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"

19042 results found.

  1. GRB 081230 Swift/UVOT Observations
  2. GRB 081230: Enhanced Swift-XRT position
  3. GRB 081230: Swift detection of a burst
  4. GRB 081226B: Fermi GBM observation
  5. GRB 081226C: Fermi GBM detection
  6. GRB 081228, Swift-BAT refined analysis
  7. VLA radio detection of GRB 081221
  8. GRB 081228: Swift/UVOT Upper Limits
  9. GRB 081228: Swift-XRT Team refined analysis
  10. GRB 081228: detection by GROND
  11. GRB 081228: Enhanced Swift-XRT position
  12. GRB 081228: TAROT Calern observatory optical observations
  13. GRB 081228: Swift detection of a burst
  14. VLA radio observation of GRB 081221
  15. GRB 081226B: Swift XRT and UVOT upper limits
  16. GRB 081226: Swift-XRT refined analysis
  17. GRB 081226A: Swift UVOT Upper Limits
  18. GRB 081226A: Swift-BAT refined analysis
  19. GRB 081226: GROND afterglow candidate
  20. GRB 081226: ROTSE-III Optical Limits
  21. GRB 081226: Swift detection of a possible short-hard burst
  22. GRB 080810: optical observations
  23. GRB 081211B: optical observations
  24. GRB 081224: Swift-XRT observation
  25. GRB 081222: MITSuME optical observation
  26. GRB 081223: Fermi GBM detection
  27. GRB 081221: GROND observations
  28. VLA radio upper limit on GRB 081222
  29. GRB 081222: Fermi GBM observation
  30. GRB 081221: Probable host galaxy in Keck imaging
  31. GRB 081204C: Fermi GBM detection
  32. GRB 081222, Swift-BAT refined analysis
  33. GRB081222 optical limit by "Pi of the Sky"
  34. GRB 081222: Swift XRT refined analysis
  35. GRB081221: Fermi GBM observation
  36. IPN triangulation of bright GRB 081215A
  37. GRB 081222: Faulkes Telescope South observations
  38. GRB 081221: Gemini-N nIR imaging
  39. GRB081222, optical observation
  40. GRB081203A: BTA observation
  41. GRB 081222: GROND Detection of the Optical/NIR Afterglow
  42. GRB081222: REM candidate afterglow
  43. GRB 081222: Swift detection of a burst with a bright optical afterglow
  44. GRB 081221: Enhanced Swift-XRT position
  45. GRB 081221: further NOT observations
  46. GRB 081221: NOT observations
  47. GRB 081221: Swift detection of a burst
  48. GRB 081217: Fermi GBM detection
  49. GRB081215A: Fermi-LAT observations
  50. GRB 081211B: Further Swift-XRT analysis
  51. GRB 081215A: Fermi GBM detection (correction to event fluence)
  52. GRB 081215A: Fermi GBM detection
  53. GRB 081118: Zadko observations
  54. Fermi Trig Num 251059717 = SGR 0044+42: MASTER prompt optical observations
  55. GRB 0811215A: MASTER prompt optical observations
  56. GRB 081215A: Andromeda inside Fermi error box: MASTER observations
  57. GRB 0811215A: Andromeda inside Fermi error box: MASTER observations
  58. Possible GRB 081211B: Swift/UVOT Upper Limits
  59. Possible GRB 081211B - Swift-XRT analysis
  60. GRB 081209: Fermi GBM detection
  61. GRB 081211B(?): Possible burst detection from Swift-BAT slew data
  62. GRB 081210, SMARTS optical/IR observations
  63. GRB 081211: Enhanced Swift-XRT position
  64. GRB 081211: Swift detection of a burst
  65. GRB081203B: optical observations
  66. GRB 081210: Enhanced Swift-XRT position
  67. GRB 081210: Swift-BAT refined analysis
  68. GRB 081210: Swift detection of a burst with optical afterglow
  69. IPN triangulation of short hard GRB 081209
  70. GRB 081203A: optical observations
  71. GRB 081206: Fermi GBM detection
  72. GRB 081128: afterglow observations
  73. GRB081203A: Ashra-1 observation of early optical and VHE-neutrino emission
  74. GRB081203A: Optical observations at Ishigaki
  75. GRB 081204: GROND Observations
  76. Radio detection of GRB 081203B with the VLA
  77. GRB081203A: Radio upper limit at 15 GHz
  78. GRB 081204B: Fermi GBM detection
  79. GRB 081204: Swift/UVOT Upper Limits
  80. GRB081203A: MITSuME optical observation
  81. GRB081203A: optical observation
  82. VLA Radio upper limit on GRB 081203A
  83. GRB 081203B: optical observations
  84. Swift/UVOT detection of GRB081203B
  85. GRB 081203B: Swift-XRT candidate afterglow.
  86. GRB 081203A: optical observations
  87. GRB 081203: Enhanced Swift-XRT position
  88. GRB 081130B: MASTER prompt optical observations
  89. GRB081203: optical observation
  90. GRB 081203: Swift detection of a burst with a bright optical counterpart
  91. GRB 081128: optical observation
  92. Swift Trigger 335971: Swift/UVOT Observations
  93. GRB 081126: afterglow photometry
  94. GRB 081126: Fermi GBM detection
  95. VLA Radio upper limit on GRB 081126
  96. GRB 081129: Fermi GBM detection
  97. GRB 081130: MASTER VWF prompt optical observations Fermi GRB
  98. GRB 081128A: optical observations
  99. Trigger 335971: Swift possible detection of a burst
  100. GRB081128: Swift/UVOT 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