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"

20356 results found.

  1. GRB 090423: Swift-BAT refined analysis
  2. GRB 090422: Swift/UVOT Upper Limits
  3. GRB 090423: UKIRT K-band observations
  4. GRB 090423: P60 Observations
  5. GRB 090418A: R and I band observation
  6. GRB 090423: Swift detection of a burst
  7. GRB 090422: Enhanced Swift-XRT position
  8. GRB 090418B: RTT150 optical observations
  9. GRB 080410: GAO 150cm telescope Optical Observation
  10. GRB 080408A: GAO 150cm telescope Optical Observation
  11. GRB 090422: Swift detection of a burst
  12. GRB 090418A: Swift/UVOT Detection of the Neighbouring Galaxy
  13. GRB 090418B: GRAS002 observatios
  14. GRB 090418A: optical observations
  15. GRB 090418B: GROND observations
  16. GRB 090419: Swift/UVOT Observations
  17. GRB 090418B: Faulkes Telescope North observations
  18. GRB 090418A: Swift/UVOT Observations
  19. GRB 090417B: Swift/UVOT Upper Limits
  20. GRB 090419: Swift-XRT refined analysis
  21. GRB 090419: GROND detection of afterglow candidate
  22. GRB 090418: Optical observations with MITSuME Okayama and Ishigaki 1m telescope
  23. VLA radio detection of GRB 090418
  24. VLA radio upper limit on GRB 090417B
  25. GRB 090419: Enhanced Swift-XRT position
  26. GRB 090418: Swift XRT refined analysis
  27. GRB 090419: Swift detection of a burst
  28. VLA observations of short burst GRB 090417A
  29. GRB 090418B: Detection of a bright burst from Swift-BAT slew data
  30. GRB 090417B: Gemini imaging
  31. GRB 090418: Enhanced Swift-XRT position
  32. GRB 090418: Swift detection of a burst with optical afterglow
  33. GRB 090417B: Subaru NIR Observations
  34. GRB 090417B: MITSuME Okayama optical upper limits
  35. GRB 090417B: optical observations
  36. GRB090417B: optical observations
  37. GRB 090417B: Swift detection of a burst
  38. GRB 090411A: Fermi GBM detection
  39. GRB 090410: GROND upper limits
  40. GRB 090410: MITSuME optical upper limits
  41. GRB 090408b: IPN Triangulation
  42. GRB 090328b: IPN Triangulation
  43. Konus-Wind and Konus-RF observations of GRB 090408b
  44. GRB 090409: Fermi GBM detection
  45. GRB090408, RIMOTS optical upper limits
  46. Swift-BAT trigger 348781: almost certainly not a burst
  47. GRB 090408B: MASTER II-Kourovka optical observations
  48. GRB 090407: GROND upper limits
  49. GRB 090407: VLT observations
  50. GRB 090407: Swift UVOT Upper Limits
  51. GRB 090407: Enhanced Swift-XRT position
  52. GRB 090407: ROTSE-III Optical Limits
  53. GRB 090407: Swift detection of a burst
  54. GRB 090404: GROND upper limits
  55. GRB 090404: further NOT observations
  56. Swift/UVOT observations of GRB090404
  57. GRB 090404: NOT observations
  58. GRB 090404: Enhanced Swift-XRT position
  59. GRB 090404: Swift detection of a burst
  60. GRB 090401B: VLA radio upper limit
  61. GRB 090401B: Upper limits of MITSuME optical observation
  62. GRB090401B, RIMOTS optical upper limits
  63. GRB 090401B: AGILE refined analysis
  64. GRB 090401B: Enhanced Swift-XRT position
  65. AGILE Gamma-ray detection of GRB 090401B
  66. GRB 090401B: Swift detection of a burst
  67. GRB 090328B: MASTER-Irkutsk prompt optical short burst observations
  68. GRB 090323: Further TLS detections - a break?
  69. GRB 090328: Radio afterglow detection
  70. GRB 090328: GROND Detection of the Optical/NIR Afterglow
  71. GRB090323: Optical observations from NOT
  72. GRB 090328: Swift UVOT observations
  73. GRB 090328: Updated position/optical afterglow candidate
  74. GRB 090323: Radio afterglow detection
  75. GRB 090320B: MASTER-Net prompt optical observations
  76. GRB 090323: Fermi GBM Spectral Analysis
  77. GRB 090323: UVOT Detection of Afterglow
  78. Konus-Wind observation of GRB 090323
  79. GRB 090323: P60 Afterglow Confirmation
  80. GRB 090323: GROND Detection of the Afterglow and Photo-z
  81. GRB 090323: Possible XRT Counterpart
  82. GRB 090320C: Fermi GBM Detection
  83. Further 15GHz observations of GRB090313
  84. X-shooter observations of GRB 090313
  85. GRB 090313: VLT spectroscopy
  86. GRB090313: radio detection with the VLA
  87. IPN Triangulation of GRB090315 and Tupi Detection of Muon Increase
  88. Further radio observation of GRB 090313
  89. GRB 090313: detection with CARMA in 3mm band
  90. GRB090305B: MASTER-net prompt optical short burst observations
  91. GRB 090313: MITSuME Okayama observation
  92. GRB 090313: Additional Gemini-S photometry
  93. GRB 090313: TAROT La Silla observatory optical detection
  94. GRB 090313: Zadko Telescope observations
  95. GRB 090313: Ongoing plateau phase
  96. GRB 090313: Swift-XRT refined analysis
  97. GRB 090313: Swift/UVOT upper limits
  98. GRB 090306B: Confirmation of the X-ray afterglow
  99. GRB 090313, GROND observations
  100. GRB 090313: Swift detection of a burst

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