Skip to main content
Retirement of GCN Classic VOEvent Brokers. 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 080229: NIR upper limit
  2. GRB 080310: early RAPTOR multicolor observations
  3. GRB 080310, Swift-BAT refined analysis
  4. GRB080210: optical observations
  5. GRB080307: optical upper limit
  6. GRB 080310: Swift-XRT refined analysis
  7. GRB 080310: Swift/UVOT Refined Analysis
  8. GRB 080310: Redshift from Keck/DEIMOS Spectra
  9. GRB 080310 - SDSS Pre-Burst Observations
  10. GRB080310 : Lulin optical observation
  11. GRB 080310: Enhanced Swift-XRT position
  12. GRB 080310: RRM optical photometry with the VLT
  13. GRB080310, detection of break in optical
  14. GRB 080310: VLT/UVES spectroscopy
  15. GRB080310, optical observations with LBT
  16. GRB 080310: Magellan redshift revision
  17. GRB 080310: Lick/Kast Spectroscopy
  18. GRB080310: Super-LOTIS suggestion of brightening
  19. GRB 080310, SMARTS optical/IR afterglow observations
  20. GRB 080310: REM observations
  21. GRB 080310: Magellan redshift
  22. GRB 080310 afterglow candidate (correction to UT time)
  23. GRB 080310: Swift detection of a burst with optical afterglow
  24. GRB 080310 afterglow candidate
  25. GRB080229, optical upper limit (Correction)
  26. GRB080307, optical upper limit
  27. GRB080307 BOAO optical afterglow observation - detection of a possible OT
  28. GRB080229, optical upper limit
  29. GRB 080307: Swift-XRT Team refined analysis
  30. GRB 080307: Swift/UVOT Upper Limits
  31. GRB 080307: Early RAPTOR Limits
  32. GRB 080307, Swift-BAT refined analysis
  33. GRB080307 - SDSS Pre-Burst Observations
  34. GRB 080307: TNT optical observation
  35. GRB080307: Optical upper limits
  36. GRB 080307: Gemini-N i-band observations - candidate afterglow
  37. GRB 080307: BOAO imaging - retraction and new limit
  38. GRB 080307: retraction of UVOT candidate
  39. GRB 080307: Enhanced Swift-XRT position
  40. GRB 080307, Preliminary Swift-BAT refined analysis
  41. GRB 080307 : BOAO optical afterglow observation
  42. GRB 080307: Optical observation with DMC/KANATA
  43. GRB 080307: Swift detection of a burst
  44. VLA possible radio detection of GRB 080229
  45. GRB 080303: Swift/UVOT follow-up of afterglow detection
  46. GRB 080303, Swift-BAT refined analysis
  47. GRB 080303: Rapid PROMPT Detections
  48. GRB080303: Swift XRT refined analysis
  49. GRB 080303: Enhanced Swift-XRT position
  50. Swift UVOT observations of GRB080229B
  51. GRB080229B: Swift XRT afterglow observation
  52. GRB 080303A: Faulkes Telescope South optical afterglow observations
  53. GRB 080303
  54. GRB 080303: Swift detection of a burst with optical afterglow
  55. GRB 080303: REM NIR afterglow candidate
  56. GRB 080303A: ROTSE-III Optical Limits
  57. GRB 080229: I-band observations from OSN
  58. GRB 080229: VLT NIR observations
  59. GRB080229: Swift XRT refined analysis
  60. GRB 080229: TNG NIR observations
  61. GRB 080229: Deep Gemini/GMOS optical observations
  62. GRB 080229: Enhanced Swift-XRT position
  63. GRB 080229: REM NIR observations
  64. GRB080229: Possible optical afterglow
  65. GRB 080229B: Gamma Ray Burst Localization by SuperAGILE
  66. UVOT analysis for GRB080229
  67. GRB 080229, Swift-BAT refined analysis
  68. GRB 080229: Faulkes Telescope South optical limit
  69. GRB 080229A: ROTSE-III Optical Limits
  70. GRB 080229: Swift detection of a bright burst
  71. Early optical shallow decay in GRB 071112C
  72. GRB080207: optical observations
  73. GRB080205: optical observations
  74. GRB080211: optical observations
  75. XRF 080109/SN2008D : GMRT upper limit at 1.28 GHz
  76. GRB 071010B : Early optical brightening detected by TAOS
  77. Swift-XRT improved positions, and new redshift limits.
  78. ESO optical and NIR observations of GRB 080218B
  79. GRB 080204: Suzaku WAM observation of the prompt emission
  80. GRB 080218B, Swift-BAT refined analysis
  81. GRB 080218B: Swift-XRT refined analysis
  82. Swift/UVOT observations of GRB080218B
  83. GRB 080218B: REM NIR early upper limits
  84. GRB 080212: Mount Abu NIR observations
  85. GRB 080218B: Enhanced Swift-XRT position
  86. GRB 080218B: GROND upper limits
  87. GRB 080218b, SMARTS optical/IR limits
  88. GRB 080218A, Swift-BAT refined analysis
  89. GRB080218B: Watcher prompt limit
  90. GRB 080211: Suzaku WAM observation of the prompt emission
  91. GRB 080218B: Swift detection of a burst
  92. GRB 080218: Swift detection of a burst
  93. Swift-XRT and UVOT observations of the IPN burst GRB 080211
  94. GRB 080212: VLT optical rapid decay
  95. GRB 080212: REM refined analysis
  96. Konus-Wind observation of GRB 080211
  97. VLA radio upper limit on GRB 080212
  98. Swift/UVOT refined analysis of GRB080212
  99. GRB 080212, Swift-BAT refined analysis
  100. GRB080212: Optical afterglow candidate observed by MITSuME Telescope

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