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"

45418 results found.

  1. GRB 130427A: CARMA 3mm observations
  2. GRB 130427B: Tentative VLT/X-shooter redshift
  3. GRB 130427A : Xinglong TNT optical observation
  4. GRB 130427A: VLT/X-shooter redshift confirmation
  5. GRB 130427A optical time series
  6. GRB 130427A, Optical Observations
  7. Konus-Wind observation of GRB 130427A
  8. GRB 130427A: Kanata/HOWPol optical imaging polarimetry
  9. GRB 130427A: Swift-XRT refined Analysis
  10. GRB 130427A: SPI-ACS/INTEGRAL observations
  11. GRB 130427A: Continued RATIR Optical and NIR Observations
  12. GRB 130427A: CARMA 85 GHz detection
  13. GRB 130427A: SNUO/SOAO/BOAO Observation
  14. GRB 130427A: VLA 5 GHz detection
  15. GRB 130427B: Swift-XRT refined Analysis
  16. GRB 130427A: NOT optical photometry and redshift
  17. GRB 130427B: MITSuME Okayama upper limits
  18. GRB 130427A: RAPTOR Bright Counterpart Before Swift Trigger
  19. GRB 130427A: T100 observations
  20. GRB 130427A: optical observations in CrAO
  21. GRB 130427A: Fermi GBM observation
  22. GRB130427A: Swift/UVOT followup observations of an Optical Afterglow
  23. GRB 130427A: Fermi-LAT detection of a burst
  24. GRB 130427A: Swift-BAT refined analysis
  25. GRB 130427B: Swift-BAT refined analysis
  26. GRB 130427A: Zadko observatory - Gingin optical observations
  27. GRB 130427B: Enhanced Swift-XRT position
  28. GRB 130427A: GMG optical observation
  29. GRB 130427A: MITSuME Okayama Optical Observation
  30. GRB 130427A: Optical Observations
  31. GRB 130427A: MAXI/GSC detection
  32. GRB 130427B: Faulkes Telescope North afterglow detection
  33. GRB 130427B: Swift detection of a burst with optical counterpart
  34. GRB 130427A: RATIR Optical and NIR Observations
  35. GRB 130427A: Weihai optical observations
  36. GRB 130427A: Continued P60 follow-up of an extremely bright optical afterglow
  37. GRB 130427A: Gemini-North redshift
  38. GRB 130427A: MITSuME Akeno Optical observation(T0+8000s~)
  39. GRB 130427A: PAIRITEL NIR Detections
  40. GRB 130427A: Faulkes Telescope North detection
  41. GRB 130427A: P60 early detection
  42. GRB 130427A: early optical observations
  43. GRB 130427A: P60 early nondetection
  44. GRB 130427A: Swift detection of a very bright burst with a likely bright optical counterpart
  45. Konus-Wind observation of GRB 130425A
  46. IPN Triangulation of GRB 130425A
  47. GRB 130420A: Continued Skynet/GORT Observations/Detections
  48. GRB 130420B: CARMA and VLA radio observations
  49. Trigger 554491: Swift detection of a spike possibly from Sgr A*
  50. GRB 130425A: Fermi GBM detection
  51. GRB 130420A: Continued RATIR Optical and NIR Observations
  52. GRB 130420A: ROTSE-III data analysis
  53. GRB 130420A: Continued RATIR Optical and NIR Observations
  54. GRB 130418A: Continued RATIR Optical and NIR Observations
  55. GRB 130420A: Redshift from 10.4m GTC
  56. GRB 130420A: Early RAPTOR Simultaneous Multi-Color Observations
  57. GRB 130420B: Fermi GBM observation
  58. GRB 130418A: WSRT radio observation
  59. Swift Trigger 554135 is probably not a GRB or transient
  60. GRB 130420B: RATIR Optical and NIR Observations
  61. GRB 130420A: Continued RATIR Optical and NIR Observations
  62. GRB 130420B: Swift-XRT refined Analysis
  63. GRB 130420A: Fermi GBM observation
  64. GRB 130420A: ISON-NM optical observations
  65. Skynet/GORT observations of GRB130420A
  66. GRB 130420B: Weihai optical upper limit
  67. GRB 130420B: Swift/UVOT Upper Limits
  68. GRB 130420A: Swift/UVOT Detection
  69. GRB130420B: GMG optical upper limit
  70. GRB 130420A: Swift-XRT refined Analysis
  71. GRB 130420B: Enhanced Swift-XRT position
  72. GRB 130420B, Swift-BAT refined analysis
  73. GRB 130420A, Swift-BAT refined analysis
  74. GRB 130420A: GMG optical observation
  75. Konus-Wind observation of GRB 130418A
  76. GRB 130420A: Enhanced Swift-XRT position
  77. GRB130420A : Xinglong TNT optical upper limit
  78. GRB 130420B: Faulkes Telescope North observations
  79. GRB 130420A: Weihai Optical Observations
  80. GRB 130420B: MASTER-Net optical observations
  81. GRB 130420B: Swift detection of a burst
  82. GRB 130420A: RATIR Optical and NIR Observations
  83. GRB 130420A: PAIRITEL NIR detections
  84. GRB 130420A: ROTSE-III Detection of Optical Counterpart
  85. GRB 130420A: Swift detection of a burst with an optical counterpart
  86. GRB 130420A: Faulkes Telescope North candidate
  87. GRB 130418A: Continued RATIR Optical and NIR Observations
  88. GRB 130418A: Swift-XRT refined Analysis
  89. Swift Trigger 553930 is not an astrophysical source
  90. GRB 130418A: SMARTS optical/IR afterglow observations
  91. GRB 130418A: Submm observations from SMA
  92. GRB 130419A, Swift-BAT refined analysis
  93. GRB 130327B: Swift/XRT source is not the afterglow
  94. GRB 130419B (Swift trigger Trigger 553930): MASTER-Net optical observations
  95. Trigger 553930: Swift detection of a possible flare from HR 5110
  96. GRB 130418A: LOAO Observation
  97. GRB 130418A, Swift-BAT refined analysis
  98. GRB 130419A: Swift detection of a burst
  99. GRB130418A: VLT/X-shooter redshift confirmation
  100. GRB 130418A: REM NIR observations

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