Swift detection of a burst
  70. GRB 090323: optical observations
  71. GRB 090423: optical limit
  72. GRB 090423: 250 GHz upper limit for a z=8.2 GRB with MAMBO-2 at the IRAM 30m
  73. GRB 080913: 250 GHz upper limit for a z=6.7 GRB with MAMBO-2 at the IRAM 30m
  74. GRB 090424: optical observations
  75. GRB 090427: GROND observations
  76. GRB 090429A: ROVOR magnitude limit
  77. ICSP VLF observation of GRB090427 from two receivers
  78. ICSP VLF observation of GRB090424 from four receivers
  79. Refined analysis of ICSP VLF observation of SGR J1550-5418 bursts on 22nd January, 2009
  80. GRB 090428B: Suzaku WAM observation of the prompt emission
  81. GRB 090424, SMARTS optical/IR afterglow monitoring
  82. GRB 090426: optical observations
  83. GRB 090429D: Fermi GBM detection
  84. GRB 090429C: Fermi GBM detection
  85. GRB 090429B: Swift/UVOT Upper Limits
  86. GRB 090429A: Swift/UVOT Upper Limits
  87. GRB 090427: pseudo-z= 1.48 from prompt emission spectrum
  88. GRB 090429B: Gemini-N further nIR observations
  89. GRB 090424: YNAO-GMG observations
  90. GRB 090429A: Swift-XRT refined analysis
  91. GRB 090429A: GROND upper limits
  92. GRB 090427C: Fermi GBM detection
  93. GRB 090427B: Fermi GBM detection
  94. GRB 090426C: Fermi GBM detection
  95. GRB 090426B: Fermi GBM detection/observation
  96. GRB 090429B: Swift XRT refined analysis
  97. GRB 090429A: Enhanced Swift-XRT position
  98. Konus-Wind observation of very bright GRB 090427
  99. GRB 090428B: Fermi GBM detection
  100. GRB 090428: Fermi GBM detection

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