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 080411: VLT redshift
  2. GRB 080411: GROND detection of optical afterglow candidate
  3. GRB080330: MAGIC telescope GeV observation
  4. GRB 080411: Swift detection of a bright burst
  5. GRB 080330: Swift-XRT refined position retraction
  6. GRB 080409: Swift-BAT refined analysis
  7. GRB 080408: GROND detection of optical/NIR afterglow candidate
  8. GRB 080330 optical observations
  9. Swift/UVOT observations of GRB080409
  10. GRB 080409: Swift XRT refined analysis
  11. UVOT/Swift Observations of GRB080408
  12. GRB 080408: Swift-XRT position of a possible afterglow
  13. GRB 080409: Enhanced Swift-XRT position
  14. GRB 080409: REM optical/NIR observations
  15. GRB 080409: Swift detection of a burst
  16. GRB 080408: Analysis of AGILE Gamma-ray data
  17. GRB 080408: GRB Localization by SuperAGILE
  18. GRB 080319A: Early RAPTOR optical limits
  19. GRB 080319B: HST observations
  20. GRB 080330: RAPTOR detection of prompt optical flash
  21. GRB 080319B: Potential Jet Break Observed by Swift-XRT and UVOT
  22. GRB 080405: Swift-BAT refined analysis
  23. GRB 080405: Swift-XRT position
  24. GRB 080405: Mars Oddysey and Swift-BAT detection, possible host galaxy
  25. GRB 080325: optical upper limit
  26. GRB 080328: GAO 150cm telescope Optical Observation
  27. GRB080330: Improved Swift XRT Position
  28. GRB 080330: Prompt PROMPT Observations
  29. GRB080330: optical observations
  30. GRB 080319B: TORTORA light curve (Correction)
  31. GRB080328, RIMOTS optical upper limit
  32. GRB080330: optical observations
  33. GRB080330: Swift XRT refined analysis
  34. GRB 080330: REM optical observations
  35. GRB 080330, SMARTS optical/IR afterglow observations
  36. GRB 080330 Swift-UVOT refined analysis
  37. GRB 080328: Suzaku WAM observation of the prompt emission
  38. GRB080330: TNT optical observations
  39. GRB 080330, Swift-BAT refined analysis
  40. Konus-Wind observation of GRB 080328
  41. GRB 080330: Redshift Confirmation from Hobby-Eberly Telescope Spectroscopy
  42. GRB080330: LOAO R-band Detection
  43. GRB 080330: GROND Observations
  44. GRB 080330: NOT redshift
  45. GRB 080330: TAROT Calern observatory optical observations
  46. GRB 080330A: PAIRITEL Infrared Detections
  47. GRB 080330: error in reported XRT position
  48. GRB080330 - SDSS Pre-Burst Observations
  49. GRB 080330: Liverpool Telescope Optical observations
  50. GRB 080330A: ROTSE-III Detection of Optical Counterpart
  51. GRB 080330: Swift detection of a burst with an optical counterpart
  52. GRB 080330: TAROT Calern observatory optical detection
  53. GRB 080319B: Continued Gemini-South followup and possible host galaxy
  54. GRB 080328: BTA optical imaging and spectroscopy
  55. GRB 080328, Swift-BAT refined analysis
  56. GRB 080328: Swift XRT refined analysis
  57. GRB 080325, Swift-BAT refined analysis
  58. Swift/UVOT observations of GRB080328
  59. GRB080325 - I and z-band Imaging
  60. GRB080319B, BVRcIc field calibration
  61. GRB 080328: Enhanced Swift-XRT position
  62. GRB080328: Faulkes Telescope North observations
  63. GRB 080328: Swift detection of a burst with an optical counterpart
  64. GRB 080325: Subaru detection of NIR afterglow candidate
  65. GRB080310, late-time photometry with LBT
  66. GRB 080325: MITSuME Akeno optical upper limits
  67. GRB080325: XRT Refined Analysis
  68. GRB 080325: GROND Observations
  69. GRB080319B: optical observations
  70. GRB 080325: Swift/UVOT Upper Limits
  71. GRB 080319C: Gemini-North spectroscopic redshift
  72. GRB 080325: Early observations from OSN
  73. GRB 080325: NIR afterglow candidate
  74. GRB 080319D: GROND Detection of the Optical Counterpart
  75. GRB 080325: Enhanced Swift-XRT position
  76. GRB 080325: Swift detection of a burst
  77. GRB 080319B : Apparent spectral evolution in very early Swift/XRT WT mode data: intrinsic or pile-up effect?
  78. IBAS Alert n. 5245: NOT a GRB
  79. GRB 080319B: Spitzer Mid-infrared Observations
  80. GRB 080319C: Suzaku WAM observation of the prompt emission
  81. GRB 080319B: Second & Third Epoch WSRT Radio Observations
  82. Radio Detection of GRB 080319B
  83. GRB 080320, Swift-BAT refined analysis
  84. GRB 080319B: Optical observation (Brno, CZ)
  85. GRB 080319D: GROND Observations
  86. GRB 080319B: TORTORA light curve
  87. GRB 080319B: optical upper limit
  88. GRB 080319D: optical upper limit
  89. GRB080319B: Time-Independent XRT Spectrum
  90. GRB 080319D, Swift-BAT refined analysis
  91. GRB 080319C: UVOT Observations
  92. GRB 080319B: UVOT Observations
  93. GRB 080319A: UVOT Observations
  94. GRB 080320: Swift XRT refined analysis
  95. GRB 080319B - CARMA mm Observations
  96. GRB 080320: Early Super-LOTIS Observations
  97. GRB 080320: J detection with FLAMINGOS
  98. GRB 080319D: Swift XRT refined analysis
  99. GRB 080320: optical limit
  100. GRB 080320: Gemini-N optical afterglow

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