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"
  1. GRB 150314A: GMG observation limit
  2. GRB 150323A: RATIR Optical Afterglow Observations
  3. GRB 150323A: P60 Optical Afterglow Candidate
  4. GRB 150323A: Swift detection of a burst
  5. Swift Triggers 635788-635794 are probably not real.
  6. Fermi GBM trigger 150319666 is not a GRB
  7. GRB 150318A: Swift-XRT refined Analysis
  8. Confirmation that Swift trigger 635306 is not an astrophysical source
  9. GRB 150314A: Further VLA observations
  10. GRB 150318A: Skynet PROMPT-CTIO Observations
  11. GRB 150318A: Swift-BAT refined analysis
  12. GRB 150318A: Swift/UVOT Upper Limits
  13. GRB 150318A : GROND upper limits
  14. Swift Trigger 635306 is probably not an astrophysical source
  15. GRB 150318A: Enhanced Swift-XRT position
  16. GRB 150318A: Swift detection of a burst
  17. GRB 150317A: Swift/UVOT Upper Limits
  18. GRB 150317A: Swift-XRT refined Analysis
  19. GRB 150317A: Swift-BAT refined analysis
  20. GRB 150317A: RATIR Optical Afterglow Detection
  21. GRB 150317A: Enhanced Swift-XRT position
  22. GRB 150317A: NOT optical observations
  23. GRB 150317A: Swift detection of a burst
  24. GRB 150314A: VLA observations
  25. GRB 150314A: Early RAPTOR Detection
  26. GRB 150220A, the review of the sky area in plate archives
  27. GRB 150314A: NOT further optical observations
  28. Konus-Wind observation of GRB 150314A
  29. GRB 150314A: Swift-XRT refined Analysis
  30. GRB 150314A: KAIT Optical Observations
  31. GRB 150314A: P60 observations
  32. GRB 150314A: Redshift from OSIRIS/GTC
  33. GRB 150314A: NOT optical observations
  34. GRB 150314A Swift-BAT refined analysis
  35. GRB 150314A: Swift/UVOT Detection
  36. GRB 150314A: Fermi GBM observation
  37. GRB 150314A: MITSuME Akeno upper limits
  38. GRB 150314A: Skynet Yerkes-41 Observations of the Optical Afterglow
  39. GRB 150314A: Fermi-LAT detection
  40. GRB 150314A: Enhanced Swift-XRT position
  41. GRB 150314A: KAIT Optical Candidate
  42. GRB 150314A: Swift detection of a bright burst
  43. GRB 150313A: MAXI/GSC detection
  44. Fermi GBM trigger 150312827 is not a GRB
  45. GRB 150309A: AAO optic upper limit
  46. GRB 150311A: Konus-Wind trigger at 16:16:24 is not a GRB
  47. GRB 150311A: MAXI/GSC possible afterglow detection
  48. GRB 150222A: CrAO optical observation
  49. Konus-Wind observation of GRB 150309A
  50. GRB 150309A: CrAO optic upper limit
  51. GRB 150309A: ISON-Kislovodsk optic upper limit
  52. Fermi GBM trigger 150311331 is not a GRB
  53. GRB 150309A: Swift-BAT refined analysis
  54. GRB 150309A: Fermi GBM detection
  55. GRB150309A: Optical observations at Crni Vrh
  56. GRB 150309A: Swift/UVOT Upper Limits
  57. GRB 150309A: MASTER prompt optical observation
  58. GRB 150309A: Swift-XRT refined Analysis
  59. GRB 150309A : Liverpool Telescope observations
  60. GRB 150309A: Enhanced Swift-XRT position
  61. GRB 150309A: BOOTES-1 and -2 upper limit
  62. GRB 150309A: Swift detection of a burst
  63. GRB 150305A: a long GRB detected by INTEGRAL
  64. GRB 150305A: Swift XRT confirms weak INTEGRAL event as a new GRB
  65. Fermi GBM trigger 150307942 is not a GRB
  66. Chandra X-ray observations of SWIFT J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka p[PFH2005] 622)
  67. Swift J0045.2+4151: analysis of XMM-Newton archival data
  68. Further UVOT Observations of Swift J0045.2+4151
  69. Fermi GBM trigger 150305751 is not a GRB
  70. GRB 150301C: VLA Observations
  71. Further X-ray observations of Swift J0045.2+4151 (aka Sw J0045 aka GRB 150301C aka [PFH2005] 622)
  72. BAT trigger 633105 (GRB 150301C): NOT r-band upper limit
  73. GRB 150302A: BOOTES-2/TELMA upper limit
  74. Trigger 633105 (aka GRB150301C): Swift/UVOT Observations of XRT Counterpart
  75. GRB 150302A: Mondy optical upper limit
  76. GRB 150302A, Swift-BAT refined analysis
  77. GRB 150302A: Swift/UVOT Upper Limits
  78. GRB 150302A: MITSuME Okayama upper limits
  79. GRB 150301C: XRT detection of a potential counterpart of BAT trigger 633105
  80. GRB 150302A: Swift-XRT refined Analysis
  81. GRB 150302A: Enhanced Swift-XRT position
  82. GRB 150301B: Swift-XRT refined Analysis
  83. GRB 150220A: further Swift-XRT observations
  84. GRB 150301B: Swift/UVOT Observations
  85. GRB 150301B: LCOGT-Sutherland observations
  86. GRB 150302A: KAIT Optical Upper Limit
  87. GRB 150302A: UVOT Observations
  88. GRB 150302A: NOT afterglow candidate
  89. GRB 150302A: Swift detection of a burst
  90. GRB 150301B: Fermi GBM detection
  91. GRB 150301B: Swift-BAT refined analysis
  92. GRB 150301B: X-shooter spectroscopy
  93. GRB 150301B: GROND afterglow observations
  94. GRB 150301A: Swift/UVOT Upper Limits
  95. GRB 150301B: Enhanced Swift-XRT position
  96. GRB 150301A: Swift-BAT refined analysis
  97. GRB 150301B: MASTER early OT detection
  98. GRB 150301A: Swift-XRT refined Analysis
  99. GRB 150301C : (Swift trigger 633105) Swift observations
  100. GRB 150301B: Swift detection of a burst with an optical afterglow

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